Dynamics of cholera epidemics from Benin to Mauritania

Abstract

BackgroundThe countries of West Africa are largely portrayed as cholera endemic, although the dynamics of outbreaks in this region of Africa remain largely unclear.Methodology/Principal findingsTo understand the dynamics of cholera in a major portion of West Africa, we analyzed cholera epidemics from 2009 to 2015 from Benin to Mauritania. We conducted a series of field visits as well as multilocus variable tandem repeat analysis and whole-genome sequencing analysis of V. cholerae isolates throughout the study region. During this period, Ghana accounted for 52% of the reported cases in the entire study region (coastal countries from Benin to Mauritania). From 2009 to 2015, we found that one major wave of cholera outbreaks spread from Accra in 2011 northwestward to Sierra Leone and Guinea in 2012. Molecular epidemiology analysis confirmed that the 2011 Ghanaian isolates were related to those that seeded the 2012 epidemics in Guinea and Sierra Leone. Interestingly, we found that many countries deemed “cholera endemic” actually suffered very few outbreaks, with multi-year lulls.Conclusions/SignificanceThis study provides the first cohesive vision of the dynamics of cholera epidemics in a major portion of West Africa. This epidemiological overview shows that from 2009 to 2015, at least 54% of reported cases concerned populations living in the three urban areas of Accra, Freetown, and Conakry. These findings may serve as a guide to better target cholera prevention and control efforts in the identified cholera hotspots in West Africa.

Prevention and control of cholera with household and community water, sanitation and hygiene (WASH) interventions: A scoping review of current international guidelines

“…Although models have highlighted within-household and human-to-human transmission as the catalyst in epidemics, interventions that target community-level transmission and the environment-to-human transmission pathways remain important for cholera prevention. Regional resurgences of cholera are a contributing factor to the burden of disease globally [21,23,24,127], with notable high incidence of disease and recurrent outbreaks in the lacustrine areas of East and Central Africa [128][129][130]. Community-level or mass population strategies in areas such as this may limit the reliance on active case finding or attendance at HCFs required by case-centred approaches, and provide interventions that also target the estimated 40 to 80% of cholera cases which are asymptomatic [19,131].…”

“…Adjusting for incomplete reporting, some 2.9 million cholera cases (1.3-4.0 million uncertainty range) and 95,000 deaths (21,000-143,000 uncertainty range) are estimated to occur across 69 cholera-endemic countries annually [20]. Sub-Saharan Africa and South Asia account for the largest proportion of global cholera morbidity and mortality [18,21], with many cities acting as transmission hotspots [21][22][23][24].…”

A molecular and epidemiological study of Vibrio cholerae isolates from cholera outbreaks in southern Ghana

“…Vibrios can survive for a long time in coastal waters contaminated by human faeces. Seven cholera pandemics have been experienced globally and it continues to cause outbreaks locally and regionally across the African continent [1,2]. The World Health Organization (WHO) estimates that in 2018, there were 1.3 to 4.0 million cases and 21,000 to 143,000 deaths due to cholera globally [1].…”

Description of the targeted water supply and hygiene response strategy implemented during the cholera outbreak of 2017–2018 in Kinshasa, DRC

“…However, rapid control of cholera outbreaks can be a major challenge in urban settings, where cholera case numbers can quickly increase [2,5]. Once cholera outbreaks expand in urban areas, cholera has often eventually spread to linked regions within the country or across international borders when infected individuals travel [6][7][8]. As a result, effective strategies to control cholera outbreaks in urban settings may play a major role in the control and prevention of the disease on a local, national and regional level.…”