19 May 2015

Research Articles of the Week, May 18th, 2015

Articles from May_18_2015

Research Committee Selected Articles for the Week of May_18_2015

Periodic solutions for a seasonally forced SIR model with impact of media coverage

In this paper, we study periodic solutions for a seasonally forced SIR model with impact of media coverage. Usually, media reports, information processing, and individuals’ alerted responses to the information can only arise as the number of infected individuals reaches and exceeds a certain level. The piecewise smooth righthand side is introduced to describe the impact of this kind of media coverage. Using Leray-Schauder degree theory, we establish new results on the existence of at least one positive periodic solution for a seasonally forced SIR model with impact of media coverage. Some numerical simulations are presented to illustrate the effectiveness of such media coverage. © 2015, Zu and Wang; licensee Springer.

A stochastic SIS epidemic model incorporating media coverage in a two patch setting

In this paper, we investigate the stochastic disease dynamics of an SIS epidemic model on two patches incorporating media coverage. We give the global existence and positivity of the solutions, and the sufficient conditions for almost surely exponentially stability of the disease-free equilibrium, which means that the disease will be stochastic extinction. Furthermore, we perform some numerical simulations to validate the analytical finding. © 2015 Elsevier Inc.

Ethics-sensitivity of the Ghana national integrated strategic response plan for pandemic influenza

Background: Many commentators call for a more ethical approach to planning for influenza pandemics. In the developed world, some pandemic preparedness plans have already been examined from an ethical viewpoint. This paper assesses the attention given to ethics issues by the Ghana National Integrated Strategic Plan for Pandemic Influenza (NISPPI). Methods: We critically analyzed the Ghana NISPPI's sensitivity to ethics issues to determine how well it reflects ethical commitments and principles identified in our review of global pandemic preparedness literature, existing pandemic plans, and relevant ethics frameworks. Results: This paper reveals that important ethical issues have not been addressed in the Ghana NISPPI. Several important ethical issues are unanticipated, unacknowledged, and unplanned for. These include guidelines on allocation of scarce resources, the duties of healthcare workers, ethics-sensitive operational guidelines/protocols, and compensation programs. The NISPPI also pays scant attention to use of vaccines and antivirals, border issues and cooperation with neighboring countries, justification for delineated actions, and outbreak simulations. Feedback and communication plans are nebulous, while leadership, coordination, and budgeting are quite detailed. With respect to presentation, the NISPPI's text is organized around five thematic areas. While each area implicates ethical issues, NISPPI treatment of these areas consistently fails to address them. Conclusions: Our analysis reveals a lack of consideration of ethics by the NISPPI. We contend that, while the plan's content and fundamental assumptions provide support for implementation of the delineated public health actions, its consideration of ethical issues is poor. Deficiencies include a failure to incorporate guidelines that ensure fair distribution of scarce resources and a lack of justification for delineated procedures. Until these deficiencies are recognized and addressed, Ghana runs the r

The impact of vaccine failure rate on epidemic dynamics in responsive networks

An SIS model based on the microscopic Markov-chain approximation is considered in this paper. It is assumed that the individual vaccination behavior depends on the contact awareness, local and global information of an epidemic. To better simulate the real situation, the vaccine failure rate is also taken into consideration. Our main conclusions are given in the following. First, we show that if the vaccine failure rate ? is zero, then the epidemic eventually dies out regardless of what the network structure is or how large the effective spreading rate and the immunization response rates of an epidemic are. Second, we show that for any positive ?, there exists a positive epidemic threshold depending on an adjusted network structure, which is only determined by the structure of the original network, the positive vaccine failure rate and the immunization response rate for contact awareness. Moreover, the epidemic threshold increases with respect to the strength of the immunization response rate for contact awareness. Finally, if the vaccine failure rate and the immunization response rate for contact awareness are positive, then there exists a critical vaccine failure rate ?c > 0 so that the disease free equilibrium (DFE) is stable (resp., unstable) if ? < ?c (resp., ? > ?c). Numerical simulations to see the effectiveness of our theoretical results are also provided. © 2015 AIP Publishing LLC.

Influenza and other respiratory viruses detected by influenza-like illness surveillance in Leyte Island, the Philippines, 2010-2013

This study aimed to determine the role of influenza-like illness (ILI) surveillance conducted on Leyte Island, the Philippines, including involvement of other respiratory viruses, from 2010 to 2013. ILI surveillance was conducted from January 2010 to March 2013 with 3 sentinel sites located in Tacloban city, Palo and Tanauan of Leyte Island. ILI was defined as fever ?38°C or feverish feeling and either cough or running nose in a patient of any age. Influenza virus and other 5 respiratory viruses were searched. A total of 5,550 ILI cases visited the 3 sites and specimens were collected from 2,031 (36.6%) cases. Among the cases sampled, 1,637 (75.6%) were children aged <5 years. 874 (43.0%) cases were positive for at least one of the respiratory viruses tested. Influenza virus and respiratory syncytial virus (RSV) were predominantly detected (both were 25.7%) followed by human rhinovirus (HRV) (17.5%). The age distributions were significantly different between those who were positive for influenza, HRV, and RSV. ILI cases were reported throughout the year and influenza virus was co-detected with those viruses on approximately half of the weeks of study period (RSV in 60.5% and HRV 47.4%). In terms of clinical manifestations, only the rates of headache and sore throat were significantly higher in influenza positive cases than cases positive to other viruses. In conclusion, syndromic ILI surveillance in this area is difficult to detect the start of influenza epidemic without laboratory confirmation which requires huge resources. Age was an important factor that affected positive rates of influenza and other respiratory viruses. Involvement of older age children may be useful to detect influenza more effectively. © 2015 Otomaru et al.

One health and cyanobacteria in freshwater systems: Animal illnesses and deaths are sentinel events for human health risks

Harmful cyanobacterial blooms have adversely impacted human and animal health for thousands of years. Recently, the health impacts of harmful cyanobacteria blooms are becoming more frequently detected and reported. However, reports of human and animal illnesses or deaths associated with harmful cyanobacteria blooms tend to be investigated and reported separately. Consequently, professionals working in human or in animal health do not always communicate findings related to these events with one another. Using the One Health concept of integration and collaboration among health disciplines, we systematically review the existing literature to discover where harmful cyanobacteria-associated animal illnesses and deaths have served as sentinel events to warn of potential human health risks. We find that illnesses or deaths among livestock, dogs and fish are all potentially useful as sentinel events for the presence of harmful cyanobacteria that may impact human health. We also describe ways to enhance the value of reports of cyanobacteria-associated illnesses and deaths in animals to protect human health. Efficient monitoring of environmental and animal health in a One Health collaborative framework can provide vital warnings of cyanobacteria-associated human health risks. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Early detection for cases of enterovirus- and influenza-like illness through a Newly Established School-Based Syndromic Surveillance System in Taipei, January 2010 ~ August 2011

School children may transmit pathogens with cluster cases occurring on campuses and in families. In response to the 2009 influenza A (H1N1) pandemic, Taipei City Government officials developed a School-based Infectious Disease Syndromic Surveillance System (SIDSSS). Teachers and nurses from preschools to universities in all 12 districts within Taipei are required to daily report cases of symptomatic children or sick leave requests through the SID-SSS. The pre-diagnosis at schools is submitted firstly as common pediatric disease syndrome-groups and re-submitted after confirmation by physicians. We retrieved these data from January 2010 to August 2011 for spatio-temporal analysis and evaluated the temporal trends with cases obtained from both the Emergency Department-based Syndromic Surveillance System (ED-SSS) and the Longitudinal Health Insurance Database 2005 (LHID2005). Through the SID-SSS, enterovirus-like illness (EVI) and influenza-like illness (ILI) were the two most reported syndrome groups (77.6% and 15.8% among a total of 19,334 cases, respectively). The pre-diagnosis judgments made by school teachers and nurses showed high consistency with physicians' clinical diagnoses for EVI (97.8%) and ILI (98.9%). Most importantly, the SID-SSS had better timeliness with earlier peaks of EVI and ILI than those in the ED-SSS. Furthermore, both of the syndrome groups in these two surveillance systems had the best correlation reaching 0.98 and 0.95, respectively (p<0.01). Spatio-temporal analysis observed the patterns of EVI and ILI both diffuse from the northern suburban districts to central Taipei, with ILI spreading faster. This novel system can identify early suspected cases of two important pediatric infections occurring at schools, and clusters from schools/families. It was also cost-effective (95.5% of the operation cost reduced and 59.7% processing time saved). The timely surveillance of mild EVI and ILI cases integrated with spatial analysis may help public healt

Community-Centered Responses to Ebola in Urban Liberia: The View from Below

The West African Ebola epidemic has demonstrated that the existing range of medical and epidemiological responses to emerging disease outbreaks is insufficient, especially in post-conflict contexts with exceedingly poor healthcare infrastructures. In this context, community-based responses have proven vital for containing Ebola virus disease (EVD) and shifting the epidemic curve. Despite a surge in interest in local innovations that effectively contained the epidemic, the mechanisms for community-based response remain unclear. This study provides baseline information on community-based epidemic control priorities and identifies innovative local strategies for containing EVD in Liberia. This study was conducted in September 2014 in 15 communities in Monrovia and Montserrado County, Liberia – one of the epicenters of the Ebola outbreak. Findings from 15 focus group discussions with 386 community leaders identified strategies being undertaken and recommendations for what a community-based response to Ebola should look like under then-existing conditions. Data were collected on the following topics: prevention, surveillance, care-giving, community-based treatment and support, networks and hotlines, response teams, Ebola treatment units (ETUs) and hospitals, the management of corpses, quarantine and isolation, orphans, memorialization, and the need for community-based training and education. Findings have been presented as community-based strategies and recommendations for (1) prevention, (2) treatment and response, and (3) community sequelae and recovery. Several models for community-based management of the current Ebola outbreak were proposed. Additional findings indicate positive attitudes towards early Ebola survivors, and the need for community-based psychosocial support. Local communities’ strategies and recommendations give insight into how urban Liberian communities contained the EVD outbreak while navigating the systemic failures of the initial state and interna

The evidence base of primary research in public health emergency preparedness: A scoping review and stakeholder consultation Health policies, systems and management

Background: Effective public health emergency preparedness and response systems are important in mitigating the impact of all-hazards emergencies on population health. The evidence base for public health emergency preparedness (PHEP) is weak, however, and previous reviews have noted a substantial proportion of anecdotal event reports. To investigate the body of research excluding the anecdotal reports and better understand primary and analytical research for PHEP, a scoping review was conducted with two objectives: first, to develop a thematic map focused on primary research; and second, to use this map to inform and guide an understanding of knowledge gaps relevant to research and practice in PHEP. Methods: A scoping review was conducted based on established methodology. Multiple databases of indexed and grey literature were searched based on concepts of public health, emergency, emergency management/preparedness and evaluation/evidence. Inclusion and exclusion criteria were applied iteratively. Primary research studies that were evidence-based or evaluative in nature were included in the final group of selected studies. Thematic analysis was conducted for this group. Stakeholder consultation was undertaken for the purpose of validating themes and identifying knowledge gaps. To accomplish this, a purposive sample of researchers and practicing professionals in PHEP or closely related fields was asked to complete an online survey and participate in an in-person meeting. Final themes and knowledge gaps were synthesized after stakeholder consultation. Results: Database searching yielded 3015 citations and article selection resulted in a final group of 58 articles. A list of ten themes from this group of articles was disseminated to stakeholders with the survey questions. Survey findings resulted in four cross-cutting themes and twelve stand-alone themes. Several key knowledge gaps were identified in the following themes: attitudes and beliefs; collaboration and system

Rural,urban and migrant differences in non-communicable disease risk-factors in middle income countries:A cross-sectional study of WHO-SAGE data

Background Understanding how urbanisation and rural-urban migration influence risk-factors for noncommunicable disease (NCD) is crucial for developing effective preventative strategies globally. This study compares NCD risk-factor prevalence in urban, rural and migrant populations in China, Ghana, India, Mexico, Russia and South Africa. Methods Study participants were 39,436 adults within the WHO Study on global AGEing and adult health (SAGE), surveyed 2007-2010. Risk ratios (RR) for each risk-factor were calculated using logistic regression in country-specific and all country pooled analyses, adjusted for age, sex and survey design. Fully adjusted models included income quintile, marital status and education. Results Regular alcohol consumption was lower in migrant and urban groups than in rural groups (pooled RR and 95%CI: 0.47 (0.31-0.68); 0.58, (0.46-0.72), respectively). Occupational physical activity was lower (0.86 (0.72-0.98); 0.76 (0.65 -0.85)) while active travel and recreational physical activity were higher (pooled RRs for urban groups; 1.05 (1.00-1.09), 2.36 (1.95-2.83), respectively; for migrant groups: 1.07 (1.0 -1.12), 1.71 (1.11-2.53), respectively). Overweight, raised waist circumference and diagnosed diabetes were higher in urban groups (1.19 (1.04-1.35), 1.24 (1.07-1.42), 1.69 (1.15-2.47), respectively). Exceptions to these trends exist: obesity indicators were higher in rural Russia; active travel was lower in urban groups in Ghana and India; and in South Africa, urban groups had the highest alcohol consumption. © 2015 Oyebode et al.

Sensitivity and Specificity of a Novel Classifier for the Early Diagnosis of Dengue

Dengue is the commonest arboviral disease of humans. An early and accurate diagnosis of dengue can support clinical management, surveillance and disease control and is central to achieving the World Health Organisation target of a 50% reduction in dengue case mortality by 2020. 5729 children with fever of <72hrs duration were enrolled into this multicenter prospective study in southern Vietnam between 2010-2012. A composite of gold standard diagnostic tests identified 1692 dengue cases. Using statistical methods, a novel Early Dengue Classifier (EDC) was developed that used patient age, white blood cell count and platelet count to discriminate dengue cases from non-dengue cases. The EDC had a sensitivity of 74.8% (95%CI: 73.0-76.8%) and specificity of 76.3% (95%CI: 75.2-77.6%) for the diagnosis of dengue. As an adjunctive test alongside NS1 rapid testing, sensitivity of the composite test was 91.6% (95%CI: 90.4-92.9%). We demonstrate that the early diagnosis of dengue can be enhanced beyond the current standard of care using a simple evidence-based algorithm. The results should support patient management and clinical trials of specific therapies. © 2015 Tuan et al.

Variability in a Community-Structured SIS Epidemiological Model

We study an SIS epidemiological model of a population partitioned into groups referred to as communities, households, or patches. The system is studied using stochastic spatial simulations, as well as a system of ordinary differential equations describing moments of the distribution of infectious individuals. The ODE model explicitly includes the population size, as well as the variability in infection levels among communities and the variability among stochastic realizations of the process. Results are compared with an earlier moment-based model which assumed infinite population size and no variance among realizations of the process. We find that although the amount of localized (as opposed to global) contact in the model has little effect on the equilibrium infection level, it does affect both the timing and magnitude of both types of variability in infection level. © 2014, Society for Mathematical Biology.

Evaluation of Inapparent Dengue Infections During an Outbreak in Southern China

Few studies evaluating inapparent dengue virus (DENV) infections have been conducted in China. In 2013, a large outbreak of DENV occurred in the city of Zhongshan, located in Southern China, which provided an opportunity to assess the clinical spectrum of disease. During the outbreak, an investigation of 887 index case contacts was conducted to evaluate inapparent and symptomatic DENV infections. Post-outbreak, an additional 815 subjects from 4 towns with, and 350 subjects from 2 towns without reported autochthonous DENV transmission, as determined by clinical diagnosis, were evaluated for serological evidence of dengue IgG antibodies. Between July and November 2013, there were 19 imported and 809 autochthonous dengue cases reported in Zhongshan. Of 887 case contacts enrolled during the outbreak, 13 (1.5%) exhibited symptomatic DENV infection, while 28 (3.2%) were inapparent. The overall I:S ratio was 2.2:1 (95% CI: 1.1-4.2:1). Post-outbreak serological data showed that the proportion of DENV IgG antibody detection from the 4 towns with and the 2 towns without reported DENV transmission was 2.7% (95% CI: 1.6%-3.8%) and 0.6% (95% CI: 0-1.4%), respectively. The I:S ratio in the 3 towns where clinical dengue cases were predominately typed as DENV-1 was 11.0:1 (95% CI: 3.7-?:1). The ratio in the town where DENV-3 was predominately typed was 1.0:1 (95% CI: 0.5-?:1). In this cross-sectional study, data suggests a high I:S ratio during a documented outbreak in Zhongshan, Southern China. These results have important implications for dengue control, implying that inapparent cases might influence DENV transmission more than previously thought. © 2015 Wang et al.

Geographic Distribution and Mortality Risk Factors during the Cholera Outbreak in a Rural Region of Haiti, 2010-2011

In 2010 and 2011, Haiti was heavily affected by a large cholera outbreak that spread throughout the country. Although national health structure-based cholera surveillance was rapidly initiated, a substantial number of community cases might have been missed, particularly in remote areas. We conducted a community-based survey in a large rural, mountainous area across four districts of the Nord department including areas with good versus poor accessibility by road, and rapid versus delayed response to the outbreak to document the true cholera burden and assess geographic distribution and risk factors for cholera mortality. A two-stage, household-based cluster survey was conducted in 138 clusters of 23 households in four districts of the Nord Department from April 22nd to May 13th 2011. A total of 3,187 households and 16,900 individuals were included in the survey, of whom 2,034 (12.0%) reported at least one episode of watery diarrhea since the beginning of the outbreak. The two more remote districts, Borgne and Pilate were most affected with attack rates up to 16.2%, and case fatality rates up to 15.2% as compared to the two more accessible districts. Care seeking was also less frequent in the more remote areas with as low as 61.6% of reported patients seeking care. Living in remote areas was found as a risk factor for mortality together with older age, greater severity of illness and not seeking care. These results highlight important geographical disparities and demonstrate that the epidemic caused the highest burden both in terms of cases and deaths in the most remote areas, where up to 5% of the population may have died during the first months of the epidemic. Adapted strategies are needed to rapidly provide treatment as well as prevention measures in remote communities. © 2015 Page et al.

Economic and Disease Burden of Dengue in Mexico

Dengue imposes a substantial economic and disease burden in most tropical and subtropical countries. Dengue incidence and severity have dramatically increased in Mexico during the past decades. Having objective and comparable estimates of the economic burden of dengue is essential to inform health policy, increase disease awareness, and assess the impact of dengue prevention and control technologies. We estimated the annual economic and disease burden of dengue in Mexico for the years 2010–2011. We merged multiple data sources, including a prospective cohort study; patient interviews and macro-costing from major hospitals; surveillance, budget, and health data from the Ministry of Health; WHO cost estimates; and available literature. We conducted a probabilistic sensitivity analysis using Monte Carlo simulations to derive 95% certainty levels (CL) for our estimates. Results suggest that Mexico had about 139,000 (95%CL: 128,000–253,000) symptomatic and 119 (95%CL: 75–171) fatal dengue episodes annually on average (2010–2011), compared to an average of 30,941 symptomatic and 59 fatal dengue episodes reported. The annual cost, including surveillance and vector control, was US$170 (95%CL: 151–292) million, or $1.56 (95%CL: 1.38–2.68) per capita, comparable to other countries in the region. Of this, $87 (95%CL: 87–209) million or $0.80 per capita (95%CL: 0.62–1.12) corresponds to illness. Annual disease burden averaged 65 (95%CL: 36–99) disability-adjusted life years (DALYs) per million population. Inclusion of long-term sequelae, co-morbidities, impact on tourism, and health system disruption during outbreaks would further increase estimated economic and disease burden. With this study, Mexico joins Panama, Puerto Rico, Nicaragua, and Thailand as the only countries or areas worldwide with comprehensive (illness and preventive) empirical estimates of dengue burden. Burden varies annually; during an outbreak, dengue burden may be significantly higher than that of the pre-

Xenosurveillance: A Novel Mosquito-Based Approach for Examining the Human-Pathogen Landscape

Globally, regions at the highest risk for emerging infectious diseases are often the ones with the fewest resources. As a result, implementing sustainable infectious disease surveillance systems in these regions is challenging. The cost of these programs and difficulties associated with collecting, storing and transporting relevant samples have hindered them in the regions where they are most needed. Therefore, we tested the sensitivity and feasibility of a novel surveillance technique called xenosurveillance. This approach utilizes the host feeding preferences and behaviors of Anopheles gambiae, which are highly anthropophilic and rest indoors after feeding, to sample viruses in human beings. We hypothesized that mosquito bloodmeals could be used to detect vertebrate viral pathogens within realistic field collection timeframes and clinically relevant concentrations. To validate this approach, we examined variables influencing virus detection such as the duration between mosquito blood feeding and mosquito processing, the pathogen nucleic acid stability in the mosquito gut and the pathogen load present in the host’s blood at the time of bloodmeal ingestion using our laboratory model. Our findings revealed that viral nucleic acids, at clinically relevant concentrations, could be detected from engorged mosquitoes for up to 24 hours post feeding by qRT-PCR. Subsequently, we tested this approach in the field by examining blood from engorged mosquitoes from two field sites in Liberia. Using next-generation sequencing and PCR we were able to detect the genetic signatures of multiple viral pathogens including Epstein-Barr virus and canine distemper virus.Together, these data demonstrate the feasibility of xenosurveillance and in doing so validated a simple and non-invasive surveillance tool that could be used to complement current biosurveillance efforts.

Epidemiological Changes in Leishmaniasis in Spain According to Hospitalization-Based Records, 1997–2011: Raising Awareness towards Leishmaniasis in Non-HIV Patients

In Spain, Leishmania infantum is endemic, human visceral and cutaneous leishmaniasis cases occurring both in the Peninsula, as well as in the Balearic Islands. We aimed to describe the clinical characteristics of leishmaniasis patients and the changes in the disease evolution after the introduction of antiretroviral therapy in 1997. In this descriptive study, we used Spanish Centralized Hospital Discharge Database for the hospitalized leishmaniasis cases between 1997 and 2011. We included in the analysis only the records having leishmaniasis as the first registered diagnosis and calculated the hospitalization rates. Disease trend was described taking into account the HIV status. Adjusted odds-ratio was used to estimate the association between clinical and socio-demographic factors and HIV co-infection. Of the total 8010 Leishmaniasis hospitalizations records, 3442 had leishmaniasis as first diagnosis; 2545/3442 (75.6%) were males and 2240/3442 (65.1%) aged between 14-65 years. Regarding disease forms, 2844/3442 (82.6%) of hospitalizations were due to visceral leishmaniasis (VL), while 118/3442 (3.4%) hospitalizations were cutaneous leishmaniasis (CL). Overall, 1737/2844 of VL (61.1%) were HIV negatives. An overall increasing trend was observed for the records with leishmaniasis as first diagnosis (p=0.113). Non-HIV leishmaniasis increased during this time period (p=0.021) while leishmaniasis-HIV co-infection hospitalization revealed a slight descending trend (p=0.717). Leishmaniasis-HIV co-infection was significantly associated with male sex (aOR=1.6; 95% CI: 1.25-2.04), 16-64 years age group (aOR=17.4; 95%CI: 2.1-143.3), visceral leishmaniasis aOR=6.1 (95%CI: 3.27-11.28) and solid neoplasms 4.5 (95% CI: 1.65-12.04). The absence of HIV co-infection was associated with lymph/hematopoietic neoplasms (aOR=0.3; 95%CI:0.14-0.57), other immunodeficiency (aOR=0.04; 95% CI:0.01-0.32) and transplant (aOR=0.01; 95%CI:0.00-0.07). Our findings suggest a significant increase of

The Effect of Meteorological Variables on the Transmission of Hand, Foot and Mouth Disease in Four Major Cities of Shanxi Province, China: A Time Series Data Analysis (2009-2013)

Increased incidence of hand, foot and mouth disease (HFMD) has been recognized as a critical challenge to communicable disease control and public health response. This study aimed to quantify the association between climate variation and notified cases of HFMD in selected cities of Shanxi Province, and to provide evidence for disease control and prevention. Meteorological variables and HFMD cases data in 4 major cities (Datong, Taiyuan, Changzhi and Yuncheng) of Shanxi province, China, were obtained from the China Meteorology Administration and China CDC respectively over the period 1 January 2009 to 31 December 2013. Correlations analyses and Seasonal Autoregressive Integrated Moving Average (SARIMA) models were used to identify and quantify the relationship between the meteorological variables and HFMD. HFMD incidence varied seasonally with the majority of cases in the 4 cities occurring from May to July. Temperatures could play important roles in the incidence of HFMD in these regions. The SARIMA models indicate that a 1° C rise in average, maximum and minimum temperatures may lead to a similar relative increase in the number of cases in the 4 cities. The lag times for the effects of temperatures were identified in Taiyuan, Changzhi and Yuncheng. The numbers of cases were positively associated with average and minimum temperatures at a lag of 1 week in Taiyuan, Changzhi and Yuncheng, and with maximum temperature at a lag of 2 weeks in Yuncheng. Positive association between the temperature and HFMD has been identified from the 4 cities in Shanxi Province, although the role of weather variables on the transmission of HFMD varied in the 4 cities. Relevant prevention measures and public health action are required to reduce future risks of climate change with consideration of local climatic conditions. © 2015 Wei et al.

Long-Run Relative Importance of Temperature as the Main Driver to Malaria Transmission in Limpopo Province, South Africa: A Simple Econometric Approach

Malaria in Limpopo Province of South Africa is shifting and now observed in originally non-malaria districts, and it is unclear whether climate change drives this shift. This study examines the distribution of malaria at district level in the province, determines direction and strength of the linear relationship and causality between malaria with the meteorological variables (rainfall and temperature) and ascertains their short- and long-run variations. Spatio-temporal method, Correlation analysis and econometric methods are applied. Time series monthly meteorological data (1998–2007) were obtained from South Africa Weather Services, while clinical malaria data came from Malaria Control Centre in Tzaneen (Limpopo Province) and South African Department of Health. We find that malaria changes and pressures vary in different districts with a strong positive correlation between temperature with malaria, r = 0.5212, and a weak positive relationship for rainfall, r = 0.2810. Strong unidirectional causality runs from rainfall and temperature to malaria cases (and not vice versa): F (1, 117) = 3.89, ? = 0.0232 and F (1, 117) = 20.08, P < 0.001 and between rainfall and temperature, a bi-directional causality exists: F (1, 117) = 19.80; F (1,117) = 17.14, P < 0.001, respectively, meaning that rainfall affects temperature and vice versa. Results show evidence of strong existence of a long-run relationship between climate variables and malaria, with temperature maintaining very high level of significance than rainfall. Temperature, therefore, is more important in influencing malaria transmission in Limpopo Province. © 2014, International Association for Ecology and Health.

Public preferences for vaccination and antiviral medicines under different pandemic flu outbreak scenarios

Background: During the 2009-2010 A(H1N1) pandemic, many people did not seek care quickly enough, failed to take a full course of antivirals despite being authorised to receive them, and were not vaccinated. Understanding facilitators and barriers to the uptake of vaccination and antiviral medicines will help inform campaigns in future pandemic influenza outbreaks. Increasing uptake of vaccines and antiviral medicines may need to address a range of drivers of behaviour. The aim was to identify facilitators of and barriers to being vaccinated and taking antiviral medicines in uncertain and severe pandemic influenza scenarios using a theoretical model of behaviour change, COM-B. Methods: Focus groups and interviews with 71 members of the public in England who varied in their at-risk status. Participants responded to uncertain and severe scenarios, and to messages giving advice on vaccination and antiviral medicines. Data were thematically analysed using the theoretical framework provided by the COM-B model. Results: Influences on uptake of vaccines and antiviral medicines - capabilities, motivations and opportunities - are part of an inter-related behavioural system and different components influenced each other. An identity of being healthy and immune from infection was invoked to explain feelings of invulnerability and hence a reduced need to be vaccinated, especially during an uncertain scenario. The identity of being a 'healthy person' also included beliefs about avoiding medicine and allowing the body to fight disease 'naturally'. This was given as a reason for using alternative precautionary behaviours to vaccination. This identity could be held by those not at-risk and by those who were clinically at-risk. Conclusions: Promoters and barriers to being vaccinated and taking antiviral medicines are multi-dimensional and communications to promote uptake are likely to be most effective if they address several components of behaviour. The benefit of using the COM-B mo

Detection of influenza-like illness aberrations by directly monitoring Pearson residuals of fitted negative binomial regression models

Background: Emerging novel influenza outbreaks have increasingly been a threat to the public and a major concern of public health departments. Real-time data in seamless surveillance systems such as health insurance claims data for influenza-like illnesses (ILI) are ready for analysis, making it highly desirable to develop practical techniques to analyze such readymade data for outbreak detection so that the public can receive timely influenza epidemic warnings. This study proposes a simple and effective approach to analyze area-based health insurance claims data including outpatient and emergency department (ED) visits for early detection of any aberrations of ILI. Methods: The health insurance claims data during 2004-2009 from a national health insurance research database were used for developing early detection methods. The proposed approach fitted the daily new ILI visits and monitored the Pearson residuals directly for aberration detection. First, negative binomial regression was used for both outpatient and ED visits to adjust for potentially influential factors such as holidays, weekends, seasons, temporal dependence and temperature. Second, if the Pearson residuals exceeded 1.96, aberration signals were issued. The empirical validation of the model was done in 2008 and 2009. In addition, we designed a simulation study to compare the time of outbreak detection, non-detection probability and false alarm rate between the proposed method and modified CUSUM. Results: The model successfully detected the aberrations of 2009 pandemic (H1N1) influenza virus in northern, central and southern Taiwan. The proposed approach was more sensitive in identifying aberrations in ED visits than those in outpatient visits. Simulation studies demonstrated that the proposed approach could detect the aberrations earlier, and with lower non-detection probability and mean false alarm rate in detecting aberrations compared to modified CUSUM methods. Conclusions: The proposed simple app

Infectious disease modeling methods as tools for informing response to novel influenza viruses of unknown pandemic potential

The rising importance of infectious disease modeling makes this an appropriate time for a guide for public health practitioners tasked with preparing for, and responding to, an influenza pandemic. We list several questions that public health practitioners commonly ask about pandemic influenza and match these with analytical methods, giving details on when during a pandemic the methods can be used, how long it might take to implement them, and what data are required. Although software to perform these tasks is available, care needs to be taken to understand: (1) the type of data needed, (2) the implementation of the methods, and (3) the interpretation of results in terms of model uncertainty and sensitivity. Public health leaders can use this article to evaluate the modeling literature, determine which methods can provide appropriate evidence for decision-making, and to help them request modeling work from in-house teams or academic groups. © 2015 The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

A rationale to unify measurements of effectiveness for animal health surveillance

Surveillance systems produce data which, once analysed and interpreted, support decisions regarding disease management. While several performance measures for surveillance are in use, no theoretical framework has been proposed yet with a rationale for defining and estimating effectiveness measures of surveillance systems in a generic way. An effective surveillance system is a system whose data collection, analysis and interpretation processes lead to decisions that are appropriate given the true disease status of the target population. Accordingly, we developed a framework accounting for sampling, testing and data interpretation processes, to depict in a probabilistic way the direction and magnitude of the discrepancy between "decisions that would be made if the true state of a population was known" and the "decisions that are actually made upon the analysis and interpretation of surveillance data". The proposed framework provides a theoretical basis for standardised quantitative evaluation of the effectiveness of surveillance systems. We illustrate such approaches using hypothetical surveillance systems aimed at monitoring the prevalence of an endemic disease and at detecting an emerging disease as early as possible and with an empirical case study on a passive surveillance system aiming at detecting cases of Highly Pathogenic Avian Influenza cases in Vietnamese poultry. © 2015 Elsevier B.V.

Avian influenza dynamics under periodic environmental conditions

Since wild birds are the major natural reservoir for all known influenza A viruses, understanding the ecology of avian influenza (AI) viruses circulating in wild birds is critical to predicting disease risk in wild and domestic birds and preventing transmission to humans. AI virus which is shed by infected birds into aquatic environments plays a pivotal role in the sustained transmission of AI. Recent laboratory experiments, however, show that viral persistence in water is highly sensitive to environmental conditions such as temperature, which varies seasonally and geographically. Here, we develop mathematical models to study the effects of time-varying environmental conditions on AI dynamics, deriving the effects of temperature on the basic reproductive number (R0), the final outbreak size, and the effective reproductive number (Re). For periodic environmental temperatures, we derive a mathematical formulation of an AI invasion threshold (Ri) and conclude that apart from the mean temperature, the amplitude of the periodic temperature profile plays a significant role in the invasion of wild bird populations by AI. In particular, both higher means and higher amplitudes (warmer and more variable temperatures) reduce the likelihood of AI invasion. We also analyze the global dynamics of the model proving that AI is uniformly persistent in the wild bird population if Ri > 1. In numerical work, we fit the model to recent experimental data and field survey data from Northern Europe. Two important and robust quantitative conclusions emerge: that direct transmission is negligible compared to indirect and that immunity wanes within about 4 weeks. The latter conclusion is of particular interest since many previous models assume lifetime immunity. We also demonstrate that time-varying temperature may be the underlying cause of several features of AI dynamics which are observed in real data. In particular, AI prevalence is observed to

Acute gastroenteritis outbreak caused by a GII.6 norovirus

Aim: To report an acute gastroenteritis outbreak caused by a genogroup 2 genotype 6 (GII.6) strain norovirus in Shanghai, China. Methods: Noroviruses are responsible for approximately half of all reported gastroenteritis outbreaks in many countries. Genogroup 2 genotype 4 strains are the most prevalent. Rare outbreaks caused by GII.6 strains have been reported. An acute gastroenteritis outbreak occurred in an elementary school in Shanghai in December of 2013. Field and molecular epidemiologic investigations were conducted. Results: The outbreak was limited to one class in an elementary school located in southwest Shanghai. The age of the students ranged from 9 to 10 years. The first case emerged on December 10, 2013, and the last case emerged on December 14, 2013. The cases peaked on December 11, 2013, with 21 new cases. Of 45 students in the class, 32 were affected. The main symptom was gastroenteritis and 15.6% (5/32) of the cases exhibited a fever. A field epidemiologic investigation showed the pathogen may have been transmitted to the elementary school from employees in a delicatessen via the first case student, who had eaten food from the delicatessen one day before the gastroenteritis episodes began. A molecular epidemiologic investigation identified the cause of the gastroenteritis as norovirus strain GII.6; the viral sequence of the student cases showed 100% homology with that of the shop employees. Genetic relatedness analyses showed that the new viral strain is closely related to previously reported GII.6 sequences, especially to a strain reported in Japan. Conclusion: This is the first report to show that norovirus strain GII.6 can cause a gastroenteritis outbreak. Thus, the prevalence of GII.6 noroviruses requires attention. © 2015 Baishideng Publishing Group Inc. All rights reserved. © 2015 The Author(s).

Estimating the United States demand for influenza antivirals and the effect on severe influenza disease during a potential pandemic

Following the detection of a novel influenza strain A(H7N9), we modeled the use of antiviral treatment in the United States to mitigate severe disease across a range of hypothetical pandemic scenarios. Our outcomes were total demand for antiviral (neuraminidase inhibitor) treatment and the number of hospitalizations and deaths averted. The model included estimates of attack rate, healthcare-seeking behavior, prescription rates, adherence, disease severity, and the potential effect of antivirals on the risks of hospitalization and death. Based on these inputs, the total antiviral regimens estimated to be available in the United States (as of April 2013) were sufficient to meet treatment needs for the scenarios considered. However, distribution logistics were not examined and should be addressed in future work. Treatment was estimated to avert many severe outcomes (5200-248 000 deaths; 4800-504 000 hospitalizations); however, large numbers remained (25 000-425 000 deaths; 580 000-3 700 000 hospitalizations), suggesting that the impact of combinations of interventions should be examined. © 2015 © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Estimates of the demand for mechanical ventilation in the United States during an influenza pandemic

An outbreak in China in April 2013 of human illnesses due to avian influenza A(H7N9) virus provided reason for US public health officials to revisit existing national pandemic response plans. We built a spreadsheet model to examine the potential demand for invasive mechanical ventilation (excluding "rescue therapy" ventilation). We considered scenarios of either 20% or 30% gross influenza clinical attack rate (CAR), with a "low severity" scenario with case fatality rates (CFR) of 0.05%-0.1%, or a "high severity" scenario (CFR: 0.25%-0.5%). We used rates-of-influenza-related illness to calculate the numbers of potential clinical cases, hospitalizations, admissions to intensive care units, and need for mechanical ventilation. We assumed 10 days ventilator use per ventilated patient, 13% of total ventilator demand will occur at peak, and a 33.7% weighted average mortality risk while on a ventilator. At peak, for a 20% CAR, low severity scenario, an additional 7000 to 11 000 ventilators will be needed, averting a pandemic total of 35 000 to 55 000 deaths. A 30% CAR, high severity scenario, will need approximately 35 000 to 60 500 additional ventilators, averting a pandemic total 178 000 to 308 000 deaths. Estimates of deaths averted may not be realized because successful ventilation also depends on sufficient numbers of suitably trained staff, needed supplies (eg, drugs, reliable oxygen sources, suction apparatus, circuits, and monitoring equipment) and timely ability to match access to ventilators with critically ill cases. There is a clear challenge to plan and prepare to meet demands for mechanical ventilators for a future severe pandemic. © 2015 Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015.

Knowledge and risk perceptions of the Ebola virus in the United States

Objectives: The Ebola epidemic has received extensive media coverage since the first diagnosed cases of the virus in the US. We investigated risk perceptions of Ebola among individuals living in the US and measured their knowledge of the virus. Method: US residents completed an online survey (conducted 14-18 November 2014) that assessed their Ebola knowledge and risk perceptions. Results: Respondents who were more knowledgeable of Ebola perceived less risk of contracting the virus and were less worried about the virus, but also regarded Ebola as more serious than less knowledgeable respondents. The internet served as a major source of additional information among knowledgeable respondents. Conclusion: The findings suggest that the provision of health information about Ebola may be effective in informing the public about Ebola risks and of preventive measures without curtailing the seriousness of the virus. Policymakers may seek to further exploit the internet as a means of delivering information about Ebola in the US and worldwide. © 2015.

Potential demand for respirators and surgical masks during a hypothetical influenza pandemic in the United States

Background.To inform planning for an influenza pandemic, we estimated US demand for N95 filtering facepiece respirators (respirators) by healthcare and emergency services personnel and need for surgical masks by pandemic patients seeking care. Methods.We used a spreadsheet-based model to estimate demand for 3 scenarios of respirator use: base case (usage approximately follows epidemic curve), intermediate demand (usage rises to epidemic peak and then remains constant), and maximum demand (all healthcare workers use respirators from pandemic onset). We assumed that in the base case scenario, up to 16 respirators would be required per day per intensive care unit patient and 8 per day per general ward patient. Outpatient healthcare workers and emergency services personnel would require 4 respirators per day. Patients would require 1.2 surgical masks per day. Results and Conclusions.Assuming that 20% to 30% of the population would become ill, 1.7 to 3.5 billion respirators would be needed in the base case scenario, 2.6 to 4.3 billion in the intermediate demand scenario, and up to 7.3 billion in the maximum demand scenario (for all scenarios, between 0.1 and 0.4 billion surgical masks would be required for patients). For pandemics with a lower attack rate and fewer cases (eg, 2009-like pandemic), the number of respirators needed would be higher because the pandemic would have longer duration. Providing these numbers of respirators and surgical masks represents a logistic challenge for US public health agencies. Public health officials must urgently consider alternative use strategies for respirators and surgical masks during a pandemic that may vary from current practices. © 2015 Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015.

Learning about health and medicine from internet data

Surveys show that around 70% of US Internet users consult the Internet when they require medical information. People seek this information using both traditional search engines and via social media. The information created using the search process offers an unprecedented opportunity for applications to monitor and improve the quality of life of people with a variety of medical conditions. In recent years, research in this area has addressed public-health questions such as the effect of media on development of anorexia, developed tools for measuring influenza rates and assessing drug safety, and examined the effects of health information on individual wellbeing. This tutorial will show how Internet data can facilitate medical research, providing an overview of the state-of-the-art in this area. During the tutorial we will discuss the information which can be gleaned from a variety of Internet data sources, including social media, search engines, and specialized medical websites. We will provide an overview of analysis methods used in recent literature, and show how results can be evaluated using publicly available health information and online experimentation. Finally, we will discuss ethical and privacy issues and possible technological solutions. This tutorial is intended for researchers of user generated content who are interested in applying their knowledge to improve health and medicine. Copyright © 2015 ACM.

Ethical issues in the response to ebola virus disease in United States emergency departments: A position paper of the American college of emergency physicians, the emergency nurses

The 2014 outbreak of Ebola virus disease (EVD) in West Africa has presented a significant public health crisis to the international health community and challenged U.S. emergency departments (EDs) to prepare for patients with a disease of exceeding rarity in developed nations. With the presentation of patients with Ebola to U.S. acute care facilities, ethical questions have been raised in both the press and medical literature as to how U.S. EDs, emergency physicians (EPs), emergency nurses, and other stakeholders in the health care system should approach the current epidemic and its potential for spread in the domestic environment. To address these concerns, the American College of Emergency Physicians, the Emergency Nurses Association, and the Society for Academic Emergency Medicine developed this joint position paper to provide guidance to U.S. EPs, emergency nurses, and other stakeholders in the health care system on how to approach the ethical dilemmas posed by the outbreak of EVD. This paper will address areas of immediate and potential ethical concern to U.S. EDs in how they approach preparation for and management of potential patients with EVD. © 2015 by the Society for Academic Emergency Medicine.

Changes in the prevalence of influenza-like illness and influenza vaccine uptake among Hajj pilgrims: A 10-year retrospective analysis of data


University of SydneySydney

School of Biological Sciences and Sydney Medical School

Modeling the effect of school closures in a pandemic scenario: Exploring two different contact matrices

Background. School closures may delay the epidemic peak of the next influenza pandemic, but whether school closure can delay the peak until pandemic vaccine is ready to be deployed is uncertain. Methods. To study the effect of school closures on the timing of epidemic peaks, we built a deterministic susceptible-infected-recovered model of influenza transmission. We stratified the U.S. population into 4 age groups (0-4, 5-19, 20-64, and ?65 years), and used contact matrices to model the average number of potentially disease transmitting, nonphysical contacts. Results.For every week of school closure at day 5 of introduction and a 30% clinical attack rate scenario, epidemic peak would be delayed by approximately 5 days. For a 15% clinical attack rate scenario, 1 week closure would delay the peak by 9 days. Closing schools for less than 84 days (12 weeks) would not, however, reduce the estimated total number of cases. Conclusions. Unless vaccine is available early, school closure alone may not be able to delay the peak until vaccine is ready to be deployed. Conversely, if vaccination begins quickly, school closure may be helpful in providing the time to vaccinate school-aged children before the pandemic peaks. © 2015 Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015.

Seroprevalence of pandemic A(H1N1) pmd09 virus antibodies in Mexican health care workers before and after vaccination

Background and Aims: In April 2009, a new strain of influenza A(H1N1) was identified in Mexico and in the U.S. In June 2009, WHO declared this a pandemic. Health care workers constituted a risk group for their close contact with infected individuals. The aim was to estimate seropositivity for A(H1N1)pdm09 in health staff at the Instituto Mexicano del Seguro Social. Methods: A two-stage cross-sectional study, before and after vaccination in the same workers, was performed on a random sample of health-care workers. A socio-occupational questionnaire was applied and serum antibodies against influenza A(H1N1)pdm09 were determined through neutralization of retroviral pseudotypes; two logistic regression models for both were constructed. Results: The average (median/mean) age of 1378 participants from 13 work centers was 41.7 years and 68.7% (947) were women. Seroprevalence for the first stage was 26.5% (365) (7.4-43%) vs. 20.8% (11) in a control group from the blood bank; for the second stage, the vaccinated group was 33% (215) (18.2-47%) and 27% (196) (11.6-50%) for the unvaccinated group. In regression models, seropositivity was associated with occupational exposure to suspected influenza infected patients, being physicians, and being vaccinated. Conclusions: Seropositivity against pandemic virus is similar to what was reported, both for vaccinated (2.8-40.9%) and unvaccinated (18.8-64.7%). Low seroprevalence in the vaccinated group indicates that between 67% and 73% were susceptible to infection. Given the relatively low vaccine-induced seropositivity, it is imperative to increase, hygiene and safety for health staff and at-risk populations, and strengthen epidemiological surveillance. © 2015 IMSS.

Context-dependent conservation responses to emerging wildlife diseases

Emerging infectious diseases pose an important threat to wildlife. While established protocols exist for combating outbreaks of human and agricultural pathogens, appropriate management actions before, during, and after the invasion of wildlife pathogens have not been developed. We describe stage-specific goals and management actions that minimize disease impacts on wildlife, and the research required to implement them. Before pathogen arrival, reducing the probability of introduction through quarantine and trade restrictions is key because prevention is more cost effective than subsequent responses. On the invasion front, the main goals are limiting pathogen spread and preventing establishment. In locations experiencing an epidemic, management should focus on reducing transmission and disease, and promoting the development of resistance or tolerance. Finally, if pathogen and host populations reach a stable stage, then recovery of host populations in the face of new threats is paramount. Successful management of wildlife disease requires risk-taking, rapid implementation, and an adaptive approach. © The Ecological Society of America.

Respiratory viruses in airline travellers with influenza symptoms: Results of an airport screening study

Background: There is very little known about the prevalence and distribution of respiratory viruses, other than influenza, in international air travellers and whether symptom screening would aid in the prediction of which travellers are more likely to be infected with specific respiratory viruses. Objectives: In this study, we investigate whether, the use of a respiratory symptom screening tool at the border would aid in predicting which travellers are more likely to be infected with specific respiratory viruses. Study design: Data were collected from travellers arriving at Christchurch International Airport, New Zealand, during the winter 2008, via a symptom questionnaire, temperature testing, and respiratory sampling. Results: Respiratory viruses were detected in 342 (26.0%) of 1313 samples obtained from 2714 symptomatic travellers. The most frequently identified viruses were rhinoviruses (128), enteroviruses (77) and influenza B (48). The most frequently reported symptoms were stuffy or runny nose (60%), cough (47%), sore throat (27%) and sneezing (24%). Influenza B infections were associated with the highest number of symptoms (mean of 3.4) followed by rhinoviruses (mean of 2.2) and enteroviruses (mean of 1.9). The positive predictive value (PPV) of any symptom for any respiratory virus infection was low at 26%. Conclusions: The high prevalence of respiratory virus infections caused by viruses other than influenza in this study, many with overlapping symptotology to influenza, has important implications for any screening strategies for the prediction of influenza in airline travellers. © 2015 Elsevier B.V.

Increasing influenza vaccination in New York City taxi drivers: A community driven approach

The Healthy People 2020 influenza immunization goal is 80% for non-institutionalized adults 18-64. However, vaccination rates remain stubbornly low. Culturally tailored approaches to communities with poor vaccine uptake are necessary. Taxi drivers are at risk for influenza and its complications, could serve as vectors for influenza infection, and could be an effective vaccination target to enhance herd immunity of the urban population. To the best of our knowledge, this is the first study related to influenza vaccination among taxi drivers. The NYC Taxi Network surveyed a convenience sample of 53 taxi drivers to understand vaccination barriers. Only 17% had been vaccinated. Results informed a pilot tailored workplace intervention, which resulted in vaccinations for 44% of unvaccinated drivers. The study revealed that older drivers were more likely to be vaccinated than younger drivers, while the most common barrier to immunization was that drivers thought vaccination was 'not necessary'. © 2015.

Neuraminidase inhibitor therapy in a military population

Background: Although neuraminidase inhibitors (NI) are the mainstay of treatment for influenza infection, prescribing practice for these agents is not well described. Additionally, benefit is contested. Objectives: We examined provider prescriptions of NI during the 2009 pandemic and post-pandemic periods. We also evaluated the effectiveness of NI in reducing severity of influenza infection. Study design: Data on NI prescription and severity of influenza infection were compiled in healthy pediatric and adult beneficiaries enrolled in a prospective study of influenza like illness conducted at five military medical centers over five years. Subjects underwent nasal swabs to determine viral etiology of their infection. Demographic, medication and severity data were collected. Subjects with positive influenza were included. Results: Two hundred sixty three subjects were influenza positive [38% [H1N1] pdm09, 38.4% H3N2, and 20.5% B); 23.9% were treated with NI. NI were initiated within 48. h in 63% of treated subjects. Although NI use increased over the five years of the study, early use declined. Most measures for severity of illness were not significantly reduced with NI; adults treated within 48. h had only a modest reduction in duration and severity of some of their symptoms. Conclusions: NI use in our population is increasing, but early use is not. NI use resulted in no reduction in complications of illness. Resolution of symptoms and reduction in severity of some symptoms were slightly better in adults who were treated early. These modest benefits do not support routine treatment with NI in otherwise healthy individuals with influenza. © 2015 Elsevier B.V.

Factors associated with hospitalization for blood-borne viral infections among treatment-seeking illicit drug users

Blood-borne viral infections (BBVIs) are important health consequences of illicit drug use. This study assessed predictors of inpatient hospital admissions for BBVIs in a cohort of 4817 clients seeking treatment for drug use in Finland. We examined clients' data on hospital admissions registered in the Finnish National Hospital Discharge Register from 1997 to 2010 with diagnoses of BBVIs. Cox proportional hazards regression analyses were separately conducted for each of the three BBVI groups to test for association between baseline variables and hospitalizations. Findings were reported as adjusted hazard ratios (aHRs). Based upon primary discharge diagnoses, 81 clients were hospitalized for HIV, 116 for hepatitis C, and 45 for other types of hepatitis. Compared to those admitted for hepatitis C and other hepatitis, drug users with HIV had higher total number of hospital admissions (294 versus 141 and 50 respectively), higher crude hospitalization rate (7.1 versus 3.4.and 1.2 per 1000 person-years respectively), and higher total length of hospital stay (2857 days versus 279 and 308 respectively). Trends in hospitalization for all BBVI groups declined at the end of follow-up. HIV positive status at baseline (aHR: 6.58) and longer duration of drug use (aHR: 1.11) were independently associated with increased risk for HIV hospitalization. Female gender (aHR: 3.05) and intravenous use of primary drug (aHR: 2.78) were significantly associated with HCV hospitalization. Having hepatitis B negative status at baseline (aHR: 0.25) reduced the risk of other hepatitis hospitalizations. Illicit drug use coexists with blood-borne viral infections. To address this problem, clinicians treating infectious diseases need to also identify drug use in their patients and provide drug treatment information and/or referral. © 2015 Elsevier Inc.

Quantitative and qualitative assessment of the bovine abortion surveillance system in France

Bovine abortion is the main clinical sign of bovine brucellosis, a disease of which France has been declared officially free since 2005. To ensure the early detection of any brucellosis outbreak, event-driven surveillance relies on the mandatory notification of bovine abortions and the brucellosis testing of aborting cows. However, the under-reporting of abortions appears frequent. Our objectives were to assess the aptitude of the bovine abortion surveillance system to detect each and every bovine abortion and to identify factors influencing the system's effectiveness. We evaluated five attributes defined by the U.S. Centers for Disease Control with a method suited to each attribute: (1) data quality was studied quantitatively and qualitatively, as this factor considerably influences data analysis and results; (2) sensitivity and representativeness were estimated using a unilist capture-recapture approach to quantify the surveillance system's effectiveness; (3) acceptability and simplicity were studied through qualitative interviews of actors in the field, given that the surveillance system relies heavily on abortion notifications by farmers and veterinarians. Our analysis showed that (1) data quality was generally satisfactory even though some errors might be due to actors' lack of awareness of the need to collect accurate data; (2) from 2006 to 2011, the mean annual sensitivity - i.e. the proportion of farmers who reported at least one abortion out of all those who detected such events - was around 34%, but was significantly higher in dairy than beef cattle herds (highlighting a lack of representativeness); (3) overall, the system's low sensitivity was related to its low acceptability and lack of simplicity. This study showed that, in contrast to policy-makers, most farmers and veterinarians perceived the risk of a brucellosis outbreak as negligible. They did not consider sporadic abortions as a suspected case of brucellosis and usually reported abortions only to

How low is the risk of influenza A(H5N1) infection?

[No abstract available]

Economic comparison of the monitoring programmes for bluetongue vectors in Austria and Switzerland

With the bluetongue virus serotype 8 (BTV-8) outbreak in 2006, vector monitoring programmes (according to EU regulation 1266/2007) were implemented by European countries to obtain information on the spatial distribution of vectors and the vector-free period. This study investigates the vector monitoring programmes in Austria and Switzerland by performing a retrospective cost analysis for the period 2006-2010. Two types of costs were distinguished: costs financed directly via the national bluetongue programmes and costs contributed in-kind by the responsible institutions and agricultural holdings. The total net costs of the monitoring programme in Austria amounted to €1,415,000, whereby in Switzerland the costs were valued at €94,000. Both countries followed the legislation complying with requirements, but differed in regard to sampling frequency, number of trap sites and sampling strategy. Furthermore, the surface area of Austria is twice the area of Switzerland although the number of ruminants is almost the same in both countries. Thus, for comparison, the costs were normalised with regard to the sampling frequency and the number of trap sites. Resulting costs per trap sample comprised €164 for Austria and €48 for Switzerland. In both countries, around 50 per cent of the total costs can be attributed to payments in-kind. The benefit of this study is twofold: first, veterinary authorities may use the results to improve the economic efficiency of future vector monitoring programmes. Second, the analysis of the payment in-kind contribution is of great importance to public authorities as it makes the available resources visible and demonstrates how they have been used. © 2015 Veterinary Record.

Responding to the Ebola virus disease in West Africa: Lessons for India

[No abstract available]

The integration of social, behavioral, and biological mechanisms in models of pathogenesis

A large part of contemporary medicine is concerned with describing and understanding the biological mechanisms involved in disease causation. Comparatively less attention has been paid to the socioeconomic and behavioral mechanisms underlying disease. This article argues for an integration of social, behavioral, and biological factors in the explanation of pathogenesis, a perspective that is in accord with the vision of pioneer public health practitioners of the 19th century, but that has gradually been overtaken by the dominance of the biomedical disease model. In recent decades, the social components of disease have been depicted as “distal” factors or used as “classificatory” devices. We explain how the integration we propose, which draws upon the concepts of “mixed mechanism” and of “lifeworld,” advances the view of several scholars of the recent past. Finally, we discuss new findings in epigenetics and psychology, where socioeconomic disparities appear to be an integral part of the explanation of health conditions, to illustrate how the integration may work in practice. © 2015 by Johns Hopkins University Press.

Prevalence of endemic enteropathogens of calves in New Zealand dairy farms

AIM: To conduct a country-wide prevalence study of bovine group A rotavirus, coronavirus, Cryptosporidium parvum, Salmonella spp. and enterotoxigenic K99+ Escherichia coli (K99) in calves on New Zealand dairy farms. METHODS: Faecal samples (n=1,283) were collected during the 2011 calving season from calves that were 1–5 and 9–21 days-old on 97 dairy farms, and were analysed for the presence of bovine group A rotavirus, coronavirus, Cryptosporidium and Salmonella spp., and K99. Farm-level prevalences were calculated and relationships between demographic variables and the presence of enteropathogens were examined using logistic regression models. RESULTS: Of the 97 farms, 93 (96%) had at least one sample infected with enteropathogens. The standardised farm prevalences of bovine group A rotavirus, bovine coronavirus and C. parvum were 46, 14 and 18%, respectively, in calves that were 1–5 days-old, and 57, 31 and 52%, respectively, in calves that were 9–21 days-old. The farm-level prevalence of K99 was 11% in calves that were 1–5 days-old. Salmonella spp. were found in three and four samples, from calves that were 1–5 and 9–21 days-old, respectively. No associations between explanatory variables and the presence of the enteropathogens were identified at the farm level. At the calf level, the odds of C. parvum shedding and of co-infection with any combination of pathogens were greater in calves that were 9–21 than 1–5 days-old. CONCLUSIONS AND CLINICAL RELEVANCE: This study provides epidemiological estimates of the prevalence of calves’ enteropathogens in New Zealand, which could be used for infection risk assessment or estimation of the environmental loads of pathogens shed in cattle faeces. © 2015 New Zealand Veterinary Association.

Comparison of spatiotemporal fusion models: A review

Simultaneously capturing spatial and temporal dynamics is always a challenge for the remote sensing community. Spatiotemporal fusion has gained wide interest in various applications for its superiority in integrating both fine spatial resolution and frequent temporal coverage. Though many advances have been made in spatiotemporal fusion model development and applications in the past decade, a unified comparison among existing fusion models is still limited. In this research, we classify the models into three categories: transformation-based, reconstruction-based, and learning-based models. The objective of this study is to (i) compare four fusion models (STARFM, ESTARFM, ISTAFM, and SPSTFM) under a one Landsat-MODIS (L-M) pair prediction mode and two L-M pair prediction mode using time-series datasets from the Coleambally irrigation area and Poyang Lake wetland; (ii) quantitatively assess prediction accuracy considering spatiotemporal comparability, landscape heterogeneity, and model parameter selection; and (iii) discuss the advantages and disadvantages of the three categories of spatiotemporal fusion models.

Zotero article collection 1(no login needed)
Zotero article collection 2(with supplementary info) (*login required)

No comments:

Post a Comment