Good news on malaria. Kind of.

It has been said that malaria has killed  more people than any other single cause in human history.  And that's not to mention the problem of ill health in people even if they don't die.  The reason for its toll seems to be the association of malaria with agriculture and settled populations that provide the right ecology for the disease.  Those populations were far larger than their ancestors', making vastly more people vulnerable than had ever lived in the past.  The evolution of genetic resistance has helped save many people, but not all that effectively.

But there's some good news from the World Health Organization.  The 2010 World Malaria Report states that the number of people who died from the disease has fallen 26 percent since 2000, 5 percent since 2009, to on the order of 655,000 deaths last year, predominantly children under the age of five.  And 2010 was the first year when no locally contracted cases of malaria were reported in the European region.  The WHO says this is because of increased use of malarial control measures such as the use of insecticide-treated mosquito nets, the increased availability of effective medicines, and the rise in the proportion of cases confirmed by testing prior to treatment, a widespread effort to reduce the spread of treatment-resistant disease.

However, WHO had previously set the goal of reducing incidence by half by 2010 from the rate in 2000, but it fell by only an estimated 17 percent (figures were not believed to be accurate enough from two dozen countries in Africa to be more precise about the rates).  The WHO has also set the goal of reducing mortality to almost none by 2015, a goal that is probably unlikely to be met, in spite of the fact that bed nets and diagnostic tests are cheap.

A story at StatesmanJournal.com questions the wisdom of setting such grandiose goals.

Dr. Robert Newman, director of WHO's malaria program, said it is disappointing not to have reduced malaria by 50 percent by last year. But, he said, it was "truly significant progress" that the parasitic disease's death rates fell by more than one-third in Africa.

He described the current goal of cutting malaria deaths to "near zero" by the end of 2015 as "aspirational," but added that it wouldn't be accomplished unless every person at risk has access to a bed net and suspected cases are properly diagnosed and treated. Newman also said it would cost $6 billion a year — about three times more than the world currently spends — to be successful.

"It is unacceptable that people continue to die from malaria for lack of a $5 bed net, a 50 cent diagnostic test and a $1 anti-malarial treatment," Newman said in an email.

The risk is that because control is so dependent on continuing donations from both the public and private spheres, when goals aren't attained, donors may stop giving.  This is the history of disease control.  And the global financial crisis isn't helping.  In fact, the Global Fund to Fight AIDS, Tuberculosis and Malaria, the primary funding agency for public health programs, currently can't fund its next round of grants.  Their financial difficulties will mean less funding for bed nets and treatment programs.  So, the danger of improved control becoming elusive is real. Yet bureaucracies, in our current 'advertising age' seem unable to keep their fund-seeking hype, in the form of these unrealistic goals, under control--and/or our population has come to be responsive only to hype.  Either way, it's not a good way to be!

We are also interested that the WHO report doesn't mention the reduction in malaria incidence that can't be explained by bed nets or treatment, something we blogged about back in September. We cited a paper published in the September issue of Malaria Journal by Meyrowitsch et al. which suggested:

...other factors not related to intervention could potentially have an impact on mosquito vectors, and thereby reduce transmission, which subsequently will result in reductions in number of infected cases. Among these factors are urbanization, changes in agricultural practices and land use, and economic development resulting in e.g. improved housing construction.

Or, they suggested, the decline might also be attributable to a decrease in the mosquito population due to changing rainfall patterns caused by climate change, an hypothesis tested by Meyrowitsch et al.  Year-to-year climate changes are going to be unpredictable, which means that their effect on mosquito populations, and thus malaria incidence and mortality, will be unpredictable as well. 

It's probably a mistake for an organization like the WHO to set unattainable goals, but it's also a mistake for them to let it seem as though they understand all the forces responsible for the epidemiology of a disease like malaria, which depends on a complex interplay of climatic, demographic, social, economic and biological factors, and is thus much more difficult to explain and predict than by simply reducing it to bed nets and treatment.  And comparably more problematic to predict rates of success or its timing.  Bed netting and treatment are crucial, of course, but its a disservice to the public health infrastructure that is working hard to control the disease to make it seem simple.

But, on a positive note, at least no one's saying that if only we could sequence, or even genotype, everyone at risk we'd have the problem licked.  Maybe if we sequenced a few mosquito nets though....