ORGANISM 7--Plasmodium species
GENERAL CHARACTERISTICS
HISTORY: Symptoms described by 1550 BC (Ebers papyrus); recovery of Countess
d'El Chinchon 1623 to 1632); associated with "bad (mal) swamp air" (aria); Laveran
described the parasite in 1880 AD.
COMMON NAME
Plasmodium vivax--Benign tertian malaria.
Plasmodium ovale--Ovale tertian malaria.
Plasmodium malariae--Quartan malaria.
Plasmodium falciparum--Malignant tertian malaria.
PATHOGENESIS: Cyclic fever and chills; aches and general malaise.
Plasmodium vivax: Usually mild; parasitemia up to five percent; 47 percent of
reported cases; relapses due to recurring liver phases (secondary exoerythrocytic);
fever cycle (chills) are every 45 hours (average).
Plasmodium ovale: Usually mild; parasitemia less than one percent; less than
one percent of reported cases; questionable relapses; fever cycle is 49 hours (average).
Plasmodium malariae: Usually mild (severe kidney involvement in children, may
be fatal); parasitemia up to one percent; less than three percent of reported cases;
longest incidence of recrudescence (up to 30 years); fever cycle is 72 hours.
Plasmodium falciparum: Usually severe (blocking of capillaries, involvement of
major organs, algid malaria, black water fever, drug resistant strains have been
recognized); parasitemia up to 40 percent; 49 percent of total reported cases; short
recrudesent relapse with no secondary exoerythrocytic phases; fever cycle is 36 to 48
hours, often asynchronous.
GEOGRAPHICAL DISTRIBUTION
P. vivax--Temperate and tropic zones.
P. ovale--Mainly Africa and western Pacific islands.
P. malariae and P. falciparum--Tropics and subtropics.
TREATMENT
MALARIOUS ATTACK: Chloroquine and Amodiaquine are very effective drugs
for rapid relief (no effect against the exoerythrocytic phase); Pyrimethamine and
Chlorquanide are slow but can eradicate tissue stages of P. falciparium.
SUPPRESSION (PREVENTION OR POSTPONEMENT OF ATTACKS):
Chloroquin e, Amodiaquine, Pyrimethamine, and Chlorquanide destroy the erythrocytic
parasite; Primaquine is effective against gametocytes and exoerythrocytic parasites.
PROPHYLAXIS: P. falciparum--pyrimethamine and primaquine: Black water
fever; corticosteroids: Resistant strains of P. falciparum; quinine, Fansidar and
Mefloquine.
MD0842
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