Detection of human immunodeficiency virus antibody among homosexual men from Bombay

Abstract

Background and objectives: In India, heterosexual transmission of HIV-infection is considered to be the major mode of transmission. However, no report is available on transmission of HIV-infection among homosexually active men. The prevalence of human immunodeficiency virus-1 (HIV-1) and human immunodeficiency virus-2 (HIV-2) infections among homosexual men from Bombay is discussed.

Goal of the study: To determine the extent of presence of anti-HIV-1, anti-HIV-2 antibodies, or both anti-HIV-1 and anti-HIV-2 antibodies among homosexual men in India.

Study design: Sixty-three blood samples were collected from two STD clinics of Bombay over a 6-month period from men with a history of homosexual behavior who were asymptomatic for HIV-infection. The mean age of the subjects was 31.6 years. For serological detection anti-HIV-1 antibody ELISA was used as the primary screening test followed by Western blot to confirm the results. For distinction between anti-HIV-1 and anti-HIV-2 antibody, line immunoassay was used. The sexually transmitted diseases (STDs) were diagnosed clinically, although Venereal Disease Research Laboratory (VDRL) tests were carried out as a routine test for screening STDs. For detection of gonorrhea, Gram stains of urethral smear were done routinely.

Results: From the 63 blood samples tested, 10 samples were reactive by ELISA for HIV-1 infection, and three samples were borderline reactive. These three samples were found to be reactive for anti-HIV-2 by the line immunoassay. The above 10 samples were also positive by Western blot for anti-HIV-1 antibody. Two blood samples were positive for both anti-HIV-1 and anti-HIV-2 antibodies. Using clinical diagnosis as the criteria, the different types of STD among the 63 subjects were as follows: condylomata (22), herpes (20), gonorrhea (15), candidiasis (3), and syphilis (3). However with VDRL, seven subjects were found to be reactive. Gram stains indicated gonorrhea in all the 15 subjects.

Conclusions: This study reports for the first time the homosexual transmission of both HIV-1 and HIV-2 infections in India, although heterosexual transmission still is the major mode of transmission of the infection. The associated incidence of STDs among these men and that a few of these subjects were bisexual make them at high risk for transmission of HIV infection.

PIP: In India, staff at the National Institute of Virology used the anti-HIV-1 antibody ELISA to conduct primary screening of blood samples from 63 men, 19-46 years old, who engaged in oral and anal intercourse with men (56 homosexuals and 7 bisexuals), who were attending 2 sexually transmitted disease (STD) clinics in Bombay over a 6-month period. Researchers wanted to determine the prevalence of HIV-1, HIV-2, or dual HIV-1 and HIV-2 infections among sexually active men who had sex with men. The Western blot test confirmed ELISA results. Staff used line immunoassay to distinguish between HIV-1 and HIV-2 infection. Ten samples reacted to ELISA for HIV-1 infection and were confirmed to be HIV-1 positive by Western blot. The 3 samples that were borderline reactive by ELISA were reactive to HIV-2 by line immunoassay. Both HIV-1 and HIV-2 infection were identified in 2 samples. Clinically-diagnosed STDs among the 63 men were: condylomata acuminata (22), herpes (20), gonorrhea (15 confirmed by gram stains of urethral smear), candidiasis (3), and syphilis (3). HIV infection was particularly common in men with condylomata infection (12 or 92.3% of all HIV-positive cases). These findings show that, even though heterosexual transmission of HIV is the most common transmission mode in India, homosexual transmission is rather frequent in a large city.