Health effects of human T-lymphotropic virus type I (HTLV-I) in a Jamaican cohort

BACKGROUND: Other than adult T-cell leukaemia (ATL) and HTLV-I associated myelopathy (HAM), the health effects of infection with human T-lymphotropic virus type I (HTLV-I) are not well defined. METHOD: A cohort of 201 confirmed HTLV-I seropositive Jamaican food service workers and 225 seronegative controls of similar age and sex from the same population was examined. A health questionnaire, physical examination, and laboratory tests were performed at enrollment into the cohort in 1987-1988. RESULTS: One of 201 HTLV-I seropositives, but no controls were diagnosed with HAM, for a prevalence of 0.5 percent (95 percent confidence interval) (CI) 0.01-2.7 percent); no cases of ATL were diagnosed. While there was no difference in current symptoms, the HTLV-I seropositive group was more likely to report a past medical history of hepatitis or jaundice (OR = 3.49, 95 percent CI: 0.93-13.08), malaria (OR = 2.13, 95 percent CI: 0.96-4.73), and dengue fever (OR = 1.37, 95 percent CI 0.82-2.29); however, these differences were of borderline statistical significance. Low income HTLV-I seropositive women had lower body weight (P , 0.01) and body mass index (P < 0.009) than their seronegative counterparts; similar differences were seen in the smaller male group. A trend toward higher prevalence of severe anaemia (haemoglobin < 10 g/dl) (12.6 percent verus 7.7 percent, P < 0.105) and a significantly lower prevalence of eosinophilia (1.0 percent verus 6.3 percent, P < 0.004) was seen among HTLV-I seropositives are asymptomatic, HAM may be diagnosed in approximately 0.5 percent of carriers. Chronic HTLV-I infection may also subtle effects on body mass and haematological parameters.(AU)

A case-control study of risk factors for seropositivity to human T-lymphotropic virus type I (HTLV-I) in Jamaica

BACKGROUND: We investigated behavioural and environmental risk factors for seropositivity to human T-lymphotropic virus type I (HTLV-I). METHODS: A nested case-control study of 201 HTLV-I seropositive subjects and 225 age and sex matched seronegative controls was performed using questionaire data from the enrollment visit of a cohort study in 1987-1988. HTLV-I serostatus was confirmed using enzyme-linked imunosorbent assay (ELISA) and Western blot. RESULTS: Among women, the number of lifetime sexual partners (P < 0.05, chi 2 trend) and the number of different men fathering a child by the woman (P < 0.06, chi 2 trend) were associated with HTLV-I seropositivity. Use by the female subject of an intrauterine device (IUD) was associated with an increased risk of seropositivity (odds ratio (OR) = 2.67, 95 percent confidence interval (CI): 1.13-6.23); condom use was rare in this population. Among male subjects, a larger number of lifetime sexual partners was also associated with HTLV-I seropositivity (P < 0.05, chi 2 trend). No association was found between HTLV-I seropositivity and educational attainment, income, or occupation. Having been breastfed as a child or receipt of a blood transfusion had elevated but imprecise OR due to very high and low prevalence of the risk factors, respectively. Several variables relating to insect or animal exposure showed no association with HTLV-I seropositivity. CONCLUSIONS: These data confirm that heterosexual intercourse is a major route of HTLV-I transmission, but do not support suggestions of insect or environmental vectors.(AU)

Risk factors and cofactors for human T-cell lymphotropic virus type 1 (HTLV-1) - associated myelopathy/tropical spastic paraparesis (HAM/TSP) in Jamaica

Human T-cell lymphotrophic virus type 1 (HTLV-1) has been etiologically associated with a neurologic syndrome called HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as well as with adult T-cell leukemia/lymphoma. The authors sought to quantify the risk in Jamaica of HAM/TSP associated with HTLV-1 infection and cofactors associated with this disease among infected individuals. Between 1988 and 1989, prevalent and incident HAM/TSP patients and controls with other neurologic diseases were enrolled in a retrospective study. A second control group was composed of HTLV-1-seropositive, asymptomatic carriers in Jamaica, ascertained in a separate study conducted in 1988. Although HTLV-1 seropositivity was not a component of the case definition for HAM/TSP, all 43 HAM/TSP patients were HTLV-1 seropsitive compared with two (4.0 percent) of the controls with other neurologic diseases. Given HTLV-1 seropositivity, one cofactor associated with the risk of HAM/TSP was young age at initial heterosexual intercourse (odds ratio = 4.00, 95 percent confidence interval 1.29-12.46 for individuals aged ó15; odds ratio = 4.26, 95 percent confidence interval 1.41-12.90 for individuals aged 16-17 years at initial intercourse). Among individuals who reported this early age at initial sexual intercourse, an increased risk of HAM/TSP was associated with having reported more than five lifetime sexual partners (odds ratio = 2.88, 95 percent confidence interval 0.90-8.70). Neither an early age at initial sexual intercourse nor the number of lifetime sexual partners was a risk factor for adult T-cell leukemia/lymphoma. These data support the hypothesis that HAM/TSP is associated with sexually acquired HTLV-1 infection, whereas adult T-cell leukemia/lymphoma is not. (AU)

Sibling adult T-cell leukemia/lymphoma and clustering of human T-Cell lymphotropic virus type I infection in a Jamaican family

BACKGROUND:- Human T-cell lymphotropic virus type I (HTLV-I) infection is endemic in Jamaica, with an estimated crude seroprevalence of 5percent. Adult T-cell lymphoma/Leukemia (ATL), a disease caused by HTLV-I, has an incidence of 1-2/100,000 in the Jamiacan population. Familial ATL has not previously been reported from Jamaica. METHODS:- Hospital records and histologic specimens of the two cases were reviewed. HTLV-I infection was confirmed by antibody testing and by polymerase chain reaction on paraffin-embedded tissue,where serum was unavailable. Family members identified by the patient's parents. After giving informed consent, family members were asked to complete an interviewer-administered questionnaire and to agree to phlebotomy. RESULTS:- ATL developed 10 years apart in two siblings from a Jamaican family at age 16 and 24 years. A study of 19 members of their extended family, including both parents, 2 grandparents, and 3 siblings, revealed an overall HTLV-I seroprevalence of 17 percent. This compared with 75 percent among parents and sibling living in the same household as the patients (AU)

Sibling ATL and familial clustering of HTLV-1 infection in a Jamaican family - abstract

Two siblings from a Jamaican family developed adult T-cell leukaemia/lymphoma (ATL) in 1979 and 1989 respectively. The latter was HTLV-1 seropositive. Our aims were, to study the seroprevalence of HTLV-1 in the household of the index cases and among relatives living in the same parish, to identify any relative with HTLV-1 associated diseases (ATL and HAM/TSP) and the presence of risk factors for acquiring HTLV-1 infection. Eighteen (18) family members including two parents, 2 grandmothers, 3 siblings, 7 uncles and 4 aunts of the index cases were studied. The medical records of the first sibling were reviewed. Both parents and 2 of the siblings' studies live in the same house as the index cases. Results of the enzyme-linked immunoabsorbent assay (ELISA) testing are shown on the pedigree. Four members of the index cases' household were antibody (Ab) positive, whereas no family member outside the household was Ab positive. The sero status of the first case of ATL is unknown as she died in 1979. HTLV-1 Ab positive and Ab negative subjects had a similar mean age 34 and 38 years respectively. Neither group reported sexual contact with prostitutes or male homosexual activity. Among 18 healthy family members, no significant lymphadenopathy or neurological abnormality was detected. The high rate of HTLV-1 seropositivity among the family in the affected household (3/4 - 75) and the family overall (3/18 = 17 per cent) of the index cases were significantly greater than the general population (5 per cent). These findings support the theory that transmission is likely to take place horizontally, by sexual contact (husband to wife) and vertically (mother to child). The persistent Ab seronegativity of the 12 year-old child in the affected household is noteworthy, and the presence of other markers of HTLV-1 infection is being investigated (AU)