Malaria Bites Back
Garner, David, Geographical
Twenty years ago doctors were hailing the eradication of malaria as a great success story. But they spoke too soon. Malaria is back with a vengeance and claiming over a million lives a year
Mosquitos are a constant irritation for people who live in tropical climates. The sound of one hovering above your bed at night is hard to ignore at the best of times, and even less welcome when you know a single bite could transmit a fatal dose of malaria. Although only the female anopheles mosquito carries malaria, over 300 million people suffer from the disease every year, and over a million die. According to the World Health Organisation (WHO), 85 per cent of deaths are in children under the age of five. This figure is likely to double as the disease overruns health controls and returns to parts of the world where it was once eradicated.
The break down of the former Soviet Union in the 1990s brought an end to large-scale malaria control programmes managed centrally by Moscow. Once, these kept the mosquito under control but now malaria has re-emerged in countries across central Asia, including Tajikistan and Azerbaijan. Plasmodium falciparum, the most deadly strain of malaria is emerging for the first time in 30 years across the southern borders of Tajikistan carried in from Afghanistan. With increasing climate change, malaria is now pushing the boundaries of its range all over the world. In the USA, cases of malaria are now regularly reported and the disease is also encroaching on new parts of Europe. Last summer saw the first reported case in Spain.
The reasons for malaria's massive expansion are complex. The breakdown of national malaria control programmes, global climate change, large-scale population displacements in war, crumbling health services in many of the worst affected countries and increasing resistance of the parasite to available treatments are all contributors. A staggering 80 per cent of all fatalities from malaria occur in sub-Saharan Africa. Poor countries such as Mozambique, long debilitated by conflict and international debts, struggle to provide adequate medical facilities. Even where hospitals and clinics do exist, appropriate drugs are often in short supply.
In early 1998, climate was a major player in the malaria epidemic that struck northeast Kenya. The outbreak followed four months of unusually heavy rainfall, resulting from the 1997-98 El Nino phenomenon. Conditions were ideal for mosquitos to breed in the massive areas of surface flood water. Health workers at the El-Das dispensary in Wajir witnessed a dramatic rise in the number of malaria cases towards the end of 1997. By the start of the following year, children under five were dying from malaria at a rate of nine a day. A widespread epidemic was underway with over 500 per cent more than usual malaria cases across the district and a dramatic increase in the severity of infections.
A second epidemic occurred in western Kenya last year in June, with a similar profile to the earlier outbreak. Malaria has only become common in this highland area over the last decade. This latest epidemic was the largest and was aggravated by poor access to effective healthcare. Aid workers say this is a common situation, especially in Africa. In the complex emergencies that have become commonplace across the continent, malaria normally constitutes up to 50 per cent of all illness. During epidemics, this can rise to over 90 per cent.
Drug-resistant strains of malaria are one of the major reasons for the global spread of the disease -- and a real challenge for the medical community. Researchers have found that the parasite can gain resistance to chemicals very quickly, particularly when the drugs are misused and courses of treatment not completed. Chloroquine, the drug of choice for both prevention and treatment of malaria since the 1940s is still the first line of treatment in most of Africa. In many countries resistance has developed so far that the drug has become largely ineffective I against the Plasmodium falciparum strain that is responsible for most fatalities. …