Cholera outbreaks and floods: An empirical analysis through the lense of urban patterns in Dar es Salaam

Albeit highly treatable and preventable, diarrhoea ranks third in terms of mortality causes in Tanzania and sub-Saharan Africa (SSA) in general. Tanzania has experienced yearly outbreaks of cholera (an acute diarrhoeal illness) until the mid-2000s, and sporadically since then with the latest one in late 2015 reporting 7,155 cumulative cases and 96 deaths (as of early November 2015, WHO).

The Dar es Salaam (Dar) region has historically been one of the areas hit the most by cholera with 72% of all cases in the current epidemic occurred in the region of Dar. Dar is also the largest city in Tanzania, and as many SSA cities, it is characterized by high levels of informality (the highest in East Africa, 65% of its population), poor water drainage systems, and fragile urban planning. Together with its location by the Indian Ocean, these characteristics make Dar highly prone to flooding, particularly during the monsoon seasons (April-May and November-December).

Cholera is mostly a waterborne disease, and long-term solutions for its control lie in economic development, as well as universal access to safe drinking water and adequate sanitation, which are crucial to prevent both epidemic and endemic cholera. As such, the main approach in the economics literature has been to evaluate practical solutions (i.e. water cleaners) in randomised control trial settings. The mechanisms between causes of diseases and transmission channels in urban settings hasn’t been properly addressed. Yet, the lack of proper infrastructure, high informality and densities are likely to explain much of the flood-prone areas in the city, which are in turn likely to be highly correlated with episodes of acute diarrhoea and cholera outbreaks

This project aims at filling this gap, by understanding the relationship between flooding, urban infrastructure and cholera incidence at the city level in Dar, considering socio-economic characteristics, existing urban infrastructure and housing conditions within the city. This is a key policy area to address, given the growing urbanization levels of Dar (and its vulnerability to climate change related-phenomena). This project will inform policy makers of the relationship between existing urban infrastructure (water drainage systems), and hence flood-prone areas, and cholera incidence within fine spatial units of Dar. It will further evaluate how much density, housing informality, and accessibility are also factors in cholera transmission in these areas. It is thus a key output for both public health and urban planning experts in Dar and Tanzania in general.