RESUMEN
Duffy blood group genotype was studied in 95 unrelated subjects from four African-Brazilian communities of the Amazon region: Trombetas, Pitimandeua, Curiaú, and Mazagão Velho. Genotyping was performed using an allele-specific primer polymerase chain reaction technique for determining the three major alleles at FY blood group, and as expected, FY*O allele was the most common one, with frequencies ranging from 56.4% in Mazagão Velho to 72.2% in Pitimandeua, whereas the FY*O/FY*O genotype was found with frequencies between 32.3% in Mazagão Velho and 58.8% in Curiaú. Genotype and allele distributions in the four Amazonian communities are consistent with a predominantly African origin with some degree of local differentiation and admixture with people of Caucasian ancestry and/or Amerindians. These results reveal that the impact of the FY*O/FY*O genotype on the transmission and endemicity of the vivax malaria deserves to be investigated in full detail in an attempt to identify the contribution of host biological factors and explain the non-homogeneous prevalence of malaria in the region expressed by its different levels of exposure
Asunto(s)
Humanos , Población Negra , Sistema del Grupo Sanguíneo Duffy/genética , Frecuencia de los Genes/genética , Brasil , Genotipo , Malaria Vivax/genética , Reacción en Cadena de la PolimerasaRESUMEN
Antibodies to human T-cell lymphotropic virus-1 and 2 (HTLV-1 and 2) were tested in 259 inhabitants (98 males and 161 females) of four villages of the Marajó Island (Pará, Brazil) using enzyme immunoassays (ELISA and Western blot). Types and subtypes of HTLV were determined by nested polymerase chain reaction (PCR) targeting the pX, env and 5 LTR regions. HTLV-1 infection was detected in Santana do Arari (2.06 percent) and Ponta de Pedras (1 percent). HTLV-2 was detected only in Santana do Arari (1.06 percent). Sequencing of the 5 LTR region of HTLV-1 and the phylogenetic analysis identified the virus as a member of the Cosmopolitan Group, subgroup Transcontinental. Santana do Arari is an Afro-Brazilian community and the current results represent the first report of HTLV-1 infection in a mocambo located in the Brazilian Amazon region.
Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Adolescente , Adulto , Persona de Mediana Edad , Anciano de 80 o más Años , Población Negra , Anticuerpos Anti-HTLV-I/sangre , Infecciones por HTLV-I/diagnóstico , Infecciones por HTLV-II/diagnóstico , Virus Linfotrópico T Tipo 1 Humano/inmunología , /inmunología , Western Blotting , Brasil/etnología , Ensayo de Inmunoadsorción Enzimática , Infecciones por HTLV-I/etnología , Infecciones por HTLV-II/etnología , Virus Linfotrópico T Tipo 1 Humano/genética , /genética , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADNRESUMEN
The Amazon region of Brazil is an area of great interest because of the large distribution of hepatitis B virus in specific Western areas. Seven urban communities and 24 Indian groups were visited in a total of 4,244 persons. Each individual was interviewed in order to obtain demographic and familial information. Whole blood was collected for serology and genetic determinations. Eleven genetic markers and three HBV markers were tested. Among the most relevant results it was possible to show that (i) there was a large variation of previous exposure to HBV in both urban and non-urban groups ranging from 0 to 59.2 por cento; (ii) there was a different pattern of epidemiological distribution of HBV that was present even among a same linguistic Indian group, with mixed patterns of correlation between HBsAg and anti-HBs and (iii) the prevalence of HBV markers (HBsAg and anti-HBs) were significantly higher (P=0.0001) among the Indian population (18.8 por cento) than the urban groups (12.5 por cento). Its possible that the host genetic background could influence and modulate the replication of the virus in order to generate HB carrier state.