The Zika Virus
- Thread starter Kaitzilla
- Start date
Berzerker
Deity
http://ecowatch.com/2016/02/12/larvicide-cause-not-zika/
they think its caused by a pesticide designed to get rid of mosquitos
they think its caused by a pesticide designed to get rid of mosquitos
If you ask me, it's a whole lot of panic over nothing. I mean, how many times are we, as a species, going to go through this same old song and dance? Every time a new disease pops up or an old one mutates and starts spreading rapidly, the whole world freaks out and starts acting like it's the end of days. Then, after a few weeks or maybe months, the disease burns itself out and life returns to normal.
Face it, the supposed super-virus that ends humanity simply is never going to occur and we, as a species, simply look foolish every time we panic over every little disease that pops up.
I don't require the whole human kind to be wiped off the earth for me to be concerned. It's enough that I or people near me have a reasonable chance to die. That kind of things have been numerous in the past and they will probably be in the future too.
Second, it's bad reasoning that because nothing has killed off the human race in the past, nothing will do it in the future either: if some virus had killed all the humans we wouldn't be here even discussing it. You couldn't say: "It's totally reasonable to fear that this will be the end of mankind, look at these numerous cases when mankind did go to extinction".
Although, I doubt that zika is a threat for mankind.
Second, it's bad reasoning that because nothing has killed off the human race in the past, nothing will do it in the future either: if some virus had killed all the humans we wouldn't be here even discussing it. You couldn't say: "It's totally reasonable to fear that this will be the end of mankind, look at these numerous cases when mankind did go to extinction".
Although, I doubt that zika is a threat for mankind.
I'm just saying there's a trend with every supposedly world-ending virus that has come along, and that trend has been that they cause some damage, but ultimately turn out to be "just another disease". And I see no reason to believe that trend will not continue well into the future, especially as our medical sciences continue to advance.
Well yeah, it's true that the media likes to make a fuzz over every possible case they can, and sometimes even if they can't.
Silurian
Deity
- Joined
- Jan 5, 2010
- Messages
- 7,567
Has anybody said that Zika is going to wipe out mankind.
The predictions I have seen are that, tens to hundreds of thousands of children will be born malformed, some in the USA. It’s a tragedy for the families, but no threat to mankind.
The mosquito is different to the one that causes malaria, this one flies in the day.
There was speculation on the BBC that there are few reported cases in Africa where the disease was first identified because people get the infection when they are young which immunises them.
There is a report of possible sexual transmission in Austin Texas.
The predictions I have seen are that, tens to hundreds of thousands of children will be born malformed, some in the USA. It’s a tragedy for the families, but no threat to mankind.
The mosquito is different to the one that causes malaria, this one flies in the day.
There was speculation on the BBC that there are few reported cases in Africa where the disease was first identified because people get the infection when they are young which immunises them.
There is a report of possible sexual transmission in Austin Texas.
You must be reading different press.
It's the nature of exponential threats. Things like war, pandemics, and campfires have the risk of growing exponentially, and so the most cost-effective time to beat them is to nip them in the bud.
You never really know ahead of time if you've applied enough counter-agent, until you see that the pandemic didn't explode. This means that all successful actions look like over-reactions in retrospect. But it's still the most cost-effective method. Especially since any leak-through is very expensive.
8 gallons of water on a doused campfire is going to be vastly more effective than 8 gallons once the fire is 3 meters in diameter.
Now, it's obviously possible to over-react, but it's vastly cheaper than under-reacting.
I'm not talking about the actions taken by the government and medical community in order to stop or prevent the spread of disease. I'm talking about the reaction of the general public to every new disease that pops up. All I'm saying is maybe people should have a little more faith in the powers-that-be on these matters since so far, their methods have kept us from getting wiped out by some random virus.
There are a couple of problems with this argument.
First, DDT was actually losing its effectiveness anyway - like most pesticides, it didn't take very long for mosquito populations to develop resistance to it. For instance, the Sri Lankan case that is often mentioned is only partly true - DDT was successful at reducing malaria incidence from millions of cases per year in the late 1940s to just 17 in 1964. The Sri Lankan government stopped spraying because it believed the problem was under control rather than because of pressure by outsiders; when malaria rates spiked again a few years later, they resumed but found that resistance had developed due to continued agricultural use. So they had to switch to different agents, mostly malathion.
Also, DDT has never been internationally banned for use in mosquito control and remains in use today where populations are not resistant or only partially resistant. The ban was on its agricultural use, which made up >99% of the total use of DDT. In addition to causing some environmental problems (the thinning effect on bird eggshells is real, and obviously it is toxic to many invertebrates), widespread agricultural use hastens the development of DDT resistance. It's important to reserve a few of the most effective chemicals for disease control and ban agricultural use in order to reduce the evolution of resistance.
I would of course support genetic engineering to control malaria, particularly the gene drive technique El Mac mentioned. CRISPR/Cas gene drives are really promising for a bunch of things like this, and it's an exciting development that I only found out about a few months ago.
Nope. From the article: ""This is the strongest evidence to date that Zika is the cause of microcephaly, CDC Director Tom Frieden told members of the House Foreign Affairs Committee. He added that the findings did not prove that the virus causes the birth defect and that more tests are needed before the link can be proven definitively."
To this day, there is no prove that Zika causes microcephaly.
Ecowatch is a bunch of conspiracy dimwits.
Thank you, thank you for your post. You have no idea how tired I am from explaining people that no, the evulh environmentalists didn't rid the humanity of the greatest and mightiest tool to fight mosquitoes. Thank you.
Wolfbeckett
Jerkin' and nonsense.
- Joined
- Apr 27, 2011
- Messages
- 2,682
Oh, come on now.
http://dwb.unl.edu/Teacher/NSF/C06/C06Links/www.altgreen.com.au/Chemicals/ddt.html
http://junkscience.com/1999/07/100-things-you-should-know-about-ddt/
http://reason.com/archives/2004/01/07/ddt-eggshells-and-me#comment
These are literally the first 3 results (first 3, I didn't look specifically for ones that support me, I just took the first 3 that came up) when I search for "does ddt thin egg shells". The most anti-ddt of the three says that the egg thinning only happens in select species of birds (most species show no effect whatsoever) and that banning it cost millions of human lives. And that's from the article that is bending over backwards trying to defend a previous anti-DDT position (the reason.com one), even they, trying to justify past comments, are forced to admit that it had a huge human death toll.
There was a study that came out shortly after all of this started being talked about that showed the shell thinning effect was real, but here's the kicker: it was thrown out because it was proven that the scientist running it intentionally fed the birds a low calcium diet. After that other scientists did more rigorous studies which showed no effect whatsoever.
As for the mosquitos becoming resistant to it, well, yes, that's what happens when a treatment is working but then you stop it before it's finished. Mosquitos reproduce quickly, efforts to contain them have to be treated the same way we treat bacterial infections. You don't stop taking your antibiotics just because you're feeling better, you finish the entire prescribed course because otherwise you end up with antibiotic resistant bacteria. We need to view mosquitos just the same way. Nobody can say with certainty what would have happened in Sri Lanka if the DDT treatments had not stopped when they did. Maybe the mosquitos would have developed resistance anyway, or maybe it would have worked and been a permanent (or at least long term) solution to the problem. I don't know, and neither does anyone else. What we do know is that stopping when they did was clearly a mistake since it didn't work. Malaria bounced back as strong as ever. The worst that could have happened if they kept using the DDT is that Sri Lanka would be in the exact same situation that they are now.
As you say the mosquitos are resistant to it now so there's no putting that particular genie back in the bottle, I'm certainly not advocating for widespread re-adoption of it at this point. In places like Sri Lanka it's questionable whether it would have any impact at all, so new technologies like the genetic ones are more promising at this point. The point that I want to drive home here is that we already had a chance to put the kibosh on malaria permanently, and that chance was destroyed by people having an emotion-driven overreaction to bad and inconclusive science. I want to make sure that we don't make that same mistake again with these kinds of new techniques that are coming out. There is a segment of the population that will scream and shout about how we shouldn't be doing these treatments either because genetic modification is immoral, and we all need to be ready to tell those people to go pound sand so that we don't have a repeat of what happened in Sri Lanka with DDT. I would like for diseases like malaria, like yellow fever, like zika, like dengue fever, to be eradicated or at least reduced as much as humanly possible and we aren't going to get there if we let people with a non-scientific ideology driven agenda dominate the discourse.
Google Scholar is definitely the place to look for scientific information about things like this. The three links you gave are an article by a chemical industry-funded think tank, a right-wing anti-environmentalist site, and a libertarian magazine. To be fair to Reason, Ronald Bailey is by far their most honest and thoughtful writer, but he's still going to be coming from an ideological position.
Here is a Google Scholar search, with the search terms 'effect of DDT on eggshells' and limited to studies that have come out since 2000, in case the early studies were flawed, as undoubtedly some were including the low-calcium one. But everything that pops up is consistent with there being a well-known, dose-dependent negative effect of DDT on eggshell thickness, with the exception of an article titled "DDT: A case study in scientific fraud" which was published in the journal of the right-wing think tank Association_of_American_Physicians_and_Surgeons. There was also an article supporting the continued use of DDT for malaria control (I agree) and a couple that noted low sensitivity for particular species of birds. It appears that there is an overwhelming scientific consensus that it causes eggshell thinning, and all the contrary sources I have turned up have turned out to be generated by right-wing political organizations.
The evidence for human health impacts seems a bit more equivocal to me - it does appear to have a nonzero, but fairly low, level of chronic toxicity. It's definitely an endocrine disruptor, and it might be a carcinogen although the evidence for that isn't really strong enough to convince me. I think the cost-benefit analysis easily favors indoor use of DDT in malaria-affected areas, which is mostly what it is used for today. It has the nice property of being a mosquito repellant as well as an insecticide, so that even resistant strains are repelled from houses that have been sprayed with it.
But yeah, the environmental consequences are real. Definitely check Google Scholar whenever someone makes a scientific claim, especially if it's a politically charged issue. There are lots of disinformation mills out there, and they will often be the first hits on the regular Google.
Here is a Google Scholar search, with the search terms 'effect of DDT on eggshells' and limited to studies that have come out since 2000, in case the early studies were flawed, as undoubtedly some were including the low-calcium one. But everything that pops up is consistent with there being a well-known, dose-dependent negative effect of DDT on eggshell thickness, with the exception of an article titled "DDT: A case study in scientific fraud" which was published in the journal of the right-wing think tank Association_of_American_Physicians_and_Surgeons. There was also an article supporting the continued use of DDT for malaria control (I agree) and a couple that noted low sensitivity for particular species of birds. It appears that there is an overwhelming scientific consensus that it causes eggshell thinning, and all the contrary sources I have turned up have turned out to be generated by right-wing political organizations.
The evidence for human health impacts seems a bit more equivocal to me - it does appear to have a nonzero, but fairly low, level of chronic toxicity. It's definitely an endocrine disruptor, and it might be a carcinogen although the evidence for that isn't really strong enough to convince me. I think the cost-benefit analysis easily favors indoor use of DDT in malaria-affected areas, which is mostly what it is used for today. It has the nice property of being a mosquito repellant as well as an insecticide, so that even resistant strains are repelled from houses that have been sprayed with it.
But yeah, the environmental consequences are real. Definitely check Google Scholar whenever someone makes a scientific claim, especially if it's a politically charged issue. There are lots of disinformation mills out there, and they will often be the first hits on the regular Google.
Farm Boy
run boy run
- Joined
- Sep 8, 2010
- Messages
- 26,668
Boots, just be careful that when you refute the dramatic overreach of the claim "DDT could have wiped out malaria and mosquitoes" that you do not fall to the same tendency to overreach the other way.
Would DDT have wiped out mosquitoes but for the agricultural use ban? Certainly not. Would insect populations have developed more stubborn immunity to the toxin? Definitely. Would large scale environmental damage have continued occurring that without the ablation of the ban? Definitely. But: You don't need to have "solved all mosquito related deaths" or something similarly stupid to pick at the horrendous cost that came with the ban. Mosquitoes as disease vectors are responsible for significant amounts of human deaths every year. Agricultural use, wide spread, did reduce the overall prevalence of mosquito populations. The useful lifecycle of DDT on controlling mosquitoes was not spent by the time it was banned for agricultural use. Therefore, and the experts darn well know and knew this, the decision was made to preserve the efficacy of the chemical long term and reduce environmental damage in the short term through the agricultural ban. This definitely did allow mosquito populations to rise faster than they would have otherwise and darn well was responsible for the non-prevention of a significant amount of loss of human life that was otherwise preventable.
Too much damned gloss over by both sides on this one.
Would DDT have wiped out mosquitoes but for the agricultural use ban? Certainly not. Would insect populations have developed more stubborn immunity to the toxin? Definitely. Would large scale environmental damage have continued occurring that without the ablation of the ban? Definitely. But: You don't need to have "solved all mosquito related deaths" or something similarly stupid to pick at the horrendous cost that came with the ban. Mosquitoes as disease vectors are responsible for significant amounts of human deaths every year. Agricultural use, wide spread, did reduce the overall prevalence of mosquito populations. The useful lifecycle of DDT on controlling mosquitoes was not spent by the time it was banned for agricultural use. Therefore, and the experts darn well know and knew this, the decision was made to preserve the efficacy of the chemical long term and reduce environmental damage in the short term through the agricultural ban. This definitely did allow mosquito populations to rise faster than they would have otherwise and darn well was responsible for the non-prevention of a significant amount of loss of human life that was otherwise preventable.
Too much damned gloss over by both sides on this one.
That's more a matter of strategy and trade-offs than anything else. Widespread agricultural use will cause a larger drop in mosquito populations in the short-term at the expense of more rapid and widespread acquisition of resistance. So lives might be saved in the short run, but there could still be a net loss in the long run. I'm not really familiar enough with the details of malaria control to know whether that strategy was the best one at the time or not.
Farm Boy
run boy run
- Joined
- Sep 8, 2010
- Messages
- 26,668
Oh, that's possible. But that would assume that by preserving DDT vulnerability we also preserved the only accessible and effective poison based control for mosquitoes for combating outbreak. Which, I guess I don't know for sure isn't true, but is a sketchy assumption. Effectiveness rates differ between chemicals, general toxicity does too, what works in heavy concentrated doses isn't always the same as lighter, broader application. It's possible, maybe even probable that the ban was the right way to go(Small comfort to the dead. But children 30 years gone are pretty quiet by this point. Especially 3rd world children). It's just plain also why we didn't do it. It was done for the environmental aspect of it. Silent Spring, all that.
What happened to all the other viruses which would (in their case) kill all Europe or the US? (eg the spread of ebola scare). I recall that supposedly reaching Florida and Spain, and then nothing happened despite tons of news coverage of it as a dreaded epidemic.
schlaufuchs
Break My Heart
Most of them are overhyped media fearmongering - Ebola in particular. Generally they're either highly infectious but not deadly enough to pose a serious health risk (like Swine Flu or West Nile or SARS) or too deadly and without a really terrifying vector like Ebola. There's also the eurocentric bias involved too. Sure ebola fizzled out in Europe and the US but it posed a prolonged and very serious health crisis in Western Africa that is really only now starting to abate. And this largely stems from US and Europe having really strong state structures that allow them to have a good hold on entry to their country and proactive and effective quarantine protocols.
Similar threads
- Locked
