Cholera Outbreak in Senegal in 2005: Was Climate a Factor?

Abstract

Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST) gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region.

Analysis of Effects of Meteorological Factors on Dengue Incidence in Sri Lanka Using Time Series Data

“…Previous studies demonstrate statistically significant associations between infectious diseases and meteorological variations such as rainfall and temperature. The effects of climate change on the endemics of infectious diseases such as cholera, malaria, and plague have been recognized [11]–[20].…”

Projections of the future occurrence, distribution, and seasonality of three Vibrio species in the Chesapeake Bay under a high‐emission climate change scenario

“…cholerae . Strains O1 and O139 can cause epidemic disease outbreaks, and studies from different regions around the world have correlated these to air and water temperature, rainfall, river discharge, and phytoplankton/zooplankton abundance and composition [ Colwell , ; Lobitz et al ., ; Rodó et al ., ; Gil et al ., ; Koelle et al ., ; Greer et al ., ; Constantin de Magny et al ., ]. Some analyses have suggested that climate change‐induced warming and eutrophication may exacerbate cholera outbreaks, with changing river flow patterns and flood events also potentially important [ Martinez‐Urtaza et al ., ; Tirado et al ., ].…”

“…Constantin de Magny et al, 2012]. Some analyses have suggested that climate change-induced warming and eutrophication may exacerbate cholera outbreaks, with changing river flow patterns and flood events also potentially important Tirado et al, 2010].…”

Recurrent Cholera Outbreaks in Sub-Saharan Africa: Moving beyond Epidemiology to Understand the Environmental Reservoirs and Drivers

“…Therefore, the current paper posits that understanding the environmental drivers and reservoirs of cholera, and the effectiveness of the prevention and control methods are critical for the eradication of cholera in SSA. This calls for a move beyond just epidemiology, to more cross-disciplinary research that includes comprehensive hydrology, environmental sciences, and climatic science studies, which are often overlooked in cholera investigations [16,17]. The current study draws largely from the recent cholera outbreaks in Zimbabwe to address three specific objectives: (1) to highlight the nature and dynamics of recent cholera outbreaks in SSA, (2) to discuss the importance of environmental drivers and reservoirs in controlling the dynamics of cholera outbreaks, and (3) to highlight future research directions and the need to harness emerging research tools to better understand the cholera dynamics.…”