The curious case of the anti-insecticide movement

Around 700,000 people die every year from Malaria. Most of these are children in Africa. Although some progress has been made in recent years, this disease remains a serious global health problem. While most people understand that malaria is transmitted by mosquitoes and can be controlled and cured, the battle against it is complex and difficult. And increasingly clear is that anti-insecticide activism by environmentalist groups is seriously undermining the fight.

The fight against malaria relies on two main interventions – controlling mosquitoes with safe and effective insecticides, and treating patients with malaria medicines. Both these interventions face the problem of resistance, either by the mosquito against the insecticide or the malaria parasite against the medicine. Thanks to advocacy, public policies and commitments from the pharmaceutical industry, progress has been made in keeping slightly ahead of parasite resistance and ensuring access to effective medicines. Regrettably the same cannot be said for insecticides.

Only four classes of insecticide are approved by the World Health Organisation (WHO) for public health purposes. Within these classes, only twelve insecticides are available for indoor residual spraying (IRS) (one organochlorine, six pyrethroids, three organophosphates and two carbamates). Although it may seem there is sufficient variation among these alternatives, not all are always suitable and their costs vary enormously. For cash-strapped African countries and donor agencies with shrinking budgets, small variations in cost could significantly affect malaria control with devastating consequences for millions of people.

Pyrethroids are used extensively in agriculture and are also the only approved class of insecticide used to treat bed nets. With the growing resistance among this class, countries could be compelled to use alternative and far more costly insecticides that do not suffer from widespread resistance. The two main alternatives available for indoor spraying against mosquitoes are either carbamates or organophosphates, but these are four and eleven times more expensive respectively. And some of these alternatives do not last as long, and so will incur even more expense with multiple rounds of spraying. Neither option is approved for use on bed nets.

With the exception of DDT, all other WHO-approved insecticides are reformulated agricultural insecticides that were adapted for public health purposes. The reason for this is simple: the public health insecticide market comprises approximately one per cent of the total. There is thus very little economic incentive to develop alternative insecticides that are specifically formulated for the public health market. Yet research and development for new insecticides for malaria control, both for indoor spraying and bed nets, as well as other public health applications, is crucial.

For decades, well-funded and highly-effective environmental campaigns have stigmatised insecticides, even though they are as essential for public health as medicines or vaccines. Regulatory costs of developing new insecticides have risen sharply, destroying what limited financial incentives remain. Moreover, anti-insecticide activists still push for alternative control interventions such as removing standing water, planting alleged mosquito-repelling trees, and using fish to eat mosquito larvae, even though none of these interventions has been shown to work effectively.

Recently my colleague Richard Tren, with Michael Miller of the Duke Global Health Institute at Duke University, published a paper in the journal Research and Reports in Tropical Medicine - see http://bit.ly/KOpzsW . They estimate that “Short of a dramatic increase in funding to cover the higher cost of new insecticides, indoor spraying coverage rates in some African countries could fall dramatically, by between 40 and 50 per cent.” In just seven sample countries examined, the number of people who could lose protection due to higher insecticide costs could be as high as 4.7 million annually. Tren and Miller note, “Not all countries will be forced to abruptly adopt alternative insecticides, nevertheless the global impact will be considerable.”

Aside from an effort funded by the Bill and Melinda Gates Foundation, there is woefully inadequate investment in the search for new public health insecticides. The global malaria control effort thus faces a potentially catastrophic dilemma and countries and donors could soon have to make some very difficult decisions about cost, access, and lives. Tren and Miller proposed several low-cost or no-cost options for policymakers to consider – all of which already exist to increase access to essential HIV/AIDS and malaria drugs. For instance, they propose new pricing models that would ensure ongoing access to insecticides for poor countries, while protecting home country markets. They also propose incentives for new public health insecticide research, such as easing the regulatory burden on profitable agricultural and horticultural products in return for investment in public health products.

For the millions of poor individuals across the globe who are exposed on a daily basis to the deadly bite of infected mosquitoes, insecticides used to kill malaria carrying mosquitoes mean the difference between life and death. The idea that malaria control programmes can operate effectively without the use of insecticides is simply barbaric and amounts to a cruel experiment being carried out on malaria sufferers. The anti-insecticide agenda has cost lives and hampers malaria control programmes. It is creating more harm than good. It should be stopped.

AUTHOR Jasson Urbach is a director of the Health Policy Unit and Africa Fighting Malaria. This article may be republished without prior consent but with acknowledgement to the author. The views expressed in the article are the author’s and are not necessarily shared by the members of the Foundation.

HPU Feature Article / 9 May 2012