Effects of dengue fever during pregnancy in French Guiana.
To determine the effects of dengue fever (DF) during pregnancy, pregnant women presenting with a dengue-like syndrome at a hospital in Saint-Laurent du Maroni, French Guiana, from 1 January 1992 to 1 April 1998 were studied. The diagnosis of DF was made by serological tests, virus isolation on AP 61 mosquito cells, and/or reverse transcriptase polymerase chain reaction analysis. Twenty-two women had either probable or confirmed DF. Dengue virus serotype 2 was detected in four cases, and dengue virus serotype 1 was detected in one. Three fetuses died following the onset of the disease, and three cases of prematurity occurred. All infants appeared normal during physical examination, and no neonatal DF was diagnosed. In conclusion, DF in pregnant women did not cause any infant abnormality, but it may have been responsible for fetal death. The rate of fetal death associated with DF (13.6%) was much higher than the mean rate for the gynecology unit at the hospital (1.9%). However, these differences were not significant, and consequently these preliminary results need to be confirmed. (+info)
Tuberculosis in the Caribbean: using spacer oligonucleotide typing to understand strain origin and transmission.
We used direct repeat (DR)-based spacer oligonucleotide typing (spoligotyping) (in association with double-repetitive element polymerase chain reaction, IS6110-restriction fragment length polymorphism [RFLP], and sometimes DR-RFLP and polymorphic GC-rich sequence-RFLP) to detect epidemiologic links and transmission patterns of Mycobacterium tuberculosis on Martinique, Guadeloupe, and French Guiana. In more than a third of the 218 strains we typed from this region, clusters and isolates shared genetic identity, which suggests epidemiologic links. However, because of limited epidemiologic information, only 14.2% of the strains could be directly linked. When spoligotyping patterns shared by two or more isolates were pooled with 392 spoligotypes from other parts of the world, new matches were detected, which suggests imported transmission. Persisting foci of endemic disease and increased active transmission due to high population flux and HIV-coinfection may be linked to the recent reemergence of tuberculosis in the Caribbean. We also found that several distinct families of spoligotypes are overrepresented in this region. (+info)
First case of yellow fever in French Guiana since 1902.
The first case of yellow fever in French Guiana since 1902 was reported in March 1998. The yellow fever virus genome was detected in postmortem liver biopsies by seminested polymerase chain reaction. Sequence analysis showed that this strain was most closely related to strains from Brazil and Ecuador. (+info)
First seroepidemiological study and phylogenetic characterization of human T-cell lymphotropic virus type I and II infection among Amerindians in French Guiana.
We investigated the serological, epidemiological and molecular aspects of human T-cell lymphotropic virus type I and II (HTLV-I/II) infection in the Amerindian populations of French Guiana by testing 847 sera. No HTLV-II antibodies were detected, but five individuals (0.59%) were seropositive for HTLV-I. Analysis of the nucleotide sequences of 522 bp of the env gene and the compete LTR showed that all of the strains from French Guiana belonged to the cosmopolitan subtype A. The similarities were greater between Amerindian and Creole strains than between Amerindian and Noir-Marron strains or than between Creole and Noir-Marron strains. Phylogenetic analysis showed two clusters: one of strains from Amerindians and Creoles, which belong to the transcontinental subgroup, and the other of strains from Noirs-Marrons, belonging to the West African subgroup. Our results suggest that the Amerindian HTLV-I strains are of African origin. (+info)
Plasmodium falciparum parasites in French Guiana: limited genetic diversity and high selfing rate.
The genetic characteristics of Plasmodium falciparum isolates collected in French Guiana, where malaria transmission is low and occurs in isolated foci, were studied. Blood samples were collected from 142 patients with symptomatic malaria and typed using a polymerase chain reaction-based strategy for merozoite surface protein-(MSP-1) block 2, the MSP-2 central domain, and glutamate-rich protein (GLURP) repeat domain polymorphism. This showed that the parasite population circulating in French Guiana presented a limited number of allelic forms (4, 2, and 3 for MSP-1 block 2, MSP-1, and GLURP, respectively) and a small number of mixed infections, contrasting with the large genetic diversity of parasite populations and infection complexity reported for Africa, Asia, and other parts of South America. Two groups of isolates displaying identical 3 loci allele combinations were further studied for the Pf332 antigen, histidine-rich protein-1, thrombospondin-related anonymous protein, and Pf60 multigene family polymorphism. Within each group, most isolates were identical for all markers tested. This suggests a high rate of self-fertilization of P. falciparum parasites in French Guiana, resulting in homogenization of the population. The implications of these findings for malaria control in areas of low endemicity are discussed. (+info)
Detection of a major gene predisposing to human T lymphotropic virus type I infection in children among an endemic population of African origin.
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. (+info)
Surveillance of dengue fever in French Guiana by monitoring the results of negative malaria diagnoses.
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. (+info)
Aedes aegypti in French Guiana: susceptibility to a dengue virus.
Twenty-seven samples of Aedes aegypti (F1 generation) from French Guiana were tested for their susceptibility to dengue serotype 2 virus. Very high infection rates were observed by indirect fluorescent antibody (IFA) test. Ae. aegypti samples were pooled according to two groups: the first group (N=10) represented mosquitoes from the urbanized area of Cayenne and surroundings, and the second group (N=17) corresponded to mosquitoes collected in the countryside. Infection rates were found to be similar in these two cases. These findings are discussed in relation with the history of Ae. aegypti in this part of the world. (+info)