Blood: Donations, transfusions and HIV

Blood: Donations, transfusions and HIV

Blood transfusions are essential treatment for excessive blood loss and for diseases such as haemophilia. If a person receives a blood transfusion with HIV-infected blood, there is a 95 percent risk they will become infected with the virus.⁴ However the chances of becoming infected with HIV through a blood transfusion varies between countries depending on the level of safety precautions in place, and there is a notable difference between developed and developing countries. In the UK, the risk is now 1 in 5 million. ⁵

The first tests for HIV in donor blood were not implemented in countries until 1985, four years after the first case of AIDS was reported. Between 1985 and 1992, the United States, France and Romania had the highest number of AIDS diagnosis as a result of HIV infection through transfusion, with more than 8,000 people in the US believed to have acquired HIV through transfusion during this period.⁶

"HIV infection continues to be a risk associated with blood transfusions"

Haemophilia is a disease characterized by the deficiency of blood clotting factors in the blood. ⁷ This condition is treated through the frequent transfusion of blood products such as plasma, which contain platelets, and clotting factors, such as factor VIII.^{8 9} Thousands of haemophiliacs contracted HIV through receiving these life saving blood products during the late 1970s and 1980s a time when blood was pooled to extract the factor VIII and not screened or treated for HIV.^{10 11} Plasma is a blood product which can be heat treated and since heat treatment was implemented in 1985, plasma is now completely safe where this method is used.¹²

The World Health Organisation (WHO) outlines a number of recommendations which countries should follow to maintain a safe and constant blood supply. These steps prevent transfusion-transmissible infections (TTI), which include HIV-1, HIV-2, hepatitis B, hepatitis C and syphilis, passing from a blood donor to the recipient of a blood transfusion.¹³ According to the recommendations countries need:

• A nationally coordinated blood transfusion service
• Voluntary unpaid donors
• To test all donated blood
• To use blood efficiently and appropriately
• To ensure a safe transfusion practice
• To have a quality systems check throughout the blood transfusion process.

The roll-out of widespread safety measures such as donor selection and screening guidelines makes the risk of HIV transmission today virtually non-existent in developed countries.¹⁴ However, where guidelines for blood safety have not been implemented or are not followed, HIV infection continues to be a risk associated with blood transfusions.

HIV and blood donors: Who can donate?

A key aspect of ensuring a safe blood supply is the screening and counselling of donors to limit the number of people infected with HIV from donating.

Voluntary, non-remunerated blood donors are those who donate on their own accord without coercion or incentives, such as money. In some countries, such as the UK, 100 percent of donations come from voluntary, non-remunerated donors. The recommendation by WHO to only use this type of donor was first made in 1975 in the form of the World Health Assembly resolution 28.72.¹⁵ These donors are sought after because they are more likely to be donating for altruistic reasons rather than for any personal gain.¹⁶ Injecting drug users are more at risk of HIV infection and often need money to fund their drug habit. If donating blood is seen as a source of income, individuals such as IDUs are more likely to donate and therefore risk the safety of blood supplies.

When an individual needs a donation and a family member steps forward to donate blood they are referred to as a 'family/replacement' donor. However, like paid donors, this type of donor often leads to higher number of HIV-infected blood donations. In many countries paid donors and family blood donors continue to make up a large percent of blood donations.¹⁷ For example, 70 percent of donations in Pakistan are from 'family and replacement' donors with a further 10 percent of donations from paid donors.¹⁸ The risk posed by these donors is illustrated by 2008 figures which show that 6.8 percent of IDUs in Pakistan admit to selling blood in return for money and in some provinces HIV prevalence in blood donations is more than 5 percent.¹⁹

The process of screening donors involves asking a series of questions about the donors' lifestyle to ensure individuals who participate in risky behavior, such as IDUs, or those who fall into a group which has a high-HIV prevalence, such as men who have sex with men, do not donate blood.^{20 21}

The most recent reported case in the US of HIV being transmitted through transfusion occurred in 2008.²² This followed a six year period whereby there were no reported HIV transmissions through transfusion. HIV transmission occurred in this case, firstly because the routine donor (and therefore often considered the safest type of donor) answered incorrectly to questions about high-risk behaviour during the donor screening questionnaire and secondly, due to being recently infected the donor was in the window period (approximately 12 days when tests are unlikely to detect HIV) which resulted in the infected blood being used.

The importance of donors answering honestly to eligibility questionnaires is emphasised by this case. It was highlighted by the CDC that although the risk of HIV transmission through blood transfusion is extremely unlikely in the United States, it should not be ruled out as a possible route for HIV transmission.²³