Are Pesticides Causing The Birth Defects In Brazil?

Are pesticides causing the birth defects in Brazil, not Zika? originally appeared on Quorathe knowledge sharing network where compelling questions are answered by people with unique insights.

Answer by Tirumalai Kamala, Immunologist, Ph.D. Mycobacteriology, on Quora.

Pesticides are unlikely to be directly involved in the Brazil birth defect issue. If they are, link is more likely indirect. By now, several groups in different countries have found Zika but not other known pregnancy-associated viruses in placenta and brain of several newborns with microcephaly as well as in miscarriages where the mothers were known to have had Zika infections in their 1st trimester. These data strengthen the link between Zika and birth defects. Proof is still a ways away, requiring larger studies, more numbers, expanded diagnostic tools to confirm Zika, not just Reverse transcription polymerase chain reaction but also culture, etc. Meantime, other questions about Zika remain unanswered, and that’s where the role of environmental factors comes into the picture. Discovered in the Zika forest in Uganda in 1947, Zika never caused outbreaks until recently.

Starting in 2007, Zika’s been cutting a swath through human populations in its path as it spread first from Africa to Asia then across the Pacific and now into Latin America. First, the outbreak in the Micronesian island of Yap in 2007, then another larger one in French Polynesia in 2013-2014. Symptoms as well becoming more severe. After all, Guillain-Barré syndrome was first documented in that French Polynesia Zika outbreak, ~40 GBS cases out of a total of ~8510 suspected Zika cases there (~0.5%) (1, 2, 3). Clearly, Zika’s changing as it moves across the world (4, 5, 6). —> Read More