Evidence for an infectious cause for leukaemia

An infectious cause for childhood leukaemia has long been suspected and a research letter published in 17 March Lancet provides new evidence in favour of this mechanism.

Kinlen and Balkwill compared the incidence of childhood leukaemia in two populations in Orkney and Shetland, UK during and after World War II. During the war, local people were outnumbered by servicemen stationed there in case of a northern invasion. This favoured unusual rural–urban population mixing, which increases contacts between susceptible individuals (more prevalent in rural areas) and possible infected individuals. The authors found that childhood leukaemia increased 3·6-fold (p=0·001) in the group of children aged 0–14 living in the islands or who were born there between 1941 and 1945, but not in the post-war cohort, compared with national Scottish rates (Lancet 2001, 357:858).

The findings are consistent with those in other examples of unusual rural–urban population mixing and suggest an underlying infectious ...