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Risk factors and context

VL incidence is usually related to many factors - rarely just one. Dr Mounir Lado explains how risk factors have been exacerbated in South Sudan.

It is important to understand that an increase in VL cases is related to many things. VL is a disease that comes in “epidemic waves”. This is illustrated in the graph below that documents the number of VL cases over time in three endemic countries in East Africa.

Graph shows the number of detected anthroponotic VL cases over time in three East African endemic countries. The number of cases increases suddenly and then drops for a period of time. This happens every 6 to 10 years, in so called “epidemic waves”.

Risk factors for VL should not be viewed in isolation. Climatic and social factors, environmental change and population trends (like increases in movement or urbanisation) can all influence the spread of visceral leishmaniasis.

In certain situations, risk factors are exacerbated and contribute to each other. In the context of conflict and insecurity, for example, patients are often unable to access medical care services. During conflict, massive displacement may take place, which can be coupled with several other important risk factors for VL, such as food insecurity and high malnutrition rates, or poor housing and exposure of people to infected sand flies.

In the following interview, Dr Mounir Lado from IMA World Health in the Republic of South Sudan explains how risk factors for VL can be exacerbated in the context of massive displacement.