Chapter 7 : Malaria, Another Fever Plague

Abstract:

Malaria is a fever plague, and it has been said that this disease has killed more than half the people who have ever lived on this planet. Today, every 10 seconds a person dies of malaria—mostly children under the age of 5 living in Africa. Worldwide malaria infections are on the rise, and as the fever plague spreads, it will continue to affect us in the places we live, work, travel to, and fight in. The human malarias caused by Plasmodium falciparum, P. vivax, P. ovale, and P. malariae are transmitted through the bite of an infected female anopheline mosquito when, during blood feeding, she injects sporozoites from her salivary glands. All of the pathology of malaria is due to parasite multiplication in erythrocytes. The primary attack of malaria begins with headache, fever, anorexia, malaise, and myalgia. P. falciparum infections are more severe and, when untreated, can result in a death rate of 25% in adults. Complications of malaria include kidney insufficiency, kidney failure, fluid-filled lungs, neurological disturbances, and severe anemia. Mosquito transmission of malaria is dependent on a complex array of factors, including the incidence of infections in the human population, the suitability of the local anopheline population—density, breeding and biting habits, the availability of susceptible or nonimmune hosts, climatic conditions, and the local geographic and hydrogeographic conditions that contribute to mosquito breeding sites. The major threat of malaria today is not an increasing range of endemicity, but rather a rise in the intensity of antimalarial drug resistance.