Fever and Tropical Infections



Fever and Tropical Infections


Amina Lalani



Introduction



  • Immigrant children most likely to visit country of origin


  • Unaware of travel risks, lack of parental knowledge of immunity


  • May not seek travel advice or malaria prophylaxis prior to visits


  • Multiple tropical infectious agents can cause fever


  • Important to consider key infections in emergency department


The Travel History: Key Elements



  • Place of travel, urban/rural


  • Exposures: water, uncooked foods, animals, insects, activities


  • Onset of symptoms and fever, duration of fever


  • Pre-travel advice, travel immunizations


  • Malaria prophylaxis and compliance


Tropical Infections


Malaria



  • Fever from the tropics is malaria until proven otherwise


  • Most deaths occur in children


  • Severe malaria < age 4; mortality decreases over age 5


  • Protozoan infection with one of four species:

    Plasmodium falciparum, vivax, ovale, and malariae


  • Transmitted by female Anopheles mosquito


  • Infected mosquito transmits the parasite to human → matures in liver → infects red blood cells and produces clinical findings of malaria



Clinical Presentation



  • Incubation period 10-20 days before symptoms


  • Short prodrome of headache, myalgias, joint pains, low fever


  • Intermittent paroxysms of high fever, chills, and sweats as parasite released from RBCs


  • Nausea, vomiting, abdominal pain, headache


  • Anemia, mild jaundice, hepatosplenomegaly


Fever Pattern



  • Classic fever spike has three stages:



    • Initial cold stage with chills


    • Hot stage with high fever


    • Profuse sweating


  • Pronounced fatigue after defervescence


  • Parasite often released in 48-72-hour cycles


  • May see characteristic fever spikes every 48-72 hours but usually persistent irregular pattern

    Note: Fever pattern cannot be used as a reliable diagnostic tool


Species


P. falciparum



  • Most severe form, especially in naïve hosts


  • Mortality rates up to 25%


  • 98% present within 2 months of return


  • Most prevalent in sub-Saharan Africa


P. vivax



  • Less severe, relapses common if dormant form not treated


  • Most prevalent on Indian subcontinent


Complications



  • Cerebral malaria



    • Most serious complication, clinical diagnosis


    • Progressive lethargy, seizures, confusion, coma


  • Acute respiratory distress syndrome, liver failure, shock


  • Hemolysis and severe anemia, hypoglycemia


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Jun 22, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Fever and Tropical Infections

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