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

DDX

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

Diagnosis

• High index of suspicion if fever + travel to endemic region
  • See CDC list by country: [[1]]
• Symptoms
  • Fever
    • Cyclic only after chronic infection
  • HA, cough, GI
  • thrombocytopenia and splenomegaly common
• check thick and thin smear initially and if neg, repeat in 12- 24 hrs

Classification

Severe Any one of the following:

1. AMS/coma
2. Severe normocytic anemia [hemoglobin < 7]
3. Renal failure
4. ARDS
5. Hypotension
6. DIC
7. Spontaneous bleeding
8. Acidosis
9. Hemoglobinuria
10. Jaundice
11. Repeated generalized seizures
12. Parasitemia >5%

Uncomplicated

1. None of the above

Treatment

1. 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

1. Treat hypoglycemia
2. Check HIV status (coinfection can lead to worse clinical outcomes)
3. Exchange transfusion for patients with:
   1. P falciparum malaria with a parasitemia greater than 10%
   2. Life-threatening complications (ie, coma, respiratory failure, coagulopathy, fulminant kidney failure)

For specific medications see current CDC recommendations: [[2]]

Disposition

1. Admission for:
   1. Patients with suspected or confirmed P falciparum or P knowlesi infection
   2. Children
   3. Pregnant women
   4. Immunodeficient individuals
2. ICU for:
   1. Severe complications (e.g.coagulopathy or end-organ failure)
   2. Cerebral malaria (e.g. AMS, repeated seizures, coma)
   3. Parasitemia
      1. >2% in pts non-immune (i.e. travelers)
      2. >5% in pts semi-immune (i.e. locals)

See Also

Travel Medicine

Source

• Mirzaian E, Durham MJ, Hess K, et al. Mosquito-borne illnesses in travelers: a review of risk and prevention. Pharmacotherapy. 2010;30(10):1031-1043