Analysis of Spatial-Temporal Environmental Risk Factors of 1990-2019 Cholera Outbreaks in Nairobi County, Kenya

Abstract

BACKGROUND : In developing countries around the world, Cholera is one of the most recurrent water diseases and it still remains a major public health threat. The risk factors differ from one region and country to another, and also vary with various environmental factors including temperature, rainfall and relative humidity. This study therefore sought to determine the spatial-temporal distribution of cholera cases in Nairobi County, Kenya for the period between 1990 and 2019. MATERIALS AND METHODS : This study applied a retrospective approach to study the historical cases of cholera recorded in Nairobi. Spatial epidemiology was applied to map the spatial-temporal variation of environmental associated with cholera outbreaks. Secondary dataset was utilized and it was analyzed using both descriptive and inferential statistics with the help of Statistical Software for Social Sciences (SPSS) version 22. Descriptive statistics included frequency distributions. Inferential statistics included regression analysis, Pearson correlation analysis and Analysis of Variance. RESULTS : The results indicated that changes in the amount of monthly rainfall in Nairobi showed a significant relationship with variation in the number of cholera cases (p-value<0.05). However, temperature had no significant relationship with changes in the number of cholera cases (p-value>0.05). The results also indicated that relatively high humidity conditions are likely to significantly cause an increase in the number of cholera cases (r=0.79, R2=0.63, p-value=0.001). CONCLUSION : The study concludes that rainfall and humidity had a significant influence on the number of cholera cases in Nairobi County. However, temperature had no significant relationship with changes in the number of cholera cases. KEYWORDS- Kenya, Cholera, Environment, Risk Factors, Spatial, Temporal