Reporting Obligations
Suspected cases must be reported immediately by phone to the Thunder Bay District Health Unit at 625-5930 or toll-free 1-888-294-6630, ext. 5930 (Monday-Friday, 8:30am to 4:30pm). After hours and on weekends/holidays call Thunder Bay Answering Service at (807) 624-1280.
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 infection often presents as a "flu-like" illness, with fever, intense headache, myalgia, nausea and other gastrointestinal symptoms; this is followed by cough, shortness of breath, dizziness, sweats and arthralgia (usually within 5 days) pulmonary edema and deterioration of cardiopulmonary function may rapidly occur. The case fatality rate is 35-50%.
Modes of transmission:
Infected rodents shed live virus in their saliva, feces and urine; transmission primarily occurs through inhalation of aerosolized rodent saliva, urine or feces; through the bites of infected rodents; and through direct contact of broken skin or mucous membrane with rodent excreta.
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 documented in North America, however there have been reports of person to person spread of the Andes virus strain in an outbreak in Argentina.
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 & 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
Testing Information & Requisition
Treatment & 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
References
- Ministry of Health and Long Term Care, Infectious Diseases Protocol - Appendix 1 (2022) Hantavirus pulmonary syndrome.
- Heymann, D.L., Control of Communicable Disease Manual (20th Ed.), Washington, American Public Health Association, 2015.
Additional Resources
Ministry of Health and Long-Term Care. "DISEASES: Hantavirus."
The Canadian Lung Association. "Hantavirus."