title: HTLV-1 infection in a population-based cohort of older persons in Guinea-Bissau, West Africa: risk factors and impact on survival.
abstract: In 1989, a population-based cohort of persons aged > or = 50 years was established in an urban area of Guinea-Bissau, West Africa. Overall, 346 persons were interviewed in detail about risk behaviors and had capillary blood drawn. Among women, 12.4% were HTLV-1 seropositive, compared with 4.6% in men. No HTLV-2 was found. Seropositivity varied considerably according to place of birth and ethnic group. In women, but not in men, HTLV-1 seropositivity was strongly associated with early sexual debut (10-14 yrs, 33.3%; 15-17 yrs, 26.0%; 18-20 yrs, 6.5%; 21+ yrs, 0%; ptrend = 0.001), lifetime number of male partners (ptrend = 0.006), and the male partner's number of co-wives (ptrend = 0.006). There was also a 3.1-fold increased risk of being HTLV-1 seropositive if the woman was also HIV-2 seropositive. In a multivariate-risk-factor analysis, the strongest association with HTLV-1 was a history of having been bitten by a monkey (n = 11; combined OR adjusted = 10.1; 95% CI 2.3-44.4). Ornamental scarification was associated with a 3.3-fold increased risk. Ethnic affiliation also significantly influenced the risk of being HTLV-1 seropositive. Follow-up performed in January 1996 revealed no difference in survival between HTLV-1-seropositive and -seronegative individuals over 6 years (rate ratio = 1.4, 95% CI 0.7-2.8). In conclusion, this population, which has very high HIV-2 seroprevalence, is also highly endemic for HTLV-1. Whereas sexual behaviors are clearly important for HTLV-1 spread in women, non-sexual risk factors were the only ones of potential importance in men. HTLV-1 had no impact on survival in this older population.
authors.affiliation: Projecto de Saúde de Bandim, Bissau, Guinea-Bissau. mme@ssi.dk
authors.forename: M
authors.initials: M
authors.lastname: Melbye
authors.forename: A G
authors.initials: AG
authors.lastname: Poulsen
authors.forename: D
authors.initials: D
authors.lastname: Gallo
authors.forename: J B
authors.initials: JB
authors.lastname: Pedersen
authors.forename: R J
authors.initials: RJ
authors.lastname: Biggar
authors.forename: O
authors.initials: O
authors.lastname: Larsen
authors.forename: F
authors.initials: F
authors.lastname: Dias
authors.forename: P
authors.initials: P
authors.lastname: Aaby
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006169:Guinea-Bissau / Q000453:epidemiology; D015658:HIV Infections / Q000150:complications; D015498:HIV-2 / Q000276:immunology; D015490:HTLV-I Infections / Q000150:complications / Q000453:epidemiology* / Q000276:immunology / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D015996:Survival Rate