Blood safety and availability
- About 92 million blood donations are collected every year. Approximately half of these blood donations are collected in high-income countries, home to 15% of the world’s population1.
- About 8000 blood centres in 159 countries report on blood donations. Annual blood donations on average per blood centre in high-income countries is 30 000 versus 3700 in low-income countries.
- National blood supplies are based almost entirely on voluntary unpaid blood donations in 62 countries: the WHO goal is for all countries to obtain all blood supplies from voluntary unpaid donors by 2020.
- 39 countries were not able to screen all blood donations for one or more of the following transfusion-transmissible infections (TTIs): HIV, hepatitis B, hepatitis C and syphilis.
- A total of 106 countries have national guidelines on the appropriate clinical use of blood, however, only 13% of low-income countries have a national haemovigilance system to monitor and improve the safety of the transfusion process.
National blood policy and organization
Blood transfusion saves lives and improves health, but many patients requiring transfusion do not have timely access to safe blood. Providing safe and adequate blood should be an integral part of every country’s national health care policy and infrastructure. WHO recommends that all activities related to blood collection, testing, processing, storage and distribution be coordinated at the national level through effective organization and a national blood policy. This should be supported by appropriate legislation to promote uniform implementation of standards and consistency in the quality and safety of blood and blood products.
In 2008, 75% of countries had a national blood policy, compared with 60% of countries in 2004. Overall, 58% of countries have specific legislation covering the safety and quality of blood transfusion:
- 69% of high-income countries
- 61% of middle-income countries
- 37% of low-income countries.
About 92 million blood donations are collected worldwide. Almost half of these are collected in high-income countries, home to 15% of the world’s population.
About 8000 blood centres in 159 countries report collecting on average of 10 000 blood donations per centre (ranging from 20 to almost 500 000). Collections at blood centres vary according to income group. The average annual donations per blood centre is 30 000 in high-income countries, 7500 in middle-income countries and 3700 in low-income countries.
There is a marked difference in the level of access to safe blood between low- and high-income countries. The whole blood donation rate is an indicator for the general availability of blood in a country. The median blood donation rate in high-income countries is 36.4 donations per 1000 people. This compares with 11.6 donations per 1000 people in middle-income countries and 2.8 donations in low-income countries (see Figure 1).
Figure 1: Whole blood donations per 1000 population
Data about the gender profile of blood donors show that globally, 30% of blood donations are given by women, although this ranges widely. In 16 of the 100 reporting countries, less than 10% donations are given by female donors. The age profile of blood donors shows that overall, 5% of donors come from the under-18 age group, 31% from people aged 18–24, 35% from the 25–44 group, 26% from 45–64 group and 3% from those over 65. In low- and middle-income countries, proportionally more young people donate blood than in high-income countries (see Table 1). Demographic information of blood donors is important for formulating and monitoring recruitment strategies.
|Table 1. The age-profile of blood donors|
|Proportion of donations|
|Age groups (years)||High-income countries||Low-income countries|
|65 and over||5.0%||0.3%|
|less than 18||8.0%||2.4%|
There are three types of blood donors:
- voluntary unpaid
An adequate and reliable supply of safe blood can be assured by a stable base of regular, voluntary, unpaid blood donors. These donors are also the safest group of donors as the prevalence of bloodborne infections is lowest among this group. The WHO goal is that all countries obtain blood supplies from voluntary unpaid donors by 2020.
- In 2008, 62 countries collected more than 99% of their blood supplies from voluntary unpaid donors (see Figure 2), compared with 39 countries in 2002.
- Compared with figures from the previous year, 70 countries reported a more than 10% increase in voluntary unpaid blood donations. Conversely, 23 low- and middle-income countries reported a more than 10% decrease in voluntary unpaid blood donations as compared to figures from previous years.
- In 40 countries, less than 25% of the blood supply is collected from voluntary unpaid blood donors, with much of the blood supply still dependent on family/replacement and paid blood donors (see Table 2).
- 26 countries still report collecting paid donations in 2008, around 800 000 donations in total.
Figure 2: Voluntary unpaid blood donations as a percentage of all blood donations
|Table 2. Percentage of family/replacement and paid blood donations|
|Family/replacement and paid blood donations|
WHO recommends that all blood donations should be screened for infection prior to use. Screening should be mandatory for HIV, hepatitis B, hepatitis C and syphilis.
- 39 countries are not able to screen all donated blood for one or more of the above infections (see Figure 3 for breakdown by infection).
- Irregular supply of test kits is one of the most commonly reported barriers to screening.
- Overall, 89% of donations are screened following basic quality procedures (following documented standard operating procedures and participation in an external quality assurance scheme): 97% in high-income countries, 82% in middle-income countries and 53% in low-income countries.
- The median prevalence rates of transfusion-transmissible infections in blood donations in high-income countries are considerably lower than in middle- and low-income countries. The median prevalence rate of HIV in blood donations in high-income countries is 0.001%, in comparison with 0.06% and 0.5% in middle- and low-income countries respectively. This difference reflects the variable prevalence amongst members of the population who are eligible to donate blood, the type of donors (such as voluntary unpaid blood donors from population at lower risk) and the effectiveness of the system of educating and selecting donors.
Figure 3. Laboratory screening of blood donations for transfusion-transmissible infections
Blood collected in an anticoagulant can be stored and transfused to a patient in an unmodified state. This is known as ‘whole blood’ transfusion. However, blood can be used more effectively if it is separated into components, such as red cell concentrates, plasma, and cryoprecipitate and platelet concentrates. In this way, it can meet the needs of more than one patient. The capacity to provide patients with the different blood components they require is still limited in low-income countries: 31% of the blood collected in low-income countries is separated into components, compared with 91% in high-income countries and 72% in middle-income countries.
Clinical use of blood
Unnecessary transfusions and unsafe transfusion practices expose patients to the risk of serious adverse transfusion reactions and transfusion-transmissible infections. Unnecessary transfusions also reduce the availability of blood products for patients who are in need.
WHO recommends that all countries have transfusion committees to implement national policy and guidelines on rational use of blood in hospitals and a national haemovigilance system to monitor and improve the safety of the transfusion process.
- 106 countries have national guidelines on the appropriate clinical use of blood.
- 57 countries have a national haemovigilance system (78% high-income countries compared with 13% of low-income countries).
- Transfusion committees are present in 76% of the hospitals performing transfusions in high-income countries, 53% in middle-income countries and 50% in low-income countries.
- Mechanisms to monitor clinical transfusion practice are present in 83% of hospitals performing transfusion in high-income countries, 56% in middle-income countries and 47% in low-income countries.
- Systems for reporting adverse transfusion events are present in 91% of hospitals performing transfusion in high-income countries, 53% in middle-income countries and 38% in low-income countries.
There are great variations between countries in the age distribution of transfused patients. For example, in Denmark, the most frequently transfused patient group is over 65 years old, with 76% of all transfusions. In Benin, the majority of transfusions (65%) are among children under five.
In high-income countries, transfusion is most commonly used for supportive care in cardiovascular surgery, transplant surgery, massive trauma, and therapy for solid and haematological malignancies. In low- and middle-income countries it is used more often in pregnancy-related complications and severe childhood anaemia.
The WHO strategy for blood safety and availability addresses five key areas:
- the establishment of well-organized, nationally-coordinated blood transfusion services to ensure the timely availability of safe blood and blood products for all patients requiring transfusion;
- the collection of blood from voluntary unpaid blood donors from low-risk populations;
- quality-assured testing for transfusion-transmissible infections, blood grouping and compatibility testing;
- the safe and appropriate use of blood and a reduction in unnecessary transfusions;
- quality systems covering the entire transfusion process, from donor recruitment to the follow-up of the recipients of transfusion.
Through its blood transfusion safety programme, WHO supports countries in developing their national blood services. The programme provides policy guidance and technical assistance to countries with the aim of working towards equitable access to safe blood and blood products and their safe and rational use.
1All data are from the WHO global database on blood safety 2008, with responses received from 164 countries, covering 92% of the world’s population.