14 research outputs found

    Eff ectiveness of reactive oral cholera vaccination in rural Haiti: a case-control study and bias-indicator analysis

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    Background Between April and June, 2012, a reactive cholera vaccination campaign was done in Haiti with an oral inactivated bivalent whole-cell vaccine. We aimed to assess the eff ectiveness of the vaccine in a case-control study and to assess the likelihood of bias in that study in a bias-indicator study. Methods Residents of Bocozel or Grand Saline who were eligible for the vaccination campaign (ie, age ≥12 months, not pregnant, and living in the region at the time of the vaccine campaign) were included. In the primary case-control study, cases had acute watery diarrhoea, sought treatment at one of three participating cholera treatment units, and had a stool sample positive for cholera by culture. For each case, four control individuals who did not seek treatment for acute watery diarrhoea were matched by location of residence, enrolment time (within 2 weeks of the case), and age (1–4 years, 5–15 years, and >15 years). Cases in the bias-indicator study were individuals with acute watery diarrhoea with a negative stool sample for cholera. Controls were selected in the same manner as in the primary case-control study. Trained staff used standard laboratory procedures to do rapid tests and stool cultures from study cases. Participants were interviewed to collect data on sociodemographic characteristics, risk factors for cholera, and self-reported vaccination. Data were analysed by conditional logistic regression, adjusting for matching factors. Findings From Oct 24, 2012, to March 9, 2014, 114 eligible individuals presented with acute watery diarrhoea and were enrolled, 25 of whom were subsequently excluded. 47 participants were analysed as cases in the vaccine eff ectiveness case-control study and 42 as cases in the bias-indicator study. 33 (70%) of 47 cholera cases self-reported vaccination versus 167 (89%) of 188 controls (vaccine eff ectiveness 63%, 95% CI 8–85). 27 (57%) of 47 cases had certifi ed vaccination versus 147 (78%) of 188 controls (vaccine eff ectiveness 58%, 13–80). Neither self-reported nor verifi ed vaccination was signifi cantly associated with non-cholera diarrhoea (vaccine eff ectiveness 18%, 95% CI –208 to 78 by self-report and –21%, –238 to 57 by verifi ed vaccination). Interpretation Bivalent whole-cell oral cholera vaccine eff ectively protected against cholera in Haiti from 4 months to 24 months after vaccination. Vaccination is an important component of eff orts to control cholera epidemics

    Achieving coordinated national immunity and cholera elimination in Haiti through vaccination: a modelling study

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    Summary: Background: Cholera was introduced into Haiti in 2010. Since then, more than 820 000 cases and nearly 10 000 deaths have been reported. Oral cholera vaccine (OCV) is safe and effective, but has not been seen as a primary tool for cholera elimination due to a limited period of protection and constrained supplies. Regionally, epidemic cholera is contained to the island of Hispaniola, and the lowest numbers of cases since the epidemic began were reported in 2019. Hence, Haiti may represent a unique opportunity to eliminate cholera with OCV. Methods: In this modelling study, we assessed the probability of elimination, time to elimination, and percentage of cases averted with OCV campaign scenarios in Haiti through simulations from four modelling teams. For a 10-year period from January 19, 2019, to Jan 13, 2029, we compared a no vaccination scenario with five OCV campaign scenarios that differed in geographical scope, coverage, and rollout duration. Teams used weekly department-level reports of suspected cholera cases from the Haiti Ministry of Public Health and Population to calibrate the models and used common vaccine-related assumptions, but other model features were determined independently. Findings: Among campaigns with the same vaccination coverage (70% fully vaccinated), the median probability of elimination after 5 years was 0–18% for no vaccination, 0–33% for 2-year campaigns focused in the two departments with the highest historical incidence, 0–72% for three-department campaigns, and 35–100% for nationwide campaigns. Two-department campaigns averted a median of 12–58% of infections, three-department campaigns averted 29–80% of infections, and national campaigns averted 58–95% of infections. Extending the national campaign to a 5-year rollout (compared to a 2-year rollout), reduced the probability of elimination to 0–95% and the proportion of cases averted to 37–86%. Interpretation: Models 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. Funding: Bill & Melinda Gates Foundation, Global Good Fund, Institute for Disease Modeling, Swiss National Science Foundation, and US National Institutes of Health

    Eternally restarting or a branch line of continuity ? Exploring consequences of external shocks on community health systems in Haiti

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    Background: Community health systems (CHS) are integral in promoting well-being in humanitarian settings, like Haiti, a country plagued by disruptive socio-political and environmental shocks over the past two decades. Haiti’s community health workers (CHWs) as critical intermediaries have persisted throughout these contextual shocks. This study explores how shocks influence CHS functionality and resilience in Haiti. Methods: We applied an inductive and deductive qualitative approach to understand the lived experience of CHS actors. A desk review of peer-review and grey literature searched 393 and identified 25 relevant documents on community health policies, guidelines, and strategies implemented over the last fifteen years in Haiti. In-depth interviews with policy and program stakeholders (n = 12), CHWs (n = 24), and CHW supervisors and community health auxiliary nurses (n = 15) were conducted. Results: Various shocks – political transitions, natural disasters, and disease outbreaks – describe Haiti’s protracted complex humanitarian setting and reveal distinct influences on CHS functionality (challenges and enablers), resilience, and mediating factors (eg, policy, financing, governance, parallel systems). Consequences of civil unrest and lockdowns (political transitions), internal displacement and infrastructural damage (natural disasters), and livelihood depletion and food insecurity (natural disasters and disease outbreaks) affect CHS functioning. CHW resilience is rooted in their generalized scope of work, intrinsic motivation, history in the community, trusting relationships, self-regulatory capacity, and adaptability. Mental health and safety among CHS actors and communities they serve pose challenges to CHS functionality and resilience, while reinforcing collaborations that promote CHW coverage and support and sustain CHS. Participants recommended government support for CHWs, collaborations stewarded by the government and complemented by partners, sub-national autonomy, and integration of disaster preparedness for all CHWs. Conclusions: Political transitions, natural disasters, and disease outbreaks in Haiti continue to profoundly influence CHS functioning, despite mitigating policy and programming efforts. This study documents the relevance of CHS in maintaining primary health care for a country in protracted crises and suggests that propositions of CHW resilience can be explored in complex humanitarian settings globally

    Seroprevalence of Vibrio cholerae in Adults, Haiti, 2017

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    In Haiti in 2017, the prevalence of serum vibriocidal antibody titers against Vibrio cholerae serogroup O1 among adults was 12.4% in Cerca-la-Source and 9.54% in Mirebalais, suggesting a high recent prevalence of infection. Improved surveillance programs to monitor cholera and guide public health interventions in Haiti are necessary

    Establishing and utilizing strategic partnerships for vaccine-preventable diseases: Best practices in Haiti

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    On March 10 to 11, 2016, the Ministère de la Santé Publique et de la Population (Ministry of Health of Haiti) and the Global Health Initiative at Henry Ford Health System hosted their Second Annual Scientific Conference entitled, “Best Practices for Establishing and Utilizing Partnerships for Vaccine-Preventable Diseases in Haiti,” at the National Laboratory in Port-au-Prince, Haiti. The conference brought together Ministry of Health officials, researchers, clinicians, academics, public health professionals, and other stakeholders to discuss vaccine programs and policies in Haiti. This forum provides a learning and discussion space to fuel strategies and public health research responding to priority areas identified by the Ministry of Health, and consequently, this forum serves as counsel for the Ministry of Health in its decision making on strategies to prevent and control infectious diseases in Haiti. The following article summarizes the presentations and conclusions of the March 2016 conference and covers a variety of important issues relating to vaccines and vaccine-preventable diseases in Haiti, including Haiti\u27s Expanded Program on Immunization, surveillance, logistical and funding challenges, and community approaches, as well as case studies detailing introduction of the pentavalent, rotavirus, oral cholera, and human papillomavirus vaccines in Haiti. Most importantly, this article highlights a model for effective partnerships for vaccines, a model that can transcend response to specific diseases and apply to all global health partnerships

    Effectiveness of reactive oral cholera vaccination in rural Haiti: a case-control study and bias-indicator analysis

    No full text
    Background: Between April and June, 2012, a reactive cholera vaccination campaign was done in Haiti with an oral inactivated bivalent whole-cell vaccine. We aimed to assess the effectiveness of the vaccine in a case-control study and to assess the likelihood of bias in that study in a bias-indicator study. Methods: Residents of Bocozel or Grand Saline who were eligible for the vaccination campaign (ie, age ≥12 months, not pregnant, and living in the region at the time of the vaccine campaign) were included. In the primary case-control study, cases had acute watery diarrhoea, sought treatment at one of three participating cholera treatment units, and had a stool sample positive for cholera by culture. For each case, four control individuals who did not seek treatment for acute watery diarrhoea were matched by location of residence, enrolment time (within 2 weeks of the case), and age (1–4 years, 5–15 years, and >15 years). Cases in the bias-indicator study were individuals with acute watery diarrhoea with a negative stool sample for cholera. Controls were selected in the same manner as in the primary case-control study. Trained staff used standard laboratory procedures to do rapid tests and stool cultures from study cases. Participants were interviewed to collect data on sociodemographic characteristics, risk factors for cholera, and self-reported vaccination. Data were analysed by conditional logistic regression, adjusting for matching factors. Findings: From Oct 24, 2012, to March 9, 2014, 114 eligible individuals presented with acute watery diarrhoea and were enrolled, 25 of whom were subsequently excluded. 47 participants were analysed as cases in the vaccine effectiveness case-control study and 42 as cases in the bias-indicator study. 33 (70%) of 47 cholera cases self-reported vaccination versus 167 (89%) of 188 controls (vaccine effectiveness 63%, 95% CI 8–85). 27 (57%) of 47 cases had certified vaccination versus 147 (78%) of 188 controls (vaccine effectiveness 58%, 13–80). Neither self-reported nor verified vaccination was significantly associated with non-cholera diarrhoea (vaccine effectiveness 18%, 95% CI −208 to 78 by self-report and −21%, −238 to 57 by verified vaccination). Interpretation: Bivalent whole-cell oral cholera vaccine effectively protected against cholera in Haiti from 4 months to 24 months after vaccination. Vaccination is an important component of efforts to control cholera epidemics. Funding: National Institutes of Health, Delivering Oral Vaccines Effectively project, and Department of Global Health and Social Medicine at Harvard Medical School
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