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Chao DL. Mathematical Modeling of Endemic Cholera Transmission. J Infect Dis 2021; 224:S738-S741. [PMID: 34550373 PMCID: PMC8687074 DOI: 10.1093/infdis/jiab472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mathematical modeling can be used to project the impact of mass vaccination on cholera transmission. Here, we discuss 2 examples for which indirect protection from mass vaccination needs to be considered. In the first, we show that nonvaccinees can be protected by mass vaccination campaigns. This additional benefit of indirect protection improves the cost-effectiveness of mass vaccination. In the second, we model the use of mass vaccination to eliminate cholera. In this case, a high population level of immunity, including contributions from infection and vaccination, is required to reach the “herd immunity” threshold needed to stop transmission and achieve elimination.
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Affiliation(s)
- Dennis L Chao
- Institute for Disease Modeling; Bill & Melinda Gates Foundation, Seattle, Washington, USA
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Michel E, Gaudart J, Beaulieu S, Bulit G, Piarroux M, Boncy J, Dely P, Piarroux R, Rebaudet S. Estimating effectiveness of case-area targeted response interventions against cholera in Haiti. eLife 2019; 8:50243. [PMID: 31886768 PMCID: PMC7041943 DOI: 10.7554/elife.50243] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/20/2019] [Indexed: 01/24/2023] Open
Abstract
Case-area targeted interventions (CATIs) against cholera are conducted by rapid response teams, and may include various activities like water, sanitation, hygiene measures. However, their real-world effectiveness has never been established. We conducted a retrospective observational study in 2015-2017 in the Centre department of Haiti. Using cholera cases, stool cultures and CATI records, we identified 238 outbreaks that were responded to. After adjusting for potential confounders, we found that a prompt response could reduce the number of accumulated cases by 76% (95% confidence interval, 59 to 86) and the outbreak duration by 61% (41 to 75) when compared to a delayed response. An intense response could reduce the number of accumulated cases by 59% (11 to 81) and the outbreak duration by 73% (49 to 86) when compared to a weaker response. These results suggest that prompt and repeated CATIs were significantly effective at mitigating and shortening cholera outbreaks in Haiti.
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Affiliation(s)
- Edwige Michel
- Ministry of Public Health and Population, Directorate of Epidemiology Laboratory and Research, Port-au-Prince, Haiti
| | - Jean Gaudart
- Aix-Marseille Université, APHM, INSERM, IRD, SESSTIM, Hop Timone, BiSTIC, Biostatistics and ICT, Marseille, France
| | | | - Gregory Bulit
- United Nations Children's Fund, Port-au-Prince, Haiti
| | - Martine Piarroux
- Centre d'Épidémiologie et de Santé Publique des Armées, Service de Santé des Armées, Marseille, France
| | - Jacques Boncy
- Ministry of Public Health and Population, National Laboratory of Public Health, Delmas, Haiti
| | - Patrick Dely
- Ministry of Public Health and Population, Directorate of Epidemiology Laboratory and Research, Port-au-Prince, Haiti
| | - Renaud Piarroux
- Sorbonne Université, Sorbonne Université, INSERM, Institut Pierre-Louis d'Epidémiologie et de Santé Publique (IPLESP), AP-HP, Hôpital Pitié-Salpêtrière, Paris, France
| | - Stanislas Rebaudet
- APHM, Hôpital Européen, Aix Marseille Université, INSERM, IRD, SESSTIM, IPLESP, Marseille, France.,Sorbonne Université, INSERM, Institut Pierre-Louis d'Epidémiologie et de Santé Publique, Paris, France
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Azman AS, Luquero FJ, Salje H, Mbaïbardoum NN, Adalbert N, Ali M, Bertuzzo E, Finger F, Toure B, Massing LA, Ramazani R, Saga B, Allan M, Olson D, Leglise J, Porten K, Lessler J. Micro-Hotspots of Risk in Urban Cholera Epidemics. J Infect Dis 2019; 218:1164-1168. [PMID: 29757428 PMCID: PMC6107744 DOI: 10.1093/infdis/jiy283] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/09/2018] [Indexed: 12/05/2022] Open
Abstract
Targeted interventions have been delivered to neighbors of cholera cases in major epidemic responses globally despite limited evidence for the impact of such targeting. Using data from urban epidemics in Chad and Democratic Republic of the Congo, we estimate the extent of spatiotemporal zones of increased cholera risk around cases. In both cities, we found zones of increased risk of at least 200 meters during the 5 days immediately after case presentation to a clinic. Risk was highest for those living closest to cases and diminished in time and space similarly across settings. These results provide a rational basis for rapidly delivering targeting interventions.
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Affiliation(s)
- Andrew S Azman
- Departments of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Francisco J Luquero
- Departments of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Epicentre, Paris, France
| | | | - Nathan Naibei Mbaïbardoum
- Epicentre, Paris, France.,Communauté des Amis de l'Informatique pour le Développement, N'Djamena, Chad
| | | | - Mohammad Ali
- Departments of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Enrico Bertuzzo
- Department of Environmental Science, Informatics and Statistics, Università Ca' Foscari Venezia, Venice, Italy
| | - Flavio Finger
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, United Kingom
| | | | - Louis Albert Massing
- Médecins sans Frontières (France), Kinshasa, The Democratic Republic of the Congo
| | - Romain Ramazani
- Médecins sans Frontières (France), Kalemie, The Democratic Republic of the Congo
| | | | | | | | | | | | - Justin Lessler
- Departments of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Rebaudet S, Bulit G, Gaudart J, Michel E, Gazin P, Evers C, Beaulieu S, Abedi AA, Osei L, Barrais R, Pierre K, Moore S, Boncy J, Adrien P, Duperval Guillaume F, Beigbeder E, Piarroux R. The case-area targeted rapid response strategy to control cholera in Haiti: a four-year implementation study. PLoS Negl Trop Dis 2019; 13:e0007263. [PMID: 30990822 PMCID: PMC6485755 DOI: 10.1371/journal.pntd.0007263] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 04/26/2019] [Accepted: 02/25/2019] [Indexed: 11/19/2022] Open
Abstract
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.
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Affiliation(s)
- Stanislas Rebaudet
- Assistance Publique–Hôpitaux de Marseille (AP-HM), Marseille, France
- Hôpital Européen Marseille, Marseille, France
- Institut Pierre-Louis d’Epidémiologie et de Santé Publique, Sorbonne Université, INSERM, Paris, France
| | | | - Jean Gaudart
- Assistance Publique–Hôpitaux de Marseille (AP-HM), Marseille, France
- Aix Marseille Univ, IRD, INSERM, SESSTIM, Marseille, France
| | - Edwige Michel
- Direction d’Epidémiologie de Laboratoire et de Recherche, Ministère de la Santé Publique et de la Population, Haiti
| | - Pierre Gazin
- Institut de Recherche pour le Développement (IRD), Marseille, France
| | | | | | - Aaron Aruna Abedi
- United Nations Children's Fund, Haiti
- Direction de la Lutte contre la Maladie, Ministère de la Santé Publique, Kinshasa, Democratic Republic of the Congo
| | - Lindsay Osei
- Assistance Publique–Hôpitaux de Marseille (AP-HM), Marseille, France
- United Nations Children's Fund, Haiti
| | - Robert Barrais
- Direction d’Epidémiologie de Laboratoire et de Recherche, Ministère de la Santé Publique et de la Population, Haiti
| | - Katilla Pierre
- Direction d’Epidémiologie de Laboratoire et de Recherche, Ministère de la Santé Publique et de la Population, Haiti
| | | | - Jacques Boncy
- Laboratoire National de Santé Publique, Ministère de la Santé Publique et de la Population, Haiti
| | - Paul Adrien
- Direction d’Epidémiologie de Laboratoire et de Recherche, Ministère de la Santé Publique et de la Population, Haiti
| | | | | | - Renaud Piarroux
- Sorbonne Université, INSERM, Institut Pierre-Louis d’Epidémiologie et de Santé Publique, AP-HP, Hôpital Pitié-Salpêtrière, Paris, France
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Rebaudet S, Moore S, Rossignol E, Bogreau H, Gaudart J, Normand AC, Laraque MJ, Adrien P, Boncy J, Piarroux R. Epidemiological and molecular forensics of cholera recurrence in Haiti. Sci Rep 2019; 9:1164. [PMID: 30718586 PMCID: PMC6361935 DOI: 10.1038/s41598-018-37706-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 12/05/2018] [Indexed: 01/01/2023] Open
Abstract
Cholera has affected Haiti with damping waves of outbreaks since October 2010. However, mechanisms behind disease persistence during lull periods remain poorly understood. By mid 2014, cholera transmission seemed to only persist in the northern part of Haiti. Meanwhile, cholera appeared nearly extinct in the capital, Port-au-Prince, where it eventually exploded in September 2014. This study aimed to determine whether this outbreak was caused by local undetected cases or by re-importation of the disease from the north. Applying an integrated approach between November 2013 and November 2014, we assessed the temporal and spatial dynamics of cholera using routine surveillance data and performed population genetics analyses of 178 Vibrio cholerae O1 clinical isolates. The results suggest that the northern part of the country exhibited a persisting metapopulation pattern with roaming oligoclonal outbreaks that could not be effectively controlled. Conversely, undetected and unaddressed autochthonous low-grade transmission persisted in the Port-au-Prince area, which may have been the source of the acute outbreak in late-2014. Cholera genotyping is a simple but powerful tool to adapt control strategies based on epidemic specificities. In Haiti, these data have already yielded significant progress in cholera surveillance, which is a key component of the strategy to eventually eliminate cholera.
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Affiliation(s)
- Stanislas Rebaudet
- Assistance Publique - Hôpitaux de Marseille, DRCI, Marseille, France. .,Hôpital Européen Marseille, Marseille, France.
| | | | - Emmanuel Rossignol
- Ministry of Public Health and Population, National Public Health Laboratory, Delmas, Haiti
| | - Hervé Bogreau
- Institut de Recherche Biomédicale des Armées, Département des Maladies Infectieuses, Unité de Parasitologie et d'Entomologie, Marseille, France.,Aix Marseille Univ, Institut Hospitalo-Universitaire Méditerranée Infection, VITROME, Marseille, France
| | - Jean Gaudart
- Aix Marseille Univ, APHM, IRD, INSERM, SESSTIM, BioSTIC, Marseille, France
| | - Anne-Cécile Normand
- Sorbonne Université, INSERM, Institut Pierre-Louis d'Epidémiologie et de Santé Publique, AP-HP, Hôpital Pitié-Salpêtrière, F-, 75013, Paris, France
| | - Marie-José Laraque
- Ministry of Public Health and Population, National Public Health Laboratory, Delmas, Haiti
| | - Paul Adrien
- Ministry of Public Health and Population, Directorate of Epidemiology Laboratory and Research, Delmas, Haiti
| | - Jacques Boncy
- Ministry of Public Health and Population, National Public Health Laboratory, Delmas, Haiti
| | - Renaud Piarroux
- Sorbonne Université, INSERM, Institut Pierre-Louis d'Epidémiologie et de Santé Publique, AP-HP, Hôpital Pitié-Salpêtrière, F-, 75013, Paris, France
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Hulland E, Subaiya S, Pierre K, Barthelemy N, Pierre JS, Dismer A, Juin S, Fitter D, Brunkard J. Increase in Reported Cholera Cases in Haiti Following Hurricane Matthew: An Interrupted Time Series Model. Am J Trop Med Hyg 2019; 100:368-373. [PMID: 30594260 PMCID: PMC6367609 DOI: 10.4269/ajtmh.17-0964] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 09/30/2018] [Indexed: 11/12/2022] Open
Abstract
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.
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Affiliation(s)
- Erin Hulland
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Saleena Subaiya
- Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Katilla Pierre
- MSPP Haiti, Directorate of Epidemiology, Laboratory and Research, Delmas, Haiti
| | | | - Jean Samuel Pierre
- MSPP Haiti, Directorate of Epidemiology, Laboratory and Research, Delmas, Haiti
| | - Amber Dismer
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stanley Juin
- Centers for Disease Control and Prevention Haiti, Tabarre, Haiti
| | - David Fitter
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
- Centers for Disease Control and Prevention Haiti, Tabarre, Haiti
| | - Joan Brunkard
- Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
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Finger F, Bertuzzo E, Luquero FJ, Naibei N, Touré B, Allan M, Porten K, Lessler J, Rinaldo A, Azman AS. The potential impact of case-area targeted interventions in response to cholera outbreaks: A modeling study. PLoS Med 2018; 15:e1002509. [PMID: 29485987 PMCID: PMC5828347 DOI: 10.1371/journal.pmed.1002509] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/19/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Cholera prevention and control interventions targeted to neighbors of cholera cases (case-area targeted interventions [CATIs]), including improved water, sanitation, and hygiene, oral cholera vaccine (OCV), and prophylactic antibiotics, may be able to efficiently avert cholera cases and deaths while saving scarce resources during epidemics. Efforts to quickly target interventions to neighbors of cases have been made in recent outbreaks, but little empirical evidence related to the effectiveness, efficiency, or ideal design of this approach exists. Here, we aim to provide practical guidance on how CATIs might be used by exploring key determinants of intervention impact, including the mix of interventions, "ring" size, and timing, in simulated cholera epidemics fit to data from an urban cholera epidemic in Africa. METHODS AND FINDINGS We developed a micro-simulation model and calibrated it to both the epidemic curve and the small-scale spatiotemporal clustering pattern of case households from a large 2011 cholera outbreak in N'Djamena, Chad (4,352 reported cases over 232 days), and explored the potential impact of CATIs in simulated epidemics. CATIs were implemented with realistic logistical delays after cases presented for care using different combinations of prophylactic antibiotics, OCV, and/or point-of-use water treatment (POUWT) starting at different points during the epidemics and targeting rings of various radii around incident case households. Our findings suggest that CATIs shorten the duration of epidemics and are more resource-efficient than mass campaigns. OCV was predicted to be the most effective single intervention, followed by POUWT and antibiotics. CATIs with OCV started early in an epidemic focusing on a 100-m radius around case households were estimated to shorten epidemics by 68% (IQR 62% to 72%), with an 81% (IQR 69% to 87%) reduction in cases compared to uncontrolled epidemics. These same targeted interventions with OCV led to a 44-fold (IQR 27 to 78) reduction in the number of people needed to target to avert a single case of cholera, compared to mass campaigns in high-cholera-risk neighborhoods. The optimal radius to target around incident case households differed by intervention type, with antibiotics having an optimal radius of 30 m to 45 m compared to 70 m to 100 m for OCV and POUWT. Adding POUWT or antibiotics to OCV provided only marginal impact and efficiency improvements. Starting CATIs early in an epidemic with OCV and POUWT targeting those within 100 m of an incident case household reduced epidemic durations by 70% (IQR 65% to 75%) and the number of cases by 82% (IQR 71% to 88%) compared to uncontrolled epidemics. CATIs used late in epidemics, even after the peak, were estimated to avert relatively few cases but substantially reduced the number of epidemic days (e.g., by 28% [IQR 15% to 45%] for OCV in a 100-m radius). While this study is based on a rigorous, data-driven approach, the relatively high uncertainty about the ways in which POUWT and antibiotic interventions reduce cholera risk, as well as the heterogeneity in outbreak dynamics from place to place, limits the precision and generalizability of our quantitative estimates. CONCLUSIONS In this study, we found that CATIs using OCV, antibiotics, and water treatment interventions at an appropriate radius around cases could be an effective and efficient way to fight cholera epidemics. They can provide a complementary and efficient approach to mass intervention campaigns and may prove particularly useful during the initial phase of an outbreak, when there are few cases and few available resources, or in order to shorten the often protracted tails of cholera epidemics.
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Affiliation(s)
- Flavio Finger
- Laboratory of Ecohydrology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Enrico Bertuzzo
- Laboratory of Ecohydrology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca’ Foscari Venezia, Venice, Italy
| | - Francisco J. Luquero
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Epicentre, Paris, France
| | - Nathan Naibei
- Communauté des Amis de l’Informatique pour le Développement–Tchad, N’Djamena, Chad
| | | | | | | | - Justin Lessler
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Dipartimento di Ingegneria Civile, Edile ed Ambientale, Università di Padova, Padova, Italy
| | - Andrew S. Azman
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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Parker LA, Rumunu J, Jamet C, Kenyi Y, Lino RL, Wamala JF, Mpairwe AM, Muller V, Llosa AE, Uzzeni F, Luquero FJ, Ciglenecki I, Azman AS. Neighborhood-targeted and case-triggered use of a single dose of oral cholera vaccine in an urban setting: Feasibility and vaccine coverage. PLoS Negl Trop Dis 2017; 11:e0005652. [PMID: 28594891 PMCID: PMC5478158 DOI: 10.1371/journal.pntd.0005652] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 06/20/2017] [Accepted: 05/19/2017] [Indexed: 02/02/2023] Open
Abstract
INTRODUCTION In June 2015, a cholera outbreak was declared in Juba, South Sudan. In addition to standard outbreak control measures, oral cholera vaccine (OCV) was proposed. As sufficient doses to cover the at-risk population were unavailable, a campaign using half the standard dosing regimen (one-dose) targeted high-risk neighborhoods and groups including neighbors of suspected cases. Here we report the operational details of this first public health use of a single-dose regimen of OCV and illustrate the feasibility of conducting highly targeted vaccination campaigns in an urban area. METHODOLOGY/PRINCIPAL FINDINGS Neighborhoods of the city were prioritized for vaccination based on cumulative attack rates, active transmission and local knowledge of known cholera risk factors. OCV was offered to all persons older than 12 months at 20 fixed sites and to select groups, including neighbors of cholera cases after the main campaign ('case-triggered' interventions), through mobile teams. Vaccination coverage was estimated by multi-stage surveys using spatial sampling techniques. 162,377 individuals received a single-dose of OCV in the targeted neighborhoods. In these neighborhoods vaccine coverage was 68.8% (95% Confidence Interval (CI), 64.0-73.7) and was highest among children ages 5-14 years (90.0%, 95% CI 85.7-94.3), with adult men being less likely to be vaccinated than adult women (Relative Risk 0.81, 95% CI: 0.68-0.96). In the case-triggered interventions, each lasting 1-2 days, coverage varied (range: 30-87%) with an average of 51.0% (95% CI 41.7-60.3). CONCLUSIONS/SIGNIFICANCE Vaccine supply constraints and the complex realities where cholera outbreaks occur may warrant the use of flexible alternative vaccination strategies, including highly-targeted vaccination campaigns and single-dose regimens. We showed that such campaigns are feasible. Additional work is needed to understand how and when to use different strategies to best protect populations against epidemic cholera.
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Affiliation(s)
- Lucy A. Parker
- Médecins Sans Frontières, Geneva, Switzerland
- CIBER Epidemiología y Salud Pública, Department of Public Health, Universidad Miguel Hernández, Alicante, Spain
| | - John Rumunu
- Republic of South Sudan Ministry of Health, Juba, South Sudan
| | | | - Yona Kenyi
- Republic of South Sudan Ministry of Health, Juba, South Sudan
| | | | | | | | | | | | | | - Francisco J. Luquero
- Epicentre, Paris, France
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | | | - Andrew S. Azman
- Médecins Sans Frontières, Geneva, Switzerland
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
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Deadly River: Cholera and Cover-Up in Post-Earthquake Haiti. Emerg Infect Dis 2016. [PMCID: PMC5088046 DOI: 10.3201/eid2211.161215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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10
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Hospitalizations and Deaths Because of Respiratory and Diarrheal Diseases Among Haitian Children Under Five Years of Age, 2011-2013. Pediatr Infect Dis J 2015; 34:e238-43. [PMID: 26244833 PMCID: PMC4610905 DOI: 10.1097/inf.0000000000000805] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Respiratory and diarrheal diseases are leading causes of morbidity and mortality among children younger than 5 years in developing countries. Data on the burden of these diseases in Haiti are scarce. METHODS We conducted a retrospective review of hospital admission registries during January 1, 2011-December 31, 2013 for children younger than 5 years in 6 hospitals in Haiti. We recorded the number of all-cause, respiratory and diarrheal disease admissions and deaths by epidemiologic week and age. RESULTS A total of 31,565 hospital admissions and 1763 deaths were recorded among children aged <5 years during the study period. Respiratory diseases accounted for 9183 (29%) hospitalizations and 301 (17%) deaths. Children aged 6-23 months had the highest percentage of hospitalizations attributable to respiratory diseases (38%), whereas children aged 36-47 months had the highest proportion of deaths attributable to respiratory diseases (37%). Respiratory disease hospitalizations followed a bimodal seasonal pattern, with peaks during May-June and October-December. Diarrheal diseases accounted for 8063 (26%) hospitalizations and 224 (13%) deaths. Children aged 6-11 months had the highest percentage of diarrhea-associated hospitalizations (39%) and deaths (29%). Diarrheal disease admissions peaked in January-April before the rainy season. CONCLUSIONS Respiratory and diarrheal diseases contributed to more than half of hospitalizations and almost a third of deaths in children younger than 5 years in Haiti. These data are essential to assess the impact of pneumococcal and rotavirus vaccines and other interventions in Haiti.
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Samson DM, Archer RS, Alimi TO, Arheart KL, Impoinvil DE, Oscar R, Fuller DO, Qualls WA. New baseline environmental assessment of mosquito ecology in northern Haiti during increased urbanization. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2015; 40:46-58. [PMID: 26047183 PMCID: PMC4458708 DOI: 10.1111/jvec.12131] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/30/2014] [Indexed: 05/14/2023]
Abstract
The catastrophic 2010 earthquake in Port-au-Prince, Haiti, led to the large-scale displacement of over 2.3 million people, resulting in rapid and unplanned urbanization in northern Haiti. This study evaluated the impact of this unplanned urbanization on mosquito ecology and vector-borne diseases by assessing land use and change patterns. Land-use classification and change detection were carried out on remotely sensed images of the area for 2010 and 2013. Change detection identified areas that went from agricultural, forest, or bare-land pre-earthquake to newly developed and urbanized areas post-earthquake. Areas to be sampled for mosquito larvae were subsequently identified. Mosquito collections comprised five genera and ten species, with the most abundant species being Culex quinquefasciatus 35% (304/876), Aedes albopictus 27% (238/876), and Aedes aegypti 20% (174/876). All three species were more prevalent in urbanized and newly urbanized areas. Anopheles albimanus, the predominate malaria vector, accounted for less than 1% (8/876) of the collection. A set of spectral indices derived from the recently launched Landsat 8 satellite was used as covariates in a species distribution model. The indices were used to produce probability surfaces maps depicting the likelihood of presence of the three most abundant species within 30 m pixels. Our findings suggest that the rapid urbanization following the 2010 earthquake has increased the amount of area with suitable habitats for urban mosquitoes, likely influencing mosquito ecology and posing a major risk of introducing and establishing emerging vector-borne diseases.
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Affiliation(s)
- Dayana M Samson
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL 33136, U.S.A..
| | - Reginald S Archer
- Department of Geography and Regional Studies, University of Miami, Miami, FL 33124, U.S.A
| | - Temitope O Alimi
- Leonard and Jayne Abess Center for Ecosystem Science and Policy, Miami, FL 33124, U.S.A
| | - Kristopher L Arheart
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL 33136, U.S.A
| | - Daniel E Impoinvil
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria/Entomology Branch, Atlanta, GA, U.S.A
| | - Roland Oscar
- National Malaria Control Program, Ministry of Public Health and Population, Port au Prince, Haiti
| | - Douglas O Fuller
- Department of Geography and Regional Studies, University of Miami, Miami, FL 33124, U.S.A
| | - Whitney A Qualls
- Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL 33136, U.S.A
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Mari L, Bertuzzo E, Finger F, Casagrandi R, Gatto M, Rinaldo A. On the predictive ability of mechanistic models for the Haitian cholera epidemic. J R Soc Interface 2015; 12:20140840. [PMID: 25631563 PMCID: PMC4345467 DOI: 10.1098/rsif.2014.0840] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/02/2015] [Indexed: 12/17/2022] Open
Abstract
Predictive models of epidemic cholera need to resolve at suitable aggregation levels spatial data pertaining to local communities, epidemiological records, hydrologic drivers, waterways, patterns of human mobility and proxies of exposure rates. We address the above issue in a formal model comparison framework and provide a quantitative assessment of the explanatory and predictive abilities of various model settings with different spatial aggregation levels and coupling mechanisms. Reference is made to records of the recent Haiti cholera epidemics. Our intensive computations and objective model comparisons show that spatially explicit models accounting for spatial connections have better explanatory power than spatially disconnected ones for short-to-intermediate calibration windows, while parsimonious, spatially disconnected models perform better with long training sets. On average, spatially connected models show better predictive ability than disconnected ones. We suggest limits and validity of the various approaches and discuss the pathway towards the development of case-specific predictive tools in the context of emergency management.
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Affiliation(s)
- Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy Laboratory of Ecohydrology ECHO/IIE/ENAC, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Enrico Bertuzzo
- Laboratory of Ecohydrology ECHO/IIE/ENAC, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Flavio Finger
- Laboratory of Ecohydrology ECHO/IIE/ENAC, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Andrea Rinaldo
- Laboratory of Ecohydrology ECHO/IIE/ENAC, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland Dipartimento di Ingegneria Civile, Edile ed Ambientale, Università di Padova, 35131 Padova, Italy
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13
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Use of the NASA Giovanni Data System for Geospatial Public Health Research: Example of Weather-Influenza Connection. ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION 2014. [DOI: 10.3390/ijgi3041372] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Moore S, Thomson N, Mutreja A, Piarroux R. Widespread epidemic cholera caused by a restricted subset of Vibrio cholerae clones. Clin Microbiol Infect 2014; 20:373-9. [PMID: 24575898 DOI: 10.1111/1469-0691.12610] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Since 1817, seven cholera pandemics have plagued humankind. As the causative agent, Vibrio cholerae, is autochthonous in the aquatic ecosystem and some studies have revealed links between outbreaks and fluctuations in climatic and aquatic conditions, it has been widely assumed that cholera epidemics are triggered by environmental factors that promote the growth of local bacterial reservoirs. However, mounting epidemiological findings and genome sequence analysis of clinical isolates have indicated that epidemics are largely unassociated with most of the V. cholerae strains in aquatic ecosystems. Instead, only a specific subset of V. cholerae El Tor 'types' appears to be responsible for current epidemics. A recent report examining the evolution of a variety of V. cholerae strains indicates that the current pandemic is monophyletic and originated from a single ancestral clone that has spread globally in successive waves. In this review, we examine the clonal nature of the disease, with the example of the recent history of cholera in the Americas. Epidemiological data and genome sequence-based analysis of V. cholerae isolates demonstrate that the cholera epidemics of the 1990s in South America were triggered by the importation of a pathogenic V. cholerae strain that gradually spread throughout the region until local outbreaks ceased in 2001. Latin America remained almost unaffected by the disease until a new toxigenic V. cholerae clone was imported into Haiti in 2010. Overall, cholera appears to be largely caused by a subset of specific V. cholerae clones rather than by the vast diversity of V. cholerae strains in the environment.
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Affiliation(s)
- S Moore
- Aix-Marseille University, UMR MD3, Marseilles, France
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15
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Baron S, Lesne J, Moore S, Rossignol E, Rebaudet S, Gazin P, Barrais R, Magloire R, Boncy J, Piarroux R. No Evidence of Significant Levels of Toxigenic V. cholerae O1 in the Haitian Aquatic Environment During the 2012 Rainy Season. PLOS CURRENTS 2013; 5:ecurrents.outbreaks.7735b392bdcb749baf5812d2096d331e. [PMID: 24077904 PMCID: PMC3783635 DOI: 10.1371/currents.outbreaks.7735b392bdcb749baf5812d2096d331e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND On October 21, 2010, Haiti was struck by a cholera epidemic for the first time in over a century. Epidemiological and molecular genetic data have clearly demonstrated that the bacterium was imported. Nevertheless, the persistence of the epidemic for more than two years, the high incidence rates in some coastal areas and the seasonal exacerbations of the epidemic during the rainy seasons have prompted us to examine the levels of toxigenic Vibrio cholerae in the Haitian aquatic environment. METHODS In July 2012, during the warm and rainy season, 36 aquatic stations were sampled to search for toxigenic V. cholerae. These stations included fresh, brackish and saline surface waters as well as waste water; the sampling sites were located in both rural and urban areas (around Port-au-Prince and Gonaïves) located in the West and Artibonite Departments. V. cholerae bacteria were detected in enrichment cultures of water samples (sample volumes included 1 L, 100 mL, 10 mL, 1 mL, 0.1 mL, 0.01 mL and 0.001 mL depending on the context). Detection methods included both culture on selective agar (for strain isolation) and PCR assays targeting the genes ompW (V. cholerae species), O1-rfb and O139-rfb (O1 and O139 V. cholerae serogroups, respectively), and the cholera toxin gene ctxA, which is present exclusively in toxigenic cholera strains. RESULTS A total of 411 culturable V. cholerae isolates from 29 stations were obtained via selective culture; however, only one of these isolates displayed a late positive reaction with polyvalent anti-O1 serum. Positive V. cholerae PCR results were obtained from each of the 32 tested stations (a total of 77 enrichments out of 107 yielded a positive result); only one sample yielded a positive V. cholerae O1 PCR result. The cholera toxin gene ctxA was never detected via PCR with either primer pair, which includes samples derived from the two stations yielding positive O1 culture or positive O1 PCR results. Therefore, we could not demonstrate the presence of toxigenic V. cholerae O1 among the 36 stations sampled. This suggests that all water samples analyzed contained less than 10 toxigenic V. cholerae O1 bacteria per liter, a level 1000-fold below the dose that has been shown to provoke cholera in healthy adults. CONCLUSIONS Currently, there is no evidence of a significant level of contamination of the aquatic environment in Haiti by the imported toxigenic V. cholerae O1 strain. The reemergence of cholera outbreaks in Haiti during rainy seasons is therefore more likely due to persisting outbreaks insufficiently tackled during the dry periods rather than the commonly suspected aquatic reservoir of toxigenic bacteria.
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Affiliation(s)
- Sandrine Baron
- ANSES (Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail), Ploufragan-Plouzané Laboratory, Ploufragan and Université Européenne de Bretagne, Rennes, France
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