New doubts on Zika as cause of microcephaly

[A.B.]

Brazil's microcephaly epidemic continues to pose a mystery -- if Zika is the culprit, why are there no similar epidemics in other countries also hit hard by the virus? In Brazil, the microcephaly rate soared with more than 1,500 confirmed cases. But in Colombia, a recent study of nearly 12,000 pregnant women infected with Zika found zero microcephaly cases. If Zika is to blame for microcephaly, where are the missing cases?

In light of this evidence, NECSI says the cause of microcephaly in Brazil should be reconsidered. One possibility that has been raised is the pesticide pyriproxyfen, which is applied to drinking water in some parts of Brazil to kill the larvae of the mosquitos that transmit Zika. Pyriproxyfen is an analogue for insect juvenile hormone which is cross reactive with retinoic acid, which is known to cause microcephaly. A physicians group in Brazil and Argentina, the Swedish Toxicology Sciences Research Center, and NECSI have called for further studies of the potential link between pyriproxyfen and microcephaly.

https://www.sciencedaily.com/releases/2016/06/160624150813.htm

 

[alkt]

i can foresee a long legal battle with various vested interest muddying the waters for many long years to come.

 

[SilverbladeTE]

Industrial chemicals NEVER causes harm, oh no siree! Perfectly safe...ah huh

 

[Marky90]

Seems more likely..

 

[wastwater]

maybe its a cattle virus

 

[GreyOwl]

i can foresee a long legal battle with various vested interest muddying the waters for many long years to come.

Yes, but they might find it hard to argue mass hysteria. Not that that's stopped them before...

 

[Groggy Doggy]

Its too bad the Olympic games will be held in Rio this August, when there are still many unanswered questions about Zika. I feel bad for the athletes that must be wondering if they are putting their health at risk simply by attending.

 

[Hip]

According to the following article, it is the Asian strain of the Zika virus, not the African strain, that may be the cause of microcephaly:

Zika virus strain 'imported from the Americas' to Africa - BBC News

The strain in Brazil is the Asian strain of Zika, and this Asian strain has now jumped into Africa, where three cases of microcephaly have appeared.


That being said, the strain in Colombia is also the Asian strain,1 so it is not clear why there are no microcephaly cases in Colombia.

 

[Seven7]

in poor country the report of cases are slow. Give it time. In Dominican rep they had the first case reported of E after zica virus been there a bit.

 

[Undisclosed]

If pesticides were the cause of the microcephaly, wouldn't there be babies born to non-infected mother's who are also microcephalic. Have there been any reports of this?

I think it's likely down to the strain causing the microcephaly.

 

[Riley]

http://www.npr.org/sections/goatsan...e-microcephaly-in-brazil-unlikely-say-experts

"In the end, the most compelling point against pyriproxyfen's role in Brazil's health issues is this: Health officials in the state of Pernambuco, the so-called epicenter of microcephaly, say that in the three cities reporting the most cases — Recife, Jaboatao and Paulista — pyriproxyfen is not in use."

 

[SilverbladeTE]

If pesticides were the cause of the microcephaly, wouldn't there be babies born to non-infected mother's who are also microcephalic. Have there been any reports of this?

I think it's likely down to the strain causing the microcephaly.

Or...both
I've long wondered how severe the synergistic affects of disease/toxins are
not much study done on it as it's terribly complex and the few things I've read over years tends to support the idea that synergies produce WAY more dangerous outcomes than could ever be expected from what should be, by individual doses/disease be practically harmless

http://www.npr.org/sections/goatsan...e-microcephaly-in-brazil-unlikely-say-experts

"In the end, the most compelling point against pyriproxyfen's role in Brazil's health issues is this: Health officials in the state of Pernambuco, the so-called epicenter of microcephaly, say that in the three cities reporting the most cases — Recife, Jaboatao and Paulista — pyriproxyfen is not in use."

possibly true, but whenever I hear the possibility of industrial accident...my "conspiracy alert meter" flashes like the blue lamp on the TARDIS

It may all just be down to a new strain
but from experience, when industrial pollution accidents happen, cover ups almost ALWAYS occur

 

[asleep]

If pesticides were the cause of the microcephaly, wouldn't there be babies born to non-infected mother's who are also microcephalic. Have there been any reports of this?

I think it's likely down to the strain causing the microcephaly.

http://www.nature.com/news/zika-and-birth-defects-what-we-know-and-what-we-don-t-1.19596

These are the most recent numbers I've seen. 854 confirmed cases of microcephaly with a lab confirmed zika association in only 97, so it looks like most have nothing to do with zika (though it's unclear if the remainder were negative or untested).

Moreover the very outbreak appears overstated as only a fraction of suspected microcephaly cases are confirmed.

Lastly, even if zika were present in most or all cases of microcephaly it would mean very little if zika is endemic in the population, much like finding evidence of EBV alone doesn't carry much weight since almost everyone has it.

 

[Undisclosed]

http://www.nature.com/news/zika-and-birth-defects-what-we-know-and-what-we-don-t-1.19596

These are the most recent numbers I've seen. 854 confirmed cases of microcephaly with a lab confirmed zika association in only 97, so it looks like most have nothing to do with zika (though it's unclear if the remainder were negative or untested).

Moreover the very outbreak appears overstated as only a fraction of suspected microcephaly cases are confirmed.

Lastly, even if zika were present in most or all cases of microcephaly it would mean very little if zika is endemic in the population, much like finding evidence of EBV alone doesn't carry much weight since almost everyone has it.

Later in the article:

[paste:font size="5"]Zika probably can cause severe brain damage in babies...3. And clinicians in Brazil say that they are seeing higher levels of unusually severe microcephaly cases.

Spectre of Ebola haunts Zika response

So the evidence that Zika infection can cause brain damage and defects such as microcephaly is “substantial and accumulating”, as the European Centre for Disease Prevention and Control concluded on 9 March.

Evidence is also mounting for a connection to Guillain–Barré syndrome(GBS), a rare auto-immune disorder that causes muscle weakness and, very rarely, paralysis or death. This is unsurprising, as many common pathogens cause GBS, with by far the biggest risk being one of the most common causes of food poisoning — Campylobacter infections from undercooked chicken. Zika’s only major public health threat would be if it causes widespread birth defects

I am not understanding your last comment-- endemic refers to regularly found in a population -- a pathogen can be endemic and cause much disease and death eg., malaria, syphilis, bacillary dysentery, tuberculosis, different types of pneumonia and influenza etc.

 

[asleep]

Later in the article:



I am not understanding your last comment-- endemic refers to regularly found in a population -- a pathogen can be endemic and cause much disease and death eg., malaria, syphilis, bacillary dysentery, tuberculosis, different types of pneumonia and influenza etc.

I'm not sure I understand the relevance of the additional part of the article to the numbers I posted. You asked if there were non-zika microcephaly cases and the epidemiology shows that most cases are in fact non-zika (or at least not known to be zika-related). If the claim is that zika causes more severe microcephaly then one would at least expect a correlation between zika and severity, but they fail to detail one if it does exist.

As for my last point, I probably should have said widespread instead of endemic, though I assumed my EBV analogy would make that clear. The point is that if, hypothetically, zika evidence is found in nearly 100% of the local population, then finding it in most/all cases of "XYZ" (in this case microcephaly) doesn't mean much as a correlation. It's an alternative answer to your original question in that even if all microcephaly cases were zika associated it doesn't necessarily rule out another cause. I've not seen anyone address how widespread it is but given its vector, its presence since at least the 50s, and its typical asymptomatic course, I think it's very plausible that zika is widespread in the region.

 

[lansbergen]

Can it not be like rubella?

 

[Undisclosed]

http://news.nationalgeographic.com/2016/03/160307-zika-virus-microcephaly-brazil-science/

Latest Science

Two scientific papers published Friday help illuminate the puzzle of how Zika affects pregnancy and how it causes brain damage. An examination of the pregnancies of 88 women in Rio de Janeiro, published in the New England Journal of Medicine, revealed “serious and frequent problems in fetal and central nervous system development” in 29 percent of the pregnancies in which women who had experienced Zika symptoms and were pregnant allowed prenatal imaging. (Some declined or could not obtained).
The women were infected not just in their first trimester but across the durations of their pregnancies. Not all of the pregnancies have come to term yet, but so far, the researchers said, there have been two miscarriages and six live births. Both the live infants and those yet to be born show a range of birth defects: not just microcephaly but calcifications in brain tissue, abnormalities of brain structure, eye disorders, clubfoot, and several children small for their gestational age.

Also Friday, researchers from Florida State University, Johns Hopkins University, and Emory University published in the journal Cell Stem Cell a description of an experiment in which they infected a range of human cells with Zika virus in the lab. The virus showed a preference for developing in and destroying cells similar to those that form the cortex, the grey matter, of the brain during fetal development: infecting up to 90 percent of them, destroying a third, and retarding the development of the rest. The cells did not appear to mount an immune response to the virus. The researchers cautioned that their work was very preliminary, but said it might provide the first steps in understanding why Zika appears to destroy infants’ brain tissue.

 

[wastwater]

I saw an article about the mode of transmission being in question,as I had wondered about this before.http://www.dailymail.co.uk/wires/ap...cal-mystery-caregiver-gets-Zika-man-died.html