Photo taken from the Gates Foundation website. They have a beautiful library of photos available here.

I always wonder what the appropriate greeting is on holidays that I myself do not celebrate. I learned that saying Happy Yom Kippur is not appropriate given that it is one of the most solemn days of the year in the Jewish year. So I am not sure whether to wish you all Happy World Malaria Day given that Malaria is one of the largest killers in the world, but for some reason I almost feel as though there is something to be happy about.

There is a lot of new momentum towards addressing malaria and compared to just a few short years ago, things are really starting to look up for those at risk of this disease in some of the most affected regions in the world. There is more awareness than over before (witness the massive discussion of malaria these past few weeks on Twitter of the disease), there is more focused research for new tools to fight against malaria (click here or here for a few interesting blog posts on the topic by myself and Christine Gorman), new initiatives are being launched, and the scale up of interventions is underway. The terms “elimination” and “eradication” are even being discussed.

I decided that for my contribution to mark this day, I would try to summarize where I think we are with malaria control today and where the main points of debate are in malaria policy circles. Despite my background as an immunologist, I don’t claim to know much about some of the cutting edge scientific or technical research, so my apologies in advance for not specifically addressing this important topic. I will also mainly focus on Africa, which is where I know the most.

Disease Burden

As with any disease that predominantly exists in the developing world, there is debate about the true incidence and burden of disease from malaria. A big challenge with malaria diagnosis is that partially because it is so common, it is usually not formally diagnosed by some clinical diagnostic test, rather it is diagnosed using symptoms. So our diagnosis of malaria tends to be sensitive but not very specific, meaning that we get a lot of false positives. False positives means that we end up treating a lot of people who probably don’t need treatment, which has repercussions for both the efficiency of any response, our estimates of diseases burden, and also can increase drug resistance.

The latest global estimates of malaria are from the 2008 World Malaria Report. Best guess thinking is that half of the world lives in an area where they are at risk of malaria, that there are about 250 million annual cases of malaria, resulting in approximately 881,000 deaths (or 2400 a day, 100 an hour, 1.5 a minute). So most cases are not fatal. Most of these deaths are of children. During the discussions leading up to World Malaria Day this week I have seen all kinds of figures in use, but these are probably the best and at least the ones from the best authority. I won’t fault people too much for rounding as is convenient to make their case as there are huge uncertainty bounds on all of these estimates. These estimates probably do not fully capture the immense morbidity of malaria, but it is likely tremendous.

Global Response

The World Health Assembly has set as a goal to achieve >80% coverage of four interventions: insecticide-treated bed nets for those at risk, effective drug treatments for any suspected or probable case of malaria, indoor residual spraying for at risk households, and intermittent preventive treatment for pregnant women in at risk areas. The Millennium Development Goal 6 also targets malaria through a relatively weakly worded goal to “have halted by 2015 and begun to reverse the incidence of malaria and other major diseases”. Like any good international statement in global health, these goals are not based on any concrete evidence base as to why these things should be achieved to this level or if these goals can be achieved but they set out some fixed target for policy makers to contemplate, and I guess that is how they are helpful. The MDG sub-goal for malaria, ignoring the “other major diseases”, is one of the goals most likely to be met for health.

On the financing side, there have been new initiatives set forward to fund malaria control programs in the past year. The Global Fund and the US PMI have been major players. UNITAID is posed to become a bigger player now at the AMFm facility has been launched.

But total financing for malaria is less well understood than it is for other diseases, such as HIV. External donors fund have begun to fund a great deal of programs for malaria, but the bulk of financing for malaria control is likely private financing (out of pocket mainly) and national budgets. Households bear the bulk of the cost of diagnosing and treating malaria, governments through public financing for hospitals pay for a great deal of treatment costs and bear the burden of the lower tax revenues and output from malaria. Donors have increasingly been financing prevention activities, such as distributing the ITNs, and increasingly treatments. It is not clear how much crowd out of expenditures donors comes from government response, or how much would be optimal, but this is rarely discussed.

There is good news about the prospects around having an effective malaria vaccine. A GKS-Biologicals vaccine candidate is progressing well and a new vaccine might be possible in the next few years. Exciting stuff.

National Responses

Most African countries have a de jure policy of free bed nets for children and pregnant women, ACTs as a first line treatment, and policies for IPT. Of course what is on paper is frequently nothing like the real world and bed nets are not always free, ACTs are rarely available affordably, even in public clinics, and it is not clear how just having a policy for IPT makes it happen. I think one of my favorite moments in all my years in global health activities is at a meeting in Amsterdam a few years back I witnessed an emotional outburst from a drug company executive who was accusing an Minister of Health of gouging patients but putting high mark ups on drugs sold through the public sector! Too funny. However, most of these policies are new and therefore represent a major trend towards improved national malaria policy reform.

Coverage of Services

There is good evidence (I never say this) that the scale up of coverage of interventions has been dramatic, at least in sub-Saharan Africa. I think it is also fair to say that despite this success, coverage is less than the targets (again, not clear if these were actually achievable goals given how much time has gone by) and progress has been uneven across interventions. This is one of my problems with such big international goals and declarations, we treat them as though they are all equally important, and they are not likely to be in this case.

Bed nets tend to be the most visible intervention, probably partially due to the fact that coverage is the easiest to measure. Bed net awareness appears to be high, bed net ownership is increasing and is probably somewhere in the 30-40% range in sub-Saharan Africa, but that there is also some evidence that bed net coverage has been more rapid in rural and less endemic areas, but this is not surprising. The hardest to reach areas where malaria tends to be worst, are just that, hard to reach.

Effectiveness of Response

This is where I think there has been the most debate, and while I agree that there is good reason to be very critical of most of the evidence of major declines in malaria morbidity and mortality due to weak study designs and poor data, I think the evidence taken together points to a story of where malaria efforts are working. I think the real debate is as to exactly what is driving these declines and how national and global responses should be adjusted to reflect this evidence. For example, how much of the reductions we are seeing is coming from bed nets vs. spraying?

The WMR2008 summarizes some of the declines reported from national surveillance estimates. Smaller countries and countries with better data have been the best documented cases of malaria decline, such as in Eritrea, Rwanda, Sao Tome and Principe, and Zanzibar. Are these smaller countries (and island countries) achieving better control because they are small or because smaller countries just have better data? But the declines have been really dramatic in all of these countries, with reported decreases of over 50% in disease burden. These are big figures, recorded over relatively short time periods (say less than a decade), and really big relative to most achievements in global health in particular.

Epidemiological studies have also documented declines at sub-national levels. A few examples of such studies come from Kenya, Rwanda, Ethiopia, and Gambia, although there are others. These studies have been dismissed as not being representative because they are sub-national. I am sure that those who dismiss these studies would probably also dismiss national studies because of poor data. Ah, there is a the rub.

Bottom Line

So big picture: lots of progress but much more left to be done. I think there is lots to celebrate on this World Malaria Day but I also hope that this new momentum around malaria control translates into more effective efforts going forward.

I hope that there is more emphasis on what works in this debate. Last week the AMFm facility to subsidize ACTs largely through private distributions channels was launched. It will begin with a multi-country “pilot” program costing well over a few hundred million dollars a year. By most people’s standards this would not really be considered a “pilot”, but hopefully there will be real interest in evaluating the full spectrum of outcomes during these earlier efforts.

I also think we need to be a bit more critical in our thinking around bed nets, I don’t think they are going to be enough to eliminate malaria and worry that they are getting far too much credit in this debate, but would be happy to be proven wrong.

I am also really happy to hear about new tools coming through the pipeline. On Thursday I participated with a Global Health Blogger teleconference organized by the Gates Foundation and was really excited to hear about cutting edge research that is coming through the pipelines, such as the potential use of ivermectin to reduce transmission (Christine Gorman writes about it here).

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