Horizontal versus vertical transmission of human immunodeficiency virus type 1 (HIV-1). Experience from southwestern Saudi Arabia.

ABSTRACT

Twenty-five confirmed cases of human immunodeficiency virus type 1 (HIV-1) infection due to blood transfusion have been documented at King Fahad Hospital (KFH) in Al-Baha, southwestern Saudi Arabia since 1986, but complete follow-up was only possible on 19 of these cases and their contacts. Seventeen cases were diagnosed as having acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) after admission to the hospital due to the deterioration of their health status. Two cases were found to be anti-HIV-1 positive on routine screening for blood donation. This cluster of HIV-1 infected patients through blood transfusion allowed us to study the efficiency of sexual transmission of HIV-1 infection between spouses, the rate of perinatal transmission of HIV-1 infection, and to see whether intrafamilial transmission is a possible route of spread of the virus. Firstly, the present results confirm our earlier observation that transmission of HIV-1 infection was more efficient from the infected husband to his wife(s) in contrast to the inefficient transmission of the infection from the infected wife to her husband. Secondly, by the age of 16 months, all nine newborns to HIV-1 infected mothers became HIV-1 infected. This highlights the importance of medical advice to those mothers regarding conception and/or breast-feeding, particularly as breast-feeding up to 2 years is not an uncommon practice among Saudi women. Finally, none of the household contacts of the 19 cases was infected until now, indicating that intrafamilial spread of HIV-1 did not occur among the population studied.

ABSTRACT

PIP In June 1986, screening for anti-HIV using enzyme immunoassay (EIA) started on all donated blood at King Fahad Hospital (KFH) in Al-Baha, southwestern Saudi Arabia. In December 1988, an HIV clinic was established at KFH and 25 adult cases were identified as HIV-1 positive who had a history of blood transfusion between 1982 and 1986. Follow-up was only possible in 19 of these cases and their contacts. When a person was found to be anti-HIV-1 positive, all family members were called for HIV testing. Contacts of HIV-1 positive patients were followed-up on a monthly basis, and those who were anti-HIV-1 positive were started on zidovudine therapy. Serum testing for anti-HIV and for HIV-Ag was done by enzyme-linked immunosorbent assays (ELISA) and confirmed by Western blot. The majority of cases were diagnosed as having AIDS (10/19) or ARC (5/19) after admission to the hospital. All AIDS cases died within 2 months after diagnosis, while those with ARC died within 1-2 years after the diagnosis. Two of the cases (cases 1 and 2) were found anti-HIV-1 positive on routine screening for blood donation, and 3 cases (cases 11, 17 and 18) were detected when their respective children were admitted and diagnosed as having AIDS. In case 6, as in case 7, the husband infected both wives. All children born before the mother had the blood transfusion and hence the infection were anti-HIV-1 negative and were still negative after 3-7 years of follow-up. In contrast, all 9 children born to HIV-1-positive mothers became infected. Although some of the infants had no evidence of infection up to 9 months of age or more, all became anti-HIV-1 positive and HIV-Ag positive by 16 months of age. These children had no blood transfusion during the 16 months period.