The need to look for more than just malaria

I was just reading a comment in the new Journal of the American Society of Tropical Medicine and Hygiene “After Malaria is controlled, what next?”

Fortunately for all of our jobs, there is little to worry about. Malaria, as a complex environmental/political/economic public health problem, won’t be controlled anytime soon. As there’s no indication that many sub-Saharan countries will effectively ameliorate their political problems and also no sign that, despite the “Rising Africa” narrative, African countries will develop in such a way that economic rewards will trickle down to the poorest of the poor, malaria transmission will continue unabated. This is a horribly unfortunate outcome for the people, particularly small children, who have to live with malaria in their daily lives.

In all of the places it occurs, malaria is merely a symptom of a greater political and economic failure.

Indeed, we really know less about the causes of suffering and death in the tropics than many believe. Even vital statistics of birth and death are unrecorded in many areas of the world, much less the accurate causes of disease and death. Some diagnoses, such as malaria, dengue fever, and typhoid fever, are often ascribed to patients’ illnesses without laboratory confirmation. Under the shadow of the umbrella of these diagnoses, other diseases are lurking. I have found significant incidences of spotted fever and typhus group rickettsioses and ehrlichiosis among series of diagnostic samples of patients suspected to have malaria, typhoid, and dengue in tropical geographic locations, where these rickettsial and ehrlichial diseases were previously not even considered by physicians to exist.4–8 Control of malaria or dengue would reveal the presence and magnitude of other currently hidden diseases and stimulate studies to identify the etiologic agents.

This is the problem with our public health fascination with malaria. We are missing all of the other pathogens and conditions which case untold suffering in the poorest and most isolated communities. It can’t be the case that malaria acts in a box. In fact, it could be the case, that multiple pathogens coordinate their efforts to extract as many human biological and behavioral resources as possible to obtain maximum opportunities for reproduction and sustenance. A public health system only designed to look for and treat a limited window of diseases misses the opportunity to disrupt what is probably a vast ecological complex.

First, we have a problem of poor diagnostics. Facilities traditionally treat most fevers presumptively as malaria, dispensing drugs appropriate to that condition. However, conditions like dengue fever exhibit similar symptoms. While is it extremely likely that dengue is all over the African continent, particularly in urban areas, there is little ability to identify true dengue cases in the public health sector, and thus, in addition to mistreating patients, the extent of the disease burden is unknown. We cannot tackle large public health issues without proper data.

Second, we have the problem of all of the “known unknowns,” that is, we know for a fact that there’s more out there than we have data for but we also know (or at least I do) that there is a greater disease ecology out there. We know that many pathogens interact with one another for their mutual advantage or to haplessly effect significantly worse outcomes. The awful synergy of HIV and TB is just one example.

OK, I’m going to go and deal with my own pathogenic tenant which I think I’ve identified as an enteric pathogen of the genus Pseudomonas, which might have taken hold opportunistically through an influenza infection. This is complete speculation, however. Data quality issues prevent a reliable diagnosis!

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About Pete Larson

Assistant Professor of Epidemiology at the Nagasaki University Institute for Tropical Medicine

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