On Tuesday, the U.S. Food and Drug Administration recommended a ban on collection of blood from people inhabiting in areas where zika virus cases have been reported. The studies on the virus would take almost a year or half to reveal any possibility of transmission of microcephaly through blood transfusion.

Microcephaly is linked to zika for causing rare birth defects in newborns despite there being no such clear evidence so far. Zika has spread in more than 30 countries in Latin America and the Caribbean. There are evidences that zika can spread through blood transfusion, but this is unknown whether the recipient of the blood develops the illness with zika transmission or not.

There are other viruses such as dengue and chikungunya, which are also caused by same mosquito that causes zika. However, both dengue and chikungunya do not cause illness to recipient on transfusion.

The people at risk to get infected with zika virus are prohibited to donate blood for almost four weeks, according to the FDA. “We believe the new recommendations will help reduce the risk of collecting blood and blood components from donors who may be infected with the Zika virus”, said Dr. Peter Marks, director of the FDA's biologics division.

There are other factors that are not known to experts and many studies on zika virus are underway. Other factor undiscovered is potential of zika to spread microcephaly. There are investigations going on into more than 4,300 cases of microcephaly. The study has declared that 460 of these cases are of microcephaly while 41 of these cases are of zika, but yet no association between both has been found.