An African mother returns in the evening from the fields where she has been working to find her young daughter has died: the fever started only the day before, and in the morning her child seemed to be coping. Sadly this is a common tragedy. Every day malaria, a parasite of the red blood cells transmitted by mosquitoes, kills more than 2,000 people. Most of these preventable deaths are in young African children.
Our two main weapons to fight malaria are insecticides to kill the mosquitoes and drugs to kill the parasites. We are losing both to resistance. In the past few years we seemed to be winning – malaria suffering and death have fallen, largely because of amazing drugs derived from Chinese traditional medicine called qinghaosu, or artemisinin. Now, resistance to these medicines has emerged in falciparum malaria parasites (the species that causes most of the deaths) in mainland south-east Asia, and is threatening to spread towards India and Africa.
All our recent gains are threatened. A study published this week in the New England Journal of Medicine provides incontrovertible evidence that the situation is deteriorating. Resistant malaria parasites are closing in on the Indian border, threatening hundreds of thousands of lives. We know that resistance to previous antimalarial drugs also emerged in south-east Asia, from the very same place in western Cambodia, and resistant parasites spread eventually to claim the lives of millions of children in Africa.
There is some good news – the study showed that a specific change in the parasites’ DNA could be used to identify resistant parasites and so help map the spread of resistance; and it showed that longer courses of treatment were still effective. But the warning signs are there. If resistance worsens or spreads, our plans to control and eliminate malaria will be foiled. The humanitarian and economic consequences will be enormous.
What can be done to stop the spread of resistant parasites? The first option, containment, will be difficult, and it has definitely not worked so far. In any case, many experts feel that it won’t be enough, as it relies upon the drugs working and, as we have now confirmed, drugs are falling like dominoes to resistance. To slow down resistance we are already using antimalarial drugs in combinations (as doctors do with drugs for TB and HIV/Aids). But as the artemisinins fail, the partner drugs come under increasing pressure, and they too fall to resistance.
There is another, bolder approach, which might stand more of a chance. That is an all-out assault on falciparum malaria, to eliminate it before it can no longer be treated effectively. It would involve mass drug administration, to the well and the sick, and quickly. It is undeniably a huge challenge – malaria is worst in remote rural areas, where people are most difficult to reach and treat, and this type of strategy has had a chequered history – which may be why health authorities have yet to accept it. But it might just be possible, and it might work – and so growing numbers of experts, myself included, believe we should try it. However difficult, it is our last hope for artemisinin. Unfortunately the window of opportunity is closing fast as resistance spreads and potentially worsens.
Eliminating falciparum malaria in south-east Asia would need drastic action involving society across a broad front, strong political commitment and determined and visionary leadership. Unfortunately malaria doesn’t pack much political punch as it mainly affects the poor and disenfranchised. The international and national organisations that deal with malaria are unused to radical action, and much more comfortable with slow consensus-building, and even slower responses. We have known about artemisinin resistance for more than seven years, but the response has been disappointing, and it has not worked. Somehow we need to learn how to respond to infectious disease threats like drug-resistant malaria quickly before they become serious, and we do not need to know everything before we take action.
Across clinical medicine we have underestimated the threats posed by new infections – including bird flu, the Mers coronavirus, Sars and the current ebola outbreak – and we have been complacent about the loss of life-saving anti-infective drugs to resistance. Many of you reading this article would not be alive if it weren’t for these miraculous medicines. Killers such as malaria, staph aureus, the pneumococcus, and gram-negative bacteria have been held at bay by inexpensive medicines which we squander and misuse in ourselves and our animal food sources.
These micro-organisms are becoming resistant faster than we can develop drugs to stop them. Falciparum malaria is just one example. Let us hope we can stop history repeating itself at a cost of millions of children’s lives.
Nicholas White is professor of Tropical Medicine at the University of Oxford and chairman of the Wellcome Trust-funded Mahidol Oxford Tropical Medicine Research Unit.