Poliomyelitis: Epidemiology and prophylaxis. 6. Geographic synchronism in poliomyelitis epidemics in Kenya

In the 1950s, van Loghem drew attention to what he called "synchronism" in the epidemics of poliomyelitis in western Europe. The 1952 epidemic in the Netherlands affected Belgium and neighbouring parts of the Federal Republic of Germany at the same time. A comparable phenomenon is described from Kenya. Notwithstanding the fact that in the three population concentrations of the country the three poliovirus types may well be endemic, epidemics of poliomyelitis repeatedly occurred synchronously in these areas. However, there seems to be no synchronism between poliomyelitis epidemics in Kenya and those in neighbouring East African countries. Tentative explanations are put forward for the similarities and differences between Europe and East Africa. The importance of the phenomenon as observed in Kenya for control by mass immunization campaigns is stressed.