Antibodies to HTLV-III in Haitian immigrants in French Guiana [letter]

A 3rd subtype of human T-cell lymphotropic viruses (HTLV-III) has recently been isolated from patients with the acquired immunodeficiency syndrome (AIDS). All American patients with AIDS and 84% of those with lymphadenopathy had antibodies to HTLV-III implicating this new member of human retroviruses together with the lymphadenopathy-associated virus as a causative agent of AIDS. Besides the AIDS epidemic affecting homosexuals and drug addicts cases of AIDS have been described in persons from Central Africa and from Haiti without a known history of homosexuality or drug addiction. Thus HTLV-III may be endemic in some groups or geographical areas. To evaulate such a possibility serum samples collected in 1983 by the Pasteur Institute of French Guiana from Haitians who had settled in Cayenne or its outskirts during the previous 10 years were studied. Approximately 10000 Haitians are living in this area which has a total of 75000 inhabitants. From a series of 600 serum samples already tested for HTLV-I 211 were selected: 15 from persons under 20 years of age 60 from those between 20 and 29 years 60 from those between 30 and 39 years 60 from those between 40 and 49 years and 16 from those over 50 years; males and females were equally represented. At the time of serum collection all persons were free of any obvious infectious disease. Use of the enzyme-linked immunosorbent assay with semipurified HTLV-III virions showed that 15 of 211 serum samples (7.1% 7 from males and 8 from females) had HTLV-III antibodies. The 15 samples were further analyzed by the more specific Western blot method: 6 of the 15 (3 from males and 3 from females) reacted with the p41 protein (molecular weight 41000) the putative envelope viral protein. These 6 persons with HTLV-III antibody had emigrated to French Guiana between 2 and 9 years previously and they ranged in age from 26 to 38 years. This represents the same age group as that of Haitians in the United States or in Haiti who have been diagnosed as having AIDS. A parallel search for HTLV-I antibodies in the same serum samples using the enzyme-linked immunosorbent assay showed that 2.7% of males and 4.9% of females had antibodies to this virus. None of the 6 HTLV-II positive samples had HTLV-I antibodies. This finding provides confirmation that HTLV-I and HTLV-III do not share antigenic components and suggests that they may have different epidemiologic patterns. Evidence in support of the latter hypothesis includes the lack of HTLV-III antibodies in other normal populations in which HTLV-I is endemic such as Surinam emigrants to the Netherlands and Okinawans. This survey among Haitains indicates that HTLV-III is endemic in certain populations. How the prevalence of HTLV-III correlates with the outbreak of AIDS in these populations remains to be determined. (full text)