UMEM Educational Pearls

Background:

Dengue is the most rapidly expanding mosquito-borne virus with an increasing incidence and geographical area.  It is most commonly found in the tropics, but there are occasional outbreaks in other places, including Texas and Hawaii.

Clinical:

Three Phases:

1.  The febrile phase lasts 2-7 dyas and is similar to other viral syndromes, often with high fever and nausea/vomiting.  Petechiae may also be present which can be induced by the application of a tourniquet.

2. The critical phase occurs after defervescence and lasts only 24-48 hours. IT is marked by increased capillary permeability and can lead to severe pulmonary edema, shock, and multisystem organ failure.

3. The recovery phase is marked by hemodynamic improvement. Some patients have a rash described as "isles of white in a sea of red." 

Some patients will develop bradycardia. Most patients have a self-limited form of the illness that is not severe, and consists of symptoms seen in the febrile phase.  The patients that develop severe dengue can have markers in the febrile phase that are associated with organ dysfunction, GI bleeding, and increased capillary permeability. Other concerning symptoms early are abdominal tenderness and persistent vomiting.

Treatment:

Treatment is supportive, mostly consisting of IV fluids, which is very effective when started early in the patient's illness.  For more information and maps of endemic areas check out the CDC or WHO websites:  http://www.cdc.gov/travel/notices/in-the-news/dengue-tropical-sub-tropical.htm or http://www.who.int/denguecontrol/en/

University of Maryland Section for Global Emergency Health

Author: Jenny Saltzberg

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General Information:
• Millions of people around the world (including our patients who travel and victims of disasters like Hurricane Sandy) are exposed to non-potable water.
• How to treat contaminated water:
      ♦ Filter cloudy water through a clean cloth or allow to settle prior to treatment
      ♦ The safest method is boiling water vigorously for 1 minute (or, at least 3 minutes at altitudes >6,000ft)
      ♦ Chemical disinfection is not as effective but, if boiling is not possible, use either:
              • 2 drops of unscented bleach (5.52% Cl) per quart/liter of water.  (Unknown strength? Add 10     drops per quart/liter.)
                -Or-
               • 5 drops of tincture of 2% iodine per quart/liter.
                     - If the water is cloudy or cold, double the chlorine or iodine.
                     - Notes: Pregnant women or people with thyroid conditions should not use iodine
       ♦ UV decontamination can be accomplished by leaving clear bottles of water in direct sun for >6 hours or special equipment, but requires clear water
• Boiling, Chlorine/Iodine, and UV will kill viruses, bacteria, and Giardia
• Only Boiling kills Cryptosporidium

Bottom Line:
• If bottled water is available, use it.
• If not, boil your water.
• In order to treat for a wide variety of pathogens, it is best to combine available methods.

University of Maryland Section for Global Emergency Health
Author: Andi Tenner
 

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• 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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