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Surveillance of measles virus detected an epidemiologic link between a refugee from Kenya and a Dutch tourist in New Jersey, USA. Identical genotype B3 sequences from patients with contemporaneous cases in the United States, Canada, and Mexico in November and December 2005 indicate that Kenya was likely to have been the common source of virus.

Yellow fever (YF) is an acute mosquito-transmitted viral infection endemic and occasionally epidemic in many countries of Africa and South America. Periodic outbreaks of yellow fever in East Africa have been reported since 1940. The largest outbreak an estimated 300000 cases occurred from 1960 to 1962 in Ethiopia. In 1966 YF reappeared in Arba-Minch Ethiopia east of Lake Abaya in an area not affected by the outbreak of 1960 to 1962. During the 1966 outbreak 2200 cases (450 deaths) were reported. Despite the prevalence of anti-YF antibody in northern Kenya (up to 14%) no outbreaks of YF were reported in Kenya until 1992 when epidemic YF emerged in Kenya for the first time with at least 54 cases and 29 deaths. Cases of hemorrhagic fever were first reported in September 1992 from the southern parts of Keiyo (Kerio Valley) Baringo and the Koibatek Districts (former Elgeyo-Marakwet and Baringo districts) in the Rift Valley Province northwest Kenya. Of the 54 patients with hemorrhagic fever 35 (67%) were male. Of the 48 patients whose definite age was known 41 (85%) were 10 to 39 years old. Twenty-one (39%) of the 54 patients had serologic evidence of recent YF infection and three of the 21 had cases confirmed by isolation of YF virus. The outbreak ended when the entire population of these districts was vaccinated. A surveillance system involving 13 sentinel sites was established 6 months after the epidemic was over. Six health facilities were located within the outbreak area of Keiyo Koibatek and Baringo districts. Seven facilities were situated in the surrounding areas of Nakuru Nyandarua Kericho and the Uasin Gishu districts. In 1994 the number of sentinel sites was increased to 18. Sentinel facilities were provided with case investigation forms and equipment for blood collection and storage. Surveillance activities were ongoing and supervisory visits were conducted once every 6 weeks. (excerpt)