Nathan Myhrvold and team’s latest inventions — as brilliant as they are bold — remind us that the world needs wild creativity to tackle big problems like malaria. And just as that idea sinks in, he rolls out a live demo of a new, mosquito-zapping gizmo you have to see to believe.
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Links to books and other items on this page and elsewhere on Greg Ladens' blog may send you to Amazon, where I am a registered affiliate. As an Amazon Associate I earn from qualifying purchases, which helps to fund this site.
Saw this earlier – fantastic!
I read at World Nut Daily that all we have to do is spray DDT everywhere and malaria will just go away. ‘Problem is, the liberals won’t let us because of some frog or something.
http://membracid.wordpress.com/2009/03/17/laser-mosquito-zapper/
The comments on that post from someone working in this lab are VERY interesting.
http://membracid.wordpress.com/2009/03/17/laser-mosquito-zapper/
The comments on that post from someone working in this lab are VERY interesting.
George.w, DDT presents health threats to just about every animal on the planet. Worse, it concentrates in the fatty tissues as it moves up the food chain. In other words, we end up poisoning ourselves with DDT. Yes, it works wonders against mosquitos, but it also kills people. Not an ideal pesticide. We have much safer pesticides to use.
The laser has cool factor, but the GIS enabled modeling is a lot more exciting to me. We already know how to control/kill mosquitoes, but applying those methods efficiently is a real hurdle.
@george.w: DDT was extremely effective against many pests; unfortunately a bit long-lived in the environment and not too good for the eggs (and mortality rates) of some birds, lizards, and other animals which we didn’t really want to kill. The best weapon against malaria though (by an enormous margin) had been the draining of wetlands – unfortunately that also wipes out entire ecosystems and if it happens to be the mangroves around the areas where the salt water meets the fresh water that’s very bad for the estuarine system and also devastating for the coastline. Go ahead and build a beach house where a mangrove had been wiped out – it’ll only be a few years before nature wipes out the beach house. So, two of the greatest historical weapons against malaria are crossed off the list of things we do. The anopheles mosquito itself is entirely harmless – well, as harmful as any other mosquito. Aside from eradicating the mosquito, people can also look at other schemes for breaking the life cycle of the malaria parasites. Mosquitoes are pretty goddamned hard to get rid of.
@travc: one trick I’d seen tried on pest control (but eradication was not considered possible) of some moths and some biting flies (though I don’t know if they ever went from experiments to commercial operations) was to use pheromones to attract all the horny males and render them infertile by various means such as gamma radiation. Well, the insects are attracted, trapped, spayed, and released – a very tedious operation. I don’t know if cutting the nuts off mosquitoes was on the list of operations.
@Bug: I think folks who have operated ultraviolet LIDARs will laugh and say they invented the super-expensive mosquito trap first. Mosquitoes aren’t so bad though since any little breeze carries the carcass away and most of the insect seems to actually burn away before it falls on the telescope mirror. The moths on the other hand were a big icky stinky problem. These days there are actually ultraviolet LEDs. If mosquitoes can be attracted efficiently by these devices then it should be possible to build solar powered bug zappers – which still won’t be cheaper than mosquito nets though and it’s still a localized personal protection scheme which doesn’t address the general problem of mosquitoes in general or the malaria parasites in particular. Well, zapping the bugs is just one option; if you can attract them there are any other number of traps to employ.
The mosquitos that carry malaria do not breed in swamps and marshes. Draining the swamps and marshes has possibly been effective with some diseases, but it makes no sense that it would have any effect on malaria.
The most effective treatment of human malaria is to eliminate the disease in its main host more or less at once (over a period of several months/a couple of years) aggressively. Once it is eliminated in the host, it will be gone until some new version emerges (which is probably less likely than one might think, but possible.)
The problem with something like this for mosquito control is the cost which for something like this is mostly in the development. If there was a market that could support the development cost, like tropical resorts for rich western tourists or military field hospitals, then the unit cost for hardware might be low enough that they could be put where there are concentrations of people.
When mosquitoes hatch, they are uninfected. They have to bite an infected individual and become infected before they can bite an uninfected individual and infect them. Unless you drive the mosquitoes to extinction, so long as there are infected humans around, all it takes is a few mosquitoes to maintain transmission. It would be easier to treat every human and eliminate malaria that way than to try and drive this particular mosquito to extinction.
Another problem is that many humans in regions where malaria is endemic have some level of immunity. They are infected, but their immune system is keeping the malaria at bay (for the most part). If you eliminate their infection, and keep them unexposed for a few years, they revert to a naïve level of susceptibility, that is they are much more susceptible to a severe infection should they be infected. If your eradication effort is only 99.99% effective, then you may cause more deaths than you prevent when the malaria expands back into the now naïve population. When some places where malaria is endemic are also places of political instability, or extreme inaccessibility, this presents problems.
I should clarify that draining the swamps can decrease malaria (maybe … maybe not) because it reduces the frequency of puddles and little holes with water in them that come along with the swamp. But draining the swamp is not efficacious.
I’ll also note that the evidence that wetland reduction works is that wetlands are reduced and malaria goes down. But do I really need to day that correlation does not necessarily bla bla bla?
Those drainage efforts were mainly in Mediterranean climates, which are already on the edge for the mosquito in question and the malarial cycle, and came along with other improvements such as the invention and distribution of anti-malarial.
Also, has anyone ever checked if the data from the largest western swamp draining project was not made up by the fascist government that did it and that we otherwise don’t trust? To my knowledge swamp draining has not been critically examined.
Mosquito vector control has been quite effective at preventing yellow fever (a viral infection) outbreaks. Malaria is a lot slower to develop (6-14 days vs 3-6 days). Yellow fever also has a shorter course so people either recover or die fairly quickly. If you drop the mosquito population temporarily while everyone either recovers or dies, then there are no more infectious people to infect mosquitoes. People with malaria stay infectious for much longer (years).
I’ve learned a lot just trying to defend the honor of Rachel Carson over the past couple of years, especially about mosquitoes, DDT, and malaria.
Greg’s mostly right, that draining the wetlands probably didn’t do the job — draining the breeding places is key.
It helps to know the enemy, you know? Mosquitoes don’t travel very far in their lifetime. I’ve seen accounts that say they rarely move more than 50 yards. So it’s not necessary to drain the swamp if it’s more than 50 yards from where people are.
Malaria-carrying mosquitoes usually breed in smaller ponds, or containers, close to human habitation. They aren’t typically swamp breeders.
Plus, malaria-carrying mosquitoes tend to bite at night, dusk to just after midnight mostly.
Plus, mosquitoes must get malaria from a human first, and then live for another two weeks for the parasite to finish its life-cycle stage in the mosquito, before the mosquito can infect another human.
So, extremely effective programs against malaria have included:
1. Draining rain gutters, tires, and potholes in the road, near houses. Any small container of water will do for the mosquito to breed. Keep them dry. Some observers notice a decrease in malaria when road maintenance improves, reducing the numbers of potholes.
2. Make sure people are shielded from mosquitoes from sundown to after midnight. The Nothing But Nets campaign gives away bednets that protect as many people as can comfortably sleep under them — the kids in a house, at least. Screens on windows, and better-sealed-against-the elements houses in the U.S. probably did more to eradicate malaria than any pesticide. CDC’s account is that malaria was effectively eradicated from the U.S., all but minor mopping up, by 1939. That’s seven years before DDT became available. We built the Panama Canal without DDT. Think about it.
3. Quick diagnoses of malaria, including which species of the parasite, improves the rate of healing, decreases death rates, and effectively reduces malaria transmission, if effective treatment follows.
4. Effective treatment includes the complete course of the medicine that works. Some of the pharmaceuticals that worked 20 years ago, don’t work any more. Serious malaria fighting involves figuring out which pharmaceuticals work, getting them to the victims, and the victims’ taking a complete course of the medicine. When humans are cured of malaria, new mosquitoes cannot get infected with malaria from them. If we just cure malaria in humans, we can laugh at mosquitoes.
As in any war, things usually work best when one uses exactly the right weapon, at the right time, with great targeting. DDT is rarely the right weapon, generally misses the lifecycle timing, and cannot be targeted carefully enough.
WorldNet Daily is a victim of the “Poison Africa to Health” disinformation campaign operated by Roger Bate and Richard Tren, no friends to science, environmental protection, or malaria fighters, whom they regularly ridicule. The goals of these two appear wholly political, to make fun of environmentalists, scientists and medical personnel, in order to make people wary of conservation, applied science, and good medicine.
No, there’s no rational explanation for their campaign.
Ed, yes, due to better hygiene the death toll due to malaria and yellow fever during the US building of the Panama Canal was relatively low, only 5,609.
http://en.wikipedia.org/wiki/Panama_canal
A small fraction of the estimated 22,000 that died during the unsuccessful French attempt.
@daedalus2u: You should visit a military field hospital to see how awesome they’re set up and how well funded they are. Some of the base hospitals are very very good (but, sadly, not all), but the field hospitals – if you’ve seen them you might not even recognize them as hospitals. They really do look like something out of ‘MASH’. Just sayin’ … you’re not likely to get money out of a military operational budget to develop anti-malaria gizmos. Especially not with the way the military budget works in the USA.
MS, yes, of course you are right, what was I thinking, they would just use higher doses of anti-malarials.
Maybe if you wrote a sub-routine for a laser that shoots down bullets to also shoot down mosquitoes.
…up until the population evolves resistance.