HIV Prevention Knowledge Base
Biomedical Interventions: Blood Safety and Availability
I. Definition of the Prevention Area
Blood transfusion is an essential part of modern medical care. Inadequate and unsafe blood supply causes avoidable deaths and transmits infectious diseases, including HIV, hepatitis B and C, and syphilis. Preventing transfusion of unsafe blood through improved screening of donors and testing processes, and increasing participation of voluntary, non-remunerated blood donors (VNRD) can significantly reduce the spread of HIV. A safe blood supply also protects the health of people living with HIV by ensuring they do not receive blood transfusions contaminated with such blood-borne infections as hepatitis B or C.
II. Epidemiological Justification for the Prevention Area
Transfusion of blood infected with HIV is one of the most effective modes of transmission of the virus. The risk of acquiring HIV infection following transfusion with HIV-positive blood has been estimated to be as high as 70 to 91 percent. Implementing a national testing and donor selection algorithm that establishes the tests to be used significantly reduces the potential of transmitting infectious diseases. In a 2009 study of Kenya’s screening algorithm, even highly rigorous nucleic acid testing (NAT) failed to outperform the national algorithm in detecting units of blood infected with HIV.
Approximately 80 percent of the world’s supply of safe blood goes to 20 percent of the population, mostly in developed countries. There is a chronic shortage of safe blood in sub-Saharan Africa where, in some areas, hemorrhage leading to blood loss accounts for up to 44 percent of maternal deaths and approximately half of transfused blood goes to children under five years of age with anemia due to malaria or malnutrition. Africa has the lowest blood donation rate per capita in the world, so often family members are asked to provide blood for the person in need of transfusion. These “replacement donors” are at greater risk for transmissible diseases than are VNRD, particularly repeat donors. In addition, blood shortages may lead to release of blood for transfusion before testing is completed, further adding to the potential for disease transmission. These problems are exacerbated in regions with high endemic rates of transmissible diseases. Therefore, it is important to recruit potential donors who are least likely to harbor transfusion-transmissible infectious agents.
The World Health Organization (WHO) and the Joint U.N. Programme on HIV/AIDS (UNAIDS) recommend VNRD as the foundation of a safe blood supply. Because VNRD donate motivated by altruism rather than by financial or institutional pressure, they are more likely to meet the medical selection criteria for safe donors, to disclose any known possibility of risk exposure, and to donate blood regularly and at properly spaced intervals. However, many countries are faced with misconceptions and fear of testing, which results in a limited number of VNRD. Countries are challenged to find creative recruitment methods to combat misconceptions about blood donation and to motivate the public to donate. Many countries have targeted youth donors under the age of 25 because youth have the lowest HIV prevalence, and blood donor mobilization activities provide opportunities to promote healthier lifestyle choices that mitigate risk over time. Some countries have created social and sporting clubs for blood donors to improve retention and create an identity and pride regarding blood donation.
III. Core Programmatic Components
The primary objective of international blood safety programs such as that of WHO is reducing transmission of infectious diseases through blood transfusion and collecting an adequate supply of blood to meet the needs of the country. This may include the following:
- Establishing supportive policies and legal frameworks for the national blood program
- Strengthening the infrastructure of the national blood transfusion service
- Increasing blood collections from VNRD
- Establishing a comprehensive quality assurance system for the blood program, covering the entire transfusion process from donor recruitment, blood collection, production of blood components, testing, storage, transport, and maintenance of the cold chain, to transfusion to the patient
- Improving the capacity of human resources through a structured training and education program
- Improving data management (patient and donor) monitoring and evaluation of all blood transfusion activities.
A key aspect of improving blood safety is testing for transmissible diseases. However, up to 13 million units, or about 40 percent of the global blood supply, are not screened for all relevant transfusion-transmissible infections. There are several reasons for this, including 1) erratic stream of blood screening supplies; 2) erratic power supply; 3) lack of trained personnel; 4) use of outdated laboratory supplies; 5) poor, out-of-date testing methods that cannot ensure safety (e.g., that do not detect recent HIV infection); 6) cost of reagents; and 7) failure to complete testing when physicians request “fresh blood” to be transfused immediately after collection from the donor, which may not allow adequate time to complete the testing process.
IV. Current Status of Implementation Experience
In a 2007 WHO survey of 148 countries, 41 reported that they were not able to test all donated blood for HIV, hepatitis B, hepatitis C, and syphilis. WHO estimates that the lack of effective screening continues to result in up to 16 million new infections with hepatitis B, 5 million new infections with hepatitis C, and 160,000 cases of HIV infection every year. Effective blood safety interventions could reduce the transmission of HIV and other infections. Blood safety initiatives could also protect investments in prevention of mother-to-child transmission of HIV (PMTCT) programming by optimizing chances that PMTCT clients do not die during childbirth because of lack of blood.
Broad uptake of HIV testing and counseling holds promise for increasing the proportion of potential donors who know their HIV status, making it an important complementary component of PEPFAR’s prevention programming. In addition, blood donor recruitment campaigns present an opportunity for HIV prevention messaging.
Over the past five years, several developing countries have made significant improvements to their national blood programs, including renovation of facilities, increased blood collection, staff training, and implementation of monitoring and evaluation systems. However, additional work is needed to ensure that all blood is screened for infectious diseases, that blood is appropriately used according to nationally established guidelines, and that an adequate supply of blood is available to meet the needs of each country. In addition, several exciting new technologies are evolving, including pathogen inactivation, which should be assessed for feasibility and cost-effectiveness in the developing world. Going forward, the foundation of a safe and adequate blood supply will be a pool of low-risk, VNRD, a stringent health history screening process, and a national testing algorithm.