The potential link between the Zika virus and an epidemic of microcephaly in Brazil is the subject of a new probe being conducted between researchers from that nation and experts from the U.S. Centers for Disease Control and Prevention (CDC). The probe will explore a possible link between the virus and a rash of birth defects in Brazil.
Microcephaly, a normally rare birth defect in which babies are born with unusually small heads, has been confirmed in 500 recent births, with nearly a thousand suspected additional cases.
Researchers will examine mothers of babies born with the condition, as well as their offspring, in an effort to determine the root cause of the sudden outbreak. The plan is to compare the results of blood tests between 100 affected pairs and 300 to 400 healthy mothers and children.
"What we're trying to do is to better define the association between children that have been diagnosed with microcephaly and whether or not they might have evidence of congenital Zika virus infection," said Erin Staples, a researcher at the CDC.
Brazil normally sees around 150 instances of microcephaly each year, among its population of 200 million people. This sudden rise in the number of cases resulted in the World Health Organization (WHO) to declare an international health emergency in that nation on Feb. 1.
The search for the underlying causes of the epidemic has been hampered by the fact that Zika antibodies are similar to those produced in response to dengue, a virus common in the region.
First detected in monkeys in 1947, the Zika virus is now present in 26 countries in the Americas, as well as several other nations around the world. However, Brazil is the only nation with the mosquito-borne virus to experience such a dramatic rise in this particular birth defect.
In an effort to assist in the study of the outbreak, the Brazilian government is lifting a ban on the export of blood outside the country.
"A new disease or syndrome like this is a global problem, and we are lucky that the Brazilians were very prompt and open with their experience," said Anne Schuchat, principal deputy director of the CDC.
The initial results of the study are expected in May 2016, although full analysis of the data could continue for several years. However, WHO believes they could prove a link between the virus and the birth defect, if there is one, within six months.
Medical experts in Argentina have cast doubts on the theory that the Zika virus is responsible for the outbreak of microcephaly, placing blame on a larvicide used in the nation.
Outside Brazil, Colombia has the greatest number of cases of Zika, but that nation has not seen any increase in the number of microcephaly births. Pregnant women there who have tested positive for Zika will be closely monitored in an effort to determine whether or not the virus is responsible for the rash of birth defects.
Rio de Janeiro will play host to the 2016 Summer Olympics, and health officials are advising pregnant women to stay away from the games in light of possible risks to their unborn children.
Photo : Day Donaldson | Flickr