(Reuters) — The mosquito-borne Zika virus could be linked to 4,000 suspected cases of microcephaly in Brazil including 49 deaths, the World Health Organization (WHO) said on Tuesday (January 26).
“Now, associated with Zika right now in Brazil, we see close to 4,000 microcephaly cases. Microcephaly again, is the condition with abnormally small heads in infants, in babies born, which normally goes along with a smaller brain development as well. Many, quite some already get stillborn, others die after birth and a few survive so we see a lot of conditions there. We have to this point recorded 49 deaths of microcephaly,” WHO spokesperson Christian Lindmeier told a newsbriefing in Geneva.
Brazil has reported 3,893 suspected cases of microcephaly, the WHO said last Friday, over 30 times more than in any year since 2010 and equivalent to 1-2 percent of all new-borns in the state of Pernambuco, one of the worst-hit areas.
No causal link between Zika and microcephaly has yet been definitively proven, Lindmeier added.
“The association between microcephaly and Zika so far is mainly a circumstantial association, laboratory tested only about I think eight cases where either foetuses or dead babies or mothers then, were tested positive for the Zika virus,” he said.
The disease’s rapid spread, to 21 countries and territories of the region since May 2015, is due to a lack of immunity among the population and the prevalence of the Aedes aegypti mosquito that carries the virus, the WHO said in a statement.
Evidence about other transmission routes is limited.
“We do know that of course the blood is contagious for a while, which also means that blood could be possibly a source of infection. Which is in general why any blood bank, or normally blood transfusion or donor centres do not take blood from people who have travelled into tropical areas, for a certain time,” the WHO spokesperson said.
The virus was first found in a monkey in the Zika forest near Lake Victoria, Uganda, in 1947, and has historically occurred in parts of Africa, Southeast Asia and the Pacific Islands. But there is little scientific data on it and it is unclear why it might be causing microcephaly in Brazil.