Laboratory diagnosis of yellow fever infections in humans, alouatta monkeys and haemagogus mosquitoes in Trinidad, 1978-1980

The yellow fever epidemic in Trinidad began with an epizootic in alouatta monkeys in November, 1978. Activity was detected by virus isolation from Alouatta monkeys and from Haemagogus mosquitoes between this date and July 1980. First reports of monkey deaths centered around the Guayaguayare forests of South Trinidad, following which the epizootic spread west to the Moruga area, and north through the Biche Forest reserve, eventually reaching the north-west Chaguaramas peninsula. Surveillance of febrile persons attending clinics and hospitals was intensified and 18 confirmed cases were identified, from 14 of whom yellow fever virus was isolated. In four cases, diagnoses were made on the basis of liver pathology only. Paired sera were obtained from 10 of 11 persons who survived, and in each case serological conversions were obtained by haemagglutination inhibition and mouse neutralization tests. Yellow Fever virus was isolated from 16 of 32 Alouatta monkeys and from 19 of 174 pools of Haemagogus mosquitoes. Two systems were used for virus isolation: the Aedes cell line AP-61 and suckling mice. The former proved to be more sensitive, detecting virus in 11.7 percent of 725 specimens inoculated whereas suckling mice detected virus in 7.9 percent of 724 specimens. In 11 instances virus was detected in an animal or mosquito pool by AP-61 but not initially by mouse inoculation whereas the converse was true in only one case (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.

Laboratory diagnosis of yellow fever infections in humans, alouatta monkeys and haemagogus mosquitoes in Trinidad, 1978-1980

The yellow fever epidemic in Trinidad began with an epizootic in alouatta monkeys in November, 1978. Activity was detected by virus isolation from Alouatta monkeys and from Haemagogus mosquitoes between this date and July 1980. First reports of monkey deaths centered around the Guayaguayare forests of South Trinidad, following which the epizootic spread west to the Moruga area, and north through the Biche Forest reserve, eventually reaching the north-west Chaguaramas peninsula. Surveillance of febrile persons attending clinics and hospitals was intensified and 18 confirmed cases were identified, from 14 of whom yellow fever virus was isolated. In four cases, diagnoses were made on the basis of liver pathology only. Paired sera were obtained from 10 of 11 persons who survived, and in each case serological conversions were obtained by haemagglutination inhibition and mouse neutralization tests. Yellow Fever virus was isolated from 16 of 32 Alouatta monkeys and from 19 of 174 pools of Haemagogus mosquitoes. Two systems were used for virus isolation: the Aedes cell line AP-61 and suckling mice. The former proved to be more sensitive, detecting virus in 11.7 per cent of 725 specimens inoculated whereas suckling mice detected virus in 7.9 per cent of 724 specimens. In 11 instances virus was detected in an animal or mosquito pool by AP-61 but not initially by mouse inoculation whereas the converse was true in only one case.

An outbreak of typhoid fever in Paramin, Trinidad

Typhoid fever was recognized in four residents of Paramin, a community of market gardeners located in the rugged mountains near Port-of-Spain. Because of the community's poor water quality and sewage disposal, an immediate effort was made to investigate and control the outbreak. Eleven additional persons with S. typhi infection were found, all of whom had onset of illness before the investigation began and could be linked to three foci of infection. All tested isolates demonstrated an identical degraded Vi phage type. No source of outbreak was found, but spread of the infection appeared to be person-to-person rather than a common source such as food or water. Water samples and Moore swabs detected no S. typhi organisms, but did demonstrate widespread faecal contamination of the springs and streams used as water sources, suggesting the potential for a water-borne outbreak of S. typhi or other enteric disease. We worked with community leaders to protect the water supply by chlorinating the centrally located school water supply for community-wide use and reminding residents to boil water and maintain good hygienic habits (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)

Surgical wound infection in an orthopaedic patient population - abstract

A pilot prospective study of surgical wound infection was undertaken on the orthopaedic wards at the Port of Spain General Hospital. Patients enrolled in the study were admitted to hospital either for surgical intervention in traumatic orthopaedic injuries or for elective orthopaedic surgery. All surgical procedures were performed in theatre. Swabs for aerobic bacteriology were taken at the time of operation and again at least once thereafter within a period of two weeks. Laboratory methods were suitable for anaerobic organisms as well; however the swab method of culturing is relatively unsuitable and no anaerobes were recovered. Incisions were regularly inspected for signs of infection, which was defined as the presence of pus; however, swabs were taken whether or not infection supervened. Of twenty-two patients enrolled to date, seventeen had traumatic injuries and five had elective surgery. Of the patients with traumatic injuries four (23 percent) developed surgical wound infection, while one (20 percent) of the patients admitted for elective surgery developed infection. This patient had incision and drainage of an osteomyelitic abscess. Of the swabs taken in theatre, 61 percent were either sterile or showed minimal growth of saprophytic organisms while 37 percent revealed organisms which were potentially pathogenic. Culture results for the post-operative wound swabs revealed a variety of organisms including Staphylococcus aureus, E. coli and Enterobacter aerogenes. A common feature of all isolates was in vitro resistance to the antibiotics frequently used for surgical wound prophylaxis. We conclude from this preliminary study that in this population of orthopaedic patients that the organisms causing wound infection cannot be reliably detected by taking cultures at the time of operation in theatre and that organisms isolated from wounds after surgery show a high degree of antibiotic resistance whether or not infection is present (AU)

A new antibiotic resistant strain of salmonella typhimurium isolated from cases of gastroenteritis at Port of Spain General Hospital - abstract

During January - 22nd November, 1979, CAREC reported 51 isolates were recovered during the months of October and November. Sensitivity testing against 11 antibiotics showed that 88 percent of the organisms were sensitive to Polymyxin B, and that 76 percent were sensitive to Cephalothin as well. In some cases 100 percent of the organisms were resistant to antibiotics such as Sulphadiazine, Chloramphenicol, Kanamycin, and Ampicillin, and 98 percent were resistant to Streptomycin and Ampicillin. With respect to Gentamicin, of the 27 cases of Salmonella typhimurium seen 12 percent were sensitive, 40 percent were resistant, and 48 percent were classified as Intermediate to this antibiotic. In contrast, during 1978 100 percent of S. typhimurium isolates were sensitive to Gentamicin. Epidemiologically, it was thought that most of the cases occurring in October and November were nosocomially transmitted, and the results of serial specimens from patients admitted to that Ward gave supportive evidence of cross-infection. Preliminary investigations have shown the emergence of a new strain of S. typhimurium with a wide spectrum of antibiotic resistance, unlike any previous strain occurring in the community (AU)

Contaminated roof-collected water as a possible cause of an outbreak of salmonellosis

Roof-collected rainwater is a common source in subtropical regions and has not been associated with human illness. In Trinidad, the West Indies, a church group attending a rural camp, developed gastrointestional illness, caused by Salmonella arechevalata. This rare serotype was isolated from stool specimens of campers, food eaten at the camp, and a water tap, which was supplied by a storage tank of roof collected rainwater. The surface of the roof, used as water catchment, was covered with bird faeces. It is postulated that rainwater, falling on the roof, washed off animal excrement which contained S. archevalata and led to the outbreak of salmonellosis through camper ingestion of contaminated food and water.(Summary)

An island-wide epidemic of salmonellosis in Trinidad traced to contaminated powdered milk

Between March 1 and November 30, 1973, an epidemic of salmonella derby gastroenteritis occurred in Trinidad. Approximately 3,000 people were affected. Cases occurred throughout the island roughly in proportion to the population, but most were in infants and small children. Household surveys of cases and a sample survey of controls indicated that the consumption of powdered milk was significantly associated with illness. Further studies showed that 7 different brands of imported powdered milk packaged at a single processing plant near Port-of-Spain were, as a group, significantly associated with salmonellosis. Investigations at the implicated processing plant disclosed several packaging procedures that could have permitted contamination during canning, but the specific mode of contamination could be demonstrated (AU)

The role of infectious diseases in mortality and morbidity of children under five in Kingston and St. Andrew

Infectious diseases in children is still important as a cause of mortality and morbidity in Jamaica. Infectious diseases (ICD 000-136) were responsible for 28.8 percent of deaths in children under five in 1968-1970 in Kingston and St. Andrew, and were major contributions to the excessive mortality in infancy and early childhood. Gastro-enteritis with a mortality rate of 216.1 per 100 000 was the single most important cause of death, but death rates for diptheria, tetanus and measles - diseases preventable by immunization, although markedly lower were still unacceptably high. Infectious disease was the most important cause of admission to the hospital, accounting for 74.7 percent of all admissions at Children's Hospital and 75 percent at the University Hospital of the West Indies during 1972. The cost of treating children in hospital is high and more effort at prevention would reduce these costs. Certain shortcomings of the Health Department of the Kingston and St. Andrew Corporation are discussed, and it is recommended that closer attention be paid to infectious disease, in particular to health education programmes designed to improve hygiene, and to improvement of the statistical services (Summary)