Zika virus is transmitted by mosquitos and through sexual contact. Many people who are infected with Zika virus do not experience any symptoms, but it does sicken some people. When pregnant women are infected, they can transmit the virus to their fetus, which is then at risk of birth defects.
The American Red Cross has been monitoring blood donations for Zika. They began in 2016 by testing pools of donations in states where the risk of the disease was thought to be highest. After about six months, they started testing for the virus in individual donations in every state. After a comprehensive analysis described in the video, scientists found that it took about $5.3 million to detect a single positive sample; only a handful were found out of millions of samples tested. It’s led some to wonder if this is a cost-effective way to minimize the risk of transmitting the virus through blood donations.
Source: CDC, NEJM