AFM Response to "WHO Promotes DDT?"

Richard Tren | 14 Oct 2023
The Lancet
In order to advance their argument that WHO has consistently supported DDT in malaria control, Overgaard and Angstriech fabricate a straw man—the better to knock it down—of those advocates who promote and are pro-DDT. This is misleading and intellectually dishonest rhetoric. Africa Fighting Malaria (AFM), who Overgaard and Angstreich mention by name, is not pro-DDT; it is anti-malaria. The evidence shows that DDT when sprayed indoors is highly effective against malaria, which is a massive killer of children. DDT's efficacy has been borne out over many decades around the world(1)(2)(3)(4). Accordingly, it would be irresponsible of AFM not to support DDT in malaria control.

Overgaard and Angstreich advocate against DDT and for Integrated Pest Management (IPM). That might be acceptable, if they cited scientific evidence demonstrating that IPM is highly effective against malaria—but they don't. Their article discloses no citations—not even one—to literature demonstrating that IPM is effective in reducing malaria transmission, parasitaemia or disease. Their words lend credibility to the idea that IPM are code words of the environmental movement's push for "anything but insecticides." The authors' bias is revealed in their statements about studies in the 1990s suggesting DDT causes cancer. They cite two studies, one for breast cancer and one for pancreatic cancer. They fail to cite later work disproving the first and casting serious doubts on the latter.(5)(6)(7)(8)

Overgaard and Angstreich's argument that WHO has always supported DDT is deeply flawed and the authors ignore the wider context in which DDT is used to control malaria. While it may be strictly true that WHO technical reports authorized DDT for malaria control, WHO and other UN organizations have worked to de-emphasize indoor residual spraying (IRS), the intervention which would utilize DDT. Several WHO technical reports, WHO Executive Board resolutions and World Health Assembly (WHA) resolutions called for malaria control to be conducted as a primary healthcare activity making IRS almost impossible. Furthermore numerous WHO documents promote environmental, biological and chemoprophylaxis measures for malaria control ahead of IRS.(9)(10)(11)(12)(13)

Evidence of this anti-insecticides agenda is found in the 1997 WHA Resolution 50.13 which calls on member states to "to take steps to reduce reliance on insecticides for control of vector-borne diseases..."(14)

Over several decades WHO misunderstood DDT's main modes of action, spatial repellency and irritancy, despite documented evidence;(15)(16) this in turn led to WHO acting against the use of DDT(17). Overgaard and Angstreich choose to ignore these facts.

Overgaard and Angstreich assert that AFM promotes DDT "as a panacea for the world's malaria problems." Such false characterizations are mischievous and in line with their straw man tactics. AFM's research and advocacy work promotes all effective and proven interventions to prevent and treat malaria. Any cursory search of our website or examination of our publications will confirm this and will demonstrate that we never promote any one intervention as a panacea.

In essence Overgaard and Angstreich present an ideological argument without evidence and cannot be taken seriously.

Competing Interests: None

Richard Tren, Director, Africa Fighting Malaria, Washington DC, USA. Dr. Donald Roberts, Professor Emeritus, Uniformed Services University of the Health Sciences, Maryland, USA;=1

References: (1)Sharp, BL, Kleimschmidt, I, Streat, E, Maharaj R, Barnes, KI, Durrheim, DN, Ridl, FC, Morris, N, Seocharan, I, Kunene, S, La Grange, JJP, Mthembu, J, Maartens, F, Martin, CL, Barreto, A. Seven years of regional malaria control collaboration - Mozambique, South Africa and Swaziland. Am. J. Trop. Med. Hyg., 76(1), 2007, pp 42-47

(2)Sharp, BL, van Wyk, P, Sikasote, JB, Banda, P, Kleinschmidt, I. Malaria control by residual insecticide spraying in Chingola and Chililabombwe, Copperbelt Province, Zambia. Trop. Med. Int. Health. 7(9) pp 732-736, Sept. 2002

(3)Roberts D, Laughlin LL, Hsheih, P, Legters, LJ. DDT, Global Strategies and a Malaria Control Crisis in South America, Emer. Infec. Dis. 3(3) pp 295-302, July-Sept 1997

(4)Shama SN, Shukla, RP, Raghavendra, K, Subbarao, SK. Impact of DDT spraying on malaria transmission in Bareilly District, Uttar Pradesh, India. J Vect Borne Dis, 42, June 2005, pp 54-60

(5)Safe SH. 1997. Is there an association between exposure to environmental estrogens and breast cancer? Environ HealthPerspect 105 Suppl 3:675-8.

(6) Lopez-Cervantes M, et al. 2004. Dichlorodiphenyldichloroethane burden and breast cancedr risk: a meta-analysis of the epidemiological evidence. Environ Health Perspect 112(2):207-14.

(7)Cocco P, Fadda D, et al. 2005. Cancer mortality among men occupationally exposed to dichlorodiphenyltrichloroethane. Cancer Res 65(20):9588-94.

(8)Porta M. Role of organochlorine compounds in the etiology of pancreatic cancer:a proposal to develop methodological standards. Epidemiology 12(2):272-6.

(9)WHO Executive Board 65th Session, Summary Records, World Health Organization, Geneva, 9-25 January 1980, p. 224

(10) WHO. Malaria control and national health goals. Report of the Seventh Asian Malaria Conference. World Health Organization Technical Report Series 680. WHO, Geneva, 1982

(11) WHO Executive Board, 71st Session, Summary Records, Geneva, 12-26 January 1983, EB/71/1983/REC/2, Committee A, p171

(12) WHO, 38th World Health Assembly, Resolutions and Decisions, World Health Organization, Geneva 7-17 May 1985, WHA 38.24

(13) WHO Executive Board, 75th Session, Summary Records, World Health Organization, Geneva, 9-24 January 1985, EB75/1985/REC/2 p264

(14) WHO 50th World Health Assembly, Resolutions and Decisions, World Health Organization, Geneva 5-14 May 1997, WHA 50.13

(15) Kennedy, JS The exitant and repellent effects on mosquitoes of sublethal contacts with DDT. Bull of Entomol Res. 1947, 37: pp 593-607

(16)Dethier, VG, Browne LB, Smith, CN, The designation of chemicals in terms of the responses they elicit for insects, J Econ Ent, 1960, 53: pp 134-136

(17) WHO Expert Committee on Malaria. Technical Report Series No. 640, World Health Organization, Geneva, 1979, p. 48