Zika Virus Spread Alarm in Americas

[Ygggdrasil]

Zika virus seems like a much more likely candidate as a cause for the microencephaly than pyriproxyfen as other viruses like cytomegalovirus and rubella are known to cause brain damage in fetuses. Recent studies have reported detecting Zika virus in the brains of aborted fetuses or stillborn babies with microencephaly. Still, these are only two cases and it's not clear in what fraction of microencephaly cases Zika virus can be found. Definitive proof will require waiting for the results of longer term studies. Similarly, a link between microencephaly and pyriproxyfen would seem to require more careful epidemiological work as well as longer term studies to establish whether a link exists or not.

Though I understand the decision to halt usage of it until more information is available, if microencephaly does turn out to be due to Zika virus, halting the use of a mosquito-control agent could do more harm than help in the end. If safer alternatives are available, it might be prudent to switch to those, however.

 

[Laroxe]

I had a look at the idea around Pyriproxyfen being a potential cause and the quotation given,
“ a chemical larvicide producing malformations in mosquitoes has been applied for 18 months, and that this poison (pyroproxyfen) is applied by the State on drinking water used by the affected population.” Whenever I see the word “poison” used like this my BS detector cuts in, so;
Its been around since 1995 with over 300 different products, used inside homes, in gardens and as a flea treatment or preventative for pets. It is also used on a range of food products including asparagus, peanuts, strawberries, and grapes. Its based on an organic (Pyrethroid) insecticide and targets the hormones that control maturation in insects, it disturbs egg-laying, hatching and keeps young insects from growing into adult forms, it rarely kills the adults. It has become increasingly popular because its considered safer than other insecticides. The chances are that anyone with a pet in the USA or Europe has a higher level of exposure than the people in NE Brazil.
The World Health Organisation reviewed this chemical for its Guidelines for Drinking-water Quality
http://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen.pdf

They suggest that massive doses are needed to produce any effect on births in mammals and even then these are not neurotoxic effects.
Oh, and there have been attempts at biological control of mosquitoes that hav'nt gone horribly wrong. They have introduced fish species like guppies and betta's that feed on larva, but generally they were not hugely effective, you can't cover all their breeding sites.

 

[OmCheeto]

Zika virus seems like a much more likely candidate as a cause for the microencephaly than pyriproxyfen as other viruses like cytomegalovirus and rubella are known to cause brain damage in fetuses. Recent studies have reported detecting Zika virus in the brains of aborted fetuses or stillborn babies with microencephaly. Still, these are only two cases and it's not clear in what fraction of microencephaly cases Zika virus can be found. Definitive proof will require waiting for the results of longer term studies. Similarly, a link between microencephaly and pyriproxyfen would seem to require more careful epidemiological work as well as longer term studies to establish whether a link exists or not.

Though I understand the decision to halt usage of it until more information is available, if microencephaly does turn out to be due to Zika virus, halting the use of a mosquito-control agent could do more harm than help in the end. If safer alternatives are available, it might be prudent to switch to those, however.

Thanks! And thank you for the NIH: Pyriproxyfen hint.
Unfortunately, as I mentioned, I have zero training in biology, and would very crackpotishly pick out only the few select words that I think I understand enough to make very foolish conclusions.

For instance(), yesterday I saw that pyriproxyfen is toxic to some fish, so today I googled: NIH: pyriproxyfen fish
and came up with the following:

The Time- and Age-dependent Effects of the Juvenile Hormone Analog Pesticide, Pyriproxyfen on Daphnia magna Reproduction
1. Introduction
...
Pyriproxyfen is also relatively lipophilic as it has an octanol/water partitioning coefficient of Kow 5.6 and a bioconcentration factor (BCF) of approximately 1500 in fish (Steginsky et al., 1994).
...

the only words I can sort of understand are:

lipophilic: tending to combine with or dissolve in lipids or fats.
bioconcentration factor: a term that was created for use in the field of aquatic toxicology. Bioconcentration can also be defined as the process by which a chemical concentration in an aquatic organism exceeds that in water as a result of exposure to a waterborne chemical.​

From just those two facts, and my rudimentary knowledge of things, I go to town googling all manner of other things, and go "Ah Ha!":

Essential fatty acids and human brain.
Chang CY1, Ke DS, Chen JY.
The human brain is nearly 60 percent fat.​

My conclusion: Fats are lipids, brains are mostly fat, and pyriproxyfen likes fats!

And beings that I worked at a medical research facility, in a clerical role only, I know that there is something called the "Blood Brain Barrier", I google to find out when that develops.

Unfortunately, after perusing about 4 or 5 of the "techno-babble" papers, trying to figure out when it develops, I revert back to wiki,
where I find, in paragraph #1: The blood–brain barrier allows the passage of water, some gases, and lipid-soluble molecules by passive diffusion...

Where I conclude: It doesn't matter when the BBB develops, as it is lipid-soluble molecule(aka pyriproxyfen) permeable! Ahhhhhh!

At which point, I decide that I should ask my old friend Vlad, who is an actual scientist where I used to work, who works with transgenic mice, about how stupid I am.
He always got mad, when I called myself stupid.

But he did email me, the world's nicest complement, about 6 months after I retired:

The following may sound nice to you: after you left the smoking area changed, it's kind of empty and boring. So you gave life to that small piece of the world. Now I smoke in silence and just talk to my thoughts.
I'll tell everyone "[Om] says "Hello"".
---Vlad

ps. Please feel free to push the "Report" button, if everything I've posted, is pure nonsense. Crackpottery should not be allowed, no matter who spews it.

 

[Laroxe]

I've just seen that Pyriproxyfen is manufactured by a company associated with Monsanto and to many this would be proof that it was developed by Satan and made by demons from the blood of innocents, its automatically a target. There is an idea that whenever people talk about poisons or toxins with no reference to the dose its a good indicator its BS, virtually anything can be toxic if you give enough, I've even seen water toxicity in real life. It doesn't seem to be particularly toxic to fish, I've seen some of the inconsistent results, but I can't see any possibility of destroying the economy major food source of an area, mosquito lava, which remember, are not killed, live in the same places as fish. There are many drugs and environmental contaminants like heavy metals that can be stored in body fat and gradually accumulate over time and can pass through the food chain, remember Mercury in Tuna. This doesn't seem to be a particular problem with Pyriproxyfen which appears to be rapidly excreted, it is fat soluble but the fats are of a type used to produce bile and excreted via this route.
In microcephaly we are talking about a developmental problem occurring very early in pregnancy when the brain is developing, so its quite a short "window" when the mother is at risk, the most damaged foetuses would spontaneously abort, but they still find elevated evidence of infection in the survivors. It might not be Zika, but all the evidence points to it, there is no evidence pointing at Pyriproxyfen and good theoretical reasons to assume its unlikely. I assume the promoters of this scare will also be opposing the use of genetically engineered mosquitoes as a control and will oppose vaccine development because we know what vaccines do, don't we,? they prevent disease.

 

[Ygggdrasil]

Just because a substance is toxic to insects or fish does not mean that it will be toxic to mammals, as the biology of the different species differs greatly. Yes, small lipophilic substances like pyriproxyfen can enter the brain, but pyriproxyfen has been tested in laboratory animals for safety, including any reproductive, developmental and neurological effects. From the WHO document @Laroxe referenced in post #52:

The developmental toxicity of pyriproxyfen has been studied in rats and rabbits. In
rats, a NOAEL for maternal toxicity was not identified, as decreased body weight
gain was observed at 100 mg/kg of body weight per day, the lowest dose tested.
Pyriproxyfen caused little developmental toxicity and was not teratogenic. In a
segment 3 study, the F1 offspring were subjected to a series of developmental tests for
possible neurotoxicity, including physical indices, tests of behaviour, motor and
sensory function and learning ability. Although there were some effects on growth at
doses of ≥300 mg/kg of body weight per day, there was no developmental
neurotoxicity at 500 mg/kg of body weight per day, the highest dose tested.

http://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen.pdf

The failure to observe teratogenic activity (i.e. pregnant lab animals fed high doses of pyriproxyfen did not give birth to animals with birth defects) or any consistent neurological defects in the children of animals fed pyrproxyfen argue against pyriproxyfen as a cause of microencephaly. Of course, humans could differ from rats and rabbits, so this is not definitive evidence against a role for pyrproxyfen either.

Is any experimental or epidemeological evidence pointing to a link between microencephaly and pyriproxyfen or is the link just pure speculation?

 

[OmCheeto]

I've just seen that Pyriproxyfen is manufactured by a company associated with Monsanto

This is why I almost didn't push the "Post Reply" button, to become engaged in this conversation, as I saw that the source paper listed "Monsanto".
From all of my research, there is no connection between Sumitomo Chemical in Japan, and Monsanto.
But, I decided, that maybe, South American vernacular, had equated the name Monsanto, with bio-tomfoolery. Much like us old people referred to "tissue" as "Kleenex", and "photo-copying" as "Xeroxing".
So I daringly pushed the button anyways, knowing that Ygggdrasil, would set the record straight.

and to many this would be proof that it was developed by Satan and made by demons from the blood of innocents, its automatically a target. There is an idea that whenever people talk about poisons or toxins with no reference to the dose its a good indicator its BS, virtually anything can be toxic if you give enough, I've even seen water toxicity in real life.

It doesn't seem to be particularly toxic to fish

Really? Please present some peer reviewed papers that say this. Otherwise...
Wait! You used the word "particularly".
I'm guessing the use of a weasel word makes you innocent...

, I've seen some of the inconsistent results, but I can't see any possibility of destroying the economy major food source of an area, mosquito lava, which remember, are not killed, live in the same places as fish. There are many drugs and environmental contaminants like heavy metals that can be stored in body fat and gradually accumulate over time and can pass through the food chain, remember Mercury in Tuna. This doesn't seem to be a particular problem with Pyriproxyfen which appears to be rapidly excreted, it is fat soluble but the fats are of a type used to produce bile and excreted via this route.
In microcephaly we are talking about a developmental problem occurring very early in pregnancy when the brain is developing, so its quite a short "window" when the mother is at risk, the most damaged foetuses would spontaneously abort, but they still find elevated evidence of infection in the survivors. It might not be Zika, but all the evidence points to it, there is no evidence pointing at Pyriproxyfen and good theoretical reasons to assume its unlikely. I assume the promoters of this scare will also be opposing the use of genetically engineered mosquitoes as a control and will oppose vaccine development because we know what vaccines do, don't we,? they prevent disease.

You might want to start a new thread: "Why are humans, such as OmCheeto, so stupid?"

 

[mfb]

Recent studies have reported detecting Zika virus in the brains of aborted fetuses or stillborn babies with microencephaly.

They probably also found that all three mothers ate bread regularly. With the given rate of Zika infections and microcephaly, it would be surprising if they did not find any examples.

I might have missed it, but are there some animal tests on Zika?

 

[Laroxe]

This is why I almost didn't push the "Post Reply" button, to become engaged in this conversation, as I saw that the source paper listed "Monsanto".
From all of my research, there is no connection between Sumitomo Chemical in Japan, and Monsanto.
But, I decided, that maybe, South American vernacular, had equated the name Monsanto, with bio-tomfoolery. Much like us old people referred to "tissue" as "Kleenex", and "photo-copying" as "Xeroxing".
So I daringly pushed the button anyways, knowing that Ygggdrasil, would set the record straight.

Really? Please present some peer reviewed papers that say this. Otherwise...
Wait! You used the word "particularly".
I'm guessing the use of a weasel word makes you innocent...
You might want to start a new thread: "Why are humans, such as OmCheeto, so stupid?"

I'm sorry if I wasn't clear in my comments, you may be right about Monsanto but this link is made repeatedly in articles that quote a report by the Physicians in the Crop-Sprayed Towns (PCST) Read more at http://thefreethoughtproject.com/do...-pesticide-birth-defects/#pAkueWdKWsSMXvpX.99
My first comment was about the fact that virtually everything can be toxic, even water, if you drink enough, in effect its the dose that makes the poison.
The previous link I used to the WHO report did review the evidence about the toxicity to fish, apparently early studies studies suggested the possibility but later studies failed to confirm this. I did use the word particularly, but I don't think weasles we used in any of the studies.So I had already provided the link to the science, I also suggested that if you wipe out the fish population in areas that use fish as a food source someone might notice, while this isn't a peer reviewed opinion, I have no problem with contrary views. Naturally I claim innocence of everything but in view of my original comments about what happens to such people maybe in this case I'll stay silent. Generally, I see nothing stupid in asking for clarification, I will try to be clearer.

 

[Ygggdrasil]

I might have missed it, but are there some animal tests on Zika?

The scientists who initially isolated the virus did a few animal tests:

In addition to experiments with more rhesus monkeys and mice, their exhaustive studies put the Zika virus into grivet and red tail monkeys, cotton rats, guinea pigs, and rabbits. The virus caused damage to neurons only in mice.

http://www.sciencemag.org/news/2016/02/zika-s-long-strange-trip-limelight

I don't know if anyone has or is doing studies on pregnant animals to test the microencephaly link. So, yes, there are many reasons to be skeptical of the Zika-microencephaly link especially given that the virus hasn't shown signs of causing microencephaly in outbreaks elsewhere and similar problems have not occurred with other viruses (though West Nile has been associated with neurological symptoms). However, given the timing of the Zika outbreak coinciding with the sharp increase in microencephaly cases, the epidemiological evidence so far has been suggestive of a link. Perhaps better epidemiological studies will show that Zika simply correlates with living in mosquito-infested areas but not with actual Zika infection, in which case the pyriproxyfen hypothesis would definitely deserve more consideration.

 

[Laroxe]

A quick update from the CDC. Hope its useful.

• Prior to 2015, Zika virus outbreaks occurred in areas of Africa, Southeast Asia, and the Pacific Islands.- May 2015, the Pan American Health Org. (PAHO) issued an alert about Zika virus infections in Brazil following increased reports of birth defects and Guillain-Barré syndrome in areas affected.

They say that as of January 2016, there has been confirmed autochthonous transmission of Zika virus in 19 countries in the Americas

As of the 10th Feb there have been 52 cases on mainland US , all being travel related, they predict;

• Zika virus will continue to spread and it will be difficult to determine how and where the virus will spread over time.

• The number of Zika cases among travellers visiting or returning to the United States will likely increase. Some 80% of cases will not be diagnosed.

• These imported cases could result in local spread of the virus in some areas of the United States.

They also provide a link to the report linking the virus to microcephaly, which gives more information around the evidence, something I hadn't seen previously was the information about the type of damage being typical of some viral infections. It seems these problems have been associated with other viruses.

The report is at;
http://www.cdc.gov/mmwr/volumes/65/wr/mm6503e2.htm

and an opinion.
The pyriproxyfen “hypothesis” ignores the fact that the use of this insecticide is very widespread in developed countries, I suspect that a 20 fold increase in the rate of microcephaly might have been noticed. Its unlikely to only effect people in Brazil, its also interesting that 1 state in Brazil suspended its use based on the concerns which the promoters of this myth presented as “Brazil Bans Pyriproxyfen.” The Brazilian government have dismissed this link all together but the concern generated may limit the use of one of the most powerful protective agents against zika available. I wonder if the people who made this link up, will be held in any way responsible for the potential damage. There is a difference between considering the evidence linking zika to the microcephaly and recognising its current limitations and considering a random chemical with no credible evidence.

 

[OmCheeto]

Sometimes, the excuses given for why pyriproxyfen isn't dangerous, strike me as... ummm...

WHO Director travels to Brazil for crisis zika
16/02/2016
...
Also, between 90 and 95 percent of this larvicide is excreted in the urine within 48 hours and tested in prenanat laboratory animals, no apparent impact on their offspring.
...

That would be really great, if the local populace were not drinking it, every day.

 

[jim mcnamara]

FWIW - the hormone system (biological pathway) involved with pyriproxyfen and invertebrates - does not exist in mammals. Humans are mammals. Fish are not invertebrates, either.

@OmCheeto - I think it is time to stop. You are off-base, considerably. Here is the last link I'm providing - this is written for non-biologists - I'm certain you can read it. The point is that the kind of stuff you are posting is essentially a destructive point of view. "Monsanto" and some other stuff you mention has got zilch to do with the issues at hand. You are delving into too many logical fallacies. Period. Please stop. Thanks.

http://www.cbsnews.com/news/health-experts-dismiss-claims-larvicide-linked-to-microcephaly/

 

[Evo]

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