Cholera in Haiti
Authors: Stanislas Rebaudet, Jean Gaudart, Renaud Piarroux
Journal: The Lancet Global Health (2020)

We carefully read the recently published study by Elizabeth Lee and colleagues (August, 2020).1Lee EC Chao DL Lemaitre JC et al.Achieving coordinated national immunity and cholera elimination in Haiti through vaccination: a modelling study.Lancet Glob Health. 2020; 8: e1081-e1089Summary Full Text Full Text PDF PubMed Scopus (5) Google Scholar We have substantial concerns about the results of the four models, which are in contrast with the current absence of actual cholera cases in Haiti since February, 2019. All four models largely failed to predict the actual collapse of the cholera epidemic over the past 18 months.1Lee EC Chao DL Lemaitre JC et al.Achieving coordinated national immunity and cholera elimination in Haiti through vaccination: a modelling study.Lancet Glob Health. 2020; 8: e1081-e1089Summary Full Text Full Text PDF PubMed Scopus (5) Google Scholar Models 1 and 3 also predicted an earlier median elimination date with no vaccination than with a high-coverage national campaign. Such major discrepancies challenge the robustness and architecture of models and might originate from three debatable assumptions. First, all models included a parameter for infectious asymptomatic individuals, although long-term asymptomatic carriers of Vibrio cholerae are very uncommon. The bacterial load required to get cholera far exceeds carriers' low level of bacterial excretion,2Cash RA Music SI Libonati JP Snyder MJ Wenzel RP Hornick RB Response of man to infection with Vibrio cholerae. I. Clinical, serologic, and bacteriologic responses to a known inoculum.J Infect Dis. 1974; 129: 45-52Crossref PubMed Scopus (203) Google Scholar and their responsibility in outbreak emergence has never been established to our knowledge. Second, models 2, 3, and 4 also included a parameter for a long-term environmental reservoir of cholera. But the long-term persistence of cholera in Haitian environments has never been confirmed and is currently under investigations by several teams on the field. Besides, the possibility of a late resurgence of cholera from environmental reservoirs has been invalidated by major worldwide studies based on the whole-genome comparison of cholera strains.3Domman D Quilici M-L Dorman MJ et al.Integrated view of Vibrio cholerae in the Americas.Science. 2017; 358: 789-793Crossref PubMed Scopus (62) Google Scholar Finally, none of the four models included the nearly 50 000 case-area targeted interventions that were implemented since 2013 through a nationwide strategy coordinated by the Haitian Ministry of Health and UNICEF.4Rebaudet S Bulit G Gaudart J et al.The case-area targeted rapid response strategy to control cholera in Haiti: a four-year implementation study.PLoS Negl Trop Dis. 2019; 13e0007263Crossref PubMed Scopus (13) Google Scholar Furthermore, Lee and colleagues failed to cite the effectiveness quasi-experimental study done in Haiti, which suggests that prompt and intense interventions could significantly shorten and mitigate cholera local outbreaks.5Michel E Gaudart J Beaulieu S et al.Estimating effectiveness of case-area targeted response interventions against cholera in Haiti.eLife. 2019; 8e50243Crossref PubMed Scopus (5) Google Scholar In summary, this modelling study provides a disconnected picture of the cholera situation in Haiti and leads to an unfounded recommendation for a national oral cholera vaccine campaign to eliminate cholera. This recommendation raises questions, since six of the authors are affiliated with four different institutions that acknowledge support from the Bill & Melinda Gates Foundation—an organisation that also strongly advocates for the oral cholera vaccine, has funded vaccine production and stockpiling, and has also proposed US$10 million for a campaign in Haiti. This evident competing interest should have been declared. We work for two French university hospitals, which have been mandated by the Haitian Ministry of Health and UNICEF-Haiti and granted by UNICEF-Haiti to provide a nationwide case-area targeted intervention strategy to control cholera with prospective epidemiological analysis and evaluation. UNICEF had no role in decision to publish and preparation of the manuscript. Achieving coordinated national immunity and cholera elimination in Haiti through vaccination: a modelling studyModels suggest that the probability of achieving zero transmission of Vibrio cholerae in Haiti with current methods of control is low, and that bolder action is needed to promote elimination of cholera from the region. Large-scale cholera vaccination campaigns in Haiti would offer the opportunity to synchronise nationwide immunity, providing near-term population protection while improvements to water and sanitation promote long-term cholera elimination. Full-Text PDF Open AccessCholera in HaitiWe were very surprised to read the recently published Article by Elizabeth Lee and colleagues1 and the linked Comment by Jeannot François.2 We believe both pieces might deeply mislead readers about the current epidemiological situation of cholera in Haiti. Full-Text PDF Open AccessCholera in Haiti – Authors' replyWe appreciate the careful consideration of our Article1 from Stanislas Rebaudet and colleagues and Jean Hugues Henrys and colleagues, but we must respectfully disagree with most of their concerns about our study. Full-Text PDF Open Access