Hope from Zambia on malaria control
Recent evidence from the Thai-Cambodia border demonstrates that the malaria parasite is becoming increasingly resistant to our most effective anti-malaria medication artemisinin. But this is not the first time that a once highly effective medication has lost its potency in this area. Resistance along the Thai-Cambodia border started with chloroquine (CQ) in the 1950s followed by sulphadoxine pyrimethamine (SP) and mefloquine. Then, like now, one of the main reasons for increased resistance is the prevalence of fake and sub-standard medicines. Indeed, research conducted by Dr. Paul Newton of Oxford University in 2006 revealed that 68 per cent of artemisinin treatments in Cambodia, Vietnam, Laos and Myanmar were fake.
Combining drug therapy for humans with effective insecticides to control the malaria- spreading mosquito would provide the one-two punch necessary to break the transmission cycle and to knock out the disease. Although this might sound simple enough there are myriad of conditions that make malaria control very complex. One of these factors is the unscrupulous practice of some dubious pharmaceutical manufacturers who produce fake and/or substandard drugs. Sub-standard drugs and those with traces of the active ingredient, as opposed to outright fakes (where there is no attempt whatsoever to include the active ingredient), are of particular concern because, in addition to affecting the patients health, they increase the probability of the malaria parasites building up resistance to good quality drugs. This has the potential to render an entire class of drugs useless and introduce serious long-term implications for our ability to fight the disease
In 2007, Africa Fighting Malaria (AFM) undertook a project to estimate the prevalence of fake and substandard drugs in the sub-Sahara African market. Over 200 samples of antimalarial treatments were collected from six malaria endemic African countries, namely, Ghana, Nigeria, Tanzania, Rwanda, Kenya and Uganda. These samples were then tested to see if they met international standards. The results of the first phase of the project were alarming.
Overall 35 per cent of the samples were substandard and failed the test, which means that one in three patients are unlikely to be cured by the proclaimed antimalarial treatments purchased. Furthermore, it was found that 33 per cent of the treatments tested were artemisinin monotherapy drugs (42 per cent of these failed the test). Approximately 80 per cent of the monotherapy drugs collected had been manufactured after the appeal from the WHO in January 2006 to stop monotherapy production. The reason for this request is because the probability of resistance emerging to combination therapies is far less than monotherapies.
In order to expand the scope of the project, in October last year, AFM began testing samples collected from Zambias major city, Lusaka, and surrounding areas. The results of the small sample of treatments collected were a welcome change to our previous experience because none of the samples tested were fake or sub-standard. However, 53 per cent of the treatments collected were either oral artemisinin monotherapies or treatments such as SP or mefloquine that should no longer have been used to treat malaria due to increased drug resistance. On average, the artemisinin monotherapy treatments had been manufactured approximately 21 months after the WHOs appeal to halt the production and withdraw these clinically inappropriate drugs from the market.
A further worrying concern was the discovery that public sector treatments were being sold in the private sector. The Zambian government should tighten controls on its medical stores. The theft of treatments bought specifically for the public sector and its subsequent sale in private shops and pharmacies must be curtailed. The theft of these drugs not only deprives public sector patients, but also costs taxpayers money.
Given the precarious nature of the situation, it is in many instances unfortunate that some large multilateral donors are actively supporting and encouraging the domestic production of antimalarial drugs. First impressions may find the local production of drugs appealing, since it has the potential to decrease transportation costs, provide local jobs, increase expertise and cut dependence on foreign suppliers. However, apart from the potential for the production of fake or substandard drugs, local manufacturers may not be as efficient in production as other established manufacturers that are already supplying the public sector on a no-profit and no-loss basis.
To protect local manufacturers from foreign competition, a government may impose high tariffs on imported pharmaceuticals. At the same time, it may offer tax incentives and subsidies to local companies. These measures constrict the supply of imported drugs, which are often of superior quality, without necessarily increasing local supply appreciably.
International donor communities wanting to increase access to medicines in developing countries through the development of local manufacturing facilities should therefore be cautious in their prescriptions, particularly if the wider policy environment in these economies is not conducive to the development of local facilities.
For the scale-up in malaria control and treatment to be sustained, it is imperative that malarial country governments monitor the sale of malaria drugs more closely. It is understandable why pharmacies and shops continue to stock and sell SP and CQ given the historic use of these drugs, their low cost, and the fact that they may provide some relief to patients and could possibly even cure them. However, drug resistance will increase if these drugs continue to be used. It is far less excusable for pharmacies to sell oral artemisinin monotherapies and for drug manufacturers to continue to market them. No new classes of antimalarial drug are expected to become available in the foreseeable future and therefore every effort should be made to protect artemisinin based combination therapies.
Along with improving oversight, the Zambian Government should continue its impressive malaria control activities, through the targeted use of insecticides for indoor residual spraying and the provision of insecticide treated nets. Prevention, as the adage goes, is always better than cure. If the Zambian Government can reduce the malaria caseload, it will not only reduce the need for malaria treatment but will also lower the probability of resistance emerging to malaria treatments.
Author: Jasson Urbach is an economist with the Health Policy Unit (a division of the Free Market Foundation) and a director of 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.
FMF Feature Article / 27 March 2009
Publish date: 27 March 2009
The views expressed in the article are the author’s and are not necessarily shared by the members of the Foundation. This article may be republished without prior consent but with acknowledgement to the author.