RESUMO
Six samples of Jamaican honey were tested for anti-bacterial activity and other biological properties. Tests involving the incorporation of honey into agar plates were the most satisfactory and showed that a wide range of bacteria were sensitive to honey. The effect depended on the type of honey used, its concentration and in some cases its non-exposure to temperatures above 100§C. The inhibitory effect is bacteriostatic and probably dependes not only on the high osmotic pressure but also on other factors which could include an enzyme-substrate system (AU)
Assuntos
Mel/análise , BactériasAssuntos
Humanos , Dengue/história , Aedes , Anticorpos/análise , Cuba , Dengue , Vírus da Dengue/isolamento & purificação , Surtos de Doenças , Testes de Inibição da Hemaglutinação , Insetos Vetores , Controle de Mosquitos , Testes de Neutralização , Panamá , Estados Unidos , Venezuela , Índias OcidentaisRESUMO
Dengue-like illness has been reported in Jamaica since 1824, although the viruses concerned were never isolated. The emphasis of this work was isolating and typing the etiologic agents involved; 679 cases were reported to the Microbiology Department, University of the West Indies, during 1968 and 1969. Primary serum samples were tested; 112 of 175 indicated recent arbovirus group B infections. Primary infections and reinfections with dengue viruses were indicated by hemagglutination-inhibition and complement-fixation tests. Challenge-virus resistance technique was used to isolate eight agents from human serum. Six of these strains have been typed as dengue-3 and two as dengue-2 viruses.(AU)
Assuntos
Humanos , Camundongos , 21003 , Dengue/epidemiologia , Dengue/microbiologia , Vírus da Dengue/isolamento & purificação , Antígenos , Sangue/microbiologia , Linhagem Celular , Testes de Fixação de Complemento , Surtos de Doenças , Testes de Inibição da Hemaglutinação , Jamaica , Rim , Cultura de Vírus , Erythrocebus patasRESUMO
Sixteen isolates were uncovered from bird sera and mosquitoes collected at Caymanas Estates, Jamaica. One of these isolates was St. Louis encephalitis virus, two isolates were not fully characterised and 13 belonged to a group that was, before now, not described in Jamaica. This group had similarities to the Coxsackie A viruses but showed no serological relationship to the Coxsackie viruses to which they were most similiar. These viruses were capable of infecting man, causing at least in some cases clinical illness and possibly may be responsible for some of the fevers of unknown origin in Jamaica. (AU)
Assuntos
Camundongos , 21003 , Aves , Viroses , Culicidae , Vírus/isolamento & purificação , Jamaica , Testes Sorológicos , Vírus/classificação , Vírus/imunologia , EcologiaRESUMO
From clinical and serological evidence, dengue is believed to be endemic in Jamaica. However, no positive confirmation had been made of this fact because the virus had not been isolated and St. Louis Encephalitis virus, a close serlogical relative of dengue, is known to be present in the island. Certain communities in the island were known to have an incidence of dengue antibody as high as 60-70 percent. Nevertheless, during the 1963 outbreak these communities suffered a high incidence of infection second only to the Kingston and St. Andrew area. Again in 1968, the Kingston and St. Andrew population was heavily affected and in some instances persons complained of having dengue twice within months. Most of our clinical cases were adults. Between January, 1968 and January, 1969, a total of 679 cases was reported. 112 of 175 tested were proved serologically to be due to recent infection. Using challenge virus resistance technique in AGMK and BSC-1 cells with echo 9 and polio 1 as challenge viruses, 20 agents were isolated. Nineteen of these were from human sera and one from a pool of Aedes aegypti mosquitoes. 31 human sera were inoculated into one-day Swiss white mice. On 14 occasions symptoms indicative of viral infection were seen. Some of our isolates have been confirmed by plaque techniques in LLC-MK2 and PS continuous pig kidney cell lines. The rapid development of high serological titres seen in individuals with classical dengue symptoms suggests a secondary immune response. This is in contrast to cases in which dengue symptoms were associated with moderate conversions, presumably primary infections. In two cases virus was isolated from specimens with coexisting dengue antibody. During the earlier part of 1968 typical symptoms were fever, joint and retro-orbital pain with occasional rash. During the latter half of the year nausea and severe abdominal distress became prominent while the rash became more frequent and total, appearing even on the palms of the hands and soles of the feet. The significance of these observations is not clearly understood, but they could bear comparison with situations reported from the Far East. There, repeated infections have resulted in extremely severe "Dengue symptoms", haemorrhage, shock and death (AU)
Assuntos
Humanos , Dengue/epidemiologia , Jamaica/epidemiologiaRESUMO
Since the outbreak of EEE in Jamaica in 1962, a continued surveillance for the virus has been maintained. It is known that birds act as reservoirs for the virus, and mosquitoes as vectors, consequently our attention directed towards ornithological and entomological investigations. Mosquitoes were caught regularly in the St. Thomas area during and after the outbreak. The surveillance among birds started some months later, and has continued to the present time. No mosquito was found infective with EEE virus, but Cache Valley virus, which is and arbovirus, was isolated from mosquitoes in the area. During the outbreak several birds (including domestic chickens) were bled and tested for circulating virus as well as for antibody to EEE virus. Fourteen of the 356 sera collected within six weeks after the outbreak showed a significant neutralizing titre to EEE virus. Among the wild birds caught subsequently, three of them (one resident and two migrants) showed sero-logical conversion to EEE virus in the St. Thomas area. About one year ago, the programme was extended to include the Black River area in St. Elizabeth. One bird in this area showed partial protection to EEE virus. These results seem to indicate that EEE virus is either endemic in the areas tested, or has been re-introduced by migrant birds. It is therefore necessary to maintain a continued surveillance to detect any activity of this virus(AU)
Assuntos
Vírus da Encefalite Equina do Leste/isolamento & purificação , JamaicaRESUMO
Seventeen percent of 238 wild birds and 36 percent of 162 domestic birds at Caymanas, Jamaica, were found to be positive for St. Louis encephalitis virus infection by hemagglutination-inhibition and neutralization tests in 1962. Conversions detected in local and sentinel chickens suggests that between March and August there probably was an increase in the transmission rate of SLE virus. This increased rate coincided with the breeding period of birds in the area. An isolation of St. Louis encephalitis virus, confirmed by the Trinidad Regional Virus Laboratories, was made from a mockingbird nestling in August. The isolate seems to be closely related to Tr 9464 and Ja 7532 viruses, which are both closely related to the Parton strain of SLE virus.(AU)
Assuntos
Camundongos , Coelhos , 21003 , Aves/microbiologia , Vírus da Encefalite de St. Louis/imunologia , Testes de Inibição da Hemaglutinação , Testes de Fixação de Complemento , Testes de Neutralização , Vírus da Dengue , JamaicaRESUMO
Three hundred and eighty nine bird sera were collected from an area with a high percentage of St. Louis encephalitis immunity in the human population. Haemagglutination-inhibition and neutralization tests showed 17 percent of wild birds and 38 percent of domestic birds positive to St. Louis. One isolation of St. Louis encephalitis was made from a wild bird. Conversion in sentinel and local chickens showed the greatest St. Louis activity from March to August. Most nestlings were found at this time, and doubtless are associated with the increased virus activity. Nestlings of Mimus polyglottos, the Jamaican Nightingale, provided the one isolate, and their high antibody rate indicates their importance in the transmission cycle; ground feeding species of wild birds and chickens are also important. St. Louis virus and antibody development were studied in laboratory infected chickens. Collection from birds and their nests revealed 10 species of haematophagus arthropods, including 8 mites, one tick, and one Philornis maggot. Culex nigripalpus was the most common mosquito biting at 20 feet above ground. Fifteen other isolates were made from birds. Thirteen of these were Coxsackie-like viruses, related to an unidentified virus from a human fever case; 2 were dissimilar to the 13, but were not characterised sufficiently.(AU)