UMEM Educational Pearls - By Andrea Tenner

• General information
  • Organism: 5 Plasmodium species (P. falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi)
    • P. falciparum is responsible for most severe disease.
    • P. vivax and P. ovale are responsible for recrudescent disease.
  • Transmission via the female Anopheles mosquito, which bites at night or in the early morning.
  • Endemic in Asia, Africa, Central America, and South America

• Clinical presentation
  • Initially, the patient presents with an acute febrile illness: fever, chills, headache, nausea, lethargy, and upper respiratory symptoms.
  • Infection with P. falciparum can further progress to severe organ dysfunction.
  • The disease course is unpredictable in the non-immune individual.

• Diagnosis
  • Thick and thin peripheral blood smears demonstrating organism
    • Thick smear – confirms Plasmodium parasites
    • Thin smear – allows speciation of Plasmodium parasites
  • Hyperparasitemia is associated with increased mortality

• Treatment
  • P. falciparum or species unidentified
    • For severe malaria, IV quinine (quinidine if quinine not available)
    • IV artusenate is available from the CDC as a quinidine/quinine alternative.
    • DO NOT USE Chloroquine for severe malaria
  • Patients with evidence of complicated malaria (>3% parasitemia, signs of organ dysfunction, alterations in mental status) should be admitted to an ICU.

University of Maryland Section for Global Emergency Health

Author: Emilie J.B. Calvello, MD, MPH

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• General Information
  • Organism: Bunyaviridae virus
  • Transmission: inhalation of aerosols contaminated with rodent urine or feces.
  • Seen in the southwestern United States, South and Central America
  • Death occurs from decreased cardiac output and circulatory failure.
• Clinical Presentation
  • Initial symptoms are nonspecific and occur 1-5 weeks after exposure: fever, malaise, myalgia, and GI upset
    • Can progress to fulminant ARDS-like picture in previously health young patients.
  • Signs NOT consistent with HPS: rash, hemorrhage, petechiae, peripheral or periorbital edema.
• Diagnosis
  • The diagnosis must initially be made clinically.
  • Lab tests may reveal nonspecific findings of thrombocytopenia, atypical lympthocytes with bandemia, hemoconcentration, and renal failure.
  • Chest film will demonstrate bilateral interstitial infiltrates.
  • Serology (ELISA) available through the CDC.
• Treatment
  • There is no specific therapy for hantavirus infection; Treatment is primarily supportive, with attention to respiratory status and oxygenation.

University of Maryland Section for Global Emergency Health

Author: Andi Tenner

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• Causative organism: members of the genus Borrelia
  • Louse Borne Relapsing Fever (LBRF)
    • Human body louse (Pediculus humanus)
    • Associated with sporadic outbreaks especially in areas with large refugee populations
  • Tick Borne Relapsing Fever (TBRF)
    • Soft ticks of the genus Ornithodoros
    • Typically found in higher elevations of the western United States as well as the central plateau region of Mexico, Central and South America and Africa
• Clinical Presentation
  • Symptoms develop 3 to 18 days after infection.
  • Onset is abrupt and may include fever, malaise, headache, arthralgias, nausea and vomiting and cough.
  • The first febrile episode lasts 3 to 6 days and then recurrences may occur after 7 to 10 days.
• Diagnosis
  • Definitive diagnosis: visualization of spirochetes on peripheral blood smear.
  • May also see leukocytosis, anemia and/or thrombocytopenia, elevation of liver function tests
  • Erythrocyte rosette formation may be present.
• Treatment
  • Antibiotics recommended for treatment include penicillin, doxycycline and erythromycin.
  • Jarisch-Herxheimer reaction common after treatment. This can be life threatening and all patients undergoing treatment should be closely monitored.

University of Maryland Section for Global Emergency Health

Author: Gentry Wilkerson

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General Information:

-As of April 5^th, 14 confirmed cases of a new influenza A virus (H7N9) have occurred in China.  Six of those have died. 

-Presumed transmission via infected poultry in bird markets, and thus far no person-to-person transmission has occurred.

-Likely susceptible to oseltamavir or inhaled zanamivir

Area of the world affected:

-China

Relevance to the US physician:

- Suspect in patients with a respiratory illness and appropriate travel history.

- Refer to CDC within 24 hours if test positive for flu A but cannot be subtyped

- If H7N9 is suspected, patients should be under droplet and airborne precautions

Bottom Line:

No human-to-human transmission from H7N9 thus far, but the possibility exists.  Any unsubtypeable influenza A patient should be placed on droplet and airborne precautions and oseltamavir or zanamivir started immediately.

University of Maryland Section of Global Emergency Health
Author: Andi Tenner, MD, MPH

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Case Presentation:

53 yo male presents with fever, myalgia, maculopapular rash, and severe polyarthralgia. He just returned from a cruise to the Caribbean islands.

Clinical Question:

What is the diagnosis?

Answer:

Chikungunya Virus

• Travelers who go to the Caribbean are at risk of getting chikungunya. Cases have been reported in Saint Martin, Martinique, and Guadeloupe. In addition, travelers to Africa, Asia, and islands in the Indian Ocean and Western Pacific are also at risk.
• Mosquito vector, incubation 3-7 days
• Joints involved are typically hands and feet, usually symmetric, severe arthralgia often debilitating
• Dx: serology - ELISA, IgM
• Treatment: IVF, NSAIDS, supportive

Bottom Line:

• Include Chikungunya in your differential of non-specific fever, rash, headache and arthralgia in travelers the Caribbean and endemic areas.

University of Maryland Section of Global Emergency Health

Author: Veronica Pei, MD

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