“Where malaria prospers most, human societies have prospered the least.”

malaria deaths, from worldmapper.org

A student in the Current Debates in Biological Anthropology class I took last term presented on malaria in Subsaharan Africa. There was a quote on one of her slides that I found a bit problematic – shrugged it off, thinking it was probably outdated, an example of “old” colonial-era prejudiced psuedoscience.

Turns out the paper she’d quoted was written in 2002. (First line of the abstract, actually – wasn’t hard to find.)

Where malaria prospers most, human societies have prospered least. The global distribution of per-capita gross domestic product shows a striking correlation between malaria and poverty, and malaria-endemic countries also have lower rates of economic growth. There are multiple channels by which malaria impedes development, including effects on fertility, population growth, saving and investment, worker productivity, absenteeism, premature mortality and medical costs.
pp 680, in Sachs & Malaney (2002) The economic and social burden of malaria, Nature

I’ve no problem with the premise (well, the entire point of the article): Malaria is a disease of poverty.

It’s a serious disease that not only disproportionately strikes the poor, but does much to reinforces their poverty – individually, and nationally.

More than 50% of the world population is at risk from malaria infection. There are endemic outbreaks in 106 countries. But 85% of the malaria infections are in Africa – and 89% of the malaria deaths. (And when you consider those are only the reported ones, the situation is even more bleak.) And with 300-500 million malaria cases each year and 1-3 million deaths (a child every 40 seconds, as charity fund-raisers will remind you). 1

Anyone who’s traveled in the tropics can attest – malaria’s preventable, but its not cheap. I’ve taken Malarone and Doxy – grumpily spending a fortune of my backpacking student budget on them. I even tried Larium, despite the reports of depression, paranoia, and hallucinations, because it costs less. (Had a 14 day week full of incredibly vivid dreams that I had difficulty separating from real memories. Much less fun than it sounds.) People born and raised in areas with malaria develop natural immunities, so the argument goes. It’s true – but there are at least 4 different types of parasites that cause malaria – and none of the expensive drugs can guarantee prevention. Further, certain groups (children, pregnant women, HIV-positive) are much more vulnerable.

Treating malaria isn’t cheap, either. There are a wide variety of drugs – some more effective than others – and the full course of treatment falls well outside of the comfortable expenditure of most of the world’s population.

It’s the assumption that this relationship is historical that bothers me. That malaria has somehow been responsible for the lack of great civilizations around the Equator – part of why Europe (and China) “prosper” and “flourish”.

What about the Mayans? Incas? Ancient Egypt? The Khmer? All of the Indian civilizations that western education doesn’t tend to cover?

I went from the lecture to coffee with a couple of friends and we started to rationalize (easier than actually looking anything up). Maybe malaria is a relatively new disease that began in Subsaharan Africa and only later spread to the New World and Asia. Maybe that was the whole civilization point – there are, after all, enough theories about the relative lack of ancient African civilizations – and it would fit perfectly with the sickle cell anemia mutation (a recessive condition in which possessing only one copy helps the bearer’s immunity to malaria)…

Except, it’s not new.

Malaria is old. Really old.

King Tut had malaria. At 30 million years old, malaria probably accompanied the human expansion out of Africa.2

Malaria has been all but eradicated from temperate regions – not only does a colder climate support fewer mosquitoes, but the base rate of the parasite’s reproduction is slower. After a mosquito bites an infected human, the parasite has to undergo a life-cycle change to be infectious to others; transmission is highly unlikely under 18° C (64° F). Intervention programs helped – better housing with screened doors and windows, pesticides, draining swamplands – but it’s really the cold winters that killed it. 3 (And, incidentally, global warming may very well reintroduce malaria into the Northern Hemisphere.)

It’s already getting worse, where it is.

Although the last century witnessed many successful programmes at country level to eliminate the parasite, the world is now facing a rapidly increasing disease burden. This has been attributed to several causes, including population movements into malarious regions, changing agricultural practices including the building of dams and irrigation schemes, deforestation, the weakening of public health systems in some poor countries, and more speculatively, long-term climate changes such as more pronounced El Niño cycles and global warming. Furthermore, resistance to drugs and insecticides used to counter this disease has been evolving in tandem with growing caseloads. With a rapidly growing population in regions with high malaria transmission, it has been estimated that in the absence of effective intervention strategies the number of malaria cases will double over the next 20 years.

pp 680, in Sachs & Malaney (2002) The economic and social burden of malaria, Nature

All of which brings us back to the Sach & Malaney’s main point:

As a general rule of thumb, where malaria prospers most, human societies have prospered least. The global distribution of per-capita gross domestic product (GDP) in 1995, adjusted for purchasing power, shows a striking and unmistakable correlation between malaria and poverty (Fig. 2). Poverty is concentrated in the tropical and subtropical zones, the same geographical boundaries that most closely frame malaria transmission. The extent of the correlation suggests that malaria and poverty are intimately related. In fact, a comparison of income in malarious and non-malarious countries indicates that average GDP (adjusted to give parity of purchasing power) in malarious countries in 1995 was US$1,526, compared with US$8,268 in countries without intensive malaria — more than a fivefold difference. Malaria-endemic countries are not only poorer than non-malarious countries, but they also have lower rates of economic growth. Between 1965 and 1990, countries in which a large proportion of the population lived in regions with Plasmodium falciparum malaria experienced an average growth in per-capita GDP of 0.4% per year, whereas average growth in other countries was 2.3% per year.

This correlation can, of course, be explained in several possible ways. Poverty may promote malaria transmission; malaria may cause poverty by impeding economic growth; or causality may run in both directions. It is also possible that the correlation is at least partly spurious, with the tropical climate causing poverty for reasons unrelated to malaria. We tend to favour the explanation that causation runs in both directions, with the causal link from malaria to underdevelopment much more powerful than is generally appreciated.

pp 682, in Sachs & Malaney (2002) The economic and social burden of malaria, Nature

Warm “rich” countries have been unable to eliminate malaria (Saudi Arabia, Oman). On an individual and household level, the key difference seems to be treatment, rather than preventative measures – as the wealthy catch malaria as often as the poor (assuming that the wealthy do take the prevantative measures which they can afford).

On a national level, as Sachs & Malaney argue, the ability of the labour force to contribute and advance is significantly hampered by malaria – now, the degree to which malaria itself is responsible, as opposed to the great plethora of concurrent poverty-related conditions (malnutrtion, etc) and infections that exacerbate the condition – I’m convinced. Community health being inter-related, co-dependent, and often cyclical, its more than worth considering not just the “lost wages” and “medicine costs” that economic analysis of disease have classically been focused on.

There are at least two broad categories of mechanisms through which malaria can impose economic costs well beyond direct medical costs and foregone incomes. The first is the effects that occur through changes in household behaviour in response to the disease, which can result in broad social costs. These include such factors as schooling, demography, migration and saving. The second are macroeconomic costs that arise specifically in response to the pandemic nature of the disease and that cannot be assessed at a household level. These include the impact of malaria on trade, tourism and foreign direct investment.
pp 683, in Sachs & Malaney (2002) The economic and social burden of malaria, Nature

They focus on the right now. Well – they take figures from the 80s on and build a model presumably applicable to the post-colonial era.

The long-term demographic outcomes they consider include higher ideal fertility and population growth (if your children keep dying, of malaria, keep having more children – the link between infant mortality and fertility being fairly well established), and the resultant effects on women (from bearing so many children) and the children (each being afforded a smaller investment of parental concern, nutrition, and education).

Modern economic theories have posited that returns to human capital are in fact increasing in scale, with the total impact on economic growth being greater than the sum of the individual contributions. The impact of malaria on economic growth rates through the mechanism of depressing the rate of human capital accumulation could be considerable….The direct costs of prevention and treatment of the disease eat into the disposable income of poor families, as do the costs of lost productivity…. malaria decreases household savings as families are forced to hire labour to compensate for days lost to morbidity.
pp 683, in Sachs & Malaney (2002) The economic and social burden of malaria, Nature

Now the argument’s entered the classic “Cycle of Poverty” / “Culture of Poverty” sphere. Then, regarding human capital and resource accumulation.

None of which speaks to whether this model can justifiably be extended into the past… Actually, nothing, other than the perhaps throw-away opening sentence (used once in the body of the paper, too!) does. I may be being overly pedantic, but regardless of whether it was the author’s point, I think its an interesting question…

That I’m still finding impossible…

Theoretically, a generalizing Marxist interpretation (taking the long-term results of malaria as defined, arguing for the social organization enabled by the lack there of) could fill in the gap. Maybe?

I’m all for biological explanations and investigating the environmental and ecological impact on cultural systems – but – the hypothesis that malaria has prevented human prosperity and cultural growth, historically, across entire regions – seems entirely too simplistic.

Not to mention that the Ancient Egyptians, Great Zimbabweans, Ancient Cambodians, and Ancient Indians prove otherwise.

Works Cited

  1. WHO (2010) World malaria report.
  2. Tanabe, K. et al. (2010) Plasmodium falciparum Accompanied the Human Expansion out of Africa. Current Biology, pp.1283-1289.
  3. Sachs & Malaney (2002) The economic and social burden of malaria, Nature