Zika is More Related to Culex-Associated Viruses

Canadian medical entomologist, Dr. Fiona Hunter, at the Zika Symposium at 2016 International Congress of Entomology
Credit: Screenshot of Dr. Fiona Hunter at the 2016 International Congress of Entomology [Fair Use]

WHO Failed to Warn Countries About Culex

We are back to square one, unfortunately. Zika is still spreading throughout the world. And the scientists who suspected Culex were also Zika vectors are being proven right. 

My intro photo shows Canadian medical entomologist, Fiona Hunter, presenting her findings at the 2016 International Congress of Entomology's Zika Symposium. 
Her slide represents what desperately needs to be acknowledged in the scientific community:
The Zika virus (ZIKV) is not a hemorrhagic disease, even though the CDC, WHO, and mainstream media only compare it to dengue (DENV) and yellow fever (YF).
Zika targets the nervous and reproductive system and is supported 99 percent within the clade shared by West Nile (WNV) and St. Louis encephalitis (SLE).[1][2]
As depicted in Dr. Hunter's slide and mentioned by Dr. Ayres:[2]

"Zika is more related to the viruses transmitted by Culex." 

I highly recommend you listen to Canadian medical entomologist, Dr. Fiona Hunter, at the Zika Symposium at 2016 International Congress of Entomology. Her talk begins at the 58:53 mark. 

Dr. Constância F. J. Ayres, also an entomologist, was the lone voice that alerted the WHO in February 2016 that the Culex genus of mosquitoes are also likely Zika vectors (particularly Culex quinquefasciatus). She pointed out that the few earliest studies did not even address the Culex genus. Her speech beings (in the same video) at the 30:12 mark.

As cited in my article Wolbachia-Infected Mosquitoes Might Reduce Dengue, Enhance Zika, and Cause a Million Souls to Become Sterile

St. Louis encephalitis virus (SLE) belongs to the family Flaviviridae (group B arboviruses). The principal reservoirs of SLE include wild birds and domestic fowl, and the virus is transmitted to humans by mosquitoes, namely Culex tarsalis, Culex quinquefasciatus, and Culex pipiens.
So it makes sense that Zika would also be found in (and possibly amplified) in birds.
Dr. Aileen Marty, a member of WHO's Advisory Group on Mass Gatherings, Risk Assessments, Command & Control, EID (Emerging Infectious Diseases) responded to my concerns with: "... none of what you have written makes sense. You are misunderstanding a lot of complex scientific data. In fact you have recompiled the data in a way that has no basis in fact."
Yet others, including Duane Gubler, a virologist at Duke-NUS Medical School in Singapore, noted that several Zika relatives spread by Culex mosquitoes (including West Nile virus) target the nervous system which ZIKV also seems to do.
According to a 1986 study by Kimura-Kuroda, J and Yasui, K called Antigenic comparison of envelope protein E between Japanese encephalitis [JE] virus and some other flaviviruses using monoclonal antibodies:[3]
Japanese encephalitis (JE) virus, belonging to West Nile (WNV) subgroup, is antigenically closely related to viruses in the same subgroup, i.e. Murray Valley encephalitis (MVE), WNV and St. Louis encephalitis (SLE) viruses.[3]
WNV is relatively close to JE virus, whereas SLE virus is the least closely related.[3] 
Dengue viruses types 1 and 2, which belong to another subgroup of flaviviruses, show markedly less antigenic homology to JE virus.[3] There are four types of dengue.
I created another cladogram, shown next (based on Dr. Fiona Hunter's slide) which includes Japanese encephalitis (JE). You'll understand why I included it further along.

15 Percent of Birds Had ZIKV (in Uganda, 1970)

Cladogram showing Zika's placement and Japanese encephalitis included
Credit: RoseWrites (Created Jan. 3, 2017) All Rights Reserved. Brain by Looie49 [Public domain], via Wikimedia Commons; Pig by Joshua Berry on flickr [Public Domain]

Japanese Encephalitis Virus Has Multiple Vectors

So, It's Reasonable to Expect That the Zika Virus Does Too

According to the study Vectors of Japanese encephalitis virus (JEV): species complexes of the vectors[5] by Sucharit S, Surathin K, and Shrestha SR, the vectors of JE include nine types of Culex, three types of Aedes, and two types of Anopheles mosquitoes.

As mentioned in the 2006 study by Tsai KH et al. Parallel Infection of Japanese Encephalitis Virus and Wolbachia within Cells of Mosquito Salivary Glands:[4]

  • Wolbachia infection is absent in many important disease-transmitting mosquitoes, including the Japanese encephalitis (JE) vector Culex tritaeniorhynchus Giles, the dengue vector Aedes aegypti (L.), and the malaria vectors (Anopheles spp.) (Kittayapong et al. 2000, Tsai et al. 2004).
  • JE [and other viruses, like Zika] must infect and subsequently pass through the epithelium of mosquito midguts to reach salivary glands for further replication before transmission can occur.
  • Whether the distribution of Wolbachia, JE virus or both is related to specific enzyme synthesis is not clear.
  • Colocalization of Wolbachia with clustered JE virions revealed that these two microorganisms live in same environment.
  • Whether the endosymbiont [Wolbachia] would interfere with the transmission of arboviruses remains to be demonstrated.
Shocked Lemur with Text about Wolbachia by RoseWrites
Credit: Red-ruffed Lemur by Mathias Appel [Public Domain] Text by RoseWrites

Wolbachia Might Enhance Pathogen Infection

Depending on the Host-Wolbachia-Pathogen Combination

As mentioned in the 2015 study by Raquin V et al. called Native Wolbachia from Aedes albopictus Blocks Chikungunya Virus Infection:[6]

"In some cases Wolbachia may have no effect or even enhance pathogen infection, depending on the host-Wolbachia-pathogen combination."

And the 2015 study by Jakob F. Strauß and Arndt Telschow called Modeling the indirect effect of Wolbachia on the infection dynamics of horizontally transmitted viruses[7] caused me to understand how linear thinking (in relation to how Zika is transmitted) is flawed. It states:

It was shown that the presence of a virus facilitates the invasion of Wolbachia. And it's important to note what Strauß and Telschow recognize "empirical data for wild populations are lacking".[7]

Eliminate Dengue states: "Our aim is to spread Wolbachia into wild mosquito populations to reduce the ability of these mosquitoes to transmit disease."[8]

The problem is: mosquitoes that are already infected with viral diseases, namely Zika, will become more easily infected with Wolbachia (which will act as a catalyst) to promote virus replication and survival.

Strauß and Telschow pointed out:
A growing number of studies report that Wolbachia directly interferes with viruses and other pathogens inside the arthropod host. This direct effect of Wolbachia can either impede or promote the pathogen's replication and survival (Zug and Hammerstein, 2015).[7]
Examples of neutral or pro-pathogenic effect of Wolbachia include: Brugia pahangi (Dutton and Sinkins, 2005); Japanese encephalitis (JE) Virus (Tsai et al.,  2006); Drosophila C Virus (Osborne et al., 2009); and Plasmodium gallinaceum (Baton et al., 2013).[7]
And two more pro-pathogenic effects of Wolbachia that I mentioned in my post Zika: The Warnings About Wolbachia and Culex Our Health Authorities are Ignoring:
Dr. Jason Rasgon at Penn State’s entomology department discovered:

Culex mosquitoes treated with Wolbachia were MORE likely to carry the virus.

At the time, Dr. Rasgon was trying to confirm if Wolbachia could help control the spread of West Nile Virus (WNV) which is transmitted by Culex mosquitoes. He expected Wolbachia to block WNV, but it didn't. 

"We had to repeat it a couple times before we actually believed the result. I can’t believe this is just a fluke. If you keep looking, you’ll probably find more examples of it." ~ Dr. Jason Rasgon

A 2014 study called Wolbachia Increases Susceptibility to Plasmodium Infection in a Natural System[9] by Zélé F et al. found:

Using a completely natural mosquito-Wolbachia-Plasmodium combination, results suggest that naturally Wolbachia-infected mosquitoes may, in fact, be better vectors of malaria than Wolbachia-free mosquitoes.[9]

The mosquitoes used in this study were the same ones that Dr. Ayres warned the WHO about in February 2016: Culex pipiens quinquefasciatus. 


Unfortunately, By Increasing Larval Mortality

Invasion of Viruses is Easier and Virus Frequencies Rise

The key result of the study by Strauß and Telschow is that Wolbachia affect the virus dynamics indirectly because Wolbachia-induced reproductive phenotypes (MK [male killing] or CI [cytoplasmic incompatibility]) reduce larval density in infected populations.[7] 
They explain:
  • Our theoretical analysis suggests that the host life cycle may be an important factor for the success or failure of such biocontrol programs.
  • A biocontrol program may be successful only in certain geographical regions or at certain time in the year. This argues for the need to carefully test for over- and under-compensation before and during the release of Wolbachia to natural populations.[7]
Dr. Anthony James, University of California-Irvine, stressed to Dr. Thomas Scott, University of California-Davis, at the Zika Symposium about this technology (and others):

"These genetic tools might not be the best strategies for ZIKV given that at this point there seem to be multiple vectors not only at the species but also at the population level. The current genetic technologies would not be appropriately applied to such complex systems."[1]

How Long Have Scientists Known About the Risks?

A study published December 28, 2008 called The Bacterial Symbiont Wolbachia Induces Resistance to RNA Viral Infections in Drosophila melanogaster[14] by Luís Teixeira, Álvaro Ferreira, and Michael Ashburner states:

"However, introducing Wolbachia to virus-transmitting vectors could be a double-edged sword. If the interaction Wolbachia-vector-virus were similar to the one seen in this report with DCV [Drosophila C virus], then it would be beneficial because it could decrease the probability of the vector being infected or transmitting the disease."[14] 

"If, however, it were similar to the interaction with FHV [Flock House virus], then there would be the risk of having healthier infected vectors with high titers of viruses, therefore INCREASING disease transmission."[14]

Notably, this same study also stated: 

"It was also reported recently that the presence of gut flora slightly increases the resistance of Aedes aegypti to Dengue virus, presumably through activation of the Toll pathway."[14]

Perhaps the claims of Wolbachia-infected Aedes reducing "the ability of these mosquitoes to transmit disease" are overblown.

Does Wolbachia Increase Larval Mortality?

According to the study by Ross, P et al. called the Costs of Three Wolbachia Infections on the Survival of Aedes aegypti Larvae under Starvation Conditions:[10] 

We find that all three Wolbachia infections [wMel, wMelPop, and wAlbB] reduce the survival of larvae relative to those that are uninfected.
Keep in mind, what happens in the natural environment is what will ultimately impact humans.
These scientists also noted:
Whether water was refreshed in each well or left unmanipulated had a dramatic effect on survival.
How often in the natural environment will water be "refreshed"?
When water was not replaced, all three Wolbachia infections reduced survival; the wMel, wAlbB and wMelPop infections decreased mean survival 15.8, 28.8 and 28.7% compared with uninfected larvae.[10]
Credit: Red-ruffed Lemur by Mathias Appel [Public Domain] Text by RoseWrites
According to Eliminate Dengue (and my correspondence with them on Facebook), they use precisely the same Wolbachia strains as mentioned in this study: wMel, wMelPop, and wAlbB.

An Analogy to Depict the Behavior of Wolbachia

Wolbachia comparison to bouncer at a party and if Zika hosts, Wolbachia helps out
Credit: Bouncer by Incase on flickr (CC-by-2.0) Happy Bouncer by Susan Sermoneta on flickr (CC-by-2.0) Text by RoseWrites

Wolbachia Acts as a Mutualistic Agent

Another study, published May 16th, 2016, called The influence of larval competition on Brazilian Wolbachia-infected Aedes aegypti mosquitoes[11] by Dutra et al. states:

In Australian Aedes aegypti mosquitoes, the wMelPop Wolbachia strain causes infected larvae to develop faster than uninfected individuals under low nutritional conditions and high larval density, whereas the opposite effect occurred when food availability was high and larval density low.[11]

Infected mosquitoes with faster development times also had elevated levels of glycogen.[11] Therefore, Wolbachia-infected mosquitoes would have more energy to fly further (or longer) and this could help in host or oviposition site location [where eggs are laid], as well as invasion.

It appears that "wMel has a complex metabolic relationship with its host, varying between parasitic and mutualistic, with this being the first example of a nutritional mutualism for this strain in mosquitoes".[11]

The Zika Virus is Behaving Like a Bacteriophage

Or is it just a phage Zika is going through?

 Zika as a bacteriophage with Wolbachia
Credit: © 2017 Rose Webster (aka RoseWrites) All Rights Reserved. Phage via NIH website; Zika virus cryo-EM by Starless [both Public Domain]

Could Wolbachia and Zika Be Working Together?

According to the 2015 study by Roman Zug and Peter Hammerstein called Wolbachia and the insect immune system: what reactive oxygen species can tell us about the mechanisms of Wolbachia-host interactions:[12]

In the host cytoplasm, Wolbachia are located within vesicles whose outermost membrane is of host origin (Louis and Nigro, 1989). This probably helps the bacteria to hide from the host immune system. 

This is eerily similar to the quote I cited in my article Zika Shrivels Testes, Drops Testosterone, and May Cause Infertility:

"Researchers have known for some time that Zika can be transmitted via semen from men to women, hiding in the testes, where it can avoid the immune system; in fact, there is mounting evidence that it can continue to replicate in the testes – and even increase the viral load – for months after infection."

Other notable points by Zug and Hammerstein include:
Given their vertical transmission through the female germline and their reproductive manipulations, Wolbachia are expected to reside primarily in the host reproductive tissues.[12]
Wolbachia are also able to infect somatic tissues, including tissues of immunological importance, such as the gut, fat body, and hemolymph (Dobson et al., 1999) (Cheng et al., 2000) (Ijichi et al., 2002) (Zouache et al., 2009) and (Frost et al., 2014).[12]
Wolbachia infection can have a profound influence on mitochondrial DNA (mtDNA) haplotype diversity (Hurst and Jiggins, 2005), and different mtDNA haplotypes can differ in mitochondrial ROS production rates (Ballard, 2005).[12]
The molecular mechanisms underlying Wolbachia-mediated antipathogenic effects are still unclear (Rainey et al., 2014; Johnson, 2015; Zug and Hammerstein, 2015).[12] 

Culex and Birds With Zika Will Acquire Wolbachia

Zika Already Present in Culex and Birds and How They Will Acquire Wolbachia
Credit: Flickr images (all CC-by-2.0): World Map by Christopher Schnese, Artic tern by NatJLN, Mesocyclops by Simon Kutcher, AFAP, Aedes mosquitoes by Ricardo (riyagi), Herring by Jacob Bøtter. Text, Colors, Culex Mosquitoes, and other images by RoseWrites

To Help Stop the Global Spread of the Zika Virus

I created a collection on Zazzle with over 70 products that promote the prevention of the spread of Zika. Every item purchased will help fund Zika research. You can even customize most of the products.[13]

I also have a devoted Facebook page called Zika: Let's Stop a Global Pandemic where you can keep up-to-date on the latest findings from the scientific community (not mainstream media).

My Related Articles About Zika:

Why We Need to Investigate Wolbachia-Infected Mosquito Releases

Birds as Reservoir Hosts of Zika: What You Are Not Being Told

Zika Shrivels Testes, Drops Testosterone, and May Cause Infertility

Author's note: All of my citations have a clickable link to their source. The list is found in the bibliography at the end of this page.