Prevalence of human immunodeficiency virus, hepatitis C virus, hepatitis B virus and syphilis among individuals attending anonymous testing for HIV in Luanda, Angola

Abstract

Background. Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis remain major infections around the world. In Angola, about 166 000 individuals are living with HIV, representing a prevalence of 1.98% in adults between 15 and 49 years of age. In a 2003 study in Luanda, 4.5% of pregnant women had antibodies to HIV and 8.1% to HBV, and 5.4% were infected with Treponema pallidum.
Objectives. The aim of this study was to determine the prevalence of HIV-1 and 2, HBV, HCV and T. pallidum serological markers, and hence the prevalence of these infections, in individuals attending a sexually transmitted disease clinic in Luanda, Angola, and the burden of these infections in the Angolan population.
Methods. Individuals attending a centre for anonymous testing for HIV were randomly included in the study. All samples were tested for HBV surface antigen (HBsAg), anti-HCV and anti-HIV-1 and 2 antibodies and antibodies to T. pallidum.

Results. A total of 431 individuals (262 women and 169 men) were studied, of whom 10.0% (43/431) were seropositive for T. pallidum
and 4.6% had active syphilis; 8.8% (38/431) were seropositive for HIV-1 and/or HIV-2 (of these, 78.9% were HIV-1-positive, 2.6% HIV-2-positive and 18.4% co-infected); 9.3% (40/431) were HBsAg-positive, while 8.1% (35/431) had antibodies to HCV. Of 102 patients with positive results, 26 (25.5%, or 6.0% of the total of 431 patients) were positive for more than one of the organisms studied. Rates of co-infection were as follows: 2.3% (10/431) for HIV/HBV, 0.9% (4/431) for HIV/HCV, and 0.9% (4/431) for HCV/HBV. Three individuals with active syphilis had viral co-infection, hepatitis B in 1 case and HIV in 2. Five individuals (1.2% of the total) were seropositive for 3 infections: HIV, hepatitis B and hepatitis C in 3 cases and HIV, hepatitis C and syphilis in 2.
Conclusions. A high prevalence of co-infection with the infections studied was found in this population, including HIV infection (8.8%). These results demonstrate the need to improve screening for and treatment of HIV and other sexually transmitted infections in Angola, and for educational campaigns to prevent not only the morbidity and mortality associated with these diseases, but also their further transmission.