HARC 005 - Prevalence of HIV-1 and HTLV-I/II Co-Infection.  The prevalence and effects of dual infection with HTLV-I/II and HIV-1 are of particular interest to Hawaii and the Pacific because of the existence of endemic infection with HTLV-I in selected ethnic groups within these Pacific communities.   Previous studies indicate that the predominant modes of transmission for HTLV-I/II resemble those of HIV-1 suggesting the increased possibility for dual infection in these population.  Furthermore, in cities in the continental United States, the seroprevalence of  HTLV, predominantly of HTLV-II, in high-risk behavior groups such as IDU is as high as 17.6%.  In Hawaii, injection drug use was reported as a

HIV-1 risk factor in 14% of AIDS cases reported up to June 30, l998 to the Hawaii Department of Health.  No systematic studies of HTLV infection have been conducted in Hawaii in high-risk behavior groups, such as in those with history of intravenous drug use.  We examined sera from 646 HIV-1-infected individuals, enrolled in the Hawaii Seropositivity and Medical Management (HSPAMM) program of the State of Hawaii, for IgG antibodies against HTLV‑I/II by enzyme immunoassay.  Screen test-positive samples were then confirmed by Western immunoblot assay.   A relatively low seroprevalence of HTLV-I/II infection was found: six of 646 (0.009%).  Most of the dually infected individuals were infected with HTLV-II and only one individual with HTLV-I infection was identified.  This extremely low seroprevalence of dual HIV-1/HTLV-I/II infection may partially be due to the overall relatively low HTLV-I/II infectivity already observed in the general population of Hawaii.  As expected, a close association of HTLV-II positivity and intravenous injection was found.  Indeed, our study confirmed that most HTLV seroreactivity among IDU is due to HTLV-II infection.  These findings parallel other studies indicating that HTLV-II infection is common among IDU throughout the United States and is more prevalent in this high-risk behavior group than any other group at risk for HIV-1 infection.  The number of dually infected individuals in this study was too limited to permit a detailed assessment of differences in clinical events or of progression of HIV-1 disease.  All six of our dually infected individuals had CD4 counts greater than 200 on their baseline HSPAMM evaluations and none had any AIDS-defining opportunistic event to date. 

Kaneshiro, B., Shikuma, C.M., Nerurkar, V.R., Richmond-Crum, S., Conrado, T., Scouza, S.,  and Yanagihara, R.:  Seroprevalence of HIV-1 and HTLVI/II co-infection in Hawaii.  Hawaii Medical Journal  (in preparation).

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