DDT use in South Africa

I’ve written several posts debunking the myth that using DDT is banned, pointing out that is used in places like South Africa. Now Professor Bunyip has finally discovered this fact and slams Tim Blair for spreading the myth:

This item from the BBC will have Tim Blair beside himself — a contortion worth seeing, given that he has long since assumed the initial improbable position of being well up himself.

South Africa had stopped using DDT in 1996. Until then the total number of malaria cases was below 10,000 and there were seldom more than 30 deaths per year. But in 2000, [South Africa] saw malaria cases skyrocket to 65,000 and 458 people were killed….

Last year [after DDT's re-introduction] only 89 deaths were recorded.

Off you go, Tim, get cracking. Several thousand words, if you please, about how your sort of statistics never lie and why, in the great right-eyed scheme of things, hundreds of little black and brown lives preserved don’t make a rational objection to a favoured theory.

Oh wait, that’s not what he wrote. He actually slams me. Apparently he thinks this story contradicts some theory he thinks I hold. What he thinks that theory is, I cannot tell.

Mind you, the BBC article is rather misleading. The only insecticide ever mentioned is DDT, so this
leaves the impression that they are spraying DDT in Mozambique:

But the disease can never be fully eradicated without neighbouring countries also jacking up their malaria control programmes.

This led to the creation of the Lubombo Spatial Development Initiative, backed by the Global Fund to Fight HIV/Aids, Malaria and TB, which has led to an 83% and 67% drop in malaria cases in Swaziland and Mozambique respectively.

But actually, they are spraying Bendiocarb. The reason why the article is so misleading isn’t hard to find. The scientific authority cited is Richard Tren from the astroturf operation Africa Fighting Malaria.

To get a better idea of what happened I thought I’d consult a scientific journal. Tropical Medicine & International Health Dec 2004:

One problem in this data set was the coincidence of different explanatory variables. In the late-1980s, imported malaria and chloroquine drug resistance peaked simultaneously and a local outbreak occurred because of agricultural practice. In the 1990s, HIV infection and SP resistance emerged simultaneously and in addition DDT was replaced with pyrethroids. Finally, in 2000/01 malaria incidence fell substantially after re-introduction of DDT spraying, introduction of a new effective antimalaria drug, and implementation of large-scale vector control in Southern Mozambique … as part of the Lubombo Spatial Development Initiative (LSDI). The relative importance of each variable can only be inferred if long time series of malaria case data and explanatory variables are available, and perhaps not even then. So the problem is not a lack of possible explanations, but the abundance of highly plausible ones

Hmm, all those other factors got left out of the BBC story.

This article from the same journal on the reasons for the switch to pyrethroids is also interesting:

However, in recent years several shortcomings of RHS have been highlighted. The effectiveness of DDT was compromised by the insecticide’s irritant effect, which led to a high proportion of bloodfed mosquitoes leaving huts and not resting indoors (Sharp et al. 1990). Frequent replastering and painting over sprayed walls has also impaired effectiveness. In 1995, more than 48% of the homesteads replastered at least some of their walls, rendering the insecticide ineffective (Mnzava et al. 1998). The switch to pyrethroid insecticides, which do not smell or leave visible deposits, has reduced the prevalence of this practice, but it remains a common occurrence, with a fifth of homesteads replastering or painting before the end of the malaria season in 1997-1998 … Other households avoid RHS altogether by locking their houses during the spraying round.

So the repellent effect of DDT makes it less effective, even though Roger Bate claimed the repellent effect meant that DDT was still effective even when the mosquitoes were resistant.

Comments

  1. #1 jet
    September 28, 2005

    Why would there be astroturf for DDT? Astroturf implies a special interest group is backing Tren, so would would this be?

  2. #2 euan
    September 28, 2005

    It’s an astroturf operation to attack conservationists for banning DDT and causing millions of excess deaths.

  3. #3 Carleton Wu
    September 28, 2005

    Jet,

    Well, it could be a proxy for attacking environmental groups in general. If they (the omnipresent evil “they”) could demonstrate that many environmental groups are either 1)scientifically backwards and/or 2)completely unmotivated by human suffering, they’ll be a leg up when the debate shifts to something more financially important (eg a carbon tax, if “they” = ExxonMobil, stricter water quality if “they” = chemical manufacturers).

    It’s all about the framing.

    Wu

    PS Read the sourcewatch link, and follow the links from there. Mining companies, ‘free market’ foundations, etc. It’s not a difficult trail to follow.

  4. #4 Carleton Wu
    September 28, 2005

    poor euan, he’s still stuck on the “DDT is banned” meme, even when the article he’s posting about demonstrates that DDT isn’t banned at all…

  5. #5 cytochrome sea
    September 28, 2005

    I don’t think I understand what the “DDT ban myth” is. If the “myth” is a worldwide ban on DDT for any use, then yes, that’s a myth. However there are countries who’ve banned DDT for any use, eg. Philippines, ?Thailand?, etc… IIRC, malaria rates in the Philippines went down after banning the use of DDT for vector control, but likely it was due to (iirc) greatly increased funding in the control programs.

    Tim: it’s nice to see you linking to the LSDI, they seem to be doing a lot of good. (although Dano might denounce them as I think most of their original funding was “Indy” :)
    With respect to the Bendiocarb link, it seems odd that they were rotating two carbamates, it looks like they stopped trying Propoxur, possibly due to research published that year indicating some of the A. Funestus group’s carbamate cross resistance, likely due to agricultural pyrethroid use. Also, the LSDI has previously recommended introducing DDT into the rotations. Likely trying to get around the Mozambique’s Ministry of Health’s non approval of the use of DDT(by itself). Regardless, the ‘important’ thing is that the infection rates are going down.

    euan: Actually there have been cases where the conservation groups have “caved in” and approved DDT use. The current example with the LSDI, with respect to the Endangered Wildlife Trust collaboration is illustrative.

  6. #6 Ian Gould
    September 28, 2005

    “Africa fighting Malaria” is reportedly funded by South African mining companies which want to use DDT rather than alternative insecticides in and around their worker camps. Allegedly not because it’s more effective but because it’s cheaper.

  7. #7 euan
    September 28, 2005

    I don’t believe that DDT has been banned. I was attempting to point out a motivation for astroturf groups to answer jet’s question. The astroturf groups want to exaggerate the restrictions on DDT in order to discredit environmentalists, hence the attacks on Rachel Carson.

  8. #8 Annabelle N Smith
    September 28, 2005

    From the Craig et al, 2004:

    Dichlorodiphenyltrichloroethane (DDT) has been successfully used for indoor residual spraying in South Africa since 1948 (Sharp et al. 1993b). For several reasons, including human breast milk contamination, community objection and INTERNATIONAL PRESSURE (Le Sueur etal. 1993b; Sharp et al. 1993b), DDT was replaced by synthetic pyrethroids in 1996.

    [emphasis added]

  9. #9 Dano
    September 28, 2005

    although Dano might denounce them as I think most of their original funding was “Indy”

    Only if they’re running a disinfo campaign to game the political economy in their favor.

    HTH,

    D

  10. #10 sellario
    September 29, 2005

    That says “Tim Lambert”, not “Tim Blair”…

    Did I miss something?

  11. #11 cytochrome sea
    September 29, 2005

    Ian: This doesn’t seem to me to be a logically consistent argument. Why would a company prefer to use a ‘less effective’ method of keeping their workers fit enough to work? Regardless, the major vector in South Africa is the A. Funestus group. The most effective control method has been well established as DDT. *Twice*. (pyrethroid IRS tests had begun in S.A. as early as 1931, DDT and BHC use began in 1946. DDT use was curtailed ~97, (followed with a corresponding increase in infections, and increase in A. Funestus pyrethroid resistance)and DDT use was again adopted in 2000. (followed by a drop in rates of infection)
    I would think any mining company lobbying effects would probably be of such a small per cent as to be on the second order of minutia.
    (I could be wrong however) Regardless, even if mining companies were a significant factor in deciding to reintroduce IRS’d DDT, which had the effect of not only saving many lives, but also saving many more people grief, (malaria isn’t a pain-free affliction) then good for them. No?

  12. #12 Carleton Wu
    September 29, 2005

    euan,

    I think that’s the second time this month I’ve misinterpreted a (hostile) summation of a stupid position as a statement supporting that position. That is, I read the statement with scare quotes around ‘astroturf’, not ‘banning’ and ‘causing millions of excess deaths’.

    At least, from your second comment that’s how Im interpreting it now. Is that right?

    Wu

  13. #13 Ian gould
    September 30, 2005

    >Ian: This doesn’t seem to me to be a logically consistent argument. Why would a company prefer to use a ‘less effective’ method of keeping their workers fit enough to work?

    You misread me – the mining companies want to use DDT because it’s cheaper, not because it’s any more or less effective than the alternatives.

  14. #14 cytochrome sea
    September 30, 2005

    Ian: I reread your post with your new explanation in mind and now see where I read you wrong, sorry about that. I believe I’ve already covered why DDT was reintroduced in S.A. as a vector control tool previously; the reasons I gave might be wrong, however, I do not think this is likely to be the case.

    I had a little time so I ‘googled’ into Africa Fighting Malaria a bit, and I think I see where the mining companies enter into the ideas you were referring to.

    It looks like two of Africa Fighting Malaria’s funding sources are The Anglo American Chairman’s Fund and
    BHP Billiton plc, which appear to be a British based (mostly) mining company’s charitable fund and an Australian based mining company.
    I couldn’t seem to find much info about malaria intervention (DDT specifically) with respect to the former, but found [this] (http://www.cid.harvard.edu/events/papers/Indust11JanAS.pdf) for the latter:

    “The plant is a joint venture, uniting BHP-Billiton, an Australian based company, Mitsubishi and the government of Mozambique. Risk of malaria infection in the site is unusually great, resulting in unacceptably heavy morbidity and mortality. Tosafeguard its local and expatriate workers as well as the local residents, Mozal entered into partnership with the national malaria control programs of Mozambique and South Africa. Ameliorative measures included efforts to reduce transmission by means of indoor residual spraying with insecticides and early recognition and treatment of cases. The Medical Research Council of South Africa assumed overall responsibility for coordinating and implementing the anti-malaria effort”

    “This USD$1.4 billion joint venture between the Australian based mining and metals company BHP-Billiton PLC, Mitsubishi and the Mozambican government encountered extremely high rates of malaria, with 7,000 episodes in two years and the deaths of 13 expatriate employees. Malaria morbidity resulted in a loss that approaches 155,000 man-hours, or about 1% of the total man-hours of work. If the average wage were USD $20,000 per year, or about USD $80 per day, malaria related lost workdays alone would have cost the firm about USD $1.6 million.Furthermore, about 40 known episodes of severe malaria required medical evacuation, which might have cost another several hundred thousand dollars. Mozal has undertaken a comprehensive anti-malaria initiative, covering both the Mozal site and the surrounding area at a cost of USD $480,000 for the first year, with a reduction to USD $360,000 for the second year with the possibility of further reductions in successive years”

    My searches were pretty cursory but I think it’s possible we might find similar programs for the Anglo American Chairman’s Fund. (or as I like to call them, the *whiteys* :)

    Since BHP Billiton plc works with Mozambique’s govt, (who won’t allow DDT *alone* to be used)it would make sense for them to fund a pro-DDT NGO to help persuade public opinion. It was interesting to me to find who else these two work with, (and what else they fund) for [instance] (http://www.bitc.org.uk/press_office/press_releases/bhppressrelease.html):

    “Tackling head-on its most challenging sector issues, BHP Billiton is committed to building long term relationships with key NGO partners, such as Oxfam and WWF as well as governments and peoples on whose land they operate”

    [more](http://www.lovelife.org.za/corporate/news/article.php?uid=340):

    “Speaking at the presentation of the 2003 Nelson Mandela Award for Health and Human Rights in Johannesburg, Mr. Trahar said that the Anglo American Chairman’s Fund would provide funding of approximately R30 million over a period of 3 years to loveLife-South Africa’s national HIV prevention programme for youth-to accelerate the roll out of loveLife’s national adolescent friendly clinic initiative (NAFCI) in communities associated with Anglo American operations in South Africa.”

    “Mr. Trahar said that this community project and partnership would form part of a collaborative effort between the Department of Health, the US-based Henry J. Kaiser Family Foundation, the Nelson Mandela Foundation and the Global Fund to fight AIDS, TB and Malaria. It would help to ensure the integration of employer-based HIV/AIDS prevention and care programmes with the services provided by public sector primary health care clinics”

    [more](http://www.childrenshospitaltrust.org.za/news.asp?PageID=217):

    “The only dedicated paediatric Trauma Unit in Africa opens”…”The Red Cross Children’s Hospital will catapult South Africa to the forefront of specialised paediatric care when it officially opens the new world-class Trauma Unit. This unit is the only dedicated paediatric Trauma Unit in Africa”…”The Discovery Health Trauma Unit in partnership with The Anglo American Chairman’s Fund is the realisation of an African Dream to provide the most vulnerable of our citizens, the children, and the best chance to a healthy childhood”

    Ok, I apologize for so much quoting and for the great length this post is acquiring. In brief, both organizations seem to do much for public health in these regions of operation. HIV/AIDS seems to be the front runner for both,
    with other public and employee specific health programs, coming second. (along with educational programs, etc…) I didn’t look into how they conduct their business, things of that nature, (ie, they might be ‘bad guys’ in other respects as far as I know) but it seems their charitable contributions aren’t too shabby. I’ll retract my assertion about the magnitude of the mining lobbying effects (wrt to the decision to reintroduce DDT in S.A.) by one order. Although I still highly doubt any direct connection, (the research alone presented more than sufficient a case for the reintroduction) in light of what I’ve just come across I’ll reiterate, good for them.

    I didn’t get into Africa Fighting Malaria’s articles but when I get some more time I’ll have a look.

  15. #15 jet
    September 30, 2005

    Ian Gould,
    “…the mining companies want to use DDT because it’s cheaper, not because it’s any more or less effective than the alternatives.”

    Wow, you can read their minds? You must have ESPN or something.

    You don’t deny cytochrome sea’s point that DDT is more effective there and that it is a good thing that AFM is lobbying for its reintroduction, but you ascribe the motivations to this as the worst possible. Yet cytochrome sea shows contributions to hiv/aids and an enormous amount of lost man-hours to malaria. It is more likely that the cost of the pesticide isn’t so much important as the effectiveness of the pesticide and that the companies are more interested in healthy workers. Otherwise why spray at all?

  16. #16 eudoxis
    September 30, 2005

    Just a small quibble:

    Tim Lambert, after quoting a paragraph about irritancy writes: “So the repellent effect of DDT makes it less effective, even though Roger Bate claimed the repellent effect meant that DDT was still effective even when the mosquitoes were resistant.” [emph. mine]

    Irritancy and repellency are two different effects. Irritancy is related to avoidance after contact with the insecticide. Repellency is related to avoidance without contact. Repellency works toward reducing contact with a host (it keeps mosquitos out of the hut) while irritancy has no effect on contact with host (unless the host is wearing the insecticide) but can be problematic as it shortens contact time with the insecticide. The present host does not benefit from insecticide irritancy.

    Pyrethroids don’t have a repellent effect, in fact, they appear to be attractants. On the other hand, they are also less irritating and contact with the insecticide results in a high knockdown rate.

    Unfortunately, vector resistance to pyrethroids is becoming a problem like it is for DDT.
    I don’t know if insecticide resistance persists after selective pressure is removed.

  17. #17 cytochrome sea
    September 30, 2005

    jet: I agree with your comment with the exceptions of “Wow, you can read their minds? You must have ESPN or something.” and “but you ascribe the motivations to this as the worst possible” only because these are shooting the *messenger* while Ian in this case was relaying the *message* while distancing himself from it as not being his own in his first post. He simply didn’t repeat his caveats in the second.
    It was a reply to my misunderstanding, so it’s my bad. (but of course, like you I don’t see the message holding up)

    eudoxis: “Unfortunately, vector resistance to pyrethroids is becoming a problem like it is for DDT.
    I don’t know if insecticide resistance persists after selective pressure is removed.”

    Indeed. The problem is DDT and pyrethroids both target voltage gated sodium channels, and a resistant mutation will confer a cross-resistance to both. Considering the widescale agricultural use of pyrethroids in the endemic regions, you probably won’t be seeing a removal of selective pressure anytime soon.

    An aside, if “per” really is a sock puppet for whom Tim asserts, it’s a shame he won’t add to this discussion as his lab (iirc) does research with cytochrome P450, I’m sure he’d have quite a bit to contribute.

  18. #18 Ian Gould
    October 1, 2005

    Jet,

    Go back to my initial post and take note of the words “reportedly” and “allegedly”.

    I saw the Sourcewatch article on Africa Fighting Malaria some time ago and repeated the claims from that article – while making clear (at least to those with normal English comprehension skills) that I wasn’t certain of the accuracy of those claims.

  19. #19 Ian gould
    October 1, 2005

    Yes, but is it a “misuse of science” issue?

    The Right for the most part don’t seem to be making claims wildly at variance with mainstream scientific thought – compare the “Intelligent Design” or Global Warming debates.

    Rather they seem to have simply misunderstood the situation and accepted reports of a proposed ban back around 2000 as factual statements of a current ban.

    Of course, when they cite reports of DDT being used in South Africa as proof that DDT use is banned, that misunderstanding begins to look rather deliberate.

    I can’t speak for others but I find the misuse an abuse of science by BOTH sides of the political spectrum one of the most disturbing and pernicious elements of contemporary politics and society.

    Why don’t I spend as much time attacking leftist misconduct? Well:

    a. the left is currently out of power in the US (the world’s most powerful country) and Australia (my homeland). Therefore the immediate prospect of serious harm arising for such misconduct is less.

    b. On this blog I simply respond on the topics Tim raises.

  20. #20 Ian Gould
    October 2, 2005

    Well that’s bizarre, my previous post was actually intended to go on the other recent DDT thread.