Malariology

Malariology is the subject of studying the issues relating to malaria as a major public health issue. It includes, therefore, the ways in which the disease may be transmitted and the inhibition of those transmission routes, the epidemiological issues of the spread of the disease and differing patterns of transmission, as well as the ways in which malaria-bearing mosquitoes may be suppressed.

Malaria is a disease spread by parasites from the family of plasmodium, which is passed to humans by mosquito bite. The parasite lives a sexual life cycle inside the mosquito and a second, asexual life cycle within the human (or other bitten creature). The mosquitoes tend to live in swampy areas and, for many centuries, the connection between the disease and the “miasmal air” (bad air or mal-aria) was known. However, it was not until careful scientific experimentation in the 19th century that the role of mosquito and plasmodium parasite was identified. Malaria has spread around most of the world, probably assisted by human exploration as outbreaks were reported in the New World in and around 1493. As Western countries tended to drain and build over swampy regions as part of economic development, it has come to be thought of as a developing-world disease, although it should be noted that it was a significant cause of death in Italy until the 20th century. Annually, there are believed to be around 250 million cases of malaria globally and perhaps 2 million deaths as a result. Treatments based on quinine and other drugs are not effective on a long-term basis and there are many parts of sub-Saharan Africa in which the population is continually infected and reinfected.

There are four main types of plasmodium that affect humans and, of these, the most virulent is that which gives rise to falciparun malaria, which requires higher temperatures to thrive and, thus, tends to be more prevalent in the very hot areas in which the poorest people tend to live. Of course, as global climate change continues to intensify, geographical regions in which this form of malaria will prove a threat to human life will spread to more affluent areas. Hence, the disease will be less easy for people in such countries to ignore in the future. Indeed, because people will have had less opportunity to develop any form of immunity or resistance, the fatality rate might increase.

Malariology provides three main approaches to controlling the spread of the disease. The first is vector control, which entails suppressing the parasites and/or the mosquitoes in which they live. The second relates to chemotherapy and provides drugs both to prevent infection and to reduce the impact of infection once it should have struck. The third is through vaccination, which will be the optimal response to prevent infection, but no vaccine has yet been developed. Although research is being conducted to sequence the mosquito genome and this seems a positive avenue, the amount of money currently available to fund the research is limited. One estimate at the turn of the century is that approximately $84 million is spent annually, which equates to some $42 per fatality. This is only a fraction of the amount of money spent on diseases that cause significant numbers of fatalities in developed countries. The likely cost of an effective vaccine would be outweighed by the public health and human resource savings that the reduction in the death rate would provide. Estimates of the impact of malaria on economic development indicate a correlation between the disease and an economic growth rate 2 percent lower than comparator countries. The computer software multimillionaire Bill Gates has been supportive of this initiative.

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