Natural history of viral markers in children infected with human T lymphotropic virus type I in Jamaica.

PURPOSE: We conducted a longitudinal analysis of human T lymphotropic virus type I (HTLV-I) viral markers in 28 Jamaican mothers and their children, who were monitored for a median of 6.2 years after the birth of the children. METHODS: The HTLV-I provirus DNA load was measured using the Taqman system (PE Applied Biosystems). The HTLV-I antibody titer was determined using the Vironstika HTLV-I/II Microelisa System (Organon Teknika). The HTLV-I Tax-specific antibody titers were measured using an enzyme-linked immunosorbent assay. Generalized estimating equations were used to describe the associations of exposure variables with sequentially measured levels of HTLV-I viral markers in children. RESULTS: The HTLV-I antibody titer increased significantly up to 1 year after infection, reaching equilibrium at a median titer of 1 : 7,786. The prevalence of Tax-specific antibody reached 80% at 2 years after infection. The provirus load increased up to 2 years after infection, reaching equilibrium at a median of 6,695 copies/100,000 peripheral blood mononuclear cells. The increase in the provirus load was significant only among children with eczema, but not among children without eczema. CONCLUSIONS: The provirus loads in children increased for an additional year after their antibody titers had stabilized, possibly as a result of the expansion of HTLV-I-infected clones. This effect was significant only for children with eczema. Among HTLV-I-infected children, eczema may be a cutaneous marker of the risk of HTLV-I-associated diseases developing in adulthood.

Persistent paradox of natural history of human T lymphotropic virus type I: parallel analyses of Japanese and Jamaican carriers.

Human T lymphotropic virus type I (HTLV-I) is endemic in southern Japan and the Caribbean, but the incidence of HTLV-I-associated diseases varies across geographic areas. We compared markers of disease pathogenesis among 51 age- and sex-matched HTLV-I carrier pairs from Japan and Jamaica. The mean antibody titer (P=.03) and detection of anti-Tax antibody (P=.002) were higher in Jamaican subjects than in Japanese subjects, but provirus load was similar between the 2 groups (P=.26). The correlation between antibody titer and provirus load was more prominent among Jamaican subjects than among Japanese subjects (P=.06). These findings underscore the differences in host immune response to HTLV-I infection in 2 populations.

Prediagnostic human T lymphotropic virus type I provirus loads were highest in Jamaican children who developed seborrheic dermatitis and severe anemia.

In a recent clinical analysis of 308 Jamaican children, human T lymphotropic virus type I (HTLV-I) infection was found to be associated with significantly higher incidence rates of seborrheic dermatitis, eczema, and persistent hyperreflexia of the lower limbs and with nonsignificantly increased rates of severe anemia and abnormal lymphocytes. Results of examination of HTLV-I viral markers in the 28 HTLV-I-infected children provided virologic support for the epidemiologic associations of HTLV-I with seborrheic dermatitis and severe anemia in childhood.

Seroincidence of human T-lymphotropic virus type I infection and characterization of seroconverters in Jamaican food handlers.

In a prospective study of food handlers in Jamaica, we estimated the age- and sex-specific seroincidence of human T-lymphotropic virus type I (HTLV-I) infection. Of 682 sexually active adults (132 males and 550 females) who were initially seronegative, 12 (1 male and 11 females) seroconverted over 8 years of follow-up. The seroincidence was 1.2 per 1,000 person-years for males and 3.2 per 1,000 person-years for females. The age-standardized incidence was 1.8 times higher for females than for males (P = 0.55). Within a median of 4 years after seroconversion, the median HTLV-I provirus load was 500 copies/105 cells, and the median antibody titer was 1:3109. Four of 12 seroconverters developed antibody to the Tax regulatory protein. HTLV-I infection in this population occurred at a rate comparable with that described for a Japanese cohort. Provirus load, titer and appearance of antibody to the Tax regulatory protein were typical of chronic carriers within a few years of seroconversion.

Virus markers associated with vertical transmission of human T lymphotropic virus type 1 in Jamaica.

In a prospective study involving 150 mothers and their offspring in Jamaica, we examined maternal viral factors associated with the risk of transmission of human T lymphotropic virus type 1 (HTLV-1). Overall, the incidence of HTLV-1 infection among children was 8.3 occurrences per 1000 person-months. A higher maternal provirus level (odds ratio [OR], 1.9 per quartile) and a higher HTLV-1 antibody titer (OR, 2.2 per quartile) were independently associated with transmission to children, whereas the presence of anti-Tax antibody was not. Higher maternal antibody titers also were associated with older age at infection among children who were breast-fed for