Transfusions blamed for two cases of Zika
Still, official says, mosquitoes are the real threat in spreading virus
A blood bank in the Brazilian city of Campinas has confirmed that two people were infected with the Zika virus after transfusions there last year. It is the first time that transmission of the disease has been linked to blood transfusions.
Brazil is in the midst of a Zika outbreak that the government has linked to a rise in the number of babies born with microcephaly — a birth defect characterized by an abnormally small head and often motor and learning difficulties.
Marcelo Carvalho, director of the hemotherapy division at the Campinas blood center, a relatively wealthy city near Sao Paulo, reported the two cases of Zika infections caused by blood transfusions, which occurred in the first part of last year.
In one case, a patient received a transfusion in March. Days after giving blood, the donor reported experiencing dengue-like symptoms. After an investigation, both he and a man who had received the transfusion were found to have Zika.
“It was just a laboratory infection. There was no clinical manifestation,” Carvalho said of the transfusion recipient. The Brazilian government says people who get Zika usually show few, if any, symptoms.
Another case of transmission by blood transfusion took place in February 2015 in a hospital run by the University of Campinas, which also runs the blood bank. A man who had been shot is believed to have caught Zika from one of about 100 blood transfusions he received during three months at the hospital, Carvalho said.
“He got fever. He had various infections during internment, multiple organs failed, he got very sick,” Carvalho said. Dengue was suspected, but results of a test of his blood that came back in December showed Zika. The patient died of the gunshot wounds. Last month, a test on the donor showed Zika.
“The donor was contacted and said that days after the donation he presented symptoms comparable with Zika and he recovered well without any complications,” Carvalho said.
He said new procedures had reduced the risk of patients getting Zika from blood transfusions.
“All the actions, as much governmental as by society, should be focused on the control of the vector, the mosquito,” Carvalho said. “The risk of transmission by transfusion is millions of times less than the risk of transmission by the mosquito.”
Worries about Zika in the blood supply have been a growing concern for health officials around the world. The American Red Cross and health officials in Canada and Britain have been urging people who have traveled to regions affected by the Zika virus to wait at least four weeks before giving blood.
Officials at the Food and Drug Administration said this week that they are assessing whether travelers who have visited places with local Zika transmission should defer donating blood. The FDA did not immediately respond to a request for comment Thursday.
The American Association of Blood Banks, the professional standards group, said that its 28day self-deferral recommendation also applies to other tropical viruses, such as dengue and chikungunya, and that it should result in only minor decreases — about 2.25 percent — in overall donations of blood.