Further studies of space-time clustering of Burkitt's lymphoma in Uganda.

All hospital-treated cases of Burkitt's lymphoma (BL), with onset of symptoms in the period 1963-68 and resident in the Lango and Acholi districts of Uganda, were identified. The average annual incidence of BL in the 6-year period was 1-87 X 10(-5), similar to that in the adjacent West Nile district. Contrary to findings in other areas of Uganda, there was no evidence of seasonal variation in the onset of cases, nor of space-time clustering, nor of a decline in the incidence of BL in the study period. An inverse relationship was noted between the median age at onset of BL and the incidence of the disease in different areas of Uganda, a finding consistent with intense malarial infection being a precipitating factor for BL. The variable observations with respect to space-time clustering of BL and seasonal variation in incidence in different areas remains unexplained, but it is suggested that a closer study of the patterns of malarial infection in these areas may help to account for the findings.