Modeling the long-term persistence of hepatitis A antibody after a two-dose vaccination schedule in Argentinean children.

BACKGROUND: Long-term seroprotection data are essential for decision-making on the need and timing of vaccine boosters. Based on data from longitudinal serological studies, modeling can provide estimates on long-term antibody persistence and inform such decision-making. METHODS: We examined long-term anti-hepatitis A virus (anti-HAV) antibody persistence in Argentinean children ≤15 years after the initial study where they completed a 2-dose course of inactivated hepatitis A vaccine (Avaxim 80U Pediatric, Sanofi Pasteur, Lyon, France). Blood serum samples were taken at baseline, 2 weeks (post first dose), 6 months (pre-booster), 6.5 months (post-booster), 10 years and 14-15 years after first vaccine dose. We fitted 8 statistical model types, predominantly mixed effects models, to anti-HAV persistence data, to identify the most appropriate and best fitting models for our data set and to predict individuals' anti-HAV levels and seroprotection rates up to 30 years post vaccination. RESULTS: Fifty-four children (mean age at enrollment 30.4 months) were enrolled up to 15 years post first vaccine dose. There were 3 distinct periods of antibody concentration: rapid rise up to peak concentration post-booster, rapid decay from post-booster to 10 years, followed by slower decay. A 3-segmented linear mixed effects model was the most appropriate for the data set. Extrapolating based on the available 14-15-year follow-up, the analysis predicted that 88% of individuals anti-HAV seronegative prior to vaccination would remain seroprotected at 30 years post vaccination and lifelong seroprotection for vaccinees seropositive prior to vaccination. CONCLUSIONS: Currently available data demonstrate that Avaxim 80U Pediatric confers to most vaccinees a high level of seroprotection against hepatitis A infection for at least 20-30 years

Estimating the global burden of endemic canine rabies

Background: Rabies is a notoriously underreported and neglected disease of lowincome countries. This study aims to estimate the public health and economic burden of rabies circulating in domestic dog populations, globally and on a country-by-country basis, allowing an objective assessment of how much this preventable disease costs endemic countries.<p></p> Methodology/Principal Findings: We established relationships between rabies mortality and rabies prevention and control measures, which we incorporated into a model framework. We used data derived from extensive literature searches and questionnaires on disease incidence, control interventions and preventative measures within this framework to estimate the disease burden. The burden of rabies impacts on public health sector budgets, local communities and livestock economies, with the highest risk of rabies in the poorest regions of the world. This study estimates that globally canine rabies causes approximately 59,000 (95% Confidence Intervals: 25- 159,000) human deaths, over 3.7 million (95% CIs: 1.6-10.4 million) disability-adjusted life years (DALYs) and 8.6 billion USD (95% CIs: 2.9-21.5 billion) economic losses annually. The largest component of the economic burden is due to premature death (55%), followed by direct costs of post-exposure prophylaxis (PEP, 20%) and lost income whilst seeking PEP (15.5%), with only limited costs to the veterinary sector due to dog vaccination (1.5%), and additional costs to communities from livestock losses (6%).<p></p> Conclusions/Significance: This study demonstrates that investment in dog vaccination, the single most effective way of reducing the disease burden, has been inadequate and that the availability and affordability of PEP needs improving. Collaborative investments by medical and veterinary sectors could dramatically reduce the current large, and unnecessary, burden of rabies on affected communities. Improved surveillance is needed to reduce uncertainty in burden estimates and to monitor the impacts of control efforts.<p></p&gt

Estimating the global burden of endemic canine rabies

Rabies is a fatal viral disease largely transmitted to humans from bites by infected animals —predominantly from domestic dogs. The disease is entirely preventable through prompt administration of post-exposure prophylaxis (PEP) to bite victims and can be controlled through mass vaccination of domestic dogs. Yet, rabies is still very prevalent in developing countries, affecting populations with limited access to health care. The disease is also grossly underreported in these areas because most victims die at home. This leads to insufficient prioritization of rabies prevention in public health agendas. To address this lack of information on the impacts of rabies, in this study, we compiled available data to provide a robust estimate of the health and economic implications of dog rabies globally. The most important impacts included: loss of human lives (approximately 59,000 annually) and productivity due to premature death from rabies, and costs of obtaining PEP once an exposure has occurred. The greatest risk of developing rabies fell upon the poorest regions of the world, where domestic dog vaccination is not widely implemented and access to PEP is most limited. A greater focus on mass dog vaccination could eliminate the disease at source, reducing the need for costly PEP and preventing the large and unnecessary burden of mortality on at-risk communities.S1 Text. Supporting bibliography.S1 Table. Estimates by country of rabies deaths, exposures, PEP use, prevented deaths, dog vaccination coverage, probability that a dog is rabid (RP), of bite victims receiving PEP (PP), DALYs, costs and 95% confidence intervals of estimates. Clusters to which countries are assigned are shown and inputs used for estimating parameters including the human development index and whetehr a country s rabies-free or endemic (RISK). Estimates of years of life lost (YLL) and DALYs (due to rabies and to adverse events from the use of nerve tissue vaccines) are shown under different assumptions (estimates under the assumption of no time discounting or age-weighting should be directly comparable to the 2010 Global Burden of Disease study).S1 Fig. Division of costs associated with rabies, prevention and control across sectors by cluster. Inset shows proportional expenditure in different clusters. Full details of countries by cluster are given in S1 Table. Asia 4 comprises: Philippines, Sri Lanka, Thailand (High PEP use); Asia 3 comprises Bhutan, Nepal, Bangladesh, Pakistan (Himalayan region); Asia 2 comprises Cambodia, Myanmar, Laos, Vietnam and Democratic People’s Republic of Korea; SADC comprises countries in the Southern African Development Community, Eurasia comprises Afghanistan, Kazakhstan, Kyrgyzstan, Mongolia, the Russian Federation, Turkmenistan, Tajikistan, and Uzbekistan.S1 Dataset. Model code and input data files including references, rationale and detail of Delphi process. The code folder contains seven R scripts: burden_model.R runs the model using data compiled in burden_1.R, after estimating parameters using: FitCovInc.R, FitPP.R, and creating Fig 2 (RabiesBurdenFig2.R). The script burden_results.R summarizes findings using the output of burden_model.R and burden_sensitivity.R runs the sensitivity analyses. The data folder contains 12 csv files called by the R code for the analyses, and one excel file (Vet. xlsx) with additional details about the data sources in vcountry2.csv and vcluster2.csv and with Delphi process estimates for dog vaccination coverage. Data sources are detailed in the relevant data sources and the details of the sources of data used in the analysis are in the supporting bibliography, S1 text.This study was funded by the UBS Optimus Foundation (http://www.ubs.com/optimusfoundation) and the Wellcome Trust (095787/Z/11/Z).http://www.plosntds.orgam201

7. Syndrome respiratoire aigu sévère : une pandémie avant l’heure (IDEA, 2012)

Cette étude de cas se situe dans la thématique de l’émergence d’un agent pathogène contagieux à potentiel pandémique. Elle a été développée pour illustrer les notions de crise de santé publique internationale, de transmission d’agents infectieux dans un contexte global et d’endiguement d’une pandémie.Retrouvez les réponses et commentaires dans la partie Guides des réponse

Trends in healthcare utilization and costs associated with pneumonia in the United States during 2008–2014

Abstract Background Pneumonia is the leading cause of morbidity and mortality worldwide. Pneumococcal conjugate vaccines have reduced the burden of pneumonia, but data on the current burden of pneumonia and its impact on the healthcare system are needed to inform the development and use of new vaccines and other preventive measures. Methods We retrospectively analyzed the frequency of pneumonia in the US during 2008–2014 using data from the MarketScan® Commercial Claims and Encounters database. Frequencies of healthcare utilization related to the index pneumonia episode were calculated using the annual number of enrolled person-years (PY) as the denominator and the number of individuals with pneumonia as the numerator. Pneumonia-associated costs were calculated as mean payment per episode during the 2 years from 2013 to 2014. Results The overall annual healthcare utilization rate for pneumonia was 15.1 per 1000 PY and decreased slightly from 2008 to 2014 (from 15.4 to 13.5 per 1000 PY). Most pneumonia-related healthcare utilization was due to office/outpatient visits (10.3 per 1000 PY; 68.3%). Emergency department/urgent care visits (2.5 per 1000 PY; 16.9%) and hospitalizations (2.2 per 1000 PY; 14.8%) contributed less. Pneumonia-related healthcare utilization was highest in children  65 years (45.0 per 1000 PY). The mean cost per pneumonia episode (95% confidence interval) was US$429.1 ($424.8–$433.4) for office/outpatient visits,$1126.9 ($1119.5–$1134.3) for emergency department/urgent care visits, and $10,962.5 ($10,822.8–$11,102.2) for hospitalization. Conclusions The burden of pneumonia on the US healthcare system remains substantial. The results presented here can help guide new vaccination strategies and other preventive interventions for reducing the remaining burden of pneumonia

Trends in healthcare utilization and costs associated with acute otitis media in the United States during 2008–2014

Abstract Background Acute otitis media (AOM) is the most common cause of pediatric medical visits and antibiotic prescriptions worldwide, but its current impact on the US healthcare system is not clear. The aim of this study was to investigate changes in the incidence of AOM from 2008, just before 13-valent pneumococcal conjugate vaccine was introduced, to 2014 using US insurance records in the Truven MarketScan® database. The study also examined the costs associated with index AOM events during the two most recent years for which data were available (2013–2014). Methods AOM cases in the MarketScan database during 2008–2014 were identified using ICD9 diagnosis codes 381.xx and 382.xx. Incidence rates of healthcare utilization related to the index AOM episode were calculated using the annual number of enrolled person-years as the denominator and the number of individuals with AOM as the numerator. AOM-associated costs were calculated as the mean payment per episode during the 2 years from 2013 to 2014. Results The overall annual rate of AOM-related healthcare utilization was 60.5 per 1000 person-years and changed little from 2008 to 2014 (range, 58.4–62.6). Most of this was due to office/outpatient visits (55.7 [range, 52.0–58.8] per 1000 person-years). Emergency department/urgent care visits (4.7 [range 3.7–6.3] per 1000 person-years) and hospitalization (0.0 [range, 0.0–0.1] per 1000 person-years) contributed little. The rate of AOM-related healthcare utilization per 1000 person-years was highest in the youngest children and declined with age (474.3 for < 1 year, 503.9 for 1 year, 316.3 for 2–4 years, 94.9 for 5–17 years, 33.1 for 18–49 years, 28.6 for 50–64 years, 23.7 for 65–74 years, 20.2 for 75–84 years, and 16.1 for ≥85 years). The mean cost per AOM episode in 2013–2014 (95% confidence interval) was $199.0 (198.4–199.6) for office or outpatient visits,$329.6 (328.2–331.0) for emergency department/urgent care visits, and $1592.9 (1422.0–1763.8) for hospitalization. Conclusions In the US, AOM-associated healthcare utilization and costs remain substantial. More effective preventive measures such as new vaccines are needed to reduce the burden of AOM

The public health benefits and economic value of routine yellow fever vaccination in Colombia.

Q2Q260-65Objectives To evaluate the public health benefits and economic value of live-attenuated yellow fever (YF) 17D vaccine in Colombia. Methods A decision tree model was used to assess the theoretical impact of routine YF vaccination of 1-year-olds (no “catch-up”) during the interepidemic period from 1980 to 2002, avoiding capturing the impact of YF vaccine introduction in 2003. The vaccine was assumed to be 99% effective, to provide lifetime protection, and to cover 85% of the target population. Costs per disability-adjusted life-year (DALY) averted were computed from payer and societal perspectives. Univariate sensitivity analyses were performed. Results During the interepidemic period, routine YF vaccination would have averted 2223 nonfatal cases of YF and 65 deaths, leading to an overall reduction of 1365 DALYs. The net cost of this vaccination would have been $25 964 813 (payer’s perspective) and$16 535 465 (societal perspective). Cost per DALY averted was $19 022 and$12 114 from payer and societal perspectives, respectively (all costs in 2015 US dollars). Vaccination was considered cost-effective from both perspectives (ie, between 1- and 3-fold the gross domestic product per capita, $7158) and remains so if price per dose was$2.75 or less and $4.66 from payer and societal perspectives, respectively. Underreporting had the largest impact on the results. Conclusions Routine toddler YF vaccination in Colombia would have been considered cost-effective in the prevaccination era. This study provides insights on the value of vaccination in an upper middle-income country

Determinants of individuals' risks to 2009 pandemic influenza virus infection at household level amongst Djibouti city residents--a CoPanFlu cross-sectional study

BACKGROUND: Following the 2009 swine flu pandemic, a cohort for pandemic influenza (CoPanFlu) study was established in Djibouti, the Horn of Africa, to investigate its case prevalence and risk predictors’ at household level. METHODS: From the four city administrative districts, 1,045 subjects from 324 households were included during a face-to-face encounter between 11th November 2010 and 15th February 2011. Socio-demographic details were collected and blood samples were analysed in haemagglutination inhibition (HI) assays. Risk assessments were performed in a generalised estimating equation model. RESULTS: In this study, the indicator of positive infection status was set at an HI titre of ≥ 80, which was a relevant surrogate to the seroconversion criterion. All positive cases were considered to be either recent infections or past contact with an antigenically closely related virus in humans older than 65 years. An overall sero-prevalence of 29.1% and a geometrical mean titre (GMT) of 39.5% among the residents was observed. Youths, ≤ 25 years and the elderly, ≥65 years had the highest titres, with values of 35.9% and 29.5%, respectively. Significantly, risk was high amongst youths ≤ 25 years, (OR 1.5-2.2), residents of District 4(OR 2.9), students (OR 1.4) and individuals living near to river banks (OR 2.5). Belonging to a large household (OR 0.6), being employed (OR 0.5) and working in open space-outdoor (OR 0.4) were significantly protective. Only 1.4% of the cohort had vaccination against the pandemic virus and none were immunised against seasonal influenza. CONCLUSION: Despite the limited number of incident cases detected by the surveillance system, A(H1N1)pdm09 virus circulated broadly in Djibouti in 2010 and 2011. Age-group distribution of cases was similar to what has been reported elsewhere, with youths at the greatest risk of infection. Future respiratory infection control should therefore be tailored to reach specific and vulnerable individuals such as students and those working in groups indoors. It is concluded that the lack of robust data provided by surveillance systems in southern countries could be responsible for the underestimation of the epidemiological burden, although the main characteristics are essentially similar to what has been observed in developed countries