RECENT OBSERVATIONS ON THE EPIDEMIOLOGY OF KALA-AZAR IN THE EASTERN AND CENTRAL STATES OF THE SUDAN

The main endemic area of kala azar (visceral leishmaniasis) in the Sud an is in Eastern State and the Blue Nile area of Central State. In ord er to obtain more recent information about kala-azar in both States, t he major hospitals and health centres were visited, the physicians and medical assistants interviewed and available records inspected. In Ea stern State a cross sectional survey of one village was carried out an d a longitudinal population based study of another village started. In this State, after a decline since 1985, a sharp increase in the numbe r of cases was noted from 1991 onwards. This increase was seen in larg e areas, especially along the Rahad and Dinder Rivers. In contrast, in Central State, there was a decline in the frequency of the disease si nce the 1960s in the area around Sennar and Singa, which was regarded as a hyperendemic focus up to about 30 years ago. It was hypothesized that this decline may be related to the extensive agricultural develop ment with regular insecticiding and the deforestation of the area. Sev eral aspects with regard to transmission of kala-azar are discussed.