Development of immunity against Plasmodium falciparum malaria: clinical and parasitologic immunity cannot be separated.
A total of 1622 individuals of all ages living under conditions of continuous malarial transmission in Liberia were enrolled in a cross-sectional study of parasite rates, positive parasite densities, and body temperatures. The age-specific Plasmodium falciparum-positive parasite densities were greatest at ages 0.5-1.0 year, then slowly declined into adulthood. The age-specific mean body temperature at parasite isodensity showed a steady decline even in the oldest age group. The results do not support the hypothesis that adults have higher body temperatures at a given parasite density than do children with the same parasite density. The age-specific P. falciparum parasite density for specific isotemperatures showed that a subgroup of children in the age group 0.5-1.0 year had low temperatures (less than 36.5 degrees C) despite high parasite densities. This indicates that low body temperature should be investigated further as a possible indicator of serious malaria in young children. Parasitologic and clinical immunity develops concomitantly and cannot be separated. The findings do not support the hypothesis that a special "anti-disease" immunity exists independently of parasitologic immunity.
Department of Infection-Immunology, Statens Seruminstitut, Copenhagen, Denmark.
E
E
Petersen
B
B
Høgh
N T
NT
Marbiah
K
K
David
A P
AP
Hanson
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000818:Animals; D001831:Body Temperature; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000276:immunology* / Q000469:parasitology; D008297:Male; D010963:Plasmodium falciparum / Q000254:growth & development / Q000276:immunology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000469:parasitology