Is HIV infection associated with an increased risk for cholera? Insights from a mathematical model.

Cholera, a waterborne gastroenteric infection, remains a significant threat to public health in sub-Saharan Africa, the region most heavily affected by HIV. It is biologically plausible that immune suppression caused by HIV infection predisposes to cholera. In this paper, a simple mathematical model is developed and comprehensively analyzed to assess whether HIV infection is associated with an increased risk for cholera or not. Analytical results of the model show that the quantities R(c) and R(h), which represents the reproductive number for cholera and HIV infection, respectively, provide threshold conditions that determine cumulative new single and dual infection cases. These threshold conditions can be used to gain important insights on the epidemiological consequences of HIV and cholera coexistence in the community. Numerical results are provided to support the analytical findings. The findings suggest that in a cholera-endemic area, HIV infection is associated with an increased risk for cholera.