Studies on sporozoite-induced and chronic infections with Plasmodium fragile in Macaca mulatta and New World monkeys.
Plasmodium fragile continues to be investigated because of its biologic similarities to the human malaria parasite, Plasmodium falciparum. Two strains of P. fragile are available for study; one strain is able to infect mosquitoes, whereas the other strain is transmissible only by blood inoculation. The Sri Lanka strain of P. fragile was transmitted to Macaca mulatta, Macaca fascicularis, Aotus lemurinus griseimembra, Aotus nancymaae, Aotus vociferans, and Saimiri boliviensis monkeys via sporozoites that developed to maturity only in Anopheles dirus mosquitoes. The prepatent periods ranged from 12 to 35 days for macaques and from 15 to 30 days for New World monkeys after intravenous injection of sporozoites. Eight rhesus monkeys were infected with the Nilgiri strain and followed for 482 days. Parasitemia in 6 animals persisted at relatively high density through the period of observation. Erythrocyte, hematocrit, and hemoglobin values reached their lowest levels 3 wk after infection and slowly recovered; however, the values did not approach preinfection levels as long as parasitemia persisted in the monkeys. The mean corpuscular volume and corpuscular hemoglobin concentration reached their peak and lowest values, respectively, at day 38 and then returned to the preinfection level. The mean corpuscular hemoglobin value decreased to its lowest level at day 87 and then returned to preinfection level.
Collins
William E
WE
Division of Parasitic Diseases and Animal Resources Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. wec1@cdc.gov
Warren
McWilson
M
Sullivan
Joann S
JS
Galland
G Gale
GG
Strobert
Elizabeth
E
Nace
Douglas
D
Williams
Allison
A
Williams
Tyrone
T
Barnwell
John W
JW
D000818:Animals; D000852:Anopheles / Q000469:parasitology; D016645:Aotidae / Q000469:parasitology; D002908:Chronic Disease; D003105:Colombia; D004906:Erythrocyte Count / Q000662:veterinary; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D007194:India; D007303:Insect Vectors / Q000469:parasitology; D008253:Macaca mulatta / Q000469:parasitology*; D008288:Malaria / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*; D008992:Monkey Diseases / Q000097:blood / Q000469:parasitology* / Q000635:transmission; D018512:Parasitemia / Q000469:parasitology / Q000635:transmission / Q000662:veterinary; D010568:Peru; D010961:Plasmodium / Q000145:classification / Q000502:physiology*; D051078:Platyrrhini / Q000469:parasitology*; D012453:Saimiri / Q000469:parasitology; D034101:Sporozoites / Q000502:physiology; D013188:Sri Lanka
D006454:Hemoglobins