There may be no direct link between Zika and microcephaly

Key points to be remembered

1. 12,000 cases of pregnancies with Zika symptoms were observed in clinical setting in Columbia, no cases of microcephaly occurred in all of these 12,000 pregnancies.

2. Pyriproxyfen, an insecticide used to curb the population has been applied to water supply in Brazil since 2014. Experimental result on rats has found that pregnant rat with overexposure to Pyriproxyfen will have a high chance of giving birth to pup that exprience developmental disorder similar to microcephaly.

3. Be mindful about the mosquitoes repellents that you use. 

Stand of WHO

According to information published on World Health Organization website, there is scientific consensus that Zika virus is a cause of microcephaly and Guillain-Barré syndrome. Links to other neurological complications are also being investigated.

In April, the CDC (center for disease control) declared Zika the cause of microcephaly in Brazil. But many experts in the medical experts doubted this direct link between Zika and microcephaly.

Different Situation in Columbia and Brazil

By June 15 2016, the World Health Organization (WHO) reports 7 Zika associated microcephaly cases in Columbia. This number is extremely small as compared to over 1,500 confirmed cases in Brazil. Population size cannot account for this huge difference as population of Colombia is one fifth of that of Brazil.

A study, published in the New England Journal of Medicine tracked 1,850 pregnant women at different phase of pregnancy. Of these 1,850 pregnant women, 532 of them were infected in the first trimester, 702 and 616 were infected in second and third trimester respectively. So far, 16%, 29% and 93% of the pregnancies have been concluded: no case of microcephaly was observed.

This result leads some doctors to doubt the direct link between Zika and microcephaly. Meanwhile, other study suggest that it may be the Pyriproxyfen, an insecticide used to curb the population of mosquitoes may be the cause of the microcephaly.

It was reported that in August 2016 that the Administration in Brazil admitted that Zika virus alone will not cause microcephaly.

Pyriproxyfen

Meanwhile, a study by a group of physicians in Argentina and Brazil provided some evidence that the use of pesticide to curb mosquitoes population may be the cause of microcephaly.

Since 2014, pyriproxyfen has been added to water supply in the epicenter of Zika to reduce mosquitoes population in Brazil. 

Rats which were pregnant, were exposed to different dosages of the pesticide. Results show that rats which were over-exposed to the pesticide will more likely to give birth to pup which has developmental disorder similar to microcephaly.

What we can learn from this?

Prevention is the best

Whether Zika is the actual cause of microcephaly, we should take every measure to prevent mosquitoes bites. Not only mosquitoes can spread Zika virus, it also spread dengue.

You can refer to here for more information on how to prevent mosquitoes bite

Pregnant women need to be mindful about what they use

Pyriproxyfen is initially used to curb mosquitoes population, but it may end up being the culprit behind the microcephaly. One thing we can learn here is that pregnant women should be mindful about what they use.

There are many mosquitoes repellent products available, we believe not all are suitable for pregnant women. It is better for pregnant women to call their gynecologists to confirm the use of mosquitoes repellent to make sure it is safe to use.