Reducing wasting in young children with preventive supplementation: a cohort study in Niger

OBJECTIVE: To compare the incidence of wasting, stunting, and mortality among children aged 6 to 36 months who are receiving preventive supplementation with either ready-to-use supplementary foods (RUSFs) or ready-to-use therapeutic foods (RUTFs). SUBJECTS AND METHODS: Children aged 6 to 36 months in 12 villages of Maradi, Niger, (n = 1645) received a monthly distribution of RUSFs (247 kcal [3 spoons] per day) for 6 months or RUTFs (500-kcal sachet per day) for 4 months. We compared the incidence of wasting, stunting, and mortality among children who received preventive supplementation with RUSFs versus RUTFs. RESULTS: The effectiveness of RUSF supplementation depended on receipt of a previous preventive intervention. In villages in which a preventive supplementation program was previously implemented, the RUSF strategy was associated with a 46% (95% confidence interval [CI]: 6%-69%) and 59% (95% CI: 17%-80%) reduction in wasting and severe wasting, respectively. In contrast, in villages in which the previous intervention was not implemented, we found no difference in the incidence of wasting or severe wasting according to type of supplementation. Compared with the RUTF strategy, the RUSF strategy was associated with a 19% (95% CI: 0%-34%) reduction in stunting overall. CONCLUSION: We found that the relative performance of a 6-month RUSF supplementation strategy versus a 4-month RUTF strategy varied with receipt of a previous nutritional intervention. Contextual factors will continue to be important in determining the dose and duration of supplementation that will be most effective, acceptable, and sustainable for a given setting

Urban Cholera transmission hotspots and their implications for Reactive Vaccination: evidence from Bissau city, Guinea Bissau

Use of cholera vaccines in response to epidemics (reactive vaccination) may provide an effective supplement to traditional control measures. In Haiti, reactive vaccination was considered but, until recently, rejected in part due to limited global supply of vaccine. Using Bissau City, Guinea-Bissau as a case study, we explore neighborhood-level transmission dynamics to understand if, with limited vaccine and likely delays, reactive vaccination can significantly change the course of a cholera epidemic

High Hepatitis E Seroprevalence Among Displaced Persons in South Sudan.

AbstractLarge protracted outbreaks of hepatitis E virus (HEV) have been documented in displaced populations in Africa over the past decade though data are limited outside these exceptional settings. Serological studies can provide insights useful for improving surveillance and disease control. We conducted an age-stratified serological survey using samples previously collected for another research study from 206 residents of an internally displaced person camp in Juba, South Sudan. We tested serum for anti-HEV antibodies (IgM and IgG) and estimated the prevalence of recent and historical exposure to the virus. Using data on individuals' serostatus, camp arrival date, and state of origin, we used catalytic transmission models to estimate the relative risk of HEV infection in the camp compared with that in the participants' home states. The age-adjusted seroprevalence of anti-HEV IgG was 71% (95% confidence interval = 63-78), and 4% had evidence of recent exposure (IgM). We estimated HEV exposure rates to be more than 2-fold (hazard ratio = 2.3, 95% credible interval = 0.3-5.8) higher in the camp than in the participants' home states, although this difference was not statistically significant. HEV transmission may be higher than previously appreciated, even in the absence of reported cases. Improved surveillance in similar settings is needed to understand the burden of disease and minimize epidemic impact through early detection and response

Public health surveillance after the 2010 Haiti earthquake: the experience of Médecins Sans Frontières

Background In January 2010, Haiti was struck by a powerful earthquake, killing and wounding hundreds of thousands and leaving millions homeless. In order to better understand the severity of the crisis, and to provide early warning of epidemics or deteriorations in the health status of the population, Médecins Sans Frontières established surveillance for infections of epidemic potential and for death rates and malnutrition prevalence. Methods Trends in infections of epidemic potential were detected through passive surveillance at health facilities serving as sentinel sites. Active community surveillance of death rates and malnutrition prevalence was established through weekly home visits. Results There were 102,054 consultations at the 15 reporting sites during the 26 week period of operation. Acute respiratory infections, acute watery diarrhoea and malaria/fever of unknown origin accounted for the majority of proportional morbidity among the diseases under surveillance. Several alerts were triggered through the detection of immediately notifiable diseases and increasing trends in some conditions. Crude and under-5 death rates, and acute malnutrition prevalence, were below emergency thresholds. Conclusion Disease surveillance after disasters should include an alert and response component, requiring investment of resources in informal networks that improve sensitivity to alerts as well as on the more common systems of data collection, compilation and analysis. Information sharing between partners is necessary to strengthen early warning systems. Community-based surveillance of mortality and malnutrition is feasible but requires careful implementation and validation

Use of a Cholera Rapid Diagnostic Test during a Mass Vaccination Campaign in Response to an Epidemic in Guinea, 2012

During the 2012 cholera outbreak in the Republic of Guinea, the Ministry of Health, supported by Médecins Sans Frontières - Operational Center Geneva, used the oral cholera vaccine Shanchol as a part of the emergency response. The rapid diagnostic test (RDT) Crystal VC, widely used during outbreaks, detects lipopolysaccharide antigens of Vibrio cholerae O1 and O139, both included in Shanchol. In the context of reactive use of a whole-cell cholera vaccine in a region where cholera cases have been reported, it is essential to know what proportion of vaccinated individuals would be reactive to the RDT and for how long after vaccination

Estimates of measles case fatality ratios: a comprehensive review of community-based studies.

BACKGROUND: Global deaths from measles have decreased notably in past decades, due to both increases in immunization rates and decreases in measles case fatality ratios (CFRs). While some aspects of the reduction in measles mortality can be monitored through increases in immunization coverage, estimating the level of measles deaths (in absolute terms) is problematic, particularly since incidence-based methods of estimation rely on accurate measures of measles CFRs. These ratios vary widely by geographic and epidemiologic context and even within the same community from year-to-year. METHODS: To understand better the variations in CFRs, we reviewed community-based studies published between 1980 and 2008 reporting age-specific measles CFRs. RESULTS: The results of the search consistently document that measles CFRs are highest in unvaccinated children under age 5 years; in outbreaks; the lowest CFRs occur in vaccinated children regardless of setting. The broad range of case and death definitions, study populations and geography highlight the complexities in extrapolating results for global public health planning. CONCLUSIONS: Values for measles CFRs remain imprecise, resulting in continued uncertainty about the actual toll measles exacts

Prognostic Accuracy of WHO Growth Standards to Predict Mortality in a Large-Scale Nutritional Program in Niger

Rebecca Grais and colleagues assess the accuracy of WHO growth standards in predicting death among malnourished children admitted to a large nutritional program in Niger

Measuring the Performance of Vaccination Programs Using Cross-Sectional Surveys: A Likelihood Framework and Retrospective Analysis

Justin Lessler and colleagues describe a method that estimates the fraction of a population accessible to vaccination activities, and they apply it to measles vaccination in three African countries: Ghana, Madagascar, and Sierra Leone

The seasonality of cholera in sub-Saharan Africa: a statistical modelling study

Background: Cholera remains a major threat in sub-Saharan Africa (SSA), where some of the highest case-fatality rates are reported. Knowing in what months and where cholera tends to occur across the continent could aid in improving efforts to eliminate cholera as a public health concern. However, largely due to the absence of unified large-scale datasets, no continent-wide estimates exist. In this study, we aimed to estimate cholera seasonality across SSA and explore the correlation between hydroclimatic variables and cholera seasonality. Methods: Using the global cholera database of the Global Task Force on Cholera Control, we developed statistical models to synthesise data across spatial and temporal scales to infer the seasonality of excess (defined as incidence higher than the 2010–16 mean incidence rate) suspected cholera occurrence in SSA. We developed a Bayesian statistical model to infer the monthly risk of excess cholera at the first and second administrative levels. Seasonality patterns were then grouped into spatial clusters. Finally, we studied the association between seasonality estimates and hydroclimatic variables (mean monthly fraction of area flooded, mean monthly air temperature, and cumulative monthly precipitation). Findings: 24 (71%) of the 34 countries studied had seasonal patterns of excess cholera risk, corresponding to approximately 86% of the SSA population. 12 (50%) of these 24 countries also had subnational differences in seasonality patterns, with strong differences in seasonality strength between regions. Seasonality patterns clustered into two macroregions (west Africa and the Sahel vs eastern and southern Africa), which were composed of subregional clusters with varying degrees of seasonality. Exploratory association analysis found most consistent and positive correlations between cholera seasonality and precipitation and, to a lesser extent, between cholera seasonality and temperature and flooding. Interpretation: Widespread cholera seasonality in SSA offers opportunities for intervention planning. Further studies are needed to study the association between cholera and climate. Funding: US National Aeronautics and Space Administration Applied Sciences Program and the Bill & Melinda Gates Foundation

A long-lasting measles epidemic in Maroua, Cameroon 2008-2009: mass vaccination as response to the epidemic.

A measles outbreak occurred in Maroua, Cameroon, from January 2008 to April 2009. In accordance with recent World Health Organization guidelines, an outbreak-response immunization (ORI) was conducted in January 2009. The aim of this study was to investigate the causes of the epidemic in order to guide vaccination strategies