Truth About Zika?

 The Washington Post reports that, almost nine months after Zika was declared a global health emergency, the virus has infected at least 650,000 people in Latin America and the Caribbean, including tens of thousands of expectant mothers.

But to the great bewilderment of scientists, the epidemic has not produced the wave of fetal deformities so widely feared when the images of misshapen infants first emerged from Brazil.

Instead, Zika has left a puzzling and distinctly uneven pattern of damage across the Americas. According to the latest U.N. figures, of the 2,175 babies born in the past year with undersize heads or other congenital neurological damage linked to Zika, more than 75 percent have been clustered in a single region: northeastern Brazil.

The pattern is so confounding that health officials and scientists have turned their attention back to northeastern ­Brazil to understand why Zika’s toll has been so much heavier there. They suspect that other, underlying causes may be to blame, such as the presence of another ­mosquito-borne virus like chikungunya or dengue. Or that environmental, genetic or immunological factors combined with Zika to put mothers in the area at greater risk.

 

“We don’t believe that Zika is the only cause,” Fatima Marinho, director of the noncommunicable disease department at Brazil’s Ministry of Health, said in an interview.

Brazilian officials were bracing for a flood of fetal deformities as Zika spread this year to other regions of the country, Marinho said. However, “we are not seeing a big increase.”

Researchers and health officials remain cautious about the lower-than-expected numbers. The latest studies have found more evidence than ever that the virus can inflict severe damage on the developing infant brain, some of which may not be evident until later in childhood.

New York’s Aedes Mosquito Program

New York’s health department has and Aedes mosquito eradiction program and is investing in new technologies to halt the rapid spread of dengue fever in the densely populated city.

An Asian tiger mosquito. Credit: CDC/Wikimedia Commons                          Asian tiger mosquito: CDC/Wikimedia

If you haven’t spent a summer in New York you may not know how tropical its climate can be. Months of sultry heat and cloudbursts make mosquito outbreaks common. Mosquitos and mosquito-borne diseases have been part of New York life for centuries but the recent establishment of Aedes Aegypti has raised new problems.  Health department trucks have been spraying pesticide in the streets and flyers on street corners urge people to stay indoors.

New York Health Department has been using a mosquito “adulticide” this year: pesticides which kill flying insects rather than their larvae. It’s  usually done as a last resort when other methods have failed but this year, New York has been spraying aggressively to eliminate Aedes albopictus, a carrier of the Zika virus, and switching to a new insecticide that specifically targets Aedes.

Like Delhi, Singapore and Miami, New York is struggling to contain Dengue outbreaks caused by Aedes aegypti, the primary carrier for a host of viruses like chikungunya and Zika. Delhi’s chikungunya outbreak resulted in more than a thousand new cases reported last week. In New York, Aedes cousing, Aedes albopictus (aka Asian tiger mosquito) has not infected anyone yet but the health department is treating the mosquito like a disease carrier. NYHD announced a three-year, $21 million Zika prevention campaign and much of that is being spent on mosquito control. At a recent event, NYHD health commissioner Dr. Mary Bassett said, “We’re just trying to kill the Aedes mosquito.”

Aedes albopictus is known to carry more than 20 viruses and was responsible for a global chikungunya epidemic ten years ago. A native of Southeast Asia, it has spread far and wide and is on the list of 100 most invasive species on the planet. The Asian tiger was first discovered in the USA in a mosquito trap in a Memphis cemetery in 1983. Since then it’s spread to 40 states and today can be found as far north as Maine. Investigators suspect it arrived in the US in used auto tires from Japan or Taiwan.

Many New Yorkers have felt its bite at a backyard barbeque. “The entire metropolitan area is infested,” says Dr. Laura Harrington, Chair of the Department of Entomology at Cornell University. She and her students are  mapping Aedes albopictus spread in the Hudson valley and have been picking up dead mosquitos from back yards across Westchester County. Long, hot summers and unpredictable weather have contributed to the growth of the mosquito in the New York area, Harrington says.

NYHD is aware that mosquito-borne diseases can spread rapidly in densely populated urban areas (Aedes is an urban, indoor mosquito) and is experimenting with the novel the BG-Sentinel trap, which has  proven useful in capturing Aedes and tracking mosquitoes in their natural habitat like back yards, cemeteries and public parks. A collapsible, fabric container the size of an ice bucket, it releases ammonia, lactic acid and a  chemical cocktail that mimic the scent of human skin. The New Yorker says the traps “smell like a hot subway car during rush hour.” The traps’ contents, a heap of dead mosquitoes, are sent to a public health lab where they are tested for the presence of Zika virus.

NYHD made a user-friendly mosquito map based on tracking data with  orange dots marking Aedes hotspots and blue dots for the Culex mosquito (West Nile virus carrier). The department is sharing this information with the public for the first time this year. The northern Queens neighbourhood of College Point, which was “ground zero” for the West Nile epidemic of 1999,  has the highest mosquito counts because local wetlands and marshes are an ideal breeding ground for Culex but now there are signs that the Asian tiger presence is growing. “I’ve picked lots of Aedes in College Point,” says Dr. James Cervino, a Queens-based marine biologist who’s been examining neighborhood mosquitoes in as part of his research on climate change. Queens, he says has a number of  “blighted areas” with thriving mosquito populations and the interactive map hotspots are just the tip of the iceberg.

Forested and swampy areas in Queens, Brooklyn, the Bronx and Staten Island are the focus of mosquito control efforts early in the season. Ponds and lakes are treated with larvicide dropped by helicopter.

Because Aedes albopictus hides in tree holes and stumps, sprayed insecticides which kill adult mosquitoes are less effective in there . The new pesticides this year may help overcome this.  Duet (the commercial name for the pesticide) has an added an ingredient, which acts as an irritant to draw mosquitoes out of their hard-to-reach spots and forces them to fly around. Once airborne, the mosquito comes in contact with an ultra-low volume spray of a synthetic pyrethroid called sumithrin, which kills them on contact. Duet was tested at the Center for Vector Biology at Rutgers University and found to be almost  100% effective on a sample of Asian Tiger mosquitoes from New Jersey.

New York has the largest outbreak of Zika cases in the US: 599 people have the disease, tough all contracted the virus overseas. Mayor Bill de Blasio pointed out that the city is home to a large Caribbean and Latin American community: “Right now, the central challenge is people who bring it back”.  Pregnant women are urged not to travel to these regions as the virus can cause severe birth defects including microcephaly. In some Bronx immigrant neighborhoods the virus is already a concern. “We have quite a few cases of pregnant women from the Dominican Republic with Zika.” said Dr. Tammy R. Gruenberg, an obstetrician at the Women’s Health Pavilion at Morris Heights Health Center.  Doctors there have been handing out prevention kits to pregnant women planning trips to a Zika-affected countries. The kit contains insect repellent spray, condoms and two donut-shaped “dunks” that kill mosquito larvae in standing water.

With temperatures dropping, the threat of locally transmitted Zika in New York is dropping but the Asian tiger mosquito is still a concern. To truly defeat Aedes, Laura Harrington feels big cities cannot just rely on larvicides and pesticides: “We’ve been spraying for decades. We need new ways to target mosquitoes, safer insecticides and rapid development of vaccines.”

 

Dengue Zika Mosquitoes

The Dengue mosquito is aedes aegypti and the zika mosquito is aedes albopictus, usually called ‘The Asian tiger mosquito’Aegypti feeds mornings and evenings, while albopictus feeds during the day. This is the dengue mosquito, Aedes Aegypti:

Dengue Pandemic Vector
Dengue Pandemic Vector

The Asian tiger mosquito particularly bites in forests during the day, so has been known as the forest day mosquito. This is Aedes Albopictus:

Aedes Albopictus the Zika Mosquito
Aedes Albopictus the Zika Mosquito

It takes an expert to tell the difference!

Depending upon region and biotype, activity peaks differ, but for the most part, they rest during the morning and night hours. They search for their hosts inside and outside of human dwellings, but are particularly active outside. The size of the blood meal depends upon the size of the mosquito, but it is usually around 2 μl. Their bites are not necessarily painful, but they are more noticeable than those from other kinds of mosquitoes. Tiger mosquitoes generally tend to bite a human host more than once if they are able to.[22][24]

Ae. albopictus also bites other mammals besides humans, as well as birds.[22][24] The females are always on the search for a host and are persistent but cautious when it comes to their blood meal and host location. Their blood meal is often broken off before enough blood has been ingested for the development of their eggs, so Asian tiger mosquitoes bite multiple hosts during their development cycle of the egg, making them particularly efficient at transmitting diseases. The mannerism of biting diverse host species enables the Asian tiger mosquito to be a potential bridge vector for certain pathogens that can jump species boundaries, for example the West Nile virus.

Here’s a video explaining the two mosquitoes’ habits:

Dengue Health Insurance?

Holy cow, now we’ve got dengue health insurance!

Dengue Mosquito Net: insurance?
Dengue Mosquito Net: insurance?

“We have now moved into digital under the overall ambit of protection focus that we have. We could have easily gone digital with a term plan or ULIPs. That was not our idea of going digital. We wanted to use a very relevant product as our strategy to go digital”, Anoop Pabby, Managing Director & CEO, DPLI told Business Line here.

DHFL Dengue Shield is an affordable Dengue Insurance Policy with premium as low as ₹ 1 per day. It is fixed benefits policy and no detailed bills at the time of claim.

An individual has the option to choose sum insured from ₹ 25,000 to ₹ 50,000. Options of both Single and annual premium payment exist in Dengue Shield where a customer can enjoy a discount of up to 21 per cent on Single Premium payment.

Pabby also said that group version of Dengue Shield would soon be available.

DPLI has signed an agreement with Itz Cash to provide customer awareness about Dengue Shield through their 20,000 plus retail touch points in Delhi for the initial phase.

Meanwhile, Pabby said that DPLI was aiming at a new business premium of ₹ 1,000 crore this fiscal. This aim represents 36 per cent increase over new business premium of ₹ 736 crore recorded in 2015-16.

srivats.kr@thehindu.co.in

Dengue Zika Larvicides

Are Dengue, Zika and GM Mosquitoes Connected by a larvicide?

Could it be that Dengue, Zika and Larvicides are connected? Dengue, and outbreak of Zica, and GM mosquitoes are being discussed in the same breath. The Zica disease is similar to dengue, and the two have long cohabited, but Zica has never afflicted as many people as seriously as it is doing in Brazil. The fact that the range for zica’s vectors overlaps the aedes aegypti range – and  that there’s a GM mosquito test going on within that vast territory – suggest that the presence of the GM mosquitos and the outbreak of zica are probably coincidental. Especially since the date of release of the GM insects is given as 2015 – hardly sufficient time to breed and spread zica so far.

Zica Map
Zica Map

There’s always a chance that an Oxitec mosquito is to blame, but here’s a persuasive article suggesting that a chemical is to blame and Zica is not the culprit:

Argentine and Brazilian doctors name larvicide as potential cause of microcephaly:

report from the Argentine doctors’ organisation, Physicians in the Crop-Sprayed Towns,[1] challenges the theory that the Zika virus epidemic in Brazil is the cause of the increase in the birth defect microcephaly among newborns.   The increase in this birth defect, in which the baby is born with an abnormally small head and often has brain damage, was quickly linked to the Zika virus by the Brazilian Ministry of Health.

However, according to the Physicians in the Crop-Sprayed Towns, the Ministry failed to recognise that in the area where most sick people live, a chemical larvicide that produces malformations in mosquitoes was introduced into the drinking water supply in 2014. This poison, Pyriproxyfen, is used in a State-controlled programme aimed at eradicating disease-carrying mosquitoes.  The Physicians added that the Pyriproxyfen is manufactured by Sumitomo Chemical, a Japanese “strategic partner” of Monsanto.

Pyriproxyfen is a growth inhibitor of mosquito larvae, which alters the development process from larva to pupa to adult, thus generating malformations in developing mosquitoes and killing or disabling them. It acts as an insect juvenile hormone or juvenoid, and has the effect of inhibiting the development of adult insect characteristics (for example, wings and mature external genitalia) and reproductive development. It is an endocrine disruptor and is teratogenic (causes birth defects), according to the Physicians.The Physicians commented: “Malformations detected in thousands of children from pregnant women living in areas where the Brazilian state added Pyriproxyfen to drinking water are not a coincidence, even though the Ministry of Health places a direct blame on the Zika virus for this damage.” Read more here….

Fighting Zika – Not The Virus Itself – Might Have Caused Birth Defects

June 26, 2016

The media said that the mosquito borne Zika virus is likely causing microcephaly as well as dozens of other illnesses. They also claimed that insecticides were not related to the development disorder. They seem to have been wrong on both cases.

Since December 2015 U.S. media ran a panic campaign round the Zika virus. That virus was said to cause many bad things including microcephaly, a development distortion of the head  of unborn babies, if the mother was infected with Zika during pregnancy.

After looking into the issue and the available data I concluded that: The Zika Virus Is Harmless:

The virus is long known, harmless and the main current scare, that the virus damages unborn children, is based on uncorroborated and likely false information.

There is absolutely no sane reason for the scary headlines and the panic they cause.The virus is harmless. It is possible, but seems for now very unlikely, that it affects some unborn children. There is absolutely no reason to be concerned about it.

As this is all well known or easy to find out why do the media create this sensation?

By March the media attributed all known human ills to Zika though every headline doing so included a telltale caveat may. I mocked these in Reading About Zika May Hurt Your Brain

[E]ven while Zika is known to be less harmful than an average flue, one headline after the other tries to create the impression that it is some really awful, new bug that may be responsible for about any ailment. That it may spread like wildfire and may have other terrible consequences. May, as in ‘the sky may fall’, is indeed the most operative word here.

There followed a collection of 35 recent “Zika may cause …” headlines.

Meanwhile doctors in the Zika affected areas in Brazil pointed out that the real cause of somewhat increased microcephaly in the region was probably the insecticide pyriproxyfen, used to kill mosquito larvae in drinking water:

The Brazilian doctors noted that the areas of northeast Brazil that had witnessed the greatest number of microcephaly cases match with areas where pyriproxyfen is added to drinking water in an effort to combat Zika-carrying mosquitoes. Pyriproxyfen is reported to cause malformations in mosquito larvae, and has been added to drinking water in the region for the past 18 months.

Pyriproxyfen is produced by a Sumitomo Chemical – an important Japanese poison giant. It was therefore unsurprising that the New York Times and others called the doctors report a “conspiracy theory” and trotted out some “experts” to debunk it.

But facts are facts and as these come to the fore the embarrassed media will now likely stay silent.

The New England Complex Systems Institute in Cambridge just published a new study that falsifies the assumed link between Zika and microcephaly. Science Daily reports:

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? Perhaps there is another reason for the epidemic in Brazil.

Well, maybe those doctors on the ground in Brazil knew what they were talking about. The scientist at the New England Complex Systems Institute also researched the pyriproxyfen thesis. They found.. Read more..

Then there’s this article from Bloomberg:

Genetically modified mosquitoes that would help fight the Zika virus are getting urgent attention from U.S. regulators as global health officials raise alarms about the pathogen’s spread. The U.S. Food and Drug Administration is in the final stages of reviewing an application from Intrexon Corp.’s Oxitec unit to conduct a field trial in the Florida Keys, Oxitec Chief Executive Officer Hadyn Parry said in a phone interview. Parry wasn’t able to provide further details on the timing of an FDA decision.
Oxitec genetically modifies the males in a breed of mosquito known as Aedes aegypti — responsible for transmitting Zika, Dengue, Chikungunya and Yellow Fever — so that their offspring die young. The Zika virus has been spreading “explosively” in South and Central America, the World Health Organization said Thursday. Developing a vaccine could take years, drugmakers and health experts have cautioned.

Here’s the background: Oxitec, an American-owned British company, has been working to develop a genetically modified mosquito in hopes of controlling dengue outbreaks on a broad scale. They breed and release millions of modified insects in populated areas where dengue is endemic. The story below,

 

In 2015 Oxitec proudly announced  that the mosquitos they’d genetically modified – which they call ‘friendly Aedes aegypti’ – had decimated the local mosquito population in a field trial in Juazeiro, Brazil by 95%. New dengue cases were way below the modelled threshold for epidemic disease transmission.

Dengue Zika juazeiro map
Dengue Zika juazeiro map

Here’s a map showing where the deformed babies are being born:

dengue zika brazil
dengue zika brazil

Zika was first confirmed in Brazil in May, 2015, but had been seen in other nations before. But Zika in Brazil does not seem to behave like the Zika they were familiar with.

Questions

  1. Why didn’t zika cause an epidemic of birth defects in any other country?
  2. How would you miss a tenfold increase in children born with most of their brain missing?
  3. Could the Zika epidemic be linked to genetically modified mosquitoes?

Oxitec released a strain of male mosquitoes in Juazeiro which create larvae that normally die in the absence of antibiotics. This is supposed to help decimate wild mosquito populations when these males are released in the wild. But Oxitec estimates 3-4% of the larvae survive to adulthood in the absence of the tetracycline antibiotic. These larvae should then be free to go on and reproduce and pass on their genes. In fact, they may be the only ones that are passing on their genes in places that have their wild mosquito population decimated by these experiments. Here are some questions whose answers we’ll post as they come in:

What is the effect on these mosquitoes that grow up with a mutilated genome?

Will the genetic modification introduce a fitness cost?

Should they have greater difficulty surviving?

What do we know about Oxitec’s mosquitoes?

Has sufficient research been done on how a genetically mutilated mosquito copes with viral infections?

Could Oxitec’s mosquito be more susceptible to certain pathogens?

Could it pass those pathogens onto humans?

Stay tuned. In the meantime, here’s the Malaysian Government’s Biosafety assessment of the Oxitec experiment. And here’s news of the first Zica lab test, developed in Germany.