Engineer Indur Goklany, a frequent contributor to WUWT and occasional commenter has more than a few things to say about commenter Ed Darrell’s views on Malaria posted on WUWT yesterday. There’s so much in fact, that I’ve dedicated a whole guest post to it. -Anthony
Guest Post by Indur Goklany
Ed Darrell has two sets of comments, one of which, I believe, is fundamentally flawed, and the other I would agree with, at the risk of being accused by Alexander Feht of being obsequious once again (See Alexander’s comment on September 11, 2010 at 11:28 am).
A. Ed Darrell on September 12, 2010 at 7:40 pm, responding to tarpon said:
In 1972, about two million people died from malaria, worldwide.
In 2008, about 880,000 people died from malaria, worldwide. That’s fewer than half the mortality the year the U.S. stopped DDT spraying on cotton.
If it’s cause-effect you were trying to establish, I think you missed.
RESPONSE: The flaws in Ed’s analysis are aplenty.
First, although the US banned DDT in 1972, its use continued in much of the rest of the world. [If I remember correctly, the Swedes had banned it earlier.] In fact, US production of DDT for developing country use continued into the mid-1980s. Also, it took a few years for US environmentalists to ensure that the US domestic ban was — in the best traditions of cultural imperialism and bearing the white man’s burden — exported to other countries [without their (informed) consent, mind you]. [Notably, the US ban was imposed only after malaria had been wiped out in the US for practical purposes. See Figure 13, here.] In addition, countries had stockpiles which they continued to use, and not all developed countries were initially on board with eliminating DDT use worldwide. Furthermore, by 2008 some developing countries that had stopped DDT use had resumed its use. So it is not meaningful to use either 1972 or 2008 as endpoints for developing global estimates for the efficacy (or lack of it) of DDT in dealing with malaria..
Second, while DDT is in many instances the cheapest and most cost-effective method of reducing malaria (where it works, because it doesn’t always work) the death and disease rates are also sensitive to other factors, none of which have remained stationary between 1972 and 2008. These factors include general health status, adequate food and nutrition, public health services, and so on. So, it makes little sense, without adequately accounting for these factors, to compare deaths for malaria (or death rates, which would be more correct) between 1972 and 2008 to say anything about the effectiveness of DDT.
Fortunately, though, we have results of some “policy experiments” which were undertaken inadvertently — undertaken, I note, without the consent of the subjects of these experiments, something that would not be allowed in any hospital in the US, I suspect. These “experiments” allow us to evaluate the benefit of DDT (or lack thereof). As noted here (pp. 7-8) in a paper published a decade ago by Africa Fighting Malaria, it was noted that:
“Given the higher costs and, possibly, the greater efficacy of DDT, it is not surprising that despite the theoretical availability of substitutes, malaria rebounded in many poor areas where (and when) DDT usage was discontinued (WHO 1999a; Roberts 1999, Roberts et al. 1997, Sharma 1996, Whelan 1992, Guarda et al. 1999, Bate 2000). For instance, malaria incidences in Sri Lanka (Ceylon) dropped from 2.8 million in the 1940s to less than 20 in 1963 (WHO 1999a, Whelan 1992). DDT spraying was stopped in 1964, and by 1969 the number of cases had grown to 2.5 million. Similarly, malaria was nearly eradicated in India in the early 1960s, and its resurgence coincided with shortages in DDT (Sharma 1996). The population at high- to medium risk of contracting malaria in Colombia and Peru doubled between 1996 and 1997 (Roberts et al. 2000b). Malaria has also reappeared in several other areas where it had previously been suppressed, if not eradicated (e.g., Madagascar, Swaziland, the two Koreas, Armenia, Azerbaijan, Turkmenistan; Roberts et al. 2000b, and references therein). Similarly, Roberts et al. (1997) showed that Latin American countries (e.g., Ecuador, Belize, Guyana, Bolivia, Paraguay, Brazil and Venezuela) which had discontinued or decreased spraying of DDT inside homes saw malaria rates increase. Guarda et al. (1999) also note that in 1988, when DDT use was discontinued, there were no cases of Plasmodium falciparium reported in Loreto, Peru. The number of cases increased to 140 in 1991. By 1997, there were over 54,000 cases and 85 deaths (see, also, Goklany 2000c).
“But the best argument for indoor-spraying of DDT is that in many areas where malaria experienced a resurgence, reinstating DDT use once again led to declines in malaria cases. For example, Ecuador, which had previously seen its malaria rates rebound once DDT spraying had been reduced, saw those rates decline once again by 61 percent since 1993, when DDT use was increased again (Roberts et al. 1997). The same cycle occurred in Madagascar where the malaria epidemic of 1984-86, which occurred after the suspension of DDT use, killed 100,000 people. After two annual cycles of DDT spraying, malaria incidence declined 90 percent (Roberts et al. 2000b).”
Since then, we have results of the on-again and off-again policy with regard to DDT from KwaZulu-Natal Province in South Africa:
“DDT spraying in that area started in 1946. By 1974, Anopheles funestes, the mosquito species associated with year-round prevalence of malaria in that region, had been eradicated [see Figure below.]. In the 1991/1992 malaria season, the number of malaria cases was around 600 in the Province of KwaZulu-Natal (KZN). However, in 1996, DDT was replaced by synthetic pyrethroids. In 1999 members of A. funestus were found in houses in KZN that had been sprayed. In 1999/2000, there were more than 40,000 cases in KZN. In 2000, DDT was brought back. By 2002, the number of cases had dropped to 3,500.” Source: Pre-edited version of Goklany (2007), pp.79-180.
See the Figure 1.
I have also provided additional references below, if one is interested in following up.
For a broader discussion, I recommend the chapter, “Applying the Precautionary Principle to DDT,” in The Precautionary Principle: A Critical Appraisal of Environmental Risk Assessment (Cato Institute, Washington, DC, 2001). A previous version of this chapter is available free at http://goklany.org/library/DDT%20and%20PP.PDF.
Figure 1: From Goklany (2007), based on R. Tren, “IRS & DDT in Africa — past and present successes,” 54th Annual Meeting, American Society of Tropical Medicine and Hygiene (ASTMH), Washington, DC, December 11-15, 2005.
B. Ed Darrell on September 13, 2010 at 2:19 pm said, “We may not beat malaria by 2014, but it won’t be because the Gates Foundation is on the wrong path.”
RESPONSE: I agree. For a long time, malaria control was neglected. Even the World Health Organization would not recommend DDT use indoors. It was revived, and even became (almost) chic thanks to a number of very high profile individuals including George Bush and Bill Gates, as well as lesser known people such as Don Roberts, Amir Attaran, Roger Bate and Richard Tren (all associated with Africa Fighting Malaria) . I delude myself into thinking that I played a minor role in helping ensure that DDT did not get banned outright under the Stockholm Convention.
Whatever people may think of Bill Gates stance on global warming, there is little doubt that he exhibited substantial political courage in espousing malaria control with DDT. That’s essentially why I was/am disappointed by his posting that set me off on this blog.
Perhaps I should have titled my piece, “Et tu Bill Gates!”
ADDITIONAL REFERENCES
D. R. Roberts, et al. “DDT, global strategies, and a malaria control crisis in South America,” Emerging Infectious Diseases 3 (1997): 295-301 (1997).
D.R. Roberts, et al., “A Probability Model of Vector Behavior: Effects of DDT Repellency, Irritancy, and Toxicity in Malaria Control,” Journal of Vector Control 25 (2000): 48-61.
Karen I. Barnes et al., “Effect of Artemether Lumefantrine Policy and Improved Vector Control on Malaria Burden in KwaZulu Natal, South Africa,” Public Library of Science Medicine (2005): DOI 10.1371/journal.pmed.0020330.
P. E. Duffy and T. K. Mutabingwa, “Rolling Back a Malaria Epidemic in South Africa,” Public Library of Science Medicine (2005): DOI: 10.1371/journal.pmed.0020368.
R. Tren, “IRS & DDT in Africa — past and present successes,” 54th Annual Meeting, American Society of Tropical Medicine and Hygiene (ASTMH), Washington, DC, December 11-15, 2005.
D. H. Roberts, “Policies to Stop/Prevent Indoor Residual Spraying for Malaria Control,” 54th Annual Meeting, ASTMH, Washington, DC, December 11-15, 2005.
I.M. Goklany, The Precautionary Principle: A Critical Appraisal of Environmental Risk Assessment (Cato Institute, Washington, DC, 2001). Chapter 2 deals with malaria and DDT.
Ed Darrell has two sets of comments, one of which, I believe, is fundamentally flawed, and the other I would agree with, at the risk of being accused by Alexander Feht of being obsequious once again (See Alexander’s comment on September 11, 2010 at 11:28 am).
A. Ed Darrell on September 12, 2010 at 7:40 pm, responding to tarpon said:
In 1972, about two million people died from malaria, worldwide.
In 2008, about 880,000 people died from malaria, worldwide. That’s fewer than half the mortality the year the U.S. stopped DDT spraying on cotton.
If it’s cause-effect you were trying to establish, I think you missed.
RESPONSE: The flaws in Ed’s analysis are aplenty.
First, although the US banned DDT in 1972, its use continued in much of the rest of the world. [If I remember correctly, the Swedes had banned it earlier.] In fact, US production of DDT for developing country use continued into the mid-1980s. Also, it took a few years for US environmentalists to ensure that the US domestic ban was — in the best traditions of cultural imperialism and bearing the white man’s burden — exported to other countries [without their (informed) consent, mind you]. [Notably, the US ban was imposed only after malaria had been wiped out in the US for practical purposes. See Figure 13, here.] In addition, countries had stockpiles which they continued to use, and not all developed countries were initially on board with eliminating DDT use worldwide. Furthermore, by 2008 some developing countries that had stopped DDT use had resumed its use. So it is not meaningful to use either 1972 or 2008 as endpoints for developing global estimates for the efficacy (or lack of it) of DDT in dealing with malaria..
Second, while DDT is in many instances the cheapest and most cost-effective method of reducing malaria (where it works, because it doesn’t always work) the death and disease rates are also sensitive to other factors, none of which have remained stationary between 1972 and 2008. These factors include general health status, adequate food and nutrition, public health services, and so on. So, it makes little sense, without adequately accounting for these factors, to compare deaths for malaria (or death rates, which would be more correct) between 1972 and 2008 to say anything about the effectiveness of DDT.
Fortunately, though, we have results of some “policy experiments” which were undertaken inadvertently — undertaken, I note, without the consent of the subjects of these experiments, something that would not be allowed in any hospital in the US, I suspect. These “experiments” allow us to evaluate the benefit of DDT (or lack thereof). As noted here (pp. 7-8) in a paper published a decade ago by Africa Fighting Malaria, it was noted that:
“Given the higher costs and, possibly, the greater efficacy of DDT, it is not surprising that despite the theoretical availability of substitutes, malaria rebounded in many poor areas where (and when) DDT usage was discontinued (WHO 1999a; Roberts 1999, Roberts et al. 1997, Sharma 1996, Whelan 1992, Guarda et al. 1999, Bate 2000). For instance, malaria incidences in Sri Lanka (Ceylon) dropped from 2.8 million in the 1940s to less than 20 in 1963 (WHO 1999a, Whelan 1992). DDT spraying was stopped in 1964, and by 1969 the number of cases had grown to 2.5 million. Similarly, malaria was nearly eradicated in India in the early 1960s, and its resurgence coincided with shortages in DDT (Sharma 1996). The population at high- to medium risk of contracting malaria in Colombia and Peru doubled between 1996 and 1997 (Roberts et al. 2000b). Malaria has also reappeared in several other areas where it had previously been suppressed, if not eradicated (e.g., Madagascar, Swaziland, the two Koreas, Armenia, Azerbaijan, Turkmenistan; Roberts et al. 2000b, and references therein). Similarly, Roberts et al. (1997) showed that Latin American countries (e.g., Ecuador, Belize, Guyana, Bolivia, Paraguay, Brazil and Venezuela) which had discontinued or decreased spraying of DDT inside homes saw malaria rates increase. Guarda et al. (1999) also note that in 1988, when DDT use was discontinued, there were no cases of Plasmodium falciparium reported in Loreto, Peru. The number of cases increased to 140 in 1991. By 1997, there were over 54,000 cases and 85 deaths (see, also, Goklany 2000c).
“But the best argument for indoor-spraying of DDT is that in many areas where malaria experienced a resurgence, reinstating DDT use once again led to declines in malaria cases. For example, Ecuador, which had previously seen its malaria rates rebound once DDT spraying had been reduced, saw those rates decline once again by 61 percent since 1993, when DDT use was increased again (Roberts et al. 1997). The same cycle occurred in Madagascar where the malaria epidemic of 1984-86, which occurred after the suspension of DDT use, killed 100,000 people. After two annual cycles of DDT spraying, malaria incidence declined 90 percent (Roberts et al. 2000b).”
Since then, we have results of the on-again and off-again policy with regard to DDT from KwaZulu-Natal Province in South Africa:
“DDT spraying in that area started in 1946. By 1974, Anopheles funestes, the mosquito species associated with year-round prevalence of malaria in that region, had been eradicated [see Figure below.]. In the 1991/1992 malaria season, the number of malaria cases was around 600 in the Province of KwaZulu-Natal (KZN). However, in 1996, DDT was replaced by synthetic pyrethroids. In 1999 members of A. funestus were found in houses in KZN that had been sprayed. In 1999/2000, there were more than 40,000 cases in KZN. In 2000, DDT was brought back. By 2002, the number of cases had dropped to 3,500.” Source: Pre-edited version of Goklany (2007), pp.79-180.
See the Figure 1.
I have also provided additional references below, if one is interested in following up.
For a broader discussion, I recommend the chapter, “Applying the Precautionary Principle to DDT,” in The Precautionary Principle: A Critical Appraisal of Environmental Risk Assessment (Cato Institute, Washington, DC, 2001). A previous version of this chapter is available free at http://goklany.org/library/DDT%20and%20PP.PDF.
Figure 1: From Goklany (2007), based on R. Tren, “IRS & DDT in Africa — past and present successes,” 54th Annual Meeting, American Society of Tropical Medicine and Hygiene (ASTMH), Washington, DC, December 11-15, 2005.
B. Ed Darrell on September 13, 2010 at 2:19 pm said, “We may not beat malaria by 2014, but it won’t be because the Gates Foundation is on the wrong path.”
RESPONSE: I agree. For a long time, malaria control was neglected. Even the World Health Organization would not recommend DDT use indoors. It was revived, and even became (almost) chic thanks to a number of very high profile individuals including George Bush and Bill Gates, as well as lesser known people such as Don Roberts, Amir Attaran, Roger Bate and Richard Tren (all associated with Africa Fighting Malaria) . I delude myself into thinking that I played a minor role in helping ensure that DDT did not get banned outright under the Stockholm Convention.
Whatever people may think of Bill Gates stance on global warming, there is little doubt that he exhibited substantial political courage in espousing malaria control with DDT. That’s essentially why I was/am disappointed by his posting that set me off on this blog.
Perhaps I should have titled my piece, “Et tu Bill Gates!”
ADDITIONAL REFERENCES
D. R. Roberts, et al. “DDT, global strategies, and a malaria control crisis in South America,” Emerging Infectious Diseases 3 (1997): 295-301 (1997).
D.R. Roberts, et al., “A Probability Model of Vector Behavior: Effects of DDT Repellency, Irritancy, and Toxicity in Malaria Control,” Journal of Vector Control 25 (2000): 48-61.
Karen I. Barnes et al., “Effect of Artemether Lumefantrine Policy and Improved Vector Control on Malaria Burden in KwaZulu Natal, South Africa,” Public Library of Science Medicine (2005): DOI 10.1371/journal.pmed.0020330.
P. E. Duffy and T. K. Mutabingwa, “Rolling Back a Malaria Epidemic in South Africa,” Public Library of Science Medicine (2005): DOI: 10.1371/journal.pmed.0020368.
R. Tren, “IRS & DDT in Africa — past and present successes,” 54th Annual Meeting, American Society of Tropical Medicine and Hygiene (ASTMH), Washington, DC, December 11-15, 2005.
D. H. Roberts, “Policies to Stop/Prevent Indoor Residual Spraying for Malaria Control,” 54th Annual Meeting, ASTMH, Washington, DC, December 11-15, 2005.
I.M. Goklany, The Precautionary Principle: A Critical Appraisal of Environmental Risk Assessment (Cato Institute, Washington, DC, 2001). Chapter 2 deals with malaria and DDT.
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I don’t know if anyone has heard, but there’s a new documentary coming out on DDT called 3 Billion and Counting . I saw a preview of it at a Q@A screening in LA. The director was there…he seems like a very legitimate, sincere guy. He started off as a total sceptic, intent on proving that DDT was toxic….imagine his surprise finding those EPA hearing papers, some 9000 odd pages. I heard there are scientists all over the world looking to track those papers down. And this guy found them!
I thought the movie was just going to be about malaria….did I get more than I bargained for…government agendas, scams, organic food (I didn’t know that stuff was sprayed with stuff like arsenic!), plus a few more shocks. There were some light hearted moments too. I was riveted the whole time I was there. I reckon I need to see it again a few times..this film goes way beyond malaria. I hear it is showing up in NY this week. Anyone going to it?
From: stereo on September 16, 2010 at 2:20 pm
O RLY? Let’s see what you said:
“excitorepellency ” is the repellent effect…
Yeah, the “-repellency” part sort of gives that away.
…even if they are immune to a degree, they don’t like the effect it has on them.
Which was made clear in my post, although “resistant” is the word of choice over “immune.”
It is also referring to use in the home, which has not been banned…
As described repeatedly elsewhere, technically not banned, except in certain countries. Also use in the home, which is included in use in buildings where humans may be found, was part of what I was talking about.
…and is encouraged if used properly.
And this is why I wrote the post! There are people NOT encouraging its use. When they are not outright saying DDT is completely bad, period, no debate, don’t use it at all, they point to mosquitoes having and developing resistance, which really doesn’t matter as DDT continues to be effective, as justification for foisting off less-effective bed nets and after-the-fact drug treatments as being just as good.
So you spent many words saying nothing in contention to my post, finishing with something that was argued upstream and not the point of my post which was to remove resistance as justification for not using DDT. And now you’re saying I’m somehow misrepresenting what was said, as you presented in your words that I just went through. Thus I still don’t think you understand what I was saying!
Eli Rabett – I agree that we should use ACT, but it is for treating, not preventing, malaria. On the other hand, DDT (and other insecticides), as well as malaria vaccines, are more for preventing malaria. Therefore, their use isn’t mutually exclusive. In any case, even if we have an effective therapy, that doesn’t mean we shouldn’t try to prevent malaria, so long as that is cost-effective. In fact, it’s better to prevent than to cure malaria, if possible. I say that since I have contracted malaria more than once – I am an Indian and spent the first 23 years of my life there — and while I obviously survived, I’d rather not have contracted it in the first place.
[As an aside, I note that my mother was diagnosed with cerebral malaria shortly before she died.]However, I attribute her death to old age; she was about 90.] [BTW, indoor DDT spraying was a regular occurrence when I was growing up, but that didn’t guarantee you wouldn’t get malaria. Also, I have always hated mosquito nets – it’s like living in a cage and cuts down airflow, which can feel suffocating if you don’t have electricity for a fan. Even my dog hates a crate.]
Tim Lambert – As Spence_UK notes, whether the number of cases after 1963 rose from a handful to 537,700 (per the figures you quoted) or 2.5 million (per the numbers I quoted) the critical point is that DDT use was effective because when it was withdrawn, cases (and deaths) rose and then when it was reintroduced, they dropped once again. It is more than likely that many Sinhalese who are alive today owe their lives to DDT usage in the 1960s (and later), even if P. falciparum was developing resistance to DDT.
Also, let’s not forget that data from other countries also indicates that cases and deaths were sensitive to the use of DDT.
However, I AM bothered by the large disparity in the reported numbers for Ceylon/Sri Lanka. But it doesn’t automatically follow from what you presented that the numbers attributed by the NY Times to the WHO special study are necessarily wrong and your source (Gramicci and Beales) is right. You have not presented any basis for this claim. I note that the passage you quote, and the link to the WHO website that you provided, both glossed over the fact that DDT use was discontinued in the early 1960s.
One explanation is that Ceylon did not, in fact, suspend DDT use in the early 1960s, but there are a number of other sources, in addition to the Whelan (1985 or 1992) and the 1971 NY Times report of the WHO study (which was much more contemporaneous to actual events than the WHO website or the Gramicci and Beales chapter), that say otherwise. These include the Zubair et al. paper noted by Spence_UK and the Pinikahana and Dixon paper that I noted.
Regardless, I hope to figure which data set is more correct and why. But it won’t be anytime soon, since I have been unable to locate the book you quote (which includes the Gramicci/Beales paper) or the Pinikahana/Dixon paper at a library that I can access readily. Although, I hope to get them via Interlibrary Loan, I would appreciate getting a copy if you have access to either of them. [Thanks. You should have my e-mail address, since I registered on your site.]
Also, note that until a truly effective vaccine comes along, it is more than likely that resistance will develop to whatever drugs and/or insecticides we use to reduce malaria. This does not mean that we shouldn’t use any drugs/insecticides, rather it tells us that we should use them judiciously, and try to maximize their utility. So, in my opinion, the argument that resistance develops misses the point, namely, that until resistance develops, the drug/insecticide is saving lives. In fact, even a malaria vaccine may, for all we know, be short-lived (in effectiveness) – think annual flu shots. However, that would be a poor reason to abandon the search for a vaccine. Even if it is effective for only a couple of years, one could potentially save a few million lives, not to mention a few hundred million cases. I think that would be an acceptable outcome.
The same logic applies to drugs and insecticides, no matter how short-lived their effectiveness.
Golkany, clearly you do not understand the life cycle of Plasmodium falciparum. If you use ACT to effect rapid cures one of the reservoirs for spreading the disease (people) is diminished substantially. You could inform yourself by looking at this ppt presentation, take note of slide 6 where one of the listed advantages of ACT is the reduction of gametocyte carriage and then look further on where the effect of ACT therapy in reducing cases is shown (btw they do consider RESIDUAL spraying of DDT in KwaZulu, but residual spraying is spraying indoors, which Tim and Ed and Eli endorse, not broadcast spraying which you endorse, which lead to the disaster in Sri Lanka).
I really don’t know why I’m doing this on my day off — nevertheless, here I go.
Eli Rabett – Thanks for the slide show. I’ll look at it very carefully. However, ACT is for treatment, not prevention – it’s really a very simple concept. It makes sense to use indoor residual spraying as part of prevention measures (again when it works) and if, despite that (and other measures), one contracts malaria, one ought to use ACT (or whatever other therapies or combination of therapies are most cost-effective). See http://www.who.int/mediacentre/factsheets/fs094/en/.
I note also that ACT is not recommended for prophylaxis. See, e.g., slides 37 and 40 of the PPT presentation, The role of Artemisinin Drugs in the treatment of malaria, at http://www.malaria-ipca.com/images/artemisinin_drugs.ppt.
Also, note the caution in slide 35 on using artemesinin and derivatives during the first trimester of pregnancy. The solution: “risks have to be balanced against the benefits.”. Exactly so.
Second, where do you get the notion that I support “broadcast spraying”? Certainly not from my writings. If you READ the Conclusion of my paper posted above on September 14, 2010 at 9:14 pm you’ll see that it states:
[Emphasis added.]
And if you read further, you’ll note that although I’m skeptical that a global DDT ban will necessarily advance well-being in developed countries, I do not oppose such a ban with respect to its impacts on such countries. For practical purposes, such a ban would be superfluous from their point of view. To quote:
However, what I really object to is people and organizations wanting to play God with other people’s lives. In the context of a global ban on DDT that seemed imminent 10 years ago, I wrote:
Re: Eli Rabett on September 16, 2010 at 6:31 am and September 17, 2010 at 5:47 am
Ah Eli, Eli… May I call you Eli? You’re just not getting it.
First some basic research, Wikipedia will suffice.
Artemisinin
Plasmodium falciparum
Plasmodium vivax
Antimalarial drug [Artemisinin-based combination therapies (ACTs)]
Plasmodium (the genus)
ACT is now recommended front-line treatment for uncomplicated P. falciparum, with limitations. It is not for severe infections, except as a possible finishing treatment after other drugs have done the bulk of the work. ACT is being used for P. vivax, however “…in combination with primaquine for radical cure.” “P. vivax is found mainly in Asia, Latin America, and in some parts of Africa.” “Overall it accounts for 65% of malaria cases in Asia and South America.” Artemisinin resistence has been growing within Cambodia. The plant Artemisia annua has been used in Chinese herbal medicine for over a thousand years in the treatment of malaria, thus resistance to artemisinin should be expected.
P. falciparum is only one of six types of malaria. (The Genus article says at least 11 of the 200+ Plasmodium species infect humans.) Thus ACT is a partial treatment of malaria, of value part of the time, whose effectiveness is already decreasing. As I’ve noted, there are other mosquito-transmitted diseases.
Use of ACT requires a medical infrastructure. Sick people and medical personnel need to be brought quickly together as soon as the need arises. Lab work also needs to done promptly, to determine which strain of Plasmodium is involved before ACT is employed. Malaria is found in very poor countries where the only way to get medical care is to walk for days, and after the journey there may only be a simple clinic capable of setting basic simple fractures and suturing of incisions and lacerations, perhaps there are some common antibiotics on hand.
Indoor spraying of DDT is effective against the mosquito-transmitted diseases, including all forms of malaria, by preventing the mosquito-to-human transmission of the diseases. Its use only needs someone showing up once a year to do the spraying.
You are extolling ACT for rapidly depleting reservoirs of P. falciparum. Why not simply prevent those reservoirs from forming in the first place? Given the potential lifelong debilitating effects of malaria, isn’t the best course of action to prevent the infections, period?
And bed nets? Why should people only be safe from malaria in their beds, when they can easily be safe throughout their entire homes, and any building they occupy?
ACT sounds good, for certain P. falciparum infections that occur like outdoors where the protection of indoor DDT spraying is unavailable, for now. Don’t oversell it.
You folk don’t get it. ACT therapy has been shown to decrease malaria cases substantially, and malaria deaths drastically. Broadcast spraying of DDT has been shown to INCREASE malaria cases and malaria deaths because of the rapid development of resistance in the mosquitos. No one is advising against residual spraying of DDT in houses, and the more effective DDT impregnated bed netting. ACT works when properly applied. The increase in resistance in SE Asia can be traced back to insufficient dosing because of the relatively high cost of ACT (Gates and the Clinton Health Initiative are sponsoring research on reducing the costs). As the NE Journal of Medicine said in 2006
“In most of Asia, South America, and the Horn of Africa, chloroquine is still needed for the treatment of vivax malaria. This situation could change, since most malaria infections are treated without any particular species having been diagnosed, and the
artemisinin-based combination treatments (with the exception of artesunate–sulfadoxine–pyrimethamine) are reliably effective against all the malarias that affect humans.”
and we have this from the Lancet
“Early parasitological diagnosis and treatment with artemisinin-based combination therapies (ACTs) are key components of worldwide malaria elimination programmes. In general, use of ACTs has been limited to patients with falciparum malaria whereas blood-stage infections with Plasmodium vivax are mostly still treated with chloroquine. We review the evidence for the relative benefits and disadvantages of the existing separate treatment approach versus a unified ACT-based strategy for treating Plasmodium falciparum and P vivax infections in regions where both species are endemic (co-endemic). The separate treatment scenario is justifiable if P vivax remains sensitive to chloroquine and diagnostic tests reliably distinguish P vivax from P falciparum. However, with the high number of misdiagnoses in routine practice and the rise and spread of chloroquine-resistant P vivax, there might be a compelling rationale for a unified ACT-based strategy for vivax and falciparum malaria in all co-endemic regions. Analyses of the cost-effectiveness of ACTs for both Plasmodium species are needed to assess the role of these drugs in the control and elimination of vivax malaria.”
It is not that ACT doesn’t work against vivax, it is that choloquinine is still effective and much less expensive. Chloroquinine clear more slowly from the blood stream and therefore can be used as a propholaxtic.
Since artemisinin is rapidly cleared from the blood stream and is expensive you would have to be an idiot to think that it should be used for propholaxis, esp in the developing countries. Using it in that way would, esp in subclinical doses, in any case probably lead to development of resistance.
Indur, I have more extesive extracts from several books here. These are just what I found on the shelves at the UNSW library. We have multiple sources in agreement on the number of cases of malaria (a malaria text book, official WHO statistics, and Gordon Harrison’s history at my link above). We only have a newspaper story giving a different figure. I think it is likely that the reporter made a mistake when reporting what the WHO report said and mistook a figure for the number of cases when DDT spraying started in 1947 for the number of cases when they restarted after suspending spraying for a few years in the 60s.
DDT spraying against malaria was suspended in 1964 not because of environmental concerns but because there were too few cases to justify its use. DDT continued to be used in agriculture. They felt that they are succeeded in eradicating malaria and the few remaining cases could be treated with drugs. This wasn’t unreasonable — that’s what had worked in temperate climates.
It seems likely that the continued use of DDT in agriculture in Sri Lanka in the 60s helped cause mosquito resistance to DDT and the resulting malaria epidemic in the 70s despite DDT spraying. This is one of the things that Rachel Carson warned about in Silent Spring, but vested interests in agriculture and pesticide manufacturers delayed action till it was too late. Sri Lanka did learn a lesson from this and banned the agricultural use of malathion to prevent it from suffering the same fate as DDT.
Re: Eli Rabett on September 17, 2010 at 6:18 pm
Well, isn’t this a fine mess.
At only the third sentence you toss out a red herring:
I’ve been proposing indoor spraying of walls, not broadcast spraying. Indur already made clear to you his position. So why are you still bringing up broadcast spraying? Besides, as I pointed out, DDT remains effective for indoor spraying even after the mosquitoes have been declared resistant so it’s a moot point anyway.
Your next line contains what logically must be false:
One, there are people advocating a total ban on DDT thus there are people by default advising against indoor spraying. Two, how can DDT-impregnated bed netting be more effective than indoor spraying? Bed nets are only protection when one is in bed, with DDT-impregnation perhaps the room the bed is in is protected as well by the same way indoor spraying protects. But indoor spraying protects the entire home, which includes where the bed resides, and protects those in the home when they are not in bed. How can protecting a part be superior to protecting the whole?
Then comes your long speech about ACT. From which I obtained “…most malaria infections are treated without any particular species having been diagnosed….” Switching to ACT as front-line treatment for all forms of malaria will hasten resistance, and ACT will be prohibitively expensive in many poverty-stricken areas, which can already be the case with the cheaper drugs. And ACT still requires a medical infrastructure to administer it, which is often lacking where malaria is prevalent.
Then your next to the last sentence is another red herring:
From the sources I linked to in my previous post it is clear it is not for prophylaxis, and I did not suggest its use as such. Indur also said it is not for prevention. So why bring it up?
Then comes your last line:
Resistance has already developed, now what is left is for it to spread. As I previously said, the plant Artemisia annua has been used in Chinese herbal medicine for over a thousand years for the treatment of malaria. Thus malaria that’s resistant to artemisinin likely already existed, thus ACT’s usefulness will be time limited.
Which still doesn’t change that ACT is an after-the-fact treatment, the superior position of stopping the infection from happening in the first place still remains. By concentrating on doing so, there will be less malaria infections, far less, thus less infections to treat with ACT thus extending the period it will remain effective.
Well, you say no one is advising against indoor spraying of DDT. I’ve promoted it. Indur has promoted it. Thus we’re all in agreement. Bring on the indoor spraying of DDT, and we’ll see what we can do about the few cases that remain.
Tim,
Thank you very much for a very interesting compendium of materials. Perhaps the number ought to be closer to half a million than 2.5 million, although it doesn’t really change my qualitative conclusions: (a) indoor spraying has saved many lives over time, (b) where it’s effective, indoor spraying is fine, especially in developing countries, but broadcast spraying isn’t, if for no reason other than the fact that it hastens the development of DDT-resistant strains, (b) costs are important, particularly for developing countries who are generally short of resources, and (c) the decision on whether or not DDT should be made by the people whose lives are most at risk.
Next time I write on DDT and Sri Lanka, I’ll certainly link to the information you provided. I hope that before then I will have figured out which of these numbers is closer to truth. Thanks, again.
Indur
Really? The facts are that a) indoor spraying with DDT is being carried out. The costs are higher than the costs of impregnated nets. Given the nocturnal feeding habits of most mosquitoes indoor spraying and nets are both efficient (but at least some of the mosquitoes have adapted to indoor spraying by not roosting immediately after feeding.) On the other hand, indoor spraying is at high enough levels now that accumulation in people is being observed and appears to be associated, among other things, with reduced semen count in men and other such goodies
http://www.scientificamerican.com/article.cfm?id=ddt-use-to-combat-malaria
“The scientists reported that DDT may have a variety of human health effects, including reduced fertility, genital birth defects, breast cancer, diabetes and damage to developing brains. Its metabolite, DDE, can block male hormones.
“Based on recent studies, we conclude that humans are exposed to DDT and DDE, that indoor residual spraying can result in substantial exposure and that DDT may pose a risk for human populations,” the scientists wrote in their consensus statement, published online today in the journal Environmental Health Perspectives.”
What the world does not need is an engineer who thinks he knows it all posting to a credulous audience in an attempt to diminish interest in other problems. Roger Bate was the nasty piece of work who invented this ploy to deflect the WHO[‘s interest in dealing with the death and disease caused by tobacco. Golkany appears to want to follow in Bates’ footsteps but the target this time is to prevent us from dealing with climate change. Bate claims he never received any funding directly, but that is a tissue thin excuse given how money flows. He certainly asked for it.
It is dangerous on many levels. First it is a real threat to those exposed to malaria because Golkany’s recommendation, if foolishly adopted, would not work. More would get sick, more would die, and as we are seeing now there are secondary effects from indoor spraying that are emerging. Second, Golkany is prescribing from ignorance. He obviously is clueless with respect to the current efforts against malaria, coordinated by the Global Fund and the WHO, and supported, among others, but significantly by the Gates Foundation and the Clinton Global initiative, otherwise, why take the Gates foundation to task. They are supporting indoor spraying where appropriate. Golkany’s is a complete strawman, no matter how he tries to walk it back now. Further, he has no idea of medicinal attack on malaria, the people who are working to reduce costs and make effective drugs universally available.
The war against Rachel Carson continues.
Eli Rabett’s one side of his mouth said on September 17, 2010 at 6:18 pm:
Eli Rabett’s other side of his mouth is now saying on September 18, 2010 at 6:32 pm how bad indoor spraying is, effectively advising against residual spraying of DDT in houses.
After which, all of his mouth is used to say in several ways that Goklany is an idiot.
Yup, we can see how Eli wants to play his game.
So let him play, while the grown-ups go on saving lives with what we know will work.
Tim Lambert says:
“Rutledge’s claim that Rachel Carson killed 3 billion people, blames her for more deaths than actually occured from all causes since 1972. But it’s the title of the movie, so it must be true, I guess.”
Lambert ought to be the last person to be talking about numbers. He continually peddled the Lancet mortality figures even after Johns Hopkins had sanctioned the academic for peddling a defective study.
At the rate Lambert and Lancet were accumulating Iraqi deaths, we would have reached a 5 trillion Iraqi war deaths toll by now.
[snip]
Treat him like any troll.
“Roger Bate was the nasty piece of work who invented this ploy to deflect the WHO[‘s interest in dealing with the death and disease caused by tobacco. ”
Really Eli?
http://volokh.com/posts/1212258084.shtml#379738
Eli believes anything I guess and then slanders people.
> volokh
You’d think someone over there would bother to look this stuff up.
It’s not hard to find actual research published recently.
http://scholar.google.com/scholar?hl=en&q=DDT+cancer&as_sdt=2001&as_ylo=2001&as_vis=1
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2022666/
Environ Health Perspect. 2007 October; 115(10): 1406–1414.
Published online 2007 July 24. doi: 10.1289/ehp.10260.
PMCID: PMC2022666 Copyright This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article’s original DOI.
Research
DDT and Breast Cancer in Young Women: New Data on the Significance of Age at Exposure
“Results
High levels of serum p,p′-DDT predicted a statistically significant 5-fold increased risk of breast cancer among women who were born after 1931. These women were under 14 years of age in 1945, when DDT came into widespread use, and mostly under 20 years as DDT use peaked. Women who were not exposed to p,p′-DDT before 14 years of age showed no association between p,p′-DDT and breast cancer (p = 0.02 for difference by age).
Conclusions
Exposure to p,p′-DDT early in life may increase breast cancer risk. Many U.S. women heavily exposed to DDT in childhood have not yet reached 50 years of age. The public health significance of DDT exposure in early life may be large….”
Hank Roberts,
Advice on reading scientific studies: 1. do not rely on a single paper; 2. check the cites to find out about subsequent findings.
One of the citations of the paper you quoted was, for example, this one:
False-Positive Results in Cancer Epidemiology: A Plea for
Epistemological Modesty by Boffetta et al., in which the study you cite was given as an example of:
… and …
Surely that could never happen in the peer reviewed literature? Oh yes it can, and indeed frequently does, particularly in fields with strong political ties and emotive aspects to them.
Hank,
You know what is DEFINITELY causing breast cancer? Birth Control Pills. Funny that a substance that limits population AND causes cancer is totally legal, but one that gives life and prosperity and is POSSIBLY cancer causing(in the same catagory as coffee and pickles) is banned. Think there is anything wrong with that?
Do you drive? Cause the odds of you getting killed in a wreck are very high. Do you dance? Careful, you might break a leg.
Do you eat sugar? Might be wary of diabetes then.
Must we sit in a box and not move, not produce, not breathe? Are we to sacrifice the lives of countless children because you dug up some “might” cause breast cancer statistics? Let’s ask those moms in Africa if they think it’s worth that risk? Why are white men in Washington deciding this for them?
Rats that were fed DDT developed 26% less cancer than the control fed mice. Even with ALL data laid on the table, kids are dying, and DDT could stop it.
Sorry, but you are gonna have to peddle that arguement somewhere else.
Eli – When you try to figure out whether you are for or against indoor spraying, let me recommend that you do some comparative risk analysis to figure out whether reducing death and disease from the various health effects that MAY BE associated with indoor DDT use is worth risking real death and disease that assuredly will result if indoor DDT use is banned. A general methodology for such an approach is presented and applied in the paper, Applying the Precautionary Principle to DDT, available at http://goklany.org/library/DDT%20and%20PP.PDF. A refinement of the methodology is provided in “Emerging Technology and Political Institutions: Is the Precautionary Principle an Effective Tool for Policymakers to Use in Regulating Emerging Technologies? Yes [but with a caveat],” in Peter M. Haas, John A. Hird, and Beth McBratney, Controversies in Globalization: Contending Approaches to International Relations (CQ Press, Washington, DC, 2009), pp. 103-115. A draft version is provided at http://goklany.org/library/Goklany%20-Precautionary%20Principle%20in%20Haas%20et%20al.pdf.
Hank Roberts – If breast cancer is sensitive to indoor DDT use (as suggested by the paper you linked to), the relationship must be weak to non-existent. At http://www.time.com/time/interactive/0,31813,1668275,00.html, there is a map showing age-adjusted breast cancer rates around the world. Based on an eyeball analysis, it doesn’t seem to be related to malaria prevalence now or the 1960s and 1970s. Off hand, meat eating might seem to be a better determinant of breast cancer rates.
In any case, I would recommend that you too do a similar risk analysis to the one recommended above. The DDT-breast cancer study that you cite concludes, “It is too soon to decide that DDT exposure has little public health significance for breast cancer risk.” On the other hand, we do know that stopping indoor residual spraying would have substantial public health risk. Moreover, if one were to compare life years lost (LYY) from an “average” malaria related death you would find it to be much greater than the average LYY from a breast cancer death (which is far more prevalent among women than men), because of the long latency times involved.
In addition, who knows, but 50-60 years hence we may even have cure for breast cancers.
I don’t know about you, but if I were a girl younger than 14 years of age and lived in a malaria-endemic area, which malaria, moreover, was amenable to be reduced through DDT, I would think it would be better to control malaria and increase the likelihood of my living to tomorow, even if that means that five to six decades hence I may be afflicted by best cancer.
But regardless of my preference, it would be unethical for me to make that decision on behalf of that girl. Such decisions are best made locally by those most affected by the decisions.
A peer-reviewed scientific paper published in 2008 in Malaria Journal by Yukich, Lengeler, Tediosi, Brown, Mulligan, Chavasse, Stevens, Justino, Conteh, Maharaj, Erskine, Mueller, Wiseman, Ghebremeskel, Zerom, Goodman, McGuire, Urrutia, Sakho, Hanson and Sharp compared several large vector control programs to prevent malaria, including both insecticide-treated nets (ITN) and indoor residual spraying (IRS). The results: Conventional ITNs cost $438-$2199 per child death averted, Long-lasting ITNs cost $502-$692 and IRS cost $3933-$4357.
Even using IRS, DDT was not the most cost effective insecticide, which was deltamethrin. Yukich et al conclude:
Twenty years ago DDT was the WHO insecticide of choice for malaria control, but better stuff has been developed since. The folks promoting DDT over better, cheaper, alternatives need to join the 21st century. The world tried to eradicate malaria using DDT last century but it failed. If we are to defeat malaria we have to use modern technology, not stuff from the 1940s.
JF Beck dissects the Ed Darrell /Tim Lambert DDT linkage and comes up with:
“Malaria, DDT and two idiots”
http://asiancorrespondent.com/rwdb-jfbeck/malaria-ddt-and-two-idiots
From: Tim Lambert on September 19, 2010 at 11:03 pm
This is truly amazing news. Especially since that is the full paper, “DDT” appears just once in the text, and “delt” doesn’t show up at all thus that full pesticide name isn’t there either. Upon reading the paper and even examining all Tables and Figures, it is clear that particular insecticides weren’t even considered, it examines more generally simply insecticide treated net (ITN) and indoor residual spraying (IRS) programs with consideration towards the new long-lasting insecticidal nets (LLIN’s). This is notable in the sole DDT mention:
I could conclude that you have deliberately attributed this non-existent “fact” to this scholarly work for the purposes of misinformation, but I shall be charitable for now and go with the general rule for such: Never attribute to malevolence what can be accounted for by incompetence. You simply didn’t know what you talked about.
Also, while you point to those child death averted numbers, you fail to note a particular distortion. Those numbers relate to children under five years of age. From the “Costing Scenarios” section:
Then this is subsequently found in the “Main Findings” section:
So you have a house with 5 people in it, of which 1 is a child under 5, they acquire 2 nets, that’s 1 child death averted. IRS is whole-house protection. They would have to acquire 5 nets to get what IRS offers on a per-person basis. Although unspecified, let’s go with that 20% figure being for children under 5. Multiply those ITN cost numbers by 2.5, then compare to IRS.
Also IRS, as described in the paper, is done on a community-wide basis. ITN’s are distributed to individuals. Once the commitment to IRS is made, entire villages are treated and protected. ITN programs have very large gaps. This is seen right off in Table 1. For the two IRS programs examined, net coverage for children under 5 was listed for one as “High” while the other is “> 95% structures.” For the 5 ITN programs it ranged from 59% to 7. Yup, down to SEVEN PERCENT.
Now to something related. You seem to have the same affliction as Eli. Above you said:
Yet at considerable length you explained to Golkany that DDT usage was halted due to economic reasons, there were too few cases remaining to warrant continued usage. Thus when it suited you, you were saying economics prevented DDT from eradicating malaria, which did indicate it was enormously successful. Now, using indoor spraying which remains effective even after the mosquitoes have been declared resistant to DDT, we could follow through to the end with DDT and eliminate malaria. Thus you appear to have shifted to saying “it” failed, indicating DDT failed, although I can be charitable and go with the alternate where you actually said the world failed, in which case with sufficient determination the world can this time succeed with DDT.
So now you’re complaining about old stuff, saying there are better, cheaper alternatives. Yet you are unable to show there is anything better and/or cheaper than indoor DDT spraying, certainly nothing as completely effective, and try to foist off this generic ITN vs IRS study as saying something specific against DDT to the point where you (inadvertently?) added a “fact” that wasn’t even in it.
You and Eli argue similarly. Much time is spent going against DDT while appearing to be reasonably considering the issues, then when you get nailed down it becomes “Anything but DDT!” Is it that hard to admit you’re an anti-DDT advocate at the start?
From the paper Tim Lambert links to:
Since Tim claims:
I suggest you send a note to the authors of the paper you cited, since they promoted DDT. It seems by your reckoning, they need to “join the 21st century”.
Note Lamberts slipperiness here – cost per death prevented is highly variable depending on a number of factors. The paper clearly shows that cost per person protected is almost identical between IRS and ITN. Of course, some of those protected by IRS will not be the most vulnerable; but in areas where IRS is used, a much greater proportion of the population will be afforded protection. A cost/benefit analysis which only includes one factor cannot be the sole basis of policy.
Lambert also claims:
Be nice to see some evidence of that, Tim. Presumably, if it was the “insecticide of choice” we should be able to find lots of 20-year old WHO literature heavily promoting the use of DDT. Should be easy for you to find evidence for your claim, then. Because until I see some evidence, I will remain extremely sceptical of that claim.
Kadaka: you beat me to it! 🙂
Spence_UK said on September 20, 2010 at 8:09 am
Ah, there’s some overlap but we each made separate points. The more, the merrier!