Once again, another year has gone by and it’s World Malaria Day. There has actually been a lot of good news in the last few years; overall, deaths and infection have decreased. But.
From the Roll Back Malaria Coalition:
The theme for World Malaria Day 2012 – “Sustain Gains, Save Lives: Invest in Malaria” – marks a decisive juncture in the history of malaria control. Whether the malaria map will keep shrinking, as it has in the past decade, or be reclaimed by the malaria parasites, depends, to a great extent, on the resources that will be invested in control efforts over the next years.
Investments in malaria control have created unprecedented momentum and yielded remarkable returns in the past years. In Africa, malaria deaths have been cut by one third within the last decade; outside of Africa, 35 out of the 53 countries, affected by malaria, have reduced cases by 50% in the same time period. In countries where access to malaria control interventions has improved most significantly, overall child mortality rates have fallen by approximately 20%.
However, these gains are fragile and will be reversed unless malaria continues to be a priority for global, regional and national decision-makers and donors. Despite the current economic climate, development aid needs to continue flowing to national malaria control programs to ensure widespread population access to life-saving and cost-effective interventions.
I have written in past years about some of the really wonderful progress that has been made. Unfortunately, we have controlled all the easy places. Now, as the coalition says in their statement, the gains are fragile.
You might have seen the news a few weeks ago that a drug resistant strain of malaria has arisen in Asia. If malaria becomes resistant to artemisinin, there are no other drugs to treat with. Much of current malaria control relies on a combined 1-2 punch of bed nets and drug treatment. When populations are displaced due to political unrest, or when economies tank and programs are discontinued, those at risk of malaria lose access to medicine and regular housing. Which puts them even more at risk.
The warning note from the RBM Coalition statement I quoted above is repeated in a new paper that came out this week:
Cohen, J., Smith, D., Cotter, C., Ward, A., Yamey, G., Sabot, O., & Moonen, B. (2012). Malaria resurgence: a systematic review and assessment of its causes Malaria Journal, 11 (1) DOI: 10.1186/1475-2875-11-122
The article is a major review of control efforts on multiple continents over the last 80 years. They find that the greatest issue in controlling malaria is economic, not biological:
“Considerable declines in malaria have accompanied increased funding for control since the year 2000, but historical failures to maintain gains against the disease underscore the fragility of these successes. Although malaria transmission can be suppressed by effective control measures, in the absence of active intervention malaria will return to an intrinsic equilibrium determined by factors related to ecology, efficiency of mosquito vectors, and socioeconomic characteristics….
The review identified 75 resurgence events in 61 countries, occurring from the 1930s through the 2000s. Almost all resurgence events (68/75 = 91%) were attributed at least in part to the weakening of malaria control programmes for a variety of reasons, of which resource constraints were the most common (39/68 = 57%). Over half of the events (44/75 = 59%) were attributed in part to increases in the potential for malaria transmission, while only 24/75 (32%) were attributed to vector or drug resistance. ” [emphasis mine]
Nearly all of the 75 resurgence events identified through this review have been ascribed to some aspect of weakening of the malaria control programme, whether because of funding shortages, complacency following successful reductions, or disruptions caused by war or natural disaster. These results suggest that technical problems such as vector resistance appear historically to have been of secondary importance for resurgence to financial and operational factors.”
This research is important, because we need to learn from our failures of the past, not repeat them. The places that are most at risk of malaria are also places where there is political unrest and little budget to support a malaria control program.
This is why “Sustain Gains” is the theme of World Malaria Day this year. We have made amazing progress-but we have in the past, too. Only by sustained effort–funded by everyone–can we continue to progress. Nothing but Nets is trying to supply bed nets to the Sudan–if you can, consider donating!
As an addendum: every time I write about malaria, some pro-DDT trolls show up. From the paper:
One of DDT’s chief advantages is its low cost , and programmes that could no longer use it due to resistance were required to switch to more expensive insecticides, raising the cost of interventions and making them harder to sustain . If, however, resistance to multiple pesticides was the primary driver of resurgence, it would have been extremely difficult to counteract, since vector control, one of the most effective tools available to malaria control programmes, would have proven useless. Instead, however, regions that made a determined effort were able to continue to make gains against malaria despite the obstacle of resistance.