Genetic characterization of an epidemic of Plasmodium falciparum malaria among Yanomami Amerindians

Malaria parasites are genetically diverse at all levels of endemicity. In c ontrast, the merozoite surface protein (MSP) alleles in samples from 2 isol ated populations of Yanomami Amerindians during an epidemic of Plasmodium f alciparum were identical. The nonvariable restriction fragment length polym orphism patterns further suggested that the sequential outbreak comprised o nly a single P. falciparum genotype, By examination of serial samples from single human infections, the MSP characteristics were found to remain const ant throughout the course of infection. An apparent clonal population struc ture of parasites seemed to cause outbreaks in small isolated villages. The use of standard molecular epidemiologic methods to measure genetic diversi ty in malaria revealed the occurrence of a genetically monomorphic populati on of falciparum within a human community.