Malaria

Malaria

 

Malaria is caused by the protozoan parasite Plasmodium spp and is transmitted by infected mosquitos.

Epidemiology

  • Incidence
    •  Worldwide distribution in tropical areas; more than 500 million cases reported every year
  • Transmission
  • Vector is the Anopheles mosquito

Organism

  • Protozoan species that cause most malarial infections in humans include: 
    • P. vivax
    • P. falciparum (~80% of cases)
    • P. ovale
    • P. malariae

Pathophysiology

  • Accumulation and sequestration of parasite-infected red blood cells in various organs, such as the heart, brain, lungs and kidneys, create characteristic features of the disease

Clinical Presentation

  • May be nonspecific – malaise, fever, myalgias
  • Progresses to splenomegaly, anemia, jaundice
  • Severe infection, usually from P. falciparum species, may cause:
    • Cerebral encephalopathy
    • Hypoglycemia
    • Hypotension
    • Liver dysfunction
    • Renal failure
    • Liver dysfunction
  • Chronic malaria can be seen with P. vivax and P. ovale

  • Diagnosis

    • Indications for testing – clinical history and symptoms with residency or travel to endemic area
    • Laboratory testing
      • Malaria smear
        • Demonstration of intraerythrocytic parasites is diagnostic
        • Should be collected when patient's temperature is rising 
      • Malaria antibody testing – is not useful in acute disease
        • Does not provide definitive speciation of Plasmodium spp.

    Treatment

    • Prophylaxis for endemic countries is usually successful if:
      • Appropriate drugs are selected for area visited
      • Patient is compliant

    Prevention

    • Personal protection measures that are helpful
      • Use DEET
      • Avoid mosquito feeding times for outdoor activities
      • Wear appropriate clothing for protection from mosquito bites

See Also