Project Summary/Abstract
Cholera is an ancient disease that has shown a remarkable ability to persist and spread in the modern
world. In WHO data for 2016, 132,121 cholera cases and 2420 deaths were reported from 38 countries.
However, taking into account likely underreporting, the global disease burden has been estimated to be in the
range of 1.3 to 4.0 million cholera cases and 21,000-143,000 deaths per year. Cholera is frequently a disease
of poverty, striking in areas with humanitarian emergencies and crumbling public health infrastructure: most
recently, this has been highlighted by the massive epidemic in Yemen, with over a million cases reported to
date. Given the intransigence of such problems, and ongoing issues with climate change, urbanization, and
population growth, cholera is likely to remain a recurring global threat to public health.
While the Indian subcontinent is the ancestral home of cholera, and epidemics may occur in crisis
situations such as currently seen in Yemen, over the past two decades sub-Saharan Africa has emerged as
the primary locus of the global cholera disease burden. Within Africa, two major regional inland “hotspots” of
cholera activity have been identified: one in the Lake Chad region, and the other in the Great Lakes region,
centered on Goma in the DRC. The WHO Global Task Force for Cholera Control has recently developed a
“global roadmap” leading toward cholera eradication, based on three strategic axes: the second of these axes
is “Prevention of disease reoccurrence by targeting multi-sectorial interventions in cholera hotspots.” Within
this roadmap, they have also placed a strong focus on the need for country-level data, with targeting of
interventions directed by an understanding of local circumstances and transmission patterns.
Goma, with a population of over 1 million (including substantial refugee populations), is on the northern
shore of Lake Kivu, bordering Rwanda; the city has had recurrent, annual cholera epidemics for at least the
past decade, with phylodynamic analysis demonstrating the persistence of a “Great Lakes” clade of V.
cholerae O1 in the region. We are proposing a targeted, multi-sectorial analysis of cholera transmission in
Goma, utilizing robust epidemiologic and phylodynamic techniques, with two major goals: 1) to further expand
our understanding of how this ancient pathogen evolves and adapts to new geographic areas and new
populations; and 2) to provide data for development of a practical, scientifically-informed plan for cholera
control in this regional cholera hotspot, building on recommendations of the WHO Global Task Force.
Specific Aims to accomplish these objectives:
• Specific Aim 1: Studies of cholera transmission and infection within households of suspected cholera cases
in Goma;
• Specific Aim 2: Identification and assessment of aquatic environmental sources/reservoirs for cholera; and
• Specific Aim 3. Phylodynamic analysis of clinical and environmental V. cholerae O1 strains.