While we are observing an after-peak of Zika cases in Colombia and expecting no longer to reach 600.000 despite stats predictions, what is going on in Brazil and what do we know as of today about Zika virus and its pathogenesis?
What has been confirmed from In vitro studies?
- Zika virus crosses placenta barriers;
- Zika virus crosses blood-brain barrier;
- Zika virus can infect fetus;
- Zika virus has neurotropism;
- Zika virus is responsible for:
- Guillain-Barré Syndrome (GBS)
- Zika virus is linked with microcephaly during the Q1 of pregnancy.
When comparing Brazil/Colombia at the time being, meaning with some delay in the observance of microcephaly due to later spread of Zika virus in Colombia, on 61.393 suspected cases, 11.239 pregnant, zero microcephaly recorded so far in this cohorte but Colombia has identified 50 microcephalies, under investigation, of which only 7 under review for Zika virus while waiting for 25 (half of the cohorte) final results. We would be close to 2/10.000 prevalence or less with regards microcephaly related to Zika virus…more or less the historical prevalence of microcephaly in Brazil (26 times above in 2016).
Questions remaining without answer:
- Has Zika virus mutated since arrival in Americas/Brazil?
- Is there possible co-infection:
- with Dengue?
- with CMV, Rubella?
- Is there possible dual cause:
- with a chemical?
- with larvicide, pesticide?
- with Global Health issues (environment,Socio-economics)?
In a previous blog, we pointed out the choice of Colombia as a control group for the prevalence of microcephaly in link with Zika virus in order to answer the question about Zika virus as causative microcephaly.
So May we confirm, as WHO and CDC are delivering statement, that microcephaly is definitively related to Zika virus? More evidence required by answering questions.
If WHO has launched a PHEIC with regards Zika virus and possible side effects/defects like Guillain-Barré Syndrome (GBS) or microcephaly, several scientists are now pointing out other root causes for explaining both the nature of the disability and the spread of the outbreak in South America, moslty in North-East Brazil.
Map of microcephaly in Brazil
By reviewing other risk factors which might be responsible or co-acting with the Zika virus, there are at least two questions unanswered about the key role of virus for microcephaly:
- Why microcephaly newborns are concentrated in North-East states of Brazil?
- Why socio-economics are impacting the rate of microcephaly in this location?
- Tentative answers raising global warming including but not limited to El Nino to increasing the spread of the zika outbreak by helping the growth of the vector (Aedes aegypti mosquito), are not totally convincing; even if climate change is acting as a promoting/contributing factor.
- How socio-economics issues could impact women of the childbearing age or pregnant?
- poverty,malnutrition,low access to health facilities or family planning;
- environmental factors (air/water/soil pollution or contamination,waste,…);
- hygiene & sanitation.
all of global health concerns…
Now by addressing the use of a huge amount of one chemical agent,pyriproxyfen larvicide, for a while in North east Brazil (also since 2014 in Argentina), in order to sterilize potable drinking water by eradicating disease-carrying mosquitos, may we review at International level the root causes tree of microcephaly in Brazil. One critical point is we shall no longer avoid the debate…
“Given these toxic effects of pesticides and that they are more heavily used in Brazil’s northeast region, it is not unreasonable to think that, at least in some cases, microcephaly may be due to excessive use of toxic pesticides and that these effects, have been unmasked by the Zika virus infection. It is also possible to think that microcephaly in children may have a multi-causal origin.”
As always, precautionary measures are recommended before validating the quote:
“Instead Abrasco suggests that this strategy is in fact driven by the commercial interests of the chemical industry, which it says is deeply integrated into the Latin American ministries of health, as well as the World Health Organization and the Pan American Health Organisation.”