Prevention of HIV transmission by blood transfusion in the developing world: achievements and continuing challenges.

In industrialized countries, the use of sensitive HIV screening tests, donor deferral, and more conservative use of blood have resulted in a dramatic decrease in the transmission of HIV infection by blood transfusion. The risk of HIV transmission in the USA by blood screened negative for HIV antibody was recently estimated at one in 440,000-660,000 donations. Despite this low risk, continued public concern has compelled blood collection agencies and policy makers to continue to search for more sensitive HIV screening tests. Genome amplification techniques are receiving increased attention and are being piloted in Germany. HIV-1 p24 antigen testing was implemented in the USA in March 1996. In the first 18 months of p24 antigen testing, an estimated 18 million blood donations were tested at a cost of US$90 million to detect three antigen-positive, antibody-negative donations. However, in many developing countries where severe anemia is widespread and the prevalence of HIV infection among blood donors is orders of magnitude greater than in industrialized countries, the blood supply is either incompletely screened or not screened at all for HIV antibody. Although the contribution of transfusion-transmitted infection to the HIV epidemic has not been accurately assessed, an estimated 5-10% of HIV infections in developing countries are due to blood transfusion. In a study conducted 1 year after implementation of HIV blood screening in the largest hospital in the capital city of the Democratic Republic of the Congo, an estimated 25% of pediatric HIV infections, and 40% of infections among children over 1 years of age, were due to transfusion. Lack of commitment by national governments and international aid organizations to this fundamental element of HIV prevention has resulted in a shortage of basic equipment, supplies, and trained personnel for blood screening. Moreover, provision of test kits alone cannot prevent HIV transmission by transfusion in resource-poor areas. More comprehensive programs are needed to improve the recruitment and retention of safe donors, essential laboratory services for blood banking and screening, technical training and supervision, appropriate use of transfusions, and the prevention of severe anemia. This article summarizes the steps being taken by developing countries to prevent HIV transmission by blood transfusion, lessons learned, and the work that still lies ahead.