Yellow fever in Trinidad and Tobago 1978-1980: epidemiological aspects

Between 1978-1979 an epidemic of yellow fever occurred in Trinidad in two phases. Eight cases occurred in December 1978-March 1979 and 10 cases occured in August-September 1979. Seven died, giving a case fatality rate of 39 per cent . All cases were male aged 16-58 years (median 22.5). Seventeen had been exposed in forests where the virus was active and none had records of being vaccinated. The high level of clinical and virological surveillance that existed made it likely that all or nearly all the cases were ascertained. Intense immunization, health education and vector control efforts also mitigated against a larger epidemic.

Entomological activities during the yellow fever epidemic in Trinidad, 1978-1980

An epidemic of sylvan yellow fever occurred in Trinidad during the period 1978 to 1980. Entomological activities were initiated at various localities where monkey (Alouatta spp.) mortalities were reported. A total of 5,468 Haemagogus janthinomys was collected and tested which resulted in the isolation of 17 strains of yellow fever virus. Two strains of the virus were isolated from a total of 49 Haemagogus leucocelaenus and these constituted the first isolations of yellow fever virus from this species of mosquito from Trinidad. Attempts to demonstrate transovarial transmission of yellow fever virus from adults feared from eggs and larvae collected in the field were unsuccessful. However, from two locations virus isolations were made at the end of rainy season (January) and at the beginning of the successive rainy season (June).

Vector control operations during a sylvatic yellow fever outbreak in Trinidad,1978-1980

An outline is given of the vector control measures adopted during the 1978-1980 yellow fever epidemic in Trinidad and the efficacy of the yellow fever plan of action is discussed.