RESUMO
The annual incidence of Q fever in French Guiana was found to have increased in 1996 and was 37/100,000 population over the last 4 years. Subsequent investigations in Cayenne and its suburbs indicated that a wild reservoir of the bacteria was responsible for the epidemiologic pattern. A case-control study showed that residence near a forest and occupations and activities that result in exposure to aerosols of dusts from the soil are risk factors for Q fever. By means of time-series analysis, a strong positive correlation between rainfall and the incidence of Q fever with a time lag of 1-3 months was found. The spatial distribution of the cases showed that transmission occurs widely throughout greater Cayenne, which is incompatible with a pinpoint source of contamination. Transmission from livestock and dissemination of the bacteria by the wind appeared to be unlikely, which strengthens the hypothesis that a wild reservoir is responsible for transmission.
Assuntos
Infecções Comunitárias Adquiridas/transmissão , Reservatórios de Doenças , Febre Q/transmissão , População Suburbana , Adolescente , Adulto , Microbiologia do Ar , Animais , Animais Selvagens , Anuros , Aves , Estudos de Casos e Controles , Gatos , Criança , Pré-Escolar , Quirópteros , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/epidemiologia , Coxiella burnetii/isolamento & purificação , Poeira , Feminino , Guiana Francesa/epidemiologia , Geografia , Cobaias , Humanos , Lactente , Masculino , Marsupiais , Exposição Ocupacional , Febre Q/diagnóstico , Febre Q/epidemiologia , Roedores , Estações do Ano , Microbiologia do Solo , População UrbanaRESUMO
Two recent cases of human infection with Tonate virus, one of which was a fatal case of encephalitis, have renewed interest in these viruses in French Guiana. The clinical aspects of confirmed and probable cases of infection with this virus indicate that it has pathogenic properties in humans similar to those of other viruses of the Venezuelan equine encephalitis complex. To determine the prevalence of antibodies to Tonate virus in the various ethnic groups and areas of French Guiana, 3,516 human sera were tested with a hemagglutination inhibition test. Of these, 11.9% were positive for the virus, but significant differences in seroprevalence were found by age, with an increase with age. After adjustment for age, significant differences were found between places of residence. The prevalence of antibody to Tonate virus was higher in savannah areas, especially in the Bas Maroni (odds ratio [OR] = 22.2, 95% confidence interval [CI] = 15.2-32.4) and Bas Oyapock areas (OR = 13.4; 95% CI = 9.8-18.4). The ethnic differences observed in this study were due mainly to differences in place of residence, except that whites were significantly less frequently infected than other ethnic groups. This study indicates that Tonate virus infection is highly prevalent in French Guiana, especially in savannah areas.
Assuntos
Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Encefalomielite Equina/epidemiologia , Adulto , Sequência de Bases , Primers do DNA , Encefalomielite Equina/diagnóstico , Encefalomielite Equina/patologia , Encefalomielite Equina/transmissão , Feminino , Guiana Francesa/epidemiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estudos SoroepidemiológicosRESUMO
We investigated the characterization of different HIV-1 subtypes present in French Guiana by use of three different methods. Serological methods were used for the initial screening, which were then confirmed by the heteroduplex mobility assay (HMA). The V3 env region was subsequently sequenced for phylogenetic analysis, to confirm the subtype of the samples, and to assign a subtype to samples that gave results that were difficult to interpret or discordant by serology or HMA. A total of 221 HIV-1 seropositive samples were typed; 110 of them were confirmed by HMA and 16 were sequenced. Of the 221 samples tested 210 patients (95%) were found to be infected with subtype B, 10 (4.5%) were infected with subtype A, and one patient was infected with subtype F. Phylogenetic analysis demonstrated that the strains from French Guiana were closely related to the subtype A and B subtypes, and that one strain was closely related to an F subtype (100% bootstrap value). Four strains from French Guiana clustered in the subtype A (99% bootstrap value) and the other strains were associated with subtype B (100% bootstrap value). The geographic position of French Guiana suggested that HIV-1 was probably introduced into the country via several routes, and thus the pattern of the HIV-1 epidemic might evolve in the near future.
Assuntos
Variação Genética , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/virologia , HIV-1/genética , Fragmentos de Peptídeos/genética , Sorodiagnóstico da AIDS , Sequência de Aminoácidos , Sequência de Bases , DNA Viral , Guiana Francesa , Proteína gp120 do Envelope de HIV/classificação , Infecções por HIV/sangue , Infecções por HIV/diagnóstico , Infecções por HIV/imunologia , HIV-1/classificação , HIV-1/imunologia , Análise Heteroduplex , Humanos , Dados de Sequência Molecular , Fragmentos de Peptídeos/classificação , FilogeniaRESUMO
Extensive studies have been carried out on native Amerindian populations living in French Guiana in an attempt to detect human T cell leukemia virus type 2 (HTLV-2). However, the first strain of this virus identified in this region was not detected in these populations, but in a Brazilian woman of Amerindian origin. Comparative analyses of the nucleotide sequences of 589 bp of the gp21 env gene and of 625 bp of the long terminal repeat (LTR) showed that this new HTLV-2 strain (HTLV-2 GUY) was of subtype A. Sequence comparison and phylogenetic analyses demonstrated that HTLV-2 GUY was closely related to a group of distinct variants of HTLV-2 subtype A strains originating mostly from Brazilian inhabitants and formerly called HTLV-2 subtype C. As there is a high level of immigration from Brazil in French Guiana, we carried out a seroepidemiological study of 175 Brazilians, mostly women (obtained from a serum databank) and 72 female Brazilian prostitutes living in French Guiana to determine whether HTLV-2 is likely to become an emerging infection in this area. No HTLV-2 infection was detected, indicating that this virus is unlikely to become prevalent in the near future.
Assuntos
Produtos do Gene env/genética , Infecções por HTLV-II/virologia , Indígenas Sul-Americanos , Proteínas Oncogênicas de Retroviridae/genética , Sequência de Bases , Brasil/etnologia , DNA Viral , Feminino , Guiana Francesa/epidemiologia , Vírus Linfotrópico T Tipo 2 Humano/classificação , Vírus Linfotrópico T Tipo 2 Humano/genética , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Estudos Soroepidemiológicos , Sequências Repetidas Terminais , Produtos do Gene env do Vírus da Imunodeficiência HumanaRESUMO
An anomalous high frequency of ATL was observed in a remote 'noir maroons' village of French Guiana. Since it is not clear if HTLV-I is responsible for different frequencies of disease in different geographical areas, we undertook a comparison of the population with a similar one located in Gabon. We found a much higher degree of gp46 surface envelope glycoprotein sequence conservation in the Guianese village than in the Gabonese one.
Assuntos
Variação Genética , Vírus Linfotrópico T Tipo 1 Humano/genética , Leucemia-Linfoma de Células T do Adulto/virologia , Sequência de Bases , Sequência Conservada , DNA Viral , Feminino , Guiana Francesa/epidemiologia , Gabão/epidemiologia , Produtos do Gene env/genética , Humanos , Leucemia-Linfoma de Células T do Adulto/epidemiologia , Masculino , Dados de Sequência Molecular , Filogenia , Proteínas Oncogênicas de Retroviridae/genética , Alinhamento de SequênciaRESUMO
Surveillance of dengue fever is mainly based on specific laboratory tests. However non-specific systems, such as clinical surveillance, are also required. In French Guiana, we have tested a non-specific laboratory surveillance system where different biological examinations performed for other reasons than the diagnosis of dengue fever were analysed as methods for dengue fever surveillance. The number of negative malaria diagnoses in Cayenne and Kourou was found to be the best indicator of dengue fever infections in these towns. This surveillance system appears to be very simple and reliable, and a test which could serve as an indicator that is likely to be found everywhere.
Assuntos
Dengue/epidemiologia , Malária/diagnóstico , Vigilância da População/métodos , Vírus da Dengue/genética , Ensaio de Imunoadsorção Enzimática , Guiana Francesa/epidemiologia , Humanos , RNA Viral/sangue , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Human T lymphotropic virus type I (HTLV-I) is a human oncoretrovirus that causes an adult T cell leukemia/lymphoma and a chronic neuromyelopathy. To investigate whether familial aggregation of HTLV-I infection (as determined by specific seropositive status) could be explained in part by genetic factors, we conducted a large genetic epidemiological survey in an HTLV-I-endemic population of African origin from French Guiana. All of the families in 2 villages were included, representing 83 pedigrees with 1638 subjects, of whom 165 (10.1%) were HTLV-I seropositive. The results of segregation analysis are consistent with the presence of a dominant major gene predisposing to HTLV-I infection, in addition to the expected familial correlations (mother-offspring, spouse-spouse) due to the virus transmission routes. Under this genetic model, approximately 1. 5% of the population is predicted to be highly predisposed to HTLV-I infection, and almost all seropositive children <10 years of age are genetic cases, whereas most HTLV-I seropositive adults are sporadic cases.
Assuntos
Infecções por HTLV-I/epidemiologia , Infecções por HTLV-I/genética , Adolescente , Adulto , África/etnologia , Fatores Etários , Criança , Pré-Escolar , Doenças Endêmicas , Feminino , Guiana Francesa/epidemiologia , Predisposição Genética para Doença , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Linhagem , Penetrância , Estudos SoroepidemiológicosRESUMO
Tonate virus, subtype IIIB of the Venezuelan equine encephalitis (VEE) complex, was first isolated in 1973 in French Guiana, South America. However, very little is known about its pathogenicity; it was considered to be responsible for only mild dengue-like syndromes. In 1998, a 2-month-old boy living along the Oyapock river in French Guiana was hospitalized for fever and generalized status myoclonus, and despite treatment the patient died 72 h after admission. Testing showed the presence of IgM specific for viruses of the VEE complex. A sensitive seminested polymerase chain reaction derived from a previous study was developed to detect viruses from the VEE complex, since no virus could be recovered from clinical specimens cultured on mosquito cells or from intracerebral inoculation into newborn mice. The genome of a virus from the VEE complex was detected in postmortem brain biopsies, and Tonate virus was identified by direct sequencing. This is the first reported case of human encephalitis due to Tonate virus.
Assuntos
Vírus da Encefalite Equina Venezuelana/classificação , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Encefalomielite Equina Venezuelana/diagnóstico , Animais , Anticorpos Antivirais/sangue , Encéfalo/virologia , Vírus da Encefalite Equina Venezuelana/genética , Vírus da Encefalite Equina Venezuelana/imunologia , Encefalomielite Equina Venezuelana/virologia , Humanos , Lactente , Masculino , Camundongos , Dados de Sequência Molecular , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
OBJECTIVES: Evaluation of the consequences of a dengue fever infection on mother and foetus during pregnancy. PATIENTS AND METHODS: Between February 1, 1992 and December 31, 1999, 172 patients with non malaria hyperthermia were tested for dengue fever infection at the maternity of the Saint-Laurent-du-Maroni hospital in French Guyana. The diagnosis was considered positive when specific IgM was present and/or with virus isolation or viral ARN detection using RT-PCR. Among the 38 cases of mothers infected by dengue fever throughout the three trimesters of pregnancy, it was possible to take 19 fetal blood samples. RESULTS: The major consequences for the mothers were risk of premature delivery in 55% of the cases, one case of severe hemorrhagic complications during a cesarean section, and one case of abruptio placentae. The consequences for the fetus were premature birth in 22% of the cases, 5 in utero fetal deaths, 4 cases of acute fetal distress during labor and 2 cases of mother-to-child transmission. CONCLUSION: In case of dengue fever infection of the mother during pregnancy, there is a serious risk of premature birth and fetal death. In case of infection close to term, there is a risk of hemorrhage for both the mother and the newborn.