economic growth by reducing the productivity of labour) but cholera is also a
disease of poverty and the poor sanitation characteristic of poor countries
increases the prevalence of cholera. Although it is more prevalent in tropical
countries, it does not mean we can label cholera as a disease of geography.
Other arguments have downplayed the influence of geography on disease,
claiming that most of the important diseases of humans and their domesticated
animals are not peculiarly tropical. It is true that smallpox, typhoid, pneumo-
nia, diphtheria, measles, bubonic plague and anthrax are found across many
physical environments and their extent of variability historically has tended to
reflect conditions of human poverty and crowding. But this does not mean, as
Blaut suggests, that there is no ‘innate unhealthiness of the tropics’ (1993:78).
Few agree with him, as many other diseases that are clearly products of a trop-
ical ecology have been labelled ‘diseases of geography’. The most widely
discussed health issue related to geography is the prevalence of malaria. At
least until recent years there was no effective prophylaxis or vector control for
malaria in the areas of high endemicity. Malaria has been brought under
control since 1945, mainly in temperate and sub-tropical environments where
its hold was more fragile in terms of mosquito population and parasite
endemicity. None of the countries with 100 per cent of their land area subject
to falciparum malaria (the most virulent form) were able to eradicate it
completely after 1945 (there have been more recent successes, as outlined in
Chapter 5). The symptoms of malaria are bouts of fever with spikes on alter-
nating days, headaches, malaise, fatigue, nausea and anaemia. Severe forms of
the disease result in organ failure,delirium, impaired consciousness, general-
ized convulsions, persistent coma and death. By the early 2000s there were an
estimated 200 million to 500 million cases per year, almost entirely concen-
trated in the tropics, and around 1 million deaths per year, 90 per cent of which
occurred in Sub-Saharan Africa. Africa’s malaria has been much harder to
control than that in other regions due to a combination of climate and biology.
The continent’s temperatures, mosquito species (the exclusively human-biting
Plasmodium falciparum) and humidity give Africa the world’s highest malaria
burden (Sachs et al 2004). Other diseases of geography (not poverty) include
dengue, yellow fever, or schistosomias which are endemic in the tropical
ecological zones and nearly absent elsewhere.
It is notoriously difficult to collect data related to health conditions, so esti-
mating the morbidity and mortality costs of malaria is not easy. In Tanzania,
for example, 80 per cent of all deaths occur at home, and half of those had no
prior contact with medical services. The principal symptom of malaria (fever)
is common to many other illnesses and accurate diagnosis requires laboratory
analysis. The impact of malaria may be missed by the data as its effects only
show up in related morbidity. Malaria has been estimated to account for around
60 per cent of all severe anaemia episodes in young infants in rural Tanzania,
and 46 per cent of severe anaemia hospital admissions among under-5s in
Kenya. Pregnant women are particularly vulnerable to malaria, experiencing
an increased risk of maternal anaemia, abortion, still birth and low birth
Geography and Economic Resources 243