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Rotavirus is responsible for 26% of diarrheal deaths in Latin America and the Caribbean. Haiti introduced the monovalent rotavirus vaccine in April 2014. The objective of this analysis is to describe the impact of the rotavirus vaccine on hospitalizations among Haitian children younger than 5 years old during the first 5 years after introduction. This analysis includes all children with diarrhea who were enrolled as part of a sentinel surveillance system at two hospitals from May 2013 to April 2019. We compare the proportion of rotavirus-positive specimens in each post-vaccine introduction year to the pre-vaccine period. To account for the potential dilution of the proportion of rotavirus-positive specimens from a waning cholera outbreak, we also analyzed annual trends in the absolute number of positive stools, fit a two-component finite-mixture model to the negative specimens, and fit a negative binomial time series model to the pre-vaccine rotavirus-positive specimens to predict the number of rotavirus diarrhea hospital admissions in the absence of rotavirus vaccination. The overall percentage of rotavirus-positive specimens declined by 22% the first year after introduction, increased by 17% the second year, and declined by 33% to 50% the subsequent 3 years. All sensitivity analyses confirmed an overall decline. We observed a clear annual rotavirus seasonality before and after vaccine introduction, with the greatest activity in December through April, and a biennial pattern, with high sharp peaks and flatter longer periods of increased rotavirus activity in alternating years, consistent with suboptimal vaccination coverage. Overall, our study shows evidence that the introduction of the rotavirus vaccine reduced the burden of severe rotavirus diarrhea.

Background In October 2010, Haiti was struck by a large-scale cholera epidemic. The Haitian government, UNICEF and other international partners launched an unprecedented nationwide alert-response strategy in July 2013. Coordinated NGOs recruited local rapid response mobile teams to conduct case-area targeted interventions (CATIs), including education sessions, household decontamination by chlorine spraying, and distribution of chlorine tablets. An innovative red-orange-green alert system was also established to monitor the epidemic at the communal scale on a weekly basis. Our study aimed to describe and evaluate the exhaustiveness, intensity and quality of the CATIs in response to cholera alerts in Haiti between July 2013 and June 2017. Methodology/principal findings We analyzed the response to 7,856 weekly cholera alerts using routine surveillance data and severity criteria, which was based on the details of 31,306 notified CATIs. The odds of CATI response during the same week (exhaustiveness) and the number of complete CATIs in responded alerts (intensity and quality) were estimated using multivariate generalized linear mixed models and several covariates. CATIs were carried out significantly more often in response to red alerts (adjusted odds ratio (aOR) [95%-confidence interval, 95%-CI], 2.52 [2.22–2.87]) compared with orange alerts. Significantly more complete CATIs were carried out in response to red alerts compared with orange alerts (adjusted incidence ratio (aIR), 1.85 [1.73–1.99]). Over the course of the eight-semester study, we observed a significant improvement in the exhaustiveness (aOR, 1.43 [1.38–1.48] per semester) as well as the intensity and quality (aIR, 1.23 [1.2–1.25] per semester) of CATI responses, independently of funds available for the strategy. The odds of launching a CATI response significantly decreased with increased rainfall (aOR, 0.99 [0.97–1] per each accumulated cm). Response interventions were significantly heterogeneous between NGOs, communes and departments. Conclusions/significance The implementation of a nationwide case-area targeted rapid response strategy to control cholera in Haiti was feasible albeit with certain obstacles. Such feedback from the field and ongoing impact studies will be very informative for actors and international donors involved in cholera control and elimination in Haiti and in other affected countries., Author summary Cholera is a potentially deadly diarrheal disease caused by toxin-secreting strains of Vibrio cholerae. The bacterium can trigger severe epidemics in countries with limited access to potable water and sanitation. Hygiene promotion, proper sanitation and improved access to safe drinking water are essential to control cholera. However, very few reports have described and evaluated the implementation of such activities in the field. Since October 2010, Haiti has been affected by one of the most severe cholera epidemics of the past few decades. In this report, we describe and evaluate the implementation of the original nationwide case-area targeted interventions (CATIs) response strategy, which was launched in July 2013 after years of insufficient response coordination and diminishing efforts to control cholera outbreaks in affected communities. Rapid implementation of education sessions, household decontamination, soap distribution and water chlorination in affected communities proved challenging but possible, even in a mountainous and decentralized country such as Haiti with tens of thousands of suspected cholera cases per year. Evaluation of the impact of the CATI-based strategy on the cholera epidemic is underway. Together with other components of a multi-sectoral approach, this rapid response strategy appears to be critical to eventually eliminate cholera in Haiti.

Matthew, a category 4 hurricane, struck Haiti on October 4, 2016, causing widespread flooding and damage to buildings and crops, and resulted in many deaths. The damage caused by Matthew raised concerns of increased cholera transmission particularly in Sud and Grand’Anse departments, regions which were hit most heavily by the storm. To evaluate the change in reported cholera cases following Hurricane Matthew on reported cholera cases, we used interrupted time series regression models of daily reported cholera cases, controlling for the impact of both rainfall, following a 4-week lag, and seasonality, from 2013 through 2016. Our results indicate a significant increase in reported cholera cases after Matthew, suggesting that the storm resulted in an immediate surge in suspect cases, and a decline in reported cholera cases in the 46-day post-storm period, after controlling for rainfall and seasonality. Regression models stratified by the department indicate that the impact of the hurricane was regional, with larger surges in the two most highly storm-affected departments: Sud and Grand’Anse. These models were able to provide input to the Ministry of Health in Haiti on the national and regional impact of Hurricane Matthew and, with further development, could provide the flexibility of use in other emergency situations. This article highlights the need for continued cholera prevention and control efforts, particularly in the wake of natural disasters such as hurricanes, and the continued need for intensive cholera surveillance nationally.

BackgroundA massive cholera epidemic struck Haiti on October 2010. As part of the national cholera elimination plan, the Haitian government, UNICEF and other international partners launched a nationwide alert-response strategy from July 2013. This strategy established a coordinated methodology to rapidly target cholera-affected communities with WaSH (water sanitation and hygiene) response interventions conducted by field mobile teams. An innovative red-orange-green alert system was established, based on routine surveillance data, to weekly monitor the epidemic.Methodology/Principal findingsWe used cholera consolidated surveillance databases, alert records and details of 31,306 response interventions notified by WaSH mobile teams to describe and assess the implementation of this approach between July 2013 and June 2017. Response to red and orange alerts was heterogeneous across the country, but significantly improved throughout the study period so that 75% of red and orange alerts were responded within the same epidemiological week during the 1st semester of 2017. Numbers of persons educated about cholera, houses decontaminated by chlorine spraying, households which received water chlorination tablets and water sources that were chlorinated during the same week as cholera alerts significantly increased. Alerts appeared to be an interesting and simple indicator to monitor the dynamic of the epidemic and assess the implementation of response activities.Conclusions/SignificanceThe implementation of a nationwide alert-response strategy against cholera in Haiti was feasible albeit with certain obstacles. Its cost was less than USD 8 million per year. Continuing this strategy seems essential to eventually defeat cholera in Haiti while ambitious long-term water and sanitation projects are conducted in vulnerable areas. It constitutes a core element of the current national plan for cholera elimination of the Haitian Government.