How serious do you find Zika Virus threat?

[Unorthodox]

https://www.washingtonpost.com/national/health-science/why-the-united-states-is-vulnerable-to-spread-of-zika-virus/2016/01/26/a8c6a9b4-c440-11e5-8965-0607e0e265ce_story.html

With the Zika virus now circulating in two dozen countries and territories across the Americas, the mosquito-borne pathogen seems destined to reach the United States and likely sooner rather than later.

What is far less certain, say public health and infectious disease experts, is Zika’s potential reach and impact here. The South is seen as especially vulnerable because of its warm, humid climate and pockets of poverty where more people live without air-conditioning or proper window screens. Plus, the region is already home to mosquitoes that can transmit the virus.

Some models estimate as many as 200 million people live in areas that might be conducive to the spread of Zika during summer months — including along the East and West coasts and much of the Midwest. That makes for a huge target as researchers scramble to determine exactly how the virus manifests itself in the human body, who is particularly at risk, and why.

Their urgency comes amid increasing reports from Brazil, the current epicenter of Zika, of thousands of newborns with a rare condition involving brain damage. Doctors there have also seen a surge in another rare syndrome known as Guillain-Barré, which can lead to paralysis. With both, a link to Zika is suspected.

Already, Brazil, Colombia, El Salvador and Jamaica have urged women to postpone pregnancy. The Centers for Disease Control and Prevention has an ever-expanding advisory urging U.S. women who are pregnant from traveling to those 24 countries and territories in the Caribbean and Central and South America that have local transmission.




President Obama received a briefing Tuesday about the situation from his health and national security teams, including Health and Human Services Secretary Sylvia Mathews Burwell, CDC Director Thomas Frieden and Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

[CDC adds U.S. Virgin islands and Dominican Republic to travel advisory] 

A day earlier, the World Health Organization’s director-general warned that the disease’s spread is “explosive.”Margaret Chan also described the circumstantial evidence connecting Zika to cases of microcephaly, in which a baby’s head and brain are abnormally small, as “extremely worrisome.”




So far, the experts are divided about what lies ahead for the United States. More than a dozen cases of the virus have been confirmed to date, including two announced Tuesday by Arkansas and Virginia state health officials. In each, the person was believed to have been infected while out of the country.

Fauci is downplaying the potential for a significant eruption of Zika here. He notes that dengue and chikungunya, diseases transmitted by the same kinds of mosquitoes, are widespread in Latin America. But their foothold in the United States has been well controlled, with only small clusters of cases.

“It is unlikely that we will have a major outbreak of Zika in this country,” Fauci said.

Yet Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, fears the opposite is true. He recalls spending much of 2014 insisting that the Ebola outbreak would not become a significant problem in the United States. He gives no such assurance now.




“I think we’re in for real trouble in the United States,” he said, considering how swiftly Zika can spread. He focuses on conditions throughout the Gulf Coast, where stagnant water sources — in uncollected garbage, discarded tires, untended bird baths — can be ideal breeding grounds for mosquitos much of the year.

“You’ve got to assume the worst-case scenario,” Hotez said.

[As Zika fear spreads, Brazilian moms opt for mosquito-resistant baby clothing]

Aedes albopictus, the Asian tiger mosquito, which can transmit the virus, is present from Florida to Connecticut and as far west as Illinois, said Laura Harrington, chair of Cornell University’s entomology department. It bites people as well as animals. A second species, Aedes aegypti, the yellow-fever mosquito, has a more limited geographic footprint and only bites people. But it is the primary “vector” for Zika’s transmission. 

Taken together, “there are many parts of the United States that are vulnerable because of where the mosquito populations are,” Harrington said.




The experts acknowledge that any projections are hampered by their lack of knowledge about the disease. It takes between 10 to 11 days for a mosquito to become fully infected to pass on the virus, according to Nikos Vasilakis, an arbovirologist at University of Texas Medical Branch in Galveston, where researchers are studying Zika in collaboration with scientists at Yale’s School of Public Health and in Brazil. They don’t yet know what the risk is for pregnant women who are bitten by an infected mosquito and contract the virus — much less what the risk is for their fetus.

The CDC has issued guidelines for both pregnant women and newborns. For example, it recommends testing for the virus when babies have microcephaly and their mothers traveled to or lived in Zika-virus regions while pregnant. On Tuesday, agency officials held a telebriefing with clinicians nationwide to go over the guidelines as part of increased vigilance and public education.

 In the Brazilian cases, most of the exposure to Zika appears to have been during the first trimester of pregnancy. But CDC officials have said there is also some evidence that a fetus can be in danger into the second trimester.

There is no drug to treat Zika or vaccine to prevent it, although Fauci said researchers are working on the latter. The most common symptoms of infection are fever, rash, joint pain and red, itchy eyes. Symptoms are usually mild and last several days to a week.



 

What you need to know about the Zika virus
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Play Video1:10


Authorities have confirmed a dozen cases of Zika virus in the United States. Here's what you need to know. (Gillian Brockell/The Washington Post)

One of the biggest problems in researching the possible link between Zika and cases of birth defects has to do with the widespread presence of dengue disease in the countries with high Zika infection, said Lyle Petersen, director of CDC’s vector-borne disease division. Humans produce antibodies in response to both viruses, but current tests cannot really differentiate between them.

“In people with previous dengue exposure, there’s no test to be able to sort that out,” Petersen explained.




Major past outbreaks of Zika occurred in the Pacific islands among small populations, and uncommon kinds of birth defects were not noticed right away. After Brazil began reporting increased prevalence of microcephaly last October, authorities in French Polynesia went back and analyzed their 2013-2014 Zika outbreak involving more than 30,000 people. They found an increase in microcephaly cases and of Guillain-Barré syndrome.

Brazil has said it wants to expand an experiment using genetically modified mosquitoes produced by a British company called Oxitec. The company says they can be effective at controlling pest populations: Altered male mosquitoes are released into the wild to mate with females. The offspring never reach adulthood, blocking the next generation from carrying diseases like dengue, chikungunya and Zika virus.

Oxitec says that trials involving its mosquitoes in Brazil, Panama and the Cayman Islands “all resulted in a greater than 90 percent suppression” of the wild Aedes aegypti  population. This month, the company announced that Piracicaba, a city in the Brazilian state of Sao Paulo, would expand its effort to eradicate disease-carrying mosquitos.

But it’s unlikely that genetically engineered mosquitoes will be buzzing around the United States anytime soon.

Beth Ranson, a spokeswoman for the Florida Keys Mosquito Control District, which has partnered with Oxitec for a proposed trial, said that before any altered bugs could be released there, the Food and Drug Administration must first complete an environment assessment of the project. Its findings must then be opened to public comment. Even once finalized, a local board would need to approve the trial — over the expected opposition of some Keys residents.

In the meantime, Ranson said, local inspectors are pushing forward with more conventional methods such as treating and eliminating breeding areas for mosquitoes.




“We’ve always been aggressive . . . [but] we’re stepping up the aggressiveness,” she said. “We don’t want dengue, chikungunya or Zika here – we don’t want any of it.”

[Unorthodox]

AFAIK, the zika virus could be spread by the entire Aedes family of mosquitos, I think the above article is incorrect in targeting 2 specific species. 

[Rusty Edge]

I was going to predict that this will be a repeat of West Nile Virus. The disease will spread much faster than predicted, but will have less of an impact.


Contagious birth defects are scarey.

You know what else is scarey? Guiome Barre Syndrome. My uncle had it years ago. So did my wife's uncle. This was before we knew each other. Some people call it "French Polio" Fortunately, they both survived, but it's a scarey, helpless feeling, knowing somebody's life is hanging by a thread, and there is very little to be done about it.

Basically it is an allergic reaction to a virus. The body attacks it's own nervous system. There is a progressive paralysis beginning at the extremities. If and when it reaches the heart, you die. If it stops before that, there is a long, slow recovery.

http://www.mayoclinic.org/diseases-conditions/guillain-barre-syndrome/basics/definition/con-20025832

[Rusty Edge]

My travel habits and mosquitos' preference for me has me concerned. I voted as such.

Kite patches aren't on the market yet. What do you recommend as mosquito protection, Uno?

[Unorthodox]

Well, I'm unsure. 

Couple interesting tidbits on Zika and Aedes Aegyptica. 

Zika originated in Aedes Aegyptica in Brazil, and has spread to other Aedes mosquitos, including the arboreal ones I would normally recommend as natural competitors and even predators.  While these don't spread it to humans, they do spread the virus among other mosquitoes. 

It's arrival is relatively shortly after widespread release of genetically modified Aedes Aegyptica mosquitos in Brazil (which is serving as a test bed) that were engineered so that females that mated with the genetically modified males would produce non-viable offspring. 

I DON'T THINK THERE'S NECCESSARILY A CORRELATION.  But it's a HELL of a coincidence. 

[Rusty Edge]

Interesting.

Even if there is no correlation between the two, it will take a long time to prove it. There will be a lot of squak about any genetically modified insect being released, regardless.

Bottom line, no relief on that front in the USA any time soon.

[Unorthodox]

There will be a lot of squak about any genetically modified insect being released, regardless.

I highly doubt you'll hear much about it to be honest, unless there proves to be a correlation.  It's just rather convenient a mosquito that was engineered to cause birth defects' species is now causing birth defects in non-target species.  The genetic mod for the mosquitoes is essentially the lysine contingency from Jurassic Park.  Without a regular feeding of whatever the denied critical piece is, the offspring cannot develop normally and thus die at the pupa stage.  Zika is closely related to West Nile and Dengu Fever, did it somehow evolve inside these engineered insects, I cannot even guess at.  It's just rather curious. 

[Rusty Edge]

http://www.nytimes.com/interactive/2016/health/what-is-zika-virus.html?_r=0

Well, I foresee myself being disqualified as a blood donor. Without a blood test, they will work from a country list and a time period, like they did with AIDS and Mad Cow.

Puerto Rico, The US Virgin Islands and basically the Lesser Antilles are already on a don't go list for pregnant women.

[Unorthodox]

Heh.

https://www.washingtonpost.com/news/to-your-health/wp/2016/01/29/heres-how-gm-mosquitos-with-self-destruct-genes-could-save-us-from-zika-virus/

Brazil is latching onto a novel, if controversial, approach to fight the spread Zika virus: genetically modified mosquitoes.

Zika virus is transmitted to humans primarily through the bite of an infected Aedes species, such as Aedes aegypti, the yellow fever mosquito.

No vaccine or treatment exists to combat the infection, which public health officials are worried may be linked to a brain defect in infants and a rare neurological syndrome that could cause paralysis in adults. The World Health Organization has expressed alarm at the explosive spread of the virus in the Americas in recent months and says as many as 3 to 4 million people could become infected.

Releasing even more of these insects into the wild seems like the last thing a Zika-stricken country needs, but Brazil’s National Biosafety Committee recently approved multiple releases of genetically modified Aedes aegypti throughout the country. Essentially, the plan is to turn their own species against them.

 [WHO: Zika virus could explosively spread, level of alarm extremely high] 

Created by Britain-based Oxitec, a spin-off company from Oxford University that is a subsidiary of Intrexon Corp., these mosquitoes contain a self-destruct mechanism within their DNA in the form of an inserted gene. This gene produces a protein called tetracycline repressible activator variant (tTAV), which ties up the cell's machinery and prevents the expression of other genes key to survival. As a result, the insect dies before it reaches adulthood.

But if reared on a diet with a special antidote — the antibiotic tetracycline, which binds and inactivates tTAV — the self-destruct mechanism will never switch on.

 [Zika virus FAQ: What is it, and what are the risks as it spreads?] 

Oxitec feeds its genetically modified mosquitoes tetracycline so they can survive and reproduce in the lab. For pest control purposes, mature males carrying the self-destruct gene are gathered up and released into the wild to mate with females. Offspring who inherit the gene will die without the tetracycline antidote, causing the mosquito population to drop drastically — and hopefully with it, the threat of disease.




“We've trialed this technology in the Cayman Islands, in Brazil and in Panama through four different trials, and we have shown up to 99 percent control of the mosquito population,” said Derric Nimmo, Product Development Manager at Oxitec, in a company video. In April, Oxitec started releasing its so-called “self-limiting” mosquitoes in Piracicaba, a city in the Campinas region of São Paulo state, and reported an 82 percent reduction in wild larvae by the end of the calendar year.

Because Aedes aegypti is considered the primary vector for dengue, Chikungunya and Zika viruses, the company has focused extensively on this species for public health applications. For surveillance purposes, its mosquito products also contain a heritable, fluorescent marker to differentiate between altered insects and wild ones. Monitoring the ratio of genetically modified vs. wild mosquitoes in traps after a release can help gauge whether more product is needed to further suppress the pest population.

This genetic approach and others — for instance, those that render insects infertile or disease-resistant — represent a new spin on the classical Sterile Insect Technique (SIT). During the 1930s and 1940s, the idea of SIT was conceived as a method of “birth control” for unwanted insect species. Males would be rendered sterile by exposing them to massive amounts of radiation, then released to mate with females. SIT was used to eradicate the screwworm, a deadly parasite of livestock, from the United States in the 1950s, and to tame pink bollworm moth populations in California's cotton fields since 1967.

 [CDC issues interim Zika guidelines for testing infants] 

Oxitec's scientists have also created self-limiting versions of common agricultural pests in the hopes of minimizing crop losses. One example is the diamondback moth, an insecticide-resistant nuisance that feeds exclusively on brassicas, such as broccoli and cabbage. Oxitec and Cornell University are planning field tests to be conducted in the summer in upstate New York, which have been granted approval by the U.S. Department of Agriculture.




One big question is whether manipulating the ecosystem in this way will have unintended, negative consequences.

Oxitec has come under criticism from various environmental groups that remain concerned about the possible effects of releasing a new strain of organism into the wild. For instance, a drastic drop in mosquito population could lead to harmful insects or other animals multiplying uncontrollably.

Supporters of genetically modified insects say self-limiting species target only one species, can still be eaten safely by predators, and are more effective/safe than insecticides. Also, the altered males and their offspring die off quickly due to the tTAV gene.

“In that sense, we're only removing Aedes aegypti and nothing else from the environment,” Nimmo said. “It's pinpoint accuracy. It's going in with a scalpel and taking away Aedes aegypti, leaving everything untouched.”







What you need to know about the Zika virus
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Play Video1:10


















 





















































Authorities have confirmed a dozen cases of Zika virus in the United States. Here's what you need to know. (Gillian Brockell/The Washington Post)

[Rusty Edge]

Well, I'm unsure. 

Couple interesting tidbits on Zika and Aedes Aegyptica. 

Zika originated in Aedes Aegyptica in Brazil, and has spread to other Aedes mosquitos, including the arboreal ones I would normally recommend as natural competitors and even predators.  While these don't spread it to humans, they do spread the virus among other mosquitoes. 

It's arrival is relatively shortly after widespread release of genetically modified Aedes Aegyptica mosquitos in Brazil (which is serving as a test bed) that were engineered so that females that mated with the genetically modified males would produce non-viable offspring. 

I DON'T THINK THERE'S NECCESSARILY A CORRELATION.  But it's a HELL of a coincidence.

What exactly are the mosquito mechanics, here?

Infection- Is it passed from feeding on the same plant or animal host?

Are there other  methods of viral transmission, such as sexual contact among mosquitos ?

Predation- Do some mosquito actually suck the blood of other species of mosquito?  Can the host survive this?

[Rusty Edge]

Jamaica reports its first case of Zika virus
http://www.usatoday.com/story/news/2016/01/30/jamaica-reports-first-case-zika-virus/79563246/


"Jamaican health officials confirmed the Caribbean nation's first case of the Zika virus Saturday in a 4-year-old child who recently returned from a trip to Texas.

The child, who has now recovered, began showing symptoms Jan. 17 after visiting the U.S. state, Jamaica's Ministry of Health said in a statement.

It's unclear whether the child picked up the virus in Jamaica or Texas."

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Well, if it's in Mexico, it would spread to Texas more easily than to Jamaica. But then again, Jamaica is only 2 or 3 days from Mexico by cruise ship, and less to the from the Lesser Antilles.

[Unorthodox]

Well, I'm unsure. 

Couple interesting tidbits on Zika and Aedes Aegyptica. 

Zika originated in Aedes Aegyptica in Brazil, and has spread to other Aedes mosquitos, including the arboreal ones I would normally recommend as natural competitors and even predators.  While these don't spread it to humans, they do spread the virus among other mosquitoes. 

It's arrival is relatively shortly after widespread release of genetically modified Aedes Aegyptica mosquitos in Brazil (which is serving as a test bed) that were engineered so that females that mated with the genetically modified males would produce non-viable offspring. 

I DON'T THINK THERE'S NECCESSARILY A CORRELATION.  But it's a HELL of a coincidence.

What exactly are the mosquito mechanics, here?

Infection- Is it passed from feeding on the same plant or animal host?

I'm not hugely up to speed on the viral shedding of the Dengu Fever and relatives.  However, mosquitoes are all aquatic as larva, I'm going to guess at the virus spreading there.  Though, female feeding on infected host and passing to the young is possible as well. 

Are there other  methods of viral transmission, such as sexual contact among mosquitos ?

Again, that's a virus question, not a mosquito one. 

Predation- Do some mosquito actually suck the blood of other species of mosquito?  Can the host survive this?

Arboreal mosquitoes (eat nectar as adults) tend to be predators at the larval stage.  (thus Uno's theory of mosquito control is to release arboreal ones)

[Valka]

We've got a decent mosquito-killing program here, one that targets the larvae and isn't as hard on the rest of the environment.

Every year people are warned what to wear/not to wear, try to avoid being active in the dawn/twilight hours (while simultaneously not being active during the hottest hours of the day), don't walk through tall grass, don't leave water standing around in bird baths, uncovered rain barrels, or tires, and numerous other ways to avoid being bitten.

My way is to basically avoid being outdoors in summer as much as possible. Mosquitoes love me, the bites drive me nuts, and as I get older my immune system tends to go haywire in weird ways. I don't dare get bitten or stung by insects.

In addition to vaccines, a stronger push for mosquito nets would help considerably in those southern countries.

[Unorthodox]

We've got a decent mosquito-killing program here, one that targets the larvae and isn't as hard on the rest of the environment.

2 most common methods:

seeding standing water with the same bacteria that is used to make genetically modified corn. (recently some resistance has been found to this thanks to the wholesale useage lately, too)
spraying of Neonicotinoids, which there is growing evidence of it harming the environment, not just the bees, but birds as well. 

[Rusty Edge]

Am I the only one here who thinks of Flash Gordon almost every time he reads the word "arboreal" , or for that matter, the nickname "Mongo" ?