Antigenic Characterization of Plasmodia

Abstract

One hundred years ago, Laveran identified plasmodia as the causative agent of malaria; the concept of vector transmission was demonstrated at the beginning of the century. Plasmodium is a unicellular protozoan parasite transmitted to humans and other vertebrates by the bite of female Anopheles mosquitoes. An estimated one-third of the world’s population lives in malaria endemic areas. About 200 million people are infected annually, and more than one million children die each year of malaria infection (World Health Organization, 1976). Although malaria infection was successfully eradicated in large areas through extensive eradication programs through the use of insecticides and chemoprophylaxis, the disease is showing a resurgence in areas in which it was formerly under reasonable control, e.g., in large areas of South America, Central America, India, and Sri Lanka (Gopalan, 1976). The current resurgence of malaria has been explained partly by operational failures and partly by biologic factors related to the development of resistance of the mosquito vector to insecticides (Pal, 1973) and of the parasite to the available chemotherapeutic agents, such as chloroquine and sulfonamides (McGregor, 1978).