Brazil’s state of Rio Grande do Sul has suspended the use of the mosquito-combating larvicide pyriproxyfen, the regional government said Sunday. The move follows a report by Argentine experts who claimed that it was the larvicide and not the Zika virus which is responsible for a wave of birth defects in Brazil, the Latin American News agency EFE reported.
Zika is widely thought to be linked with a wave of cases of microcephaly, a disease in which infants are born with abnormally small heads. The World Health Organization declared the Zika virus a world health emergency earlier this month.
A report conducted by the Argentine group Physicians in the Crop-Sprayed Towns (PCST), however, has pointed to pyriproxyfen, added to drinking water supplies to prevent the development of mosquito larvae, as the possible source of the birth defects.
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Despite the fact that neither a link between larvicide and microcephaly, or Zika and microcephaly, has been conclusively proven, Rio Grande do Sul Health Secretary Joao Gabbardo said that the "suspicion" of a correlation led his team to "suspend" the use of the chemical.
"We cannot run that risk," Gabbardo said.
Hospital staff Oswaldo Cruz prepares to draw blood from baby who has microcephaly, at the Oswaldo Cruz Hospital in Recife, Brazil, Jan. 26, 2016. | Reuters
“Previous Zika epidemics did not cause birth defects in newborns, despite infecting 75 percent of the population in those countries,” the Argentine report said. “Also, in other countries such as Colombia there are no records of microcephaly; however, there are plenty of Zika cases.”
In response to Rio Grande do Sul’s ban of the larvicide and the recent report, Brazil’s Health Minister Marcelo Castro reiterated that the larvicide presents no danger to the public, calling the claims “rumors.”
"That is a rumor lacking logic and sense. It has no basis. (The larvicide) is approved by (the National Sanitary Monitoring Agency) and is used worldwide. Pyriproxyfen is recognized by all regulatory agencies in the whole world," the minister told reporters while in the northeastern city of Salvador.
The report added that the pesticide, also known as SumiLarv, is manufactured by Sumitomo Chemical, which has collaborated with the controversial Monsanto Company in Brazil and Argentina on weed control.
"There is no scientific basis for such a claim," Sumitomo Chemical said in a statement, according to EFE, emphasizing that its product has been approved by the World Health Organization since 2004 and the U.S. Environmental Protection Agency since 2001.
While officials in Colombia have said that there are no recorded cases of Zika-infected pregnant women bearing children with microcephaly, Colombia has still followed the dozens of regional and international governments warning pregnant women to stay away from areas with mosquito infestations.
Brazil’s government has vowed to fight the spread of the Zika virus, with President Dilma Rousseff declaring a war on the mosquitoes responsible for spreading the Zika virus, and committing numerous resources to aid affected populations by finding a vaccine.
The U.S. Centers for Disease Control strongly linked the birth defects in Brazil to the Zika virus in testimony before the U.S. Senate.
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