Hantavirus Pulmonary Syndrome
Reporting Obligations
All suspected and confirmed cases must be reported to the local Health Unit.
Epidemiology
Aetiologic Agent
Hantavirus is a virus in the family Bunyaviridae. More than 25 antigenically distinguishable viral species exist, each associated primarily with a single rodent species.
Clinical Presentation
Hantavirus pulmonary syndrome (HPS) infection often presents as a “flu-like” illness, with fever, headache, myalgia, dizziness, nausea and other gastrointestinal symptoms. This is followed by cough, shortness of breath, and hypotension; pulmonary edema and deterioration of cardiopulmonary function may occur rapidly. Most cases show an elevated hematocrit, hypoalbuminemia, and thrombocytopenia. The case fatality rate is 35–50%.
Modes of Transmission
Infected rodents shed live virus in their saliva, feces and urine, with maximal virus concentration in the lungs. Transmission primarily occurs through inhalation of aerosolized virus particles from rodent saliva, urine or feces; through the bites of infected rodents; and through direct contact of broken skin or mucous membrane with rodent excreta. Indoor exposure in closed, poorly ventilated homes, vehicles and outbuildings with visible rodent infestation is particularly important.
Incubation Period
Not completely defined, however most often it has been found to be approximately 2 weeks after exposure, with a range from a few days to 6 weeks.
Period of Communicability
No person-to-person spread has been documented in North America. However, nosocomial and household transmission of Andes virus has been documented in Argentina and Chile, although it is believed to be rare and associated with direct contact.
Risk Factors/Susceptibility
All persons without prior infection are presumed to be susceptible, however protection and duration of immunity from previous infection is unknown. Rural dwellers, cottagers and campers are most at risk in endemic areas. Also any indoor exposure in closed, poorly ventilated areas with viable rodent infestation increases susceptibility to infection.
- Storing food sources in a manner that would make it available to rodents
- Having open holes or other possible rodent entrances to human dwellings
- Contact with wild rodents and direct contact with areas where there is evidence of rodents
Diagnosis and Laboratory Testing
Confirmed Case: Laboratory confirmation of infection with clinically compatible signs and symptoms:
- Detection of Immunoglobulin M (IgM) antibodies or a significant (i.e., fourfold or greater) rise in hantavirus-specific Immunoglobulin G (IgG) antibody titres OR
- Detection of hantavirus-specific nucleic acid amplification test (NAAT) in an appropriate clinical specimen OR
- Detection of hantavirus antigen by immunohistochemistry
Clinical Evidence:
- A febrile illness (Temperature > 38.3° C [101° F] oral) requiring supplemental oxygen AND
- Bilateral diffuse infiltrates (may resemble acute respiratory distress syndrome [ARDS]) AND
- Develops within 72 hours of hospitalization in a previously healthy person OR
- Unexplained illness resulting in death plus an autopsy examination demonstrating non-cardiogenic pulmonary edema without an identifiable specific cause of death
Treatment and Case Management
Treatment for respiratory symptoms is under the direction of the attending health care provider. No specific treatment or cure. Provide education about the illness and how to prevent exposure.
Patient Information
Additional Resources
The Canadian Lung Association. “Hantavirus.“
Public Health Agency of Canada. “Hantavirus.”
References
Ministry of Health and Long-Term Care, Infectious Diseases Protocol, 2022.