As the eyes of the world turn to Rio de Janeiro, host of this summer’s Olympic Games, a discussion has exploded about the Zika virus and its potential threat to athletes and tourists, as well as the possibility of a global pandemic. To get the facts, we went to Dr. Rodrigo Brindeiro, director of the Biology Institute at the Federal University of Rio de Janeiro—one of the leading research institutions in Brazil. Dr. Brindeiro, a molecular biologist and geneticist, is part of the team at the university’s Laboratory of Molecular Virology that is currently studying both how the Zika virus affects fetal brain development and potential treatment options. We spoke to him at his laboratory. This interview has been edited for clarity.
Can you give a threat assessment of Zika? How widespread is it? How dangerous is it? And who is most at risk?
We are just now gathering all of the information about this global threat. The virus was first identified in 1947 when it was discovered in the Zika forest in Uganda. Very few knew about it. They just knew that it was a mild virus. Then it spread epidemically in the 1970s to West Africa and then Southeast Asia. Various Zika-related syndromes including microcephaly [abnormal smallness of the head, a congenital condition associated with incomplete brain development] were found in fetuses and babies, but reported instances were very low and they thought it was not directly related to the presence of the virus. Only when they made a retrospective kind of analysis did they find that there was this relationship. It must be noted that microcephaly is only one aspect of this syndrome. It includes a whole series of neurological disorders. And that happened in widespread fashion only in Brazil.
There were so many other theories about what was causing high incidence of microcephaly: trying to say that it was not because of the Zika virus, but because of pesticides and insecticides, and things like that. But it’s not that, and we can prove the relationship between Zika and microcephaly because there were cases of pregnant women with twins in the northeast of Brazil. One was absolutely healthy and the other has microcephaly. If it was about chemicals, this would not happen…. In Brazil, as in many other places, it wasn’t required to report cases of microcephaly to public-health officials. Now it is. So when Zika came, we didn’t have the baseline to compare the frequency of microcephaly happening because of Zika or not. For a pregnant woman that is exposed to Zika virus, there is a 30 percent chance that the fetus will develop the disease. There is much we don’t know, for example we know nothing about infants, infected after they were born. But we know that there is possibility of something very severe.
For adults, Zika infection normally gives a rash and a mild fever or the infected will show no symptoms at all and it will just go away in several days. But for 5 percent of those infected, you can have the development of neurological complications like meningitis, encephalitis, or myelitis. And you have some severe cases for example here in the University Hospital with elderly people developing these kinds of neurological disorders.