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The threat of artemisinin resistance to Africa: Are we prepared?

29 Jan 2015
WWARN Published Date

WWARN Regional Scientific Director for East Africa, Dr Ambrose Talisuna,  features in the latest Malaria Control and Evaluation Partnership in Africa (MACEPA) newsletter. The article looks at using timely and accurate data to slow the spread of artemisinin resistance.

Malaria and other leading infectious diseases such as HIV/AIDS and tuberculosis afflict the poorest populations of the world, mainly in sub-Saharan Africa. However, unlike HIV/AIDS or tuberculosis, malaria kills mostly children younger than five years old, pregnant women, and vulnerable groups that have little say on public health priorities and expenditure.1 Early diagnosis and prompt treatment—key components of an effective malaria control strategy—have been hampered by the serial development of resistance to the most common drugs. In the early 2000s, the World Health Organization (WHO) recommended the adoption of artemisinin-based combination therapies (ACTs) as the gold standard for treating non-complicated malaria. Most African countries now recommend ACTs as the first-line regimen for treating uncomplicated malaria. Unfortunately, the global malaria treatment policy is now under threat as recent reports from South-East Asia suggest emerging resistance to the artemisinin class of drugs.2 The potential public health impact of artemisinin resistance in Africa is compounded by the demise of systematic drug-resistance surveillance due to lack of funding and the changing technical requirements for monitoring ACT efficacy.

Fortunately, there are a number of activities that will make a positive impact in tackling the public health threat in Africa posed by artemisinin resistance. For example, understanding the factors that drive resistance in malaria-endemic countries in Africa could help identify areas where the most significant risk factors occur. Such high-risk areas could be selected as sentinel surveillance sites for drug resistance. In addition, malaria-endemic countries in Africa should regularly collect information on key parameters such as:

  • Drug use, including regulatory approval, procurement, and distribution systems; adequacy of essential drug lists; drug availability, use, and misuse; drug coverage; treatment sources (formal or informal); and drug quality.
  • Large population settlement and movement, urbanization, networks of high volume transit and migration within and between countries, mobile communities, and volumes of migration from areas of confirmed resistance into Africa—classified as Tier One by the WHO Global Plan for Artemisinin Resistance Containment (GPARC).

At present, the focus is rightly on artemisinin-resistance containment in South-East Asia. However, given the increased human population movement between Asia and Africa, we must recognize that it is only a matter of time before artemisinin-resistant malaria spreads to Africa. A concerted, urgent effort is required to reactivate sub-regional networks for antimalarial-resistance monitoring as was the case in the era of chloroquine and sulfadoxine-pyrimethamine.

The Worldwide Antimalarial Resistance Network (WWARN) was established as a global community to support this endeavor in close collaboration with WHO. WWARN has developed a suite of research procedures, analysis tools, and services to assist countries in collecting quality-assured data that will facilitate monitoring for emergent antimalarial resistance. This is a challenging mandate. Increased investments, and attention to prevention and widespread adoption of ACTs, have helped to decrease malaria morbidity and mortality in many countries. The potential emergence of drug-resistant parasites in Africa must not be allowed to derail the successes won by the global case-management policy. There are no new effective drugs to replace ACTs on the horizon for at least ten years, and the loss of ACT efficacy could be a global public health disaster.

To prevent or slow the spread of antimalarial resistance, particularly to ACTs, malaria-endemic countries need accurate and timely intelligence. The collaborative platform that WWARN has built will coordinate global efforts to integrate data from different studies and disciplines (clinical, in vitro, molecular, pharmacological, and drug quality). Remaining concerns focus on the many areas where there is no information on ACT efficacy, or where the available information is fragmented, difficult to access, stored in different formats, or of poor quality. There is, therefore, an urgent need to improve data quality, strengthen existing resources, cover regional gaps, and compile existing data in a standardized way.

We do not know where and when artemisinin resistance will emerge in Africa. Whereas chloroquine resistance took over 20 years (1957 to 1978/79) to emerge in Africa after initial reports in South-East Asia, increased population movement between the two continents suggests the threat for Africa is imminent. As a matter of priority, all malaria-endemic countries in Africa should conduct regular studies, according to WHO guidelines, to monitor the efficacy of ACTs.

References

Contact information:

Email: ambrose.talisuna@wwarn.org