Brazil Dismisses New Causes Linked to Microcephaly

By Lise Alves, Senior Contributing Reporter

SÃO PAULO, BRAZIL – As the Brazilian government conducts massive campaigns to destroy breeding grounds of the Aedes aegypti mosquito, which transmits the Zika virus that may be linked to the increased number of babies born with microcephaly in the country, local and foreign reports have other sources as being the cause of the neurological disorder.

Rumors that tainted vaccines given to pregnant women were the cause of the increase in microcephaly in the country were quickly dismissed by both the World Health Organization (WHO) and Brazil’s Ministry of Health.

“The vaccines that the organization recommends to pregnant women and that are offered by the SUS (unified, public health system) are secure and efficient,” said the statement released by the organization.

According to the WHO, vaccine for measles, neonatal tetanus and flu, being pointed out as being possible sources of microcephaly, are safe and should continue to be administered. Government sources reported more than seventy million doses of measles vaccines have been given to women of childbearing age in Brazil.

There were also reports last week that Argentinian doctors had linked the larvicide Pyriproxyfen, commonly used in drinking water to kill the Aedes aegypti mosquitoes was actually the source of the birth defect. The rumor increased when the Southern state of Rio Grande do Sul decided to suspend the use of the chemical in its water supply. According to the Ministry of Health, the chemical has been approved by the WTO and has been thoroughly tested by Brazilian health agency Anvisa.

“There are no epidemiological studies showing the association between use of pyriproxifen and microcephaly,” said the statement released by the Ministry. “Unlike the relationship between the Zika virus and microcephaly, that already had confirmation attested in tests that indicated the presence of the virus in samples of blood, tissue and amniotic fluid, the association between the use of pyriproxifen and microcephaly has no scientific basis,” it added, noting that in some locations that do not use the pyriproxifen cases of microcephaly were also reported.

Since late last year more than 3,700 cases of Zika virus have been reported in Brazil and dozens of microcephaly cases linked to the virus have been confirmed.