Discussion: Congenital birth defects and the Zika virus

[Pathfinder]

...
Are there reasons other than Zika (for example, pesticides) that might explain the increase in microcephaly cases in Brazil?

Microcephaly can happen for many reasons, including genetics, maternal infections, and being close to or touching toxins during pregnancy. Results of recent epidemiologic and laboratory studies performed in Brazil strongly support, but don?t yet prove, a link between Zika virus infection during pregnancy and microcephaly. For example, a report in the MMWR on February 10, 2016, presents findings from pathologic studies showing the presence of Zika virus in the brains of infants born with microcephaly and in placental tissues from early miscarriages.

Several media reports in February 2016 suggested that a pesticide called pyriproxyfen might be linked with microcephaly. These media reports appear to be based on a February 3 publication authored by an Argentine physicians organization, which claims that the use of pyriproxyfen in drinking water in Brazil is responsible for the country?s increase in microcephaly cases.

The World Health Organization has approved the use of pyriproxyfen for the control of disease-carrying mosquitos. Pyriproxyfen is a registered pesticide in Brazil and other countries, it has been used for decades, and it has not been linked with microcephaly. In addition, exposure to pyriproxyfen would not explain recent study results showing the presence of Zika virus in the brains of infants born with microcephaly.

CDC is working closely with international partners to study infants with microcephaly to better understand what role various factors, including Zika virus, may play in this birth defect.
...
http://www.cdc.gov/zika/pregnancy/question-answers.html

 

[Emily]

Great find Emily. One more thing: I read somewhere - no link - that a combination of insecticides can multiply the estrogenic effects of pyriproxyfen.

I think you are onto something there with the synergy concept. There must be something complex happening in the NE Brazil cluster. My guess is that an environmental factor is somehow altering the metabolism of the placenta. Virologists posed the possibility of another virus being involved, so I'm still disappointed that CDC did not test for LCMV. (We find what we seek?)

I also wonder if standards regarding medical imaging of pregnant women are different than in the US, since some viruses can interact with ionizing radiation. With most pregnant women infected with Zika virus delivering healthy babies, the secondary risk factor must be very limited either by dose, timing, or host genetics...or a combination of all of those.

Pyriproxyfen seems to have better safety testing as far as teratogenic effects on pregnancy than the Bti they use in Recife, where Brazil says most of the cluster cases are located, (though I did wonder is that where they are reported, but the cases are mostly rural women from the outskirts of the city coming into the city for diagnosis?) It sounds like poorer women with no running water get whatever is used added directly to individual water storage containers kept at their homes. I was surprised and saddened that was the case.

Whatever caused the high number of microcephaly cases in NE Brazil prior to the Zika outbreak , might not be a teratogen itself at all. It might be something that allows teratogens to concentrate in the womb. And that is a possibility I have never seen tested for with pesticides, adjuvants or the 'inactive' chemicals used in individual formulations.

Yet it seems chemicals can certainly act in that way:

Kimmel, C. A., Wilson, J. G. and Schumacher, H. J. (1971), Studies on metabolism and identification of the causative agent in aspirin teratogenesis in rats. Teratology, 4: 15?24. doi:10.1002/tera.1420040104

Abstract Pregnant Wistar rats treated orally at day 9, 10, or 11 with 250, 500, 750, or 1000 mg/kg aspirin showed a teratogenic dose-response relation at each treatment time, but a decreased overall embryonic susceptibility as treatment was applied later in gestation. The types of abnormalities produced generally correlated with the state of development at the time of treatment. Treatment of animals at day 9 with 510 mg/kg benzole acid and 2 hours later with 250 or 500 mg/kg aspirin caused a significant increase in percentage of malformations above effects observed after 250 or 500 mg/kg aspirin alone. Determination of free salicylate in embryos and maternal serum after treatment at day 11 with sodium salicylate with or without benzoic acid pretreatment indicated that benzoic acid significantly increased the concentration of salicylate in both embryos and serum 6 and 12 hours after salicylate treatment and throughout the observed period. Thin-layer chromatography of tissues from these animals revealed only salicylic acid in both embryos and maternal serum, thus implicating salicylic acid as the causative agent in aspirin teratogenesis.

You'll find benzoic acid even in 'natural' insect repellents and lots of other things that aren't so greenwashed.
http://www.britannica.com/science/benzoic-acid

 

[Emily]

Atmospheric Environment 62 (2012) 272e280

Benzoic acid is abundantly present in automobile exhausts

http://www.aljazeera.com/indepth/fea...072338596.html

In Brazil, are the poor more likely to contract zika?
Poor infrastructure and sanitation means run-down neighbourhoods may be hardest hit by mosquito-borne viruses like zika. Sam Cowie | 12 Feb 2016 07:13 GMT | Health, Latin America, Brazil, Zika virus

...

In Ibura, a poor neighbourhood in Recife, north eastern Brazil, [], 27, breastfeeds her three-month-old daughter, []."I hope that she will be able to walk, talk and go on to study," [] says.

[] has microcephaly, a condition which causes babies to be born with smaller-than-average heads and suffer varying degrees of brain damage, leading to developmental problems and severe learning difficulties. Some die shortly after birth.

Experts say it is very likely that Giovanna will require full-time care for the rest of her life, putting enormous pressure on [], a mother of four who earns only $250 a month working as a toll booth attendant, and who receives $25 in government child benefits. Her husband is unemployed...

 

[sharon sanders]

NEJM - Zika Virus Infection in Pregnant Women in Rio de Janeiro — Preliminary Report

Study: Zika Virus Infects Human Cortical Neural Progenitors and Attenuates Their Growth


My family continues to watch the developments. We don;t know if the mosquito abatement programs currently in Florida will virtually stop the transmission via mosquitoes or not. Florida has really great success with the infrequent dengue or chikungunya case. I am hopeful.

As to the sexual transmission - so much is still unknown. Caution is the way to go. Condoms can help and should be free.

A vaccine is still years away.

 

[Pathfinder]

NEJM - Zika Virus Infection in Pregnant Women in Rio de Janeiro — Preliminary Report

Study Finds Zika Damages Babies at All Stages of Pregnancy

MAR 4 2016, 6:38 PM ET
by MAGGIE FOX

The babies of women infected with Zika virus while they are pregnant can suffer the effects at any stage of gestation, researchers reported Friday in a troubling look at how Zika affects unborn children.
...
They also found the virus causes a range of birth defects beyond microcephaly.

They suggest a name for these effects: Zika virus congenital syndrome. Babies have been born with a range of brain and eye defects and some have also been abnormally small.

The findings, together with other studies, support what most experts already believe: that Zika is causing an epidemic of birth defects.
...
"Despite mild clinical symptoms, Zika virus infection during pregnancy appears to be associated with grave outcomes, including fetal death, placental insufficiency, fetal growth restriction and central nervous system injury," they wrote in their report, published in the New England Journal of Medicine.
...
"We saw problems with the fetus or the pregnancy at eight weeks, 22 weeks, 25 weeks, and we saw problems at 35 weeks," said Dr. Karin Nielsen, professor of clinical pediatrics at the David Geffen School of Medicine at the University of California Los Angeles, who helped organize the study.

"Even if the fetus isn't affected the virus appears to damage the placenta, which can lead to fetal death," Nielsen said...
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"Any woman with Zika virus should be handled as a high-risk pregnancy," Nielsen told NBC News.

"There's more than microcephaly. There is a spectrum of disease. There are parts of the brain that are not formed. There are calcifications in the brain. There is in-utero growth restriction."
...

http://www.nbcnews.com/storyline/zi...a-damages-babies-all-stages-pregnancy-n532086

 

[Emily]

88% of the women had positive results for dengue-specific IgG antibodies at study entry.

 

[sharon sanders]

CDC Issues Updated Zika Recommendations: Timing of Pregnancy after Zika Exposure, Prevention of Sexual Transmission, Considerations for Reducing Unint
ended Pregnancy in Areas with Zika Transmission - March 25, 2016

 

[sharon sanders]

[h=1]Zika Virus and Birth Defects ? Reviewing the Evidence for Causality[/h] Sonja A. Rasmussen, M.D., Denise J. Jamieson, M.D., M.P.H., Margaret A. Honein, Ph.D., M.P.H., and Lyle R. Petersen, M.D., M.P.H.
April 13, 2016DOI: 10.1056/NEJMsr1604338

http://www.nejm.org/doi/full/10.1056/NEJMsr1604338?query=featured_home


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My daughter is still waiting and watching for developments into the fall 2016. This is the prudent thing to do. What we do not know is how, in real life, will Zika emerge into Florida. Are the existing mosquito controls enough to basically stop the spread among the mosquito population? We just don't know at this point. If she decides to start a family she will be working closely with her health care practitioners to assess the risks.

 

[Emily]

I read that CDC article in NEJM and noted a huge discrepancy between the CDC's estimate of microcephaly rates in the US vs what a Seattle expert in the condition estimates the rates to be:

CDC:

Microcephaly is a rare defect that is estimated to occur in 6 infants per 10,000 liveborn infants in the United States.

vs

Expert says microcephaly more common than autism, but gets much less attention and research money

(He did include 'mild' microencephaly, but the case in the article describes what I think is a milder case yet the challenges are significant.)

Now here are the CDC's autism rates:
http://www.cdc.gov/ncbddd/autism/data.html

About 1 in 68 children has been identified with autism spectrum disorder (ASD) according to estimates from CDC's Autism and Developmental Disabilities Monitoring (ADDM) Network

We seem to already have a big problem in our own backyards as far as birth defects go.

 

[Laidback Al]

Full CDC press release referring to the NEJM article referenced by Sharon Sanders in post #68 above.

CDC Concludes Zika Causes Microcephaly and Other Birth Defects
Scientists at the Centers for Disease Control and Prevention (CDC) have concluded, after careful review of existing evidence, that Zika virus is a cause of microcephaly and other severe fetal brain defects. In the report published in the New England Journal of Medicine, the CDC authors describe a rigorous weighing of evidence using established scientific criteria.

?This study marks a turning point in the Zika outbreak. It is now clear that the virus causes microcephaly. We are also launching further studies to determine whether children who have microcephaly born to mothers infected by the Zika virus is the tip of the iceberg of what we could see in damaging effects on the brain and other developmental problems,? said Tom Frieden, M.D., M.P.H., director of the CDC. ?We?ve now confirmed what mounting evidence has suggested, affirming our early guidance to pregnant women and their partners to take steps to avoid Zika infection and to health care professionals who are talking to patients every day. We are working to do everything possible to protect the American public.? Background

The report notes that no single piece of evidence provides conclusive proof that Zika virus infection is a cause of microcephaly and other fetal brain defects. Rather, increasing evidence from a number of recently published studies and a careful evaluation using established scientific criteria supports the authors? conclusions.

The finding that Zika virus infection can cause microcephaly and other severe fetal brain defects means that a woman who is infected with Zika during pregnancy has an increased risk of having a baby with these health problems. It does not mean, however, that all women who have Zika virus infection during pregnancy will have babies with problems. As has been seen during the current Zika outbreak, some infected women have delivered babies that appear to be healthy.

Establishing this causal relationship between Zika and fetal brain defects is an important step in driving additional prevention efforts, focusing research activities, and reinforcing the need for direct communication about the risks of Zika. While one important question about causality has been answered, many questions remain. Answering these will be the focus of ongoing research to help improve prevention efforts, which ultimately may help reduce the effects of Zika virus infection during pregnancy.

At this time, CDC is not changing its current guidance as a result of this finding. Pregnant women should continue to avoid travel to areas where Zika is actively spreading. If a pregnant woman travels to or lives in an area with active Zika virus transmission, she should talk with her healthcare provider and strictly follow steps to prevent mosquito bites and to prevent sexual transmission of Zika virus. We also continue to encourage women and their partners in areas with active Zika transmission to engage in pregnancy planning and counseling with their health care providers so that they know the risks and the ways to mitigate them.

The CDC is now satisfied that a Zika virus infection during pregnancy may cause congenital brain defects.

In post #1, I noted

Birth defects are a serious problem around the world. Every year an estimated 6% of the worldwide births (almost 8 million infants) suffer from some kind of birth defect. (link) According to the World Health Organization only 50% of congenital birth defects can be associated with a specific cause. (link) There is been little public concern about worldwide congenital defects the until recent media reports concerning the possible effects of the Zika virus on pregnant women from Brazil.

While the world struggles to control Zika virus infections, especially among pregnant women, we need to continue to focus on reducing all kinds of congenital birth defects. Emily's post above reminds us that there are other birth defects that require attention and funding.

The NEJM article notes that for the United States

Microcephaly is a rare defect that is estimated to occur in 6 infants per 10,000 liveborn infants in the United States.25

In contrast, based on CDC data as noted by Emily above, autism spectrum disorder occurs at a rate of about 147 individuals per 10,000 in the United States.

Within the fear and frenzy of the spread of the Zika virus, we must continue to provide funding to help control all forms of congenital anomalies.

 

[sharon sanders]

Agreed, everything possible should be done to prevent all types of congenital anomalies.

Dr. Frieden said that never before has a mosquito bite caused a congenital birth defect. For those of us who live in areas where mosquitoes are prolific, this is quite a challenge. While future parents know the many established risks of bringing a child into the world, it is quite an impossible assignment for both the husband and wife to avoid all mosquito bites for the entire conception and pregnancy period. Is this a year? More? Quite something to effectuate.....

 

[Laidback Al]

Even in our modern age with technological and scientific advances, the risks to bringing a child into this world seem to be growing every year.

 

[Emily]

Even in our modern age with technological and scientific advances, the risks to bringing a child into this world seem to be growing every year.

I think that could be true, Al. The fetal brain disruption syndrome seen in the worst Zika cases was never even described until 1984, though there might have been a few cases earlier. In a video, the Seattle expert said he only has seen about 1 case a year for the past 20 years.

They have only been able to guess at what is causing this, but in one case they noted that the mother had taken birth control pills during her whole pregnancy. Maybe endocrine disruption is playing a part in many of these responses to environmental stimuli, including viruses.

 

[sharon sanders]

Please see:

Study - Dengue Virus Antibodies Enhance Zika Virus Infection

 

[sharon sanders]

Please see:

US - CDC: Florida investigation links four recent Zika cases to local mosquito-borne virus transmission - July 29, 2016


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When the FDA issued an advisory yesterday for 2 countries in South Florida to immediately stop all blood collections until Zika testing is performed on each donation, my daughter and I had another conversation.

She is still waiting to see what happens before getting pregnant. We knew that July and August would be a critical time to see if Zika would make a jump from the Caribbean (especially Puerto Rico) to Florida. At this time she is not "panicking" but is still looking to the her employer, the state of Florida, and the CDC to see if joint actions can stop the progression.

As all citizens of Florida can attest - it is impossible to avoid all mosquito bites for a year. I am still hopeful that the local and state authorities can effectively prevent Zika spread as happens with the occasional dengue and chikungunya case.

 

[Pathfinder]

From the CDC link above:

?All the evidence we have seen indicates that this is mosquito-borne transmission that occurred several weeks ago in several blocks in Miami,? said Tom Frieden...

 

[sharon sanders]

Dr. Frieden did not answer whether women should delay pregnancy.

For now..my daughter is waiting to see what happens in the next few months. Earlier this year she decided to wait until late Fall to decide. Nothing happening in the last few days has changed her plan.

As a disclosure - my family has no financial ties to the tourism industry.

We are going to call this as we see it.

 

[DataMom]

We're located in Central North Carolina. We have A Aegypti, A. Albopictus, and some Culex mosquitoes here. Since early Spring, my family & a friend have been testing different mosquito repellents under different circumstances. We've also fitted the doors with mosquito-safe screens, and the dogs have spot-on coverage for mosquitoes. However, I was bitten in a changing room on an unsprayed part of my body at a local department store while trying on clothes, in another store when one flew down the front of my blouse, and I had 2 mosquitoes fly up my "skort" and bite. I don't see any way to totally avoid mosquito bites - short of bathing in mosquito repellent every few hours. That isn't going to happen. We'll be coming to Florida at Christmas for a "Celebration of Life" on Sanibel Island.

 

[sharon sanders]

As expected there is controversy developing about the travel advice to Florida at this time.

First - I would like to say that when anyone travels anywhere they need to always review their medical conditions with their medical practitioners before travel. This is standard advice for all travel.

I can only relate what my family is doing. At this time, besides delaying pregnancy until late Fall, we are doing nothing else out of the ordinary.

I think some of the media reaction is based on exploitation of "bad" news. Also, some experts tend to downplay disease events based on their particular slant.

The reality is that we do not know yet what the overall effect will be in Florida.

It is a lifestyle in Florida to protect against, watch, and avoid mosquitoes. This is not new for residents or visitors.

It is more of the same disease concerns - but now one with a severe complication for pregnancy.

If you are planning to visit South Florida - as usual - consult your medical practitioner before you travel anywhere.

Always - if you are pregnant - follow your medical practitioners advice.

and....

NEVER RELY ON MEDICAL ADVICE FROM THE INTERNET.

 

[sharon sanders]

So now the CDC has a travel advisory for a neighborhood in Miami. Please see:


Florida - 10 new local Zika cases in Miami cluster - and CDC arrives to help - August 1, 2016

US - CDC: Advice for people living in or traveling to Wynwood, a neighborhood in Miami, Florida - August 1, 2016 - Pregnant women should not travel there


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I think everyone should follow the CDC's advice.

This is not a surprise. My family started to take action early this year and I publicly posted about it. Anyone who visits or lives in Florida knows about the mosquitoes here.