PUNE: Can SARS-CoV-2 be transmitted through
blood transfusion? A case from Pune has become central to the debate on this contentious route.
The patient in the city, a man with a severe form of blood cancer, had received blood stem cells from his Covid-positive son in June. It has been just over six months, but he hasn't shown any signs of infection.
Haematologist Sameer Melinkeri, associated with the patient’s treatment at the Deenanath Mangeshkar Hospital, said this was the first
bone marrow transplant in the country from a
donor confirmed as Covid-positive.
The case also supports the argument that
Covid may not be transmitted through blood. But experts said Covid transmission through blood transfusion cannot be completely ruled out.
"It is possible there was nil or not enough virus in the bone marrow cells to cause infection," said virologist and former director of
the National Institute of Virology, Deepak Gadkari. "The situation can be different when there is a requirement for a large quantity or multiple transfusions of blood and blood products."
A similar case — from Thailand — was reported in the journal Bone Marrow Transplantation. A Covid-positive boy — in an emergency procedure — donated bone marrow to his seven-year-old sister who has thalassemia. The recipient girl has stayed negative for the
pandemic virus.
"But blood or bone marrow donation from Covid positive donors is not recommended," Gadkari said.
The senior expert, in fact, called for mandatory testing for Covid-19. "We have experience with
HIV,
hepatitis B, and hepatitis C viruses. Guidelines on mandatory SARC-CoV-2 testing of blood donors should come soon from regulatory bodies," he said.
Christian Medical College (CMC)
Vellore's haematologist Biju George was of a different view. He said, "In any healthy person who develops Covid-19, viral loads of SARS-CoV-2 in the throat and lungs are high during infection. But during this time, the virus is rarely detected in the blood and bone marrow."
George also drew attention to anecdotal reports of apheresis platelets being transfused from an asymptomatic donor (who tested positive for Covid later) into a patient who urgently needed platelet transfusion.
Apheresis is a medical procedure that involves removing whole blood from a donor or patient and separating it into individual components so that one particular component can be removed. The rest of the components are then re-introduced into the bloodstream of the patient or donor.
"Follow-ups did not detect Covid-19 in the patient who received the platelet transfusion from a positive donor," George said.
He, however, added that infected persons should never donate blood or bone marrow. "It is generally recommended that whenever possible, if a donor develops Covid-19 infection, the transplant is either deferred or an alternate donor is used," George said.
But in emergency situations — just like the Pune case — and if the donor contracts Covid just before the transplant, the likelihood of the recipient developing active infection seems low, at least from published reports, he said.
He added, “Antivirals may have a role (although not studied) in preventing Covid-19 in the recipient. The fact that the patient did not demonstrate any illness adds to the mounting pile of evidence that this virus may not be transmitting through blood.”