Bluetongue epidemiology in the Caribbean region: serological and entomological evidence from a pilot study in Barbados

Variations in the percentages of lambs seroconverting to bluetongue viruses was seen between sites and years in Barbados. Transmission at some sites was nearly absent whereas all lambs at one site became seropositive. The agar gel immunodiffusion test for bluetongue gave consistent results in series of serum samples from 112 of 121 sentinel lambs. Collections of biting midges in association with sheep yielded six species. Culicoides insignis Lutz, C. pusillus Lutz, C. phlebotomus (Williston), C. furens (Poey), C. jamaicensis Edwards and C. trilineatus Fox. The first two species comprised 92 percent of those caught during a sentinel lamb study and were the predominant species trapped for virus isolation. No viruses were recovered from 5517 C. insignis, 614 C. pusillus, three C. trilineatus and two C. furens placed into pools during two brief intensive trapping operations. (AU)

Bluetongue epidemiology in the Caribbean region: serological and entomological findings from a pilot sentinel system in Trinidad and Tobago

When monitored by the agar gel immunodiffusion test for antibody to bluetongue viruses, a sentinel flock of twenty-five lambs remained seropositive through the year, whereas in a sentinel herd of twenty calves only two individuals seroconverted and these became negative again within 2 months. A light trap operated with the calf herd yielded high numbers of culicoides insignis Lutz (over 18,000 per trap night) along with C. filariferus Hoffman, C. pusillus Lutz, C. leopoldi Ortiz, C. foxi Ortiz, C. limai Barretto, C. diabolicus Hoffman and C. guyanensis Floch and Abonnenc. Culicoides were trapped at the sheep station which had housed the lambs 3 years following the sentinel study. No virus was isolated from pools of C. insignis, C. filariferus and C. pusillus. Six outer species were collected in insufficient numbers to warrant attempted virus isolations. (AU)

Screwworm (Diptera: calliphoridae) myiasis in the Southern Caribbean, and proposals for its management

In a random sample of animal producers and animal health personnel, 33 percent of the respondents in Trinidad, 15 percent in Guyana, and 11 percent in Suriname recalled at least one case of human myiasis due to Cochliomyia hominivorax (Coquerel). During 1981, respondents in Suriname (88 percent), Guyana (85 percent), and Trinidad and Tobago (82 percent) found at least one case of myiasis in their livestock, mainly cattle, pigs, and dogs. Feral animals- e.g., jaguars- were also found to be infested. The initial wounds were mainly the umbilicus neonates, whereas arbitrary cuts, castration wounds, and vampire bite were also affected. Fifty-three to 78 percent of all respondents examined their livestock daily for wounds and infestation by the screwworm. Daily examinations of livestock are now done as a result of the screwworm threat. Annual estimates of losses (in U.S. dollars) due to surveillance and medication ranged from $4.82 to $10.71 per animal. These national losses amounted to $0.30 million (Suriname) $1.02 million (Trinidad and Tobago), and $4.33 million (Guyana). Other losses, such as failure to thrive, reduction in milk production, and hide injury due to screwworm activity, were not available. Most producers found that the greatest infestation occurred in the wet season. Also, most (68 to 83 percent) found the screwworm to be second in importance to the Boophilus spp. ticks as a pest of livestock, but of greater significance than biting flies such as tabanids and stable flies. Eradication of the screwworm can be recommended for the islands of Trinidad and Tobago. Eradication for Suriname and Guyana seems feasible only on the 100-km wide coastal strips, where most human and livestock populations exist. (AU)

Campylobacteriosis in Jamaican cattle

Infertility is a widespread problem among cattle herds in Jamaica and an intergovernmental project was initiated to investigate the problem. One aspect of the project included diagnosis of campylobacteriosis (vibriosis), which was suspected in some herds but had not been confirmed in the laboratory. Tests were undertaken in late 1978 using improved techniques for handling and transporting specimens to the laboratory. Campylobacter fetus subspecies fetus was isolated from five of six herds tested. The diagnosis of C fetus infection has led to improvements in farm management and a better appreciation of more efficient artificial insemination and veterinary services. (Summary)