Friday, November 19, 2010

Mosquitoes, Annoying As Hell and Saving Lives!

Using Mosquitoes to Stop Mosquitoes: The Awesomeness of GMOs

Image Credit: Alvesgaspar, Wikipedia commons. Creative Commons Attribution 3.0

As I walked to school today through piles of snow on the side of the road and sidewalk I was reminded of just one of the wonderful things about winter: there are absolutely none of those little bloodsuckers known as 'mosquitoes'. Not only do you have to deal with persistent whining next to your ear and an itch that won't quit no matter how much you scratch, mosquitoes are flying little hypodermic needles some of which are filled with pathogens that unbelievably may exceed the harm done by incessant biting.

For example:
West Nile Virus
Those of you who live in North America may be familiar with this virus, which had its first confirmed case in Canada in 2002. Remember? The time that came before SARS, but after the E-coli outbreak? Still before those C. Difficile outbreaks. West Nile Virus infections are usually asymptomatic (that is, symptom-free, and not in a good way). Still, those affected don’t generally get sick, so you don’t have to worry right? WRONG! Although many people don’t get sick, those who do have the risk of a list of symptoms that will make you feel worse than that third 'Matrix' movie. Key among these is meningitis (inflammation of the lining of the brain and/or spinal cord) and encephalitis (inflammation of the brain), either of which can do more than use up your sick days, by being potentially crippling if not lethal.

Now surviving is happy news right? The answer is Maybe: Studies have suggested that the long term affects including muscle weakness and paralysis, fatigue, headaches, confusion, depression, concentration issues and memory loss. Now I'm not saying you have to start worrying about getting West Nile Virus (right now, anyway, but maybe tomorrow, or the day after; no pressure) because it's unlikely. But wouldn’t it be nice if we could keep you from getting the virus all together?
Remember, people, this virus is why we had the government telling us to empty our birdbaths, blow-dry any puddles, and report any stagnant pools of water to the government hotline that sent out the guys with the flamethrowers. It's those those mosquitoes that breed like a house on fire in 'em, which will only further the spread of this potentially life-threatening disease that is further harmful because of its profoundly annoying method of transmission.

Malaria
Anyone who has traveled to Africa or even some Caribbean countries know about malaria OR at least know enough to go get anti malaria medications. Malaria is just another disease that is spread by-- what? Cats? Witches? FOREIGNERS? Worse: it's those nasty little mosquitoes doing the damage. Like the West Nile Virus it too can be deadly especially if untreated. Malaria symptoms usually present within the first two weeks of being infected and include fever, headache and vomiting (kind of like the flu), this is quickly followed by disrupting the blood supply to vital organs which as you can probably guess kills you. Again like the West Nile Virus we here in North America don’t have to worry so much about malaria (unless, for whatever reason, the climate shifts dramatically, but what are the chances of that happening... again?). So: it's unlikely that we will get it. Also, we can take preventative measures and if we get it we can seek medication to treat it. So then, why is it one of the leading causes of death in undeveloped countries? Aside from the lack of medications in many of these locations, the parasites that cause malaria infections have also developed resistance to many medications, making treating the infection about as easy as picking the little microscopic bastards out by hand. It’s great that there are medication options against malaria but what if we could end its transmission all together, wouldn’t that be better?
You may be tempted to suggest systematically killing every one of them, but, read on-

Dengue
This is a disease you have probably not heard much of and the real question is “WHY NOT!?” According to the World Health Organization (the fine folks who brought us and advisory during our H1N1 days) 2.5 Billion people are at risk of Dengue infections, that is almost 40% of the world’s population. Now this would be OK, except that Dengue doesn’t only result in flu-like symptoms but can also cause death resulting from hemorrhagic fever (that's like a regular fever, only you're bleeding from every orifice you care about, and from some of the ones you don't). Now-- you may be thinking “Why not just treat everyone and avoid the potentially lethal complication of the fever?” The answer is simple: There is no specific treatment for Dengue itself (although the fevers themselves can be treated in some countries, and not just by the popular methods of Voodoo and Thetan manipulation), and as of today (Nov 18, 2010), there are no vaccines for Dengue Fever. The WHO also notes that- “...[t]he only way to prevent dengue virus transmission is to combat the disease-carrying mosquitoes”.

“Well, like, getting people to pathologically hate mosquitoes should be a problem,” You're thinking. “does this mean we get our DDT back?”

But how do we both prevent the transmission of these diseases AND satisfy our bloodlust against the tiny-winged scourge of outdoor happiness? Tiny mosquito-sized condoms? Anti-insect missiles?

Actually, we can use mosquitoes. I know I said Mosquitoes the very pest I have just been showing is horrible but take a deep breath and read on.

Now, I know what you're thinking (and no, I'm not free Thursday, but thanks for thinking of me): “How do we use Mosquitoes, the very carriers of the disease, and possibly the most annoying thing on the face of this planet (except for people who talk on cellphones during movies)-- how can they stop the disease?! Well, research by the UK based firm Oxitec, in conjunction the Mosquito Research and Control Unit, have used GMO (genetically modified organisms) to answer just that. I, on the other hand, without the budget for GMO, will answer using the comparatively cheap technology of paragraphs:

Oxitec has developed a mosquito with a toxin in it that causes the mosquitoes to die! But, how does it help kill the infected mosquitoes?

Well, by selecting male mosquitoes in the lab and releasing them in the wild, the males, which don’t bite, are able to mate with the wild females and transmit this mutation (the toxin producing gene) to their children. Usually this means the larvae (the children) never hatch and if they do, they die shortly thereafter. Of course, this could be a problem in the lab where they need to grow the mosquitoes and select males to release into the wild and yet again, repeating the process over and over, yadda yadda yadda. Oxitec has the answer: toxin production is suppressed in the presence of a dietary antitoxin provided in the lab. Now our carefully constructed mosquito war can continue BUT who will win: the GMO or the Diseased ones?

Although this method doesn’t inhibit the surviving mosquitoes from transmitting the disease, it does drastically reduce the size of the surviving population and ideally, this will be below the size required to support dengue transmission. In a press release earlier this month, Oxitec claimed to have had complete success in their first field trail, and it appears that another is soon to be underway in Malaysia. Scientists associated with the trial found that in just six months they were able to reduce the species population size by 80%. Assuming repeated efforts are just as successful, we may be facing the day where we can finally enjoy our summer without worrying that you'll be drained of blood.

Now, all there is between you and the perfect summer afternoon is melanoma-inducing solar radiation, chronically debilitating levels of industrial pollutants in the air, and the walking fire hazard that is your uncle behind a barbecue after seven gin gimlets.

One step at a time, people.



Now with Vaccines being so difficult to make, and Oxitec claiming success, this presents a whole new area for work, and one that Bill Gates supports. Maybe in the future we can uses a similar approach to eradicate other diseases, those new and drug-resistant types, of which there are no shortage (see Alexandru’s article on NDM1). If we eliminate the ability to carry the disease we potentially could eliminate the disease altogether, without resorting to splicing in genes that code for self-lighting firecrackers, or upgrading our hand sanitizers to napalm derivatives; unless of course it mutates, something pathogens seem to be quite good at.

References

http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/diseases-maladies/wnv-vno-eng.php
http://www.who.int/topics/malaria/en/
http://www.who.int/mediacentre/factsheets/fs117/en/index.html
http://www.sciencemag.org/content/330/6007/1030.full?rss=1
http://www.scidev.net/en/news/malaysia-to-release-gm-mosquitoes-into-the-wild.html
http://www.scidev.net/en/news/doomed-mosquitos-could-cut-dengue-infection-rate.html
http://www.scidev.net/en/news/biosafety-meeting-must-address-gm-insects-.html
http://www.malaysiakini.com/letters/147602
http://www.malaysiakini.com/letters/147700
http://ca.news.yahoo.com/s/reuters/101111/science/science_us_dengue_mosquitoes
http://www.oxitec.com/wp-content/uploads/2010/02/Feb-2010-Oxitec-newsletter5.pdf
http://www.oxitec.com/wp-content/uploads/2010/11/Oxitec-MRCU-press-release.pdf

2 comments:

  1. Well Done, Ari. Very informative article. I loved it!

    ReplyDelete
  2. I heard always about dnegue, malaria, chikungunya etc. But diseases like west nile virus, zika virus etc are very new for me. As all this diseases spread by mosquito

    ReplyDelete