International Journal of Infectious Diseases (Sep 2022)

Cholera outbreaks in sub-Saharan Africa during 2010-2019: a descriptive analysis

  • Qulu Zheng,
  • Francisco J Luquero,
  • Iza Ciglenecki,
  • Joseph F Wamala,
  • Abdinasir Abubakar,
  • Placide Welo,
  • Mukemil Hussen,
  • Mesfin Wossen,
  • Sebastian Yennan,
  • Alama Keita,
  • Justin Lessler,
  • Andrew S Azman,
  • Elizabeth C Lee

Journal volume & issue
Vol. 122
pp. 215 – 221

Abstract

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Background: Cholera remains a public health threat but is inequitably distributed across sub-Saharan Africa. Lack of standardized reporting and inconsistent outbreak definitions limit our understanding of cholera outbreak epidemiology. Methods: From a database of cholera incidence and mortality, we extracted data from sub-Saharan Africa and reconstructed outbreaks of suspected cholera starting in January 2010 to December 2019 based on location-specific average weekly incidence rate thresholds. We then described the distribution of key outbreak metrics. Results: We identified 999 suspected cholera outbreaks in 744 regions across 25 sub-Saharan African countries. The outbreak periods accounted for 1.8 billion person-months (2% of the total during this period) from January 2010 to January 2020. Among 692 outbreaks reported from second-level administrative units (e.g., districts), the median attack rate was 0.8 per 1000 people (interquartile range (IQR), 0.3-2.4 per 1000), the median epidemic duration was 13 weeks (IQR, 8-19), and the median early outbreak reproductive number was 1.8 (range, 1.1-3.5). Larger attack rates were associated with longer times to outbreak peak, longer epidemic durations, and lower case fatality risks. Conclusions: This study provides a baseline from which the progress toward cholera control and essential statistics to inform outbreak management in sub-Saharan Africa can be monitored.

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