The journey of donated blood: from my veins to yours, with love

By 9am on a typical day at the Groote Schuur Hospital blood bank, more than a dozen blood tests have been done for patients needing transfusions; donated blood is sent out as quickly as it comes in.

In the Western Cape, as in the rest of South Africa, blood stocks are critically low this winter and donors are desperately needed.

Within minutes of my arrival at the blood bank, a request comes in for two units of blood for a man who has been stabbed. The facility manager, Mpholisi Mbengo, says the Groote Schuur blood bank, one of eight in the Western Cape, dispenses an average of 200 units a day.

I donated blood (my type is O-) this week at a clinic in Hout Bay, and wondered what the steps would be in its journey to the eventual recipient. 

The Western Cape Blood Service (WCBS), the only major blood service in the country besides the South African National Blood Service (SANBS), gave me the answers. I would not be able to trace my own blood to its new home in a fellow-human, however, to protect the privacy of the recipient. 

The Hout Bay Scout Hall was icy at 3pm on Monday when people began walking in to donate: two test tubes samples and a 450ml unit of blood each. In winter, when it is cold and people get sick or go away for school holidays, donations drop — but the need for them does not.

At the clinic, donors fill in a health and behaviour screening questionnaire, do a fingerprick test for iron levels and have their blood pressure taken, before sitting down for a quick prick in the arm to start the collection.

At 7pm when the nursing staff packed up, 21 units of blood were driven to labs at the WCBS headquarters in Ndabeni.

Nadia Petersen, manager of the transfusion virology lab,  showed me around the two fully automated processing facilities. “Our turnaround time is about five hours. Samples that come in this morning, will be labelled and ready to go out by this afternoon.”

Near the first door, test tubes are stacked into a fridge where an automated claw removes the caps from samples, slotting them into a container. These shuttle silently along a track until they reach large machines where the testing begins, without human contact or contamination.

To make sure donor blood is safe,  it is tested for HIV, hepatitis B and C, and syphilis. “If a person is HIV positive, we will do further confirmatory testing. We will ask the donor to come in for counselling and give them a letter with their results,” says Pietersen.

“For hepatitis, we will give them a letter and the results for a doctor, so they do not have to redo the tests. Only three people are authorised to see the names,”  she says. “Positive results are uncommon, only 2%-3% of donations a year, and they are all discarded.”

Centrifuge machines that resemble washing machines separate the blood into three components: plasma,  red blood cells and platelets. 

Pregnant women are among those given whole blood, while plasma may be used for burn patients and platelets for people with leukaemia.

Most of the provincial stocks are stored at this facility, which sends units to  blood banks as needed. Pietersen says: “Our stocks now are low, particularly of O-, which is used a lot in emergency cases.”

People like me are known as “universal donors” because O- blood can be used in transfusions for any blood type; it is in high demand by hospitals because it is the most common blood type and because it can be used for emergency transfusions.

At Groote Schuur, Mbengo points to empty hooks on the O- shelves in the cold room. 

The SANBS is currently reporting low blood stocks of O+  and B+  blood, at four days and 3.7 days respectively. When stocks drop to three days availability, this becomes critical.

Much of the work at the Groote Schuur blood bank involves testing the blood of patients to determine their blood type and matching it to donor blood. 

On average this process, including testing for clotting, takes about two hours from the time the patient sample comes in to the blood being labelled and issued.  Thirteen patients’ blood had already been tested by 9am on the day I visited, said Mbengo.

In an average month the Groote Schuur blood bank, the second biggest in the province after Tygerberg Hospital’s, sends out more than 4,500 units of red blood cells (excluding the plasma and platelet donations), he says.

“Every day we get calls from the maternity wards, for women who have haemorrhaged or had emergency C-sections, from trauma for patients with gunshot or stab wounds, from surgery wards and from medical wards, who have patients with leukaemia and lymphomas,” he says.  

*The WCBS has five fixed blood donation centres in Cape Town and sends out 10-12 mobile units daily from its head office and Paarl, Worcester and George branches. Contact it or the SANBS if you want to donate.