The Evaluation of Human Herpesvius 8 Infection in Tobago

HHV-8 seropositivity was associated with prevalent prostate cancer among African-Caribbean Tobago men (Odds ratio [O.R.] = 2.24; 95% confidence interval [C.I.], 1.29-3.90). To understand this association, HHV-8 seropositivity among African-Caribbean Tobago women, modes of HHV-8 sexual transmission, the natural history of HHV-8 seropositivity, and the relationship between HHV-8 and incident prostate cancer were examined. A cross-sectional study was conducted in 213 Tobago women, ages 18-65 years. Age-specific rates were compared to those previously observed in men. Logistic regression analyses were performed to determine the association between HHV-8 seropositivity and sexual behaviors among women. A 9-year prospective cohort study was conducted among 407 Tobago men at risk for incident prostate cancer, ages 40-81 years. HHV-8 seroconversion and seroreversion rates and their 95% C.I. were calculated using a Poisson distribution. A case-cohort study was conducted among 90 and 407 Tobago men, ages 40-81 years, with incident prostate cancer and at risk for incident prostate cancer, respectively. Cox proportional hazards modeling for case-cohort design was used to examine the association between baseline HHV-8 seropositivity and incident prostate cancer. All serum/plasma were tested for HHV-8 seropositivity by immunofluorescence assay. Among women, HHV-8 seroprevalence was 14.1%, with no difference with men of similar age (p-value = .741). There was a significant but minimal association between HHV-8 seropositivity and age less than and equal to 17 years at first sexual intercourse among women (O.R. = 2.51, 95% C.I. = 1.09-5.78). Among men at risk for incident prostate cancer, HHV-8 seroconversion and seroreversion rates were 0.5 (95% C.I., 0.22-0.99) and 2.52 (95% C.I., 1.09-4.96) per 100 person-years, respectively. There were inverse associations between baseline HHV-8 seropositivity and screen-detected incident prostate cancer when age and baseline prostate cancer screening results (Hazard ratio [H.R.] = 0.454, 95% C.I., 0.221 - 0.933) and age (H.R. = 0.517, 95% C.I., 0.262 - 1.020) were considered.Sexual activity may not be the predominant mode of HHV-8 transmission among women. HHV-8 is probably acquired at younger ages, less than 40 years among men. HHV-8 seropositivity may not be related to prostate cancer incidence. The public health significance of these studies is to reduce HHV-8 infection and prostate cancer in Tobago