Blood transfusions are used around the world to provide an extra boost of red blood cells to those with anemia, certain types of cancer, and people suffering from severe bleeding due to surgery, an accident, or childbirth. However, according to a report in The Lancet Haematology, we are suffering a global blood shortage, with a majority of countries lacking a sufficient supply.

The blood used in transfusions mainly comes from healthy volunteers who kindly donate their blood to those in need, but often, supply fails to meet demand. The researchers behind the new study wanted to determine where blood supplies are falling short around the world so that the issue may be addressed. By determining the quantity of blood required to treat certain conditions and the prevalence of those conditions globally, they concluded that 61 percent of countries they sampled did not have a sufficient blood supply for transfusions.

The authors note that every country in central, eastern, and western sub-Saharan Africa, Oceania (excluding Australasia), and South Asia did not have enough blood to meet transfusion requirements. Overall, 119 countries out of a total of 195 lacked sufficient blood supplies. Among these countries, the unmet need for blood was equal to an average of 1,849 blood units per 100,000 people. A unit is roughly the amount required during a transfusion, which is about a pint, the amount taken during a donation. 

The issue is particularly prevalent in low- and middle-income countries, despite the fact that lower-income countries generally had a lower demand for blood than high-income ones. Richer nations mainly required blood for transfusions to treat heart disease patients and those suffering from serious injuries. Meanwhile, lower-income nations, such as those in sub-Saharan Africa, were more likely to require blood to treat tuberculosis, respiratory diseases, and nutritional deficiencies like lack of iron.

The researchers also found that the World Health Organization currently underestimates how much blood needs to be donated to satisfy demand. At present, it sets a target of 10 to 20 donations per 1,000 people in a population. However, the researchers found that to satisfy blood demand in 2017, all of the 195 countries would have to up this target, with some Eastern European nations requiring as many as 40 donations per 1,000 people.

While Denmark was found to have the largest blood supply – 14,704 blood product units per 100,000 people – the nations that suffer the most include India, Madagascar, and South Sudan, where demand was found to be 75 times greater than supply.

The researchers note that there are limitations to their study as they may have underestimated blood requirements in certain countries, such as those where tropical diseases are rife, but nevertheless hope that their findings will inform health professionals and policymakers.  

"Other studies have focused on blood safety, such as the risk of transmitting infections such as HIV, but ours is the first to identify where the most critical shortages lie, and therefore where the most work needs to be done by governments to increase donation, scale-up transfusion services and develop alternatives," explained study author Christina Fitzmaurice of the University of Washington.