After returning from a month-long visit to the Acapulco area of Mexico, a 32 year-old, previously healthy, Hispanic male presented to the emergency department with nausea and vomiting, right upper abdominal pain, myalgias and difficulty breathing. He also reported a several day history of fever, headache, dental pain and nosebleeds, with some episodes of diarrhea without gross blood. He self-treated these symptoms by taking ibuprofen and acetaminophen. The decedent, who had lived in the United States for the last ten years, stayed at a guest ranch with family members during his visit. His family reported that he was bitten many times by mosquitoes, but they were not aware of any rash, swollen joints, or skin changes.

At initial presentation to the emergency room, the patient's blood pressures were labile, responding to IV fluids and then dropping. A computed tomography (CT) scan of the head did not show bleeding or acute disease, the chest X-ray was clear, and an electrocardiogram showed sinus tachycardia with no acute abnormalities. A chest CT scan showed some ascitic fluid and mild pericardial effusion. Laboratory results were markedly abnormal, including elevated creatinine, anemia, low platelet count, and elevated liver function tests. The patient became progressively hypotensive, started developing mental status changes, and subsequently had a seizure and died.

An autopsy revealed generalized edema throughout the patient's tissues with splenomegaly. The liver was within normal limits and there was no pulmonary embolism. Tissue samples were sent to the Centers for Disease Control and Prevention (CDC) for immunohistochemistry, which was strongly suggestive of infection with dengue virus. Serology results are pending.

Dengue virus is a flavivirus with four antigenically distinct serotypes. Previous infection with a different dengue serotype is the most important risk factor for dengue hemorrhagic fever (DHF), therefore, this manifestation is more common among those who live in areas of endemic disease than among travelers. This particular traveler may have been at increased risk for DHF because he resided in Mexico during his childhood.

Although dengue virus is unlikely to be used as an agent of bioterrorism, clinicians should be aware that the occurance of viral hemorrhagic fever syndromes among their patients may signify a potential bioterrorism event. The CDC classifies several viral hemorrhagic fever viruses, including Lassa virus, Marburg virus, and Ebola virus, as agents of highest concern for their potential to be used as bioterrorist weapons.

Any disease of suspected bioterrorism origin is immediately notifiable in Washington State. In addition, any critical illness or death in a previously healthy person, that is unexplained after initial testing, is also immediately notifiable. In King County, please report any condition that is immediately notifiable by calling (206) 296-4774, day or night. Please see the complete list of notifiable communicable diseases and related conditions at: www.metrokc.gov/health/providers/epidemiology/reporting.htm