Don't Blame Zika, Alternative Theories for South American Birth Defects

A group of Argentine physicians claim that the sudden microcephaly outbreak in Brazil was not driven by the Zika virus, but by a larvicide injected into the country's water supplies.

In Brazil's microcephaly epidemic, one vital question remains unanswered: how did the Zika virus suddenly learn how to disrupt the development of human embryos? The answer may lie in a sequence of 'jumping DNA' used to engineer the virus's mosquito vector - and released into the wild four years ago in the precise area of Brazil where the microcephaly crisis is most acute.

Large numbers of babies with borderline normal heads were born Brazil as far back as 2012, two years before the Zika virus is thought to have entered the country, say researchers searching for answers to urgent questions.

Brazilian health officials and the World Health Organization deny links between a well-known pesticide, Pyriproxyfen, and microcephaly. They point to Zika.

In late 2014, the Ministry of Health of Brazil announced the introduction of the Tdap (Tetanus, diphtheria, and acellular pertussis) vaccine for all pregnant women in that country as part of its routine vaccination program. The move was aimed at trying to contain the resurgence of pertussis in Brazil. In December 2015, the Brazilian government…

After many false alarms, the government is considering tightening the guidelines establishing when health care providers should report infants born with abnormally small heads.

Rumors have replicated through social media and word of mouth, frustrating Brazilian officials as they grapple with a mysterious pathogen.