Zika Virus
disease is a nationally notifiable condition in US. As of June 2017, there were
1,997 pregnant women with laboratory evidence of Zika.
There were 8
pregnancy losses and 88 infants born with Microcephaly in US, with the
worldwide estimate being 2,300.
Zika is
spread mostly by the bite of an infected Aedes species mosquito (Ae. aegypti
and Ae. albopictus), although sexual transmission has also been documented.
Although,
Zika virus no longer constitutes an international public health emergency but
according to WHO ‘Zika is here to stay.’
"Although
Zika's spread has waned, it still holds the potential for an explosive
epidemic. If it were to reemerge in the Americas or jump to another part of the
world, it would significantly threaten a new generation of children born with
disabilities such as microcephaly." said Lawrence Gostin, a global health
law expert from Georgetown University.
In this Ted
Talk Molecular biologist Nina Fedoroff takes us around the world to understand
Zika's origins and how it spread, proposing a controversial way to stop the
virus -- and other deadly diseases -- by preventing infected mosquitoes from
multiplying.
A research team from Mexico has determined that three species of wild-caught Culex are Zika vectors. Culex tarsalis are found almost everywhere in the U.S. and Canada. Study: http://www.biorxiv.org/content/early/2017/06/19/151951
ReplyDeleteProblem is: the public has been inundated by millions of images of Aedes and repeatedly told "daytime-active" or "daytime-biters".
Culex, the more worrisome vector, predominantly seek humans for a bloodmeal from July through October. And they are nighttime-active. https://www.youtube.com/watch?v=wAAvJGnBmd4
Bti (Bacillus thuringiensis serotype israelensis) is a group of bacteria that helps eradicate mosquitoes, fungus gnats, and blackflies – yet has almost zero effect on other organisms.
A 1985 study concluded granular formulations of Bti controlled Ae. aegypti in tires for 19 to 33 days and Bti briquets exhibited larvicidal activity in large containers for 26 to 78 days. Source: https://www.ncbi.nlm.nih.gov/pubmed/2466106
A 2003 study stated Bti are highly effective against mosquito larvae at very low doses and safe for other non-targeted organisms. Source: https://www.ncbi.nlm.nih.gov/pubmed/15119068
And Mesocyclops longisetus (a type of zooplankton) prefers to eat Aedes larvae, however, Wolbachia-infected mosquito releases have ruined this form of mosquito eradication. And since 2014, we've had seabirds (esp. arctic terns) and planktivorous fish (herring and recently right whales) dying en masse or having massive breeding failures.
My point with Culex and Wolbachia is simply this: there is more than one vector involved and a dangerous co-factor (Wolbachia). And almost 1/2 of bulbuls (a popular pet bird in southeast Asia) had Zika (Okia et al. 1971). We have yet to pinpoint all the vectors, reservoir and amplifying hosts, and what Wolbachia is doing to vertebrate species.
It is dangerous to introduce genome editing to such complex systems.
The study Detection of Wolbachia genes in a patient with non-Hodgkin's lymphoma by Chen, Dong, et al. 2015 clearly states:
"Wolbachia spp. should be further evaluated as causes of human infection, especially as Wolbachia infection of mosquitoes is increasingly considered to be a tool for interfering with mosquito-borne transmission of human pathogens."
Notably, the filariodea coxI gene was not found in their study which points to direct infection of Wolbachia from mosquito to human.
But to keep things more on point for the discussion at hand:
"Using CRISPR-Cas9 to edit a genome can result in hundreds of unintended mutations being introduced. For the report, researchers sequenced the genomes of mice that had already undergone CRISPR-Cas9 procedures. They then scrutinized the edited genomes for any changes in the mouse genes—and they found plenty." Source: http://www.newsweek.com/unexpected-mutations-new-gene-editing-technology-crispr-618235
Thanks, RoseWrites for your valuable input on the topic.
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