Brazil Zika cases raise concern of virus transmission beyond mosquitoes
Two cases of Zika being transmitted through blood transfusions were reported in Brazil on February 4, adding to concerns over the virus that has been linked to severe birth defects and is typically spread through mosquito bites.
The disclosure of the blood transfusion cases in the industrial city of Campinas near Sao Paulo came two days after Texas authorities said a person became infected through sex. Concern over the virus is mounting as Brazil prepares to host the Olympic Games in August, with tens of thousands of athletes and tourists anticipated.
There is no vaccine or treatment for Zika, which has caused outbreaks in at least 26 countries in the Americas. Brazil researchers hope to develop a treatment that could be tested in humans in a year.
Dr. Marcelo Addas Carvalho, director of the blood center at the University of Campinas, said genetic testing confirmed that a man who received a blood transfusion from a Zika-infected man in March 2015 became infected with the virus, although he did not develop symptoms.
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Carvalho said that infection probably was caused by the transfusion but genetic tests have not yet been conducted to confirm it. He said it was very unlikely the infection was caused by a mosquito bite because the patient was in a hospital intensive care unit for three months.
The patient later died from his gunshot wounds and not the Zika infection, health officials and Carvalho said.
Carvalho sought to downplay the Zika threat arising from blood transfusions, saying such transmission of the virus is very rare and not an important factor in the outbreak.
"Governments and society in general should focus on eliminating the mosquito, which is the main form of transmission," Carvalho added.
Brazil estimates that up to 1.5 million people have been infected in the country. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to Zika.
Researchers have identified evidence of Zika infection in 17 of these cases, either in the baby or in the mother, but have not confirmed that Zika can cause microcephaly.
The World Health Organization declared a global health emergency related to Zika on February 1, citing the microcephaly threat.
