Satellite Based Assessment of Hydroclimatic Conditions Related to Cholera in Zimbabwe

Abstract

IntroductionCholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008.Principal FindingsClimatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began.DiscussionSatellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.

21st century research in urban WASH and health in sub-Saharan Africa: methods and outcomes in transition

“…Studies link cholera incidence with environmental WASH factors such as elevation, insufficient drainage or waste dumps (Osei and Duker 2008;Schaetti et al 2010;Luque Fernandez et al 2012) and also couple the risk of poor sanitation with climate factors (e.g. increased rainfall) (Sasaki et al 2009;Jutla et al 2015).…”

Quantification of Rotavirus Diarrheal Risk Due to Hydroclimatic Extremes Over South Asia: Prospects of Satellite‐Based Observations in Detecting Outbreaks

“…The proposed model shows lag components, which allowed us to forecast the disease outbreaks 1 to 2 months in advance. The satellite data-driven forecasts also effectively captured the increased vulnerability of dry-cold regions of the country, compared to the wet-warm regions.Recent studies indicate that hydrologic processes and climatic variability strongly influence the outbreak of these diseases (Akanda et al, 2013;Bandyopadhyay et al, 2012;Gurarie & Seto, 2009;Jutla et al, 2015; Remais et al, 2008). Moreover, the risk posed of the diarrheal diseases and uncertainty of the impacts are increasing HASAN ET AL.…”

“…Recent studies indicate that hydrologic processes and climatic variability strongly influence the outbreak of these diseases (Akanda et al, 2013;Bandyopadhyay et al, 2012;Gurarie & Seto, 2009;Jutla et al, 2015; Remais et al, 2008). Moreover, the risk posed of the diarrheal diseases and uncertainty of the impacts are increasing HASAN ET AL.…”

Satellite Based Predictability of Water Sensitive Infectious Diseases

“…Once the trigger of disease is initiated, transmission of cholera is accelerated by fecal-oral transmission, and ultimately, a disease outbreak. For example, hydroclimatological conditions namely, warm temperatures preceding a heavy rainfall, and subsequent inadequate safe water supply and poor sanitation will increase the likelihood of a cholera outbreak (Faruque et al, 2005;Jutla et al, 2015;Rinaldo et al, 2012). A natural disaster can act as a catalyst in the interaction of contaminated water and the human population.…”

“…Outbreaks of cholera over the last several decades in South Asia, Africa, and South America have occurred mostly along coastal areas (Colwell, 1996a;Constantin de Magny et al, 2008;Jutla et al, 2010). While the coastal regions remain the largest natural reservoirs of vibrios, epidemiological evidence suggests an increase in cholera incidence inland as well (Rebaudet et al, 2013 Sudan reported significant number of cholera cases in recent decades (Jutla et al, 2015). Three empirical observations motivate the exploration of possible connections of natural disasters with the ecology of vibrios in the aquatic environment: (i) laboratory and field studies suggest significant correlation between plankton abundance and pathogenic cholera bacteria (Alam et al, 2006b;Huq et al, 2005;Singleton et al, 1982); (ii) changing climate has now been linked to increased incidence of natural disasters, resulting in stress on water availability in regions where population vulnerability interacts with hydroclimatic extremes (Leaning and Guha-Sapir, 2013;McMichael, 2009) and (iii) changes in intensity and seasonality of hydroclimatological processes can be expected to affect ecological niches of vibrios.…”