Malaria

Background

• Caused by parasitic protozoa species of the genus Plasmodium (P ovale, P vivax, P malariae, P knowlesi, and P falciparum) carried by the Anopheles mosquito
  • P falciparum most severe
• Failure to consider for febrile illness following travel, even if seemingly temporally remote, can result in significant morbidity or mortality, especially in children and pregnant or immunocompromised patients
• Chemoprophylaxsis does not guarantee protection
• CDC Malaria Hotline: 770-488-7788
• Malaria is a US nationally notifiable disease and all cases should be reported

Traveler Precautions

The CDC recommends travelers to malaria-endemic regions take the following precautions:

• Chemoprophylaxis
• Use of insecticide-treated bed nets
• Use of DEET-containing insect repellents
• Wear long-sleeve shirts and pants

Clinical Features

• Fever + exposure to endemic country
  • Cyclic fever only after chronic infection
• Headache, cough, GI symptoms

Classification

Severe

• Any one of the following:
  • AMS/coma
  • Severe normocytic anemia [hemoglobin < 7]
  • Renal failure
  • ARDS
  • Hypotension
  • DIC
  • Spontaneous bleeding
  • Acidosis
  • Hemoglobinuria
  • Jaundice
  • Repeated generalized seizures
  • Parasitemia >5%

Uncomplicated

• None of the above

Differential Diagnosis

Fever in traveler

• Normal causes of acute fever!
• Malaria
• Dengue
• Leptospirosis
• Typhoid fever
• Typhus
• Viral hemorrhagic fevers
  • Ebola virus disease
  • Marburg virus disease
  • Lassa fever
  • Crimean-Congo hemorrhagic fever
• Chikungunya
• Yellow fever
• Rift valley fever
• Q fever
• Amebiasis
• Zika virus

Diagnostic Evaluation

• First smear positive in >90% of cases
  • If initial negative, must be repeated BID x 2-3 days for proper exclusion of malaria
  • Determines degree of parasitemia and type (i.e. P. falciparum)
• Additional lab findings
  • Normocytic anemia
  • Thrombocytopenia
  • ↑ ESR
  • ↑ LDH
  • LFT abnormalities
  • ↑ Cr
  • Hyponatremia
  • Hypoglycemia
  • False positive VDRL

Management

• Mixed infections involving more than one species of Plasmodium may occur in areas of high endemicity (have a low threshold for including treatment for P falciparum)
• Hyponatremia in the setting of hypovolemia does not require treatment beyond rehydration
• Treat hypoglycemia
• Check HIV status (coinfection can lead to worse clinical outcomes)
• Exchange transfusion for patients with:
  • P falciparum malaria with a parasitemia greater than 10%
  • Life-threatening complications (ie, coma, respiratory failure, coagulopathy, fulminant kidney failure)

For specific dosing see the CDC Recommendations or call the Malaria CDC Hotline(855) 856-4713

Uncomplicated Malaria

• Atovaquone-proguanil OR
• Arthemeter-lumefantrine OR
• Quinine plus Tetracycline, doxycycline, or clindamycin

Severe Malaria

• Intravenous quinidine plus tetracycline, or doxycycline or clindamycin

Cerebral Malaria

• Insufficient evidence for or against giving antiepileptics
• For severe cerebral edema, mannitol and steroids have not shown a demonstrable benefit

Disposition

• Admit for:
  • Patients with suspected or confirmed P falciparum or P knowlesi infection
  • Young children
  • Pregnant women
  • Immunocompromised patients

• Admit to ICU for:
  • Severe complications (e.g.coagulopathy or end-organ failure)
  • Cerebral malaria (e.g. AMS, repeated seizures, coma)
  • Parasitemia
    • >2% in pts non-immune (i.e. travelers)
    • >5% in pts semi-immune (i.e. locals)

See Also

• Travel Medicine
• Parasitic Diseases