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 (AU)

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) (AU)

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 percent. 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 (AU)

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.

Surveillance and management of sylvatic yellow fever in Trinidad (1988-1989) - abstract

Howler monkey (Aloutta sp) deaths in the Southeastern forests of Trinidad were reported in December, 1988. This paper reports the laboratory and field investigations and preventive measures which were undertaken, in view of the known association between such deaths and yellow fever (YF) activity. A total of 47,640 adult mosquitoes were captured in several forest regions in Trinidad during the period December 1988 to October, 1989. Mosquitoes were identified, pooled and processed for virus isolation. Blood and organs from 5 dead Howler monkeys submitted between December 1988 and March, 1989 were examined for the presence of YF virus. Virus isolation was done by innoculation of material in AP61 (Ades pseudo-scutellaris) tissue culture and in 2-day-old Swiss albino mice, followed by identification of YF isolates by immunoflourescence, using monoclonal antibody and standard mouse neutralization tests, respectively. Fourty-four species of mosquito belonging to 14 genera were identified. From 654 mosquito pools, 6 YF isolates were obtained from only 2 species: five isolates from haemagogus janthinomys (December, 1988) and 1, for the first time locally, from Sabethes chloropterus (January, 1989). YF virus was isolated from blood and organs of 2 Howler monkeys captured on February 22 and March 2, 1989. There were no human cases of YF. Yellow fever activity appeared to be confined to the southeast part of the island. Preventive measures included mass targeted YF immunization (400,000 doses administered in 3 months), intensified vector control operations and reduced human contact with forest mosquitoes by the existing ban on hunting (AU)

Serum cholinesterase levels of vector control workers in Trinidad, West Indies (1979-1982)

During the period 1979-1982, serum cholinesterase levels were determined in blood samples collected from workers employed at the Insect Vector Control Division, Trinidad, W.I. A total of 1,162 blood samples were collected, of which 116 showed suppressed cholinesterase levels. Those workers with low serum cholinesterase levels included 46 residual spraymen, 66 Aedes aegypti operators and 4 controls. The difference in numbers of spraymen and Aedes operators with low cholinesterase levels was significant (p<.001). No significant differences were found in the number of Aedes operators with low cholinesterase levels from North and South Trinidad. Similarly, no differences were found in the number of residual spraymen from North and South Trinidad with low cholinesterase levels. A total of 7 Aedes operators and 4 residual spraymen had persistently low serum cholinesterase levels. It is likely that the main areas of absorption were the hands and forearms, with further absorption occurring via respiration. The need for continuous monitoring and supervision of vector control workers who handle insecticides is stressed (AU)

Fansidar resistant falciparum import to Trinidad from Tanzania

A 27 year old Tanzanian female with an acute P. falciparum malaria infection failed to respond to the recommended radical Fansidar treatment. The case is classified as RII resistance because after 7 days, parasitemia clearance was not achieved. The infection was certainly acquired in Tanzania but diagnosed and treated in a non-malarious country. This is possibly the first case of Fansidar resistant falciparum malaria found sensitive to Chloroquine. Chloroquine and Primaquine effectively eradicated the P. falciparum malaria from the patient. (AU)

A case of imported plasmodium ovale infection in Trinidad, West Indies

The first imported case of Plasmodium ovale malaria in Trinidad, West Indies is described in a Dutch engineer who had previously worked in West Africa. Available data suggests that the infection may have been acquired one year previously (AU)