RESUMO
A community survey of human T cell lymphotropic virus type I (HTLV-I) in Montserrat, West Indies, identified 22 instances in which 2 HTLV-I-seropositive adults lived within 60 m of each other (close pairs), compared with 7.8 expected (P < .001). Five of these close pairs were mother-offspring or husband-wife. The remaining 17 pairs were of unrelated members in separate households. The percentages of male-female (41%), female-female (41%), and male-male (18%) types in these 17 pairs were very similar to those among the 1377 similarly defined pairs in which neither or only 1 member was seropositive, affording no support for extramarital heterosexual activity as an explanation for the clustering observed. Thus, the demography of HTLV-I was not accounted for completely by sexual and mother-to-offspring transmission. The predominance of clustering of unrelated HTLV-I-seropositive individuals in locations with high mosquito infestation raised the possibility of sporadic transmission of HTLV-I by hematophagous insects.
Assuntos
Infecções por HTLV-I/epidemiologia , Adolescente , Adulto , Aedes , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antivirais/análise , Demografia , Dengue/epidemiologia , Exposição Ambiental , Feminino , Infecções por HTLV-I/transmissão , Humanos , Insetos Vetores , Masculino , Pessoa de Meia-Idade , Índias Ocidentais/epidemiologiaRESUMO
A community survey of human T cell lymphotropic virus type I (HTLV-I) in Montserrat, West Indies, identified 22 instances in which 2 HTLV-I-seropositive adults lived within 60 m of each other (close pairs), compared with 7.8 expected (P<.001). Five of these close pairs were mother offspring or husband-wife. The remaining 17 pairs were of unrelated members in separate households. The percentages of male-female (41 percent), female-female (41 percent), and male-male (18 percent) types in these 17 pairs were similar to those among the 1377 similarly defined pairs in which neither or only 1 member was seropositive, affording no support for extramarital heterosexual activity as an explanation for the clustering observed. Thus, the demography of HTLV-I was not accounted for completely by sexual and mother-to-offspring tranmission. The predominace of clustering of unrelated HTLV-I-seropositive individuals in locations with high mosquito infestation raised the possibility of sporadic transmission of HTLV-I by hematophagous insects (AU)
Assuntos
21003 , Humanos , Feminino , Masculino , Idoso , Adulto , Idoso de 80 Anos ou mais , Infecções por HTLV-I/epidemiologia , Aedes , Anticorpos Antivirais/análise , Demografia , Dengue/epidemiologia , Exposição Ambiental , Infecções por HTLV-I/transmissão , Índias Ocidentais/epidemiologia , Insetos VetoresRESUMO
Over 80 percent of the adult population of three villages in Montserrat donated blood samples for screening for HTLV-I and dengue antibodies. Twenty-five (7.2 percent) of the 349 samples tested were positive for HTLV-I antibodies and 17 of them live in 4 clusters of neighbouring households which was statistically significant. This clustering was not primarily due to viral or mother-to-child transmission but was the result of related and unrelated seropositive individuals living near to each other far more frequently than by chance alone. Two hundred and two (61 percent) of 331 samples tested were seropositive for dengue. Dengue seropositivity prevalence rates increased markedly with age and showed a strong difference in prevalence by altitude. This high prevalence of dengue seropositivity was surprising since no epidemics of dengue fever were reported in Montserrat. There is no evidence to support the hypothesis that the same insect vectors have a role in both dengue and HTLV-I transmission. However, the clustering observed, the inverse relation between HTLV-I sero prevalence and altitude and the failure of HTLV-I to establish itself in temperate climates, justify the need for further studies (AU)
Assuntos
Humanos , Adulto , Vírus Linfotrópico T Tipo 1 Humano , Dengue/epidemiologia , Índias Ocidentais , Anticorpos Anti-HTLV-I , Insetos Vetores , AltitudeRESUMO
Four monoclonal antibodies produced against Plasmodium falciparum recognize an antigen in merozoites that is localized in rhoptries, as judged by a punctate, double dot fluorescence pattern. All four antibodies bound to the same affinity purified antigen in a two site immunoradiometric assay. Immunoprecipitation of antigen by monoclonal antibody followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis yielded protein bands of 80, 66 and 42 kDa. Western blotting gave bands of 80 and 66 kDa only with three of the antibodies: the fourth did not blot. Based on protease inhibitor data the 66 kDa band is considered to be a cleavage product of the 80 kDa band, but the 42 kDa band does not appear to derive from the latter and may be a coprecipitation product. This group of antigens labels with both [35S]methionine and [3H]histidine. Two of the monoclonal antibodies inhibited merozoite invasion of erythrocytes. One of these inhibitors recognizes a variable epitope, whereas the second recognizes a highly conserved epitope present in all 106 primary isolates of P. falciparum tested from Brazil, Thailand and Papua New Guinea.