| Disease/Syndrome |
Malaria |
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| Category |
Infection, Travel |
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| Acute/Chronic |
Acute-Severe |
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| Synonyms |
Plasmodium falciparum; P. vivax; P. ovale; P. malariae |
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| Biomedical References |
Search PubMed |
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| Comments |
EPIDEMIOLOGY: From 1995-2004, 7,944 cases of malaria among USA civilians (43 fatal cases) were reported to the CDC. Of the fatal cases, 80% were acquired from sub-Saharan Africa, and 88% were caused by P. falciparum. Worldwide, malaria causes about 400 million infection and one million deaths annually. [CDC Travel, p. 212-3] FINDINGS: Mosquitoes bite humans and release sporozoites into the blood. The sporozoites infect human hepatocytes. One to two weeks later, the hepatocytes release merozoites into the blood. Malarial paroxysms are associated with the invasion and rupture of red blood cells by these merozoites. Paroxysms are marked by fever, chills, headache, and nausea followed by profuse sweating. Other findings that may occur in all forms of malaria are anemia, jaundice, splenomegaly, and hepatomegaly. For P. vivax and P. ovale, infected hepatocytes can rest in a latent stage for 2-3 years. [Merck Manual, p. 1241-7] In one series of 160 patients in a travel clinic, symptoms were as follows: fever (100%), headache (100%), weakness (94%), night sweats (91%), arthralgias (59%), myalgias (56%), diarrhea (13%), and abdominal pain (8%). The WHO criteria for severe malaria are any one of the following: cerebral malaria, respiratory distress, prostration, hyperparasitemia, severe anemia, hypoglycemia, jaundice, renal insufficiency, hemoglobinuria, shock, cessation of eating and drinking, repeated vomiting, and hyperpyrexia. P. falciparum can cause pulmonary edema and ARDS by sequestering in the tiny veins and capillaries of the lungs. [PPID, p. 3121-44] Patients with P. falciparum malaria usually present within 4-6 weeks of their return from an endemic area. The fever pattern in falciparum malaria is "hectic." Cough and dyspnea are present in fewer than 20% of patients. Splenomegaly is present in about 25% of cases. Even less common are jaundice, abdominal pain, hepatomegaly, and an urticarial rash. The WBC count is usually normal or slightly low (high in 5% of cases). Kidney function tests are usually normal at the time of presentation in the clinic. [ID, p. 2295] Inadequately treated patients with falciparum malaria may develop severe malaria: acute encephalopathy and coma, severe anemia, jaundice, renal failure, hypoglycemia, respiratory distress, and rarely, bleeding diathesis and shock. The other three malarias do not usually cause life-threatening disease. [CCDM, p. 324-40] Thrombocytopenia and petechial rash may occur in severe P. falciparum infections. [Wilson, p. 248] |
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| Latency/Incubation |
9 days to 2 weeks (P. falciparum); 12-18 days (P. vivax & P. ovale); 18-40 days (P. malariae); Some strains of P. vivax from temperate areas: 8-10 months; [CCDM, p. 326-7] |
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| Diagnostic |
Microscopic examination of blood films by expert is most sensitive method. Dipstick tests for HRP-2 or pLDH have Sn/Sp of 77%/100% and 83%/100%, respectively. [PPID, p. 3131] |
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| ICD-9 Code |
084 |
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| Effective Antimicrobics |
Yes |
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| Scope |
Large areas of Central and South America, Hispanola, Africa, Asia, Eastern Europe, and South Pacific; |
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| Reference Link |
CDC - Malaria |
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| Related Information in Haz-Map |
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| Symptoms/Findings |
Symptoms/Findings associated with this disease:
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| Job Tasks |
High risk job tasks associated with this disease:
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