Hantavirus pulmonary syndrome (HPS), commonly referred to as hantavirus
disease, is a febrile illness characterized by bilateral interstitial pulmonary
infiltrates and respiratory compromise usually requiring supplemental oxygen and
clinically resembling acute respiratory disease syndrome (ARDS). The typical prodrome
consists of fever, chills, myalgia, headache, and gastrointestinal symptoms. Typical
clinical laboratory findings include hemoconcentration, left shift in the white
blood cell count, neutrophilic leukocytosis, thrombocytopenia, and circulating
immunoblasts.
Clinical case definition
An illness characterized by one or more of the following clinical
features:
A febrile illness (i.e., temperature greater than 101.0 F
[greater than 38.3 C]) characterized by bilateral diffuse interstitial edema
that may radiographically resemble ARDS, with respiratory compromise requiring
supplemental oxygen, developing within 72 hours of hospitalization, and occurring
in a previously healthy person
An unexplained respiratory illness resulting in death, with
an autopsy examination demonstrating noncardiogenic pulmonary edema without
an identifiable cause
Laboratory criteria for diagnosis
Detection of hantavirus-specific immunoglobulin M or rising
titers of hantavirus-specific immunoglobulin G, or
Detection of hantavirus-specific ribonucleic acid sequence
by polymerase chain reaction in clinical specimens, or
Detection of hantavirus antigen by immunohistochemistry
Case classification
Confirmed: a clinically compatible
case that is laboratory confirmed
Comment
Laboratory testing should be performed or confirmed at a reference
laboratory. Because the clinical illness is nonspecific and ARDS is common, a
screening case definition can be used to determine which patients to test. In
general, a predisposing medical condition (e.g., chronic pulmonary disease, malignancy,
trauma, burn, and surgery) is a more likely cause of ARDS than HPS, and patients
who have these underlying conditions and ARDS need not be tested for hantavirus.