Cholera Transmission in Ouest Department of Haiti: Dynamic Modeling and the Future of the Epidemic

Abstract

In the current study, a comprehensive, data driven, mathematical model for cholera transmission in Haiti is presented. Along with the inclusion of short cycle human-to-human transmission and long cycle human-to-environment and environment-to-human transmission, this novel dynamic model incorporates both the reported cholera incidence and remote sensing data from the Ouest Department of Haiti between 2010 to 2014. The model has separate compartments for infectious individuals that include different levels of infectivity to reflect the distribution of symptomatic and asymptomatic cases in the population. The environmental compartment, which serves as a source of exposure to toxigenic V. cholerae, is also modeled separately based on the biology of causative bacterium, the shedding of V. cholerae O1 by humans into the environment, as well as the effects of precipitation and water temperature on the concentration and survival of V. cholerae in aquatic reservoirs. Although the number of reported cholera cases has declined compared to the initial outbreak in 2010, the increase in the number of susceptible population members and the presence of toxigenic V. cholerae in the environment estimated by the model indicate that without further improvements to drinking water and sanitation infrastructures, intermittent cholera outbreaks are likely to continue in Haiti.

Deadly River: Cholera and Cover-Up in Post-Earthquake Haiti

“…Although initial epidemic spikes were followed by a rapid decline in case numbers, cholera remains a critical public health problem for Haiti. Of immediate concern, the number of cases in the first 4 months of 2016 (close to 14,000 reported cases) exceeds the reported case numbers for the same period in 2014 and 2015 ( 1 ), consistent with the hypothesis that cholera in Haiti is becoming endemic, potentially with the establishment of environmental reservoirs ( 2 , 3 ). …”

Controlling cholera in the Ouest Department of Haiti using oral vaccines

“…The challenges in the computation of the basic reproductive number and the effective reproductive number have been discussed in detail in previous work [20]. Incidence data were collected by Ministry of Health Haiti (Ministère de la Santé Publique et de la Population (MSPP) [23] and compiled by the Pan American Health Organization (PAHO) [24].…”

Cholera in Cameroon, 2000-2012: Spatial and Temporal Analysis at the Operational (Health District) and Sub Climate Levels

“…We [48, 49] and others [50–52] have previously demonstrated a lag in the effects of climatic events on cholera case occurrence, particularly when transmission of V . cholerae O1 infections are primarily associated with exposure to environmental reservoirs and/or contaminated water sources.…”