RIO DE JANEIRO (AP) — The suspected number of cases of microcephaly, a rare brain defect in babies, continues to rise in Brazil, reaching 3,893 since authorities began investigating the surge in October, Health Ministry officials said Wednesday.
Fewer than 150 cases of microcephaly were seen in the country in all of 2014. Brazil's health officials say they're convinced the jump is linked to a sudden outbreak of the Zika virus, a mosquito-borne disease similar to dengue, though the mechanics of how the virus might affect babies remain murky.
Infants with microcephaly have smaller than normal heads and their brains do not develop properly. Many fetuses with the condition are miscarried, and many others die during birth or shortly after. Those who survive tend to suffer from developmental and health problems.
The ministry's emergency response official, Wanderson Oliveira, said at a news conference in Brasilia on Wednesday that the reported cases are being investigated to determine whether they are really cases of microcephaly. He stressed that the situation is very much in flux and "will change every day."
Another official, Claudio Maierovitch, who heads the ministry's transmissible disease department, said officials are learning quickly about microcephaly and Zika, but much still remains unknown.
"With Zika, it's all new," he said, adding that Wednesday's announcement that the virus had been detected in the placenta of a woman who miscarried in the first trimester was one more piece of the puzzle. The announcement was made by the Fiocruz research institute's branch in the southern state of Parana.
Maierovitch said Brazil was working to ramp up its capacity to test for the Zika virus. Officials hope Brazilian labs will soon be able to process 20,000 Zika tests per month, compared with the current 1,000. Brazil has also invested in developing a vaccine against the illness, though Maierovitch said development would likely take three to five years.
HE said that the introduction of genetically modified sterile mosquitoes could be a potential tool in the fight against Zika, as well as diseases such as dengue and chikungunya that are also transmitted by the Aedis aegypti mosquito. Recent tests by a British biomedical company suggest their sterile mosquitoes succeeded in drastically reducing local mosquito populations. However, Maierovitch cautioned that such a solution is not yet ready to be used on a large scale.
For the moment, the best way to prevent transmission is by doing away with stagnant water where the insects breed, using repellent and wearing covering clothing, he said.
The reported cases of microcephaly remain concentrated in Brazil's poor northeastern region. However, the developed southeast where Rio de Janeiro and Sao Paulo are located is the second hardest-hit region.
In Sao Paulo, Army troops are being used to help health agents combat the proliferation of the Aedes aegypti mosquito. Teams made up of health agents and up to four soldiers each fanned out through the megacity's middle class Vila Madalena neighborhood on Wednesday checking for and removing areas of stagnant water.
The U.S. Centers for Disease Control and Prevention last week advised pregnant women to avoid traveling to Brazil and several other countries in the Americas where Zika outbreaks have occurred. The warning comes months ahead of the Aug. 5-21 Olympic Games, which Rio de Janeiro is hosting, and some tourism professionals have voiced concern that it could scare visitors away.
Associated Press writer Stan Lehman in Sao Paulo contributed to this report.