Hantaviruses – Serology and PCR

Consistent with O. Reg. 671/92 of the French Language Services Act, laboratory testing information on this page is only available in English because it is scientific or technical in nature and is for use only by qualified health care providers and not by members of the public.

Background
This page provides information on the hantavirus testing available through Public Health Ontario (PHO).

Hantaviruses are RNA viruses in the Hantaviridae family.^1-3 The term “hantavirus” describes multiple distinct virus species that are rodent-borne and primarily infect humans through the inhalation of virus particles in aerosolized rodent excreta, including urine, feces, or saliva.^4-6 Person-to-person transmission of hantaviruses is uncommon, but evidence of limited transmission has been noted with one species (Andes virus) in Southern South America.^7,8
Individual hantavirus species differ in their geographic distribution and have unique rodent reservoir hosts and clinical syndromes. The two primary diseases caused by hantaviruses are Hantavirus Pulmonary Syndrome (HPS) and Hemorrhagic Fever with Renal Syndrome (HFRS). Different hantavirus species are associated with each disease, and the severity of illness can vary depending on the hantavirus species involved.
Hantavirus infections in Canada are uncommon, however, sporadic cases of HPS caused by the Sin Nombre virus have been documented in Western Canadian provinces.^2,3 Additional HPS cases have been reported elsewhere in the Americas.⁴ In contrast, cases of HFRS are more often reported in Europe and Asia⁴, with rare cases identified previously in North America among rat breeders or owners⁵.

Requests for hantavirus serology and PCR testing are referred by PHO to the National Microbiology Laboratory (NML) in Winnipeg. Testing of individuals suspected of infection with the Andes viruses requires consultation with the Ministry of Health, PHO and other provincial health system partners.

Updates as of May 7, 2026:

Testing information now includes additional detail on the Andes virus, a specific species of hantavirus that may spread from person to person in rare cases, including a recent event in April 2026. Both PCR and serologic testing for the Andes virus is available at the NML.
If testing for Andes virus is being considered for a symptomatic individual with travel to and potential exposures in areas endemic for or with active transmission of this hantavirus species (e.g., Southern South America), consult the Ministry of Health Notification Pathway for Special Pathogens for a description of the provincial algorithm for managing special pathogens, including the Andes virus. Do not call PHO’s laboratory Customer Service Centre to request Andes virus testing.
Specimens SHOULD NOT be collected for any diagnostic laboratory testing, including Andes virus, until a coordination call with provincial health system partners and subject matter experts organized by the Ministry of Health occurs.
The PHO specimen submission requirements, including the need to complete the Vector-borne and Zoonotic Virus Testing Intake Form, remain in effect.
Requests for hantavirus testing that are not suspicious of Andes virus infection (e.g., no relevant travel or exposures) will continue to be processed through the typical PHO laboratory pathway.

*Uncontrolled print copy. Valid only on day of print: 09 May 2026.

Testing Indications

A clinical risk assessment for hantavirus infection, with specific evaluation of epidemiologic factors and exposure history, is recommended before submitting a test request. This information must be provided on the Vector-borne and Zoonotic Virus Testing Intake Form when submitting specimens, for review by a PHO Microbiologist.

Individuals that meet the following criteria may be eligible for hantavirus testing:

Compatible signs/symptoms following a recent rodent exposure AND
Recent travel to or residence in areas endemic for or with active HPS^2,3 or HFRS⁴ causing hantaviruses OR
Other clinical situations (these require discussion with a PHO Microbiologist)

Exposures relevant to hantavirus infection may include contact with rodents, their urine, feces, saliva or nesting materials, particularly in situations that facilitate inhalation of aerosolized virus particles. This may include outdoor activities in rural areas or other environments (e.g. cleaning rodent excreta at home). The incubation period for most hantaviruses varies and can be up to 8 weeks post-exposure.⁴

Signs and symptoms of HPS and HFRS may overlap at onset, and can include but are not limited to, fever, headache, myalgias, abdominal pain. As the disease progresses, the clinical features of HPS and HFRS typically diverge, and can include the development of shortness of breath, bilateral pneumonia for HPS, or hemorrhagic manifestations for HFRS, among other findings.

Serologic testing is the preferred method for hantavirus testing, however, PCR may be useful in the early acute stage of infection. Both tests should be requested for individuals with acute signs/symptoms of infection.

Testing is not indicated for asymptomatic individuals.

Acceptance/Rejection Criteria

Specimens received without the appropriate forms (see: Submission and Collection Notes), and specimens that do not meet the criteria above are subject to cancellation.

Specimens that are submitted to PHO for Andes virus testing where the appropriate notifications described in the Notification Pathway for Special Pathogens have not been followed are subject to cancellation.

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
Hantavirus Serology	General Test Requisition Vector-borne and Zoonotic Virus Testing Intake Form	Serum	5.0 mL blood or 1.0 mL serum	Red top or Serum Separator tubes (SST)
Hantavirus PCR	General Test Requisition Vector-borne and Zoonotic Virus Testing Intake Form	Serum	5.0 mL blood or 1.0 mL serum	Red top or Serum Separator tubes (SST)
Hantavirus PCR	General Test Requisition Vector-borne and Zoonotic Virus Testing Intake Form	Whole blood	1.5 mL blood	EDTA, heparin or citrate tubes (can be submitted as aliquots in sterile 1.5 – 2.0 mL screw cap tubes).
Hantavirus PCR	General Test Requisition Vector-borne and Zoonotic Virus Testing Intake Form	CSF and other body fluids	0.5 mL	Sterile container Sterile 1.5-2.0 mL screw cap tubes.
Hantavirus PCR	General Test Requisition Vector-borne and Zoonotic Virus Testing Intake Form	Tissues	n/a	Fresh or frozen tissues- Sterile container Formalin-fixed tissues- place in sterile plastic containers, clearly identified as being in formalin. Paraffin embedded tissues- can be sent as entire blocks or 4-6 µm sections in a plastic tube or vial.

Submission and Collection Notes

Label the specimen container(s) with the patient’s first and last name, date of collection, and one other unique identifier such as the patient’s date of birth or Health Card Number. For additional information see: Criteria for Acceptance of Patient Specimens. Failure to provide this information may result in rejection or testing delay

Each specimen submitted for testing must be accompanied by a separate PHO General Test Requisition, with all fields completed.

Clinical information and relevant travel and exposure histories for zoonotic viruses must be provided on the Vector-borne and Zoonotic Virus Testing Intake Form. This information will be reviewed by a PHO Microbiologist to determine eligibility. Failure to provide this information may result in rejection or testing delays.

Test requests for hantaviruses require approval by a PHO Microbiologist. Submission of the mandatory Vector-borne and Zoonotic Virus Testing Intake Form will initiate the review process at PHO provided the form contains all necessary information. Requests received without the form, forms submitted with insufficient information or insufficient justification for testing are subject to cancellation.

Specimens for Andes virus testing should not be collected until the decision to proceed with testing has been confirmed during the provincial health systems partners coordination call.

If additional infectious disease testing is required, a separate tube of blood should be collected for hantavirus testing. Notify laboratory staff at your local microbiology laboratory that the patient is being investigated for hantavirus. All tests (Hantavirus and non-Hantavirus tests) can be listed on the same PHO requisition.

Due to laboratory biosafety requirements, other infectious disease tests submitted to PHO at the same time may be deferred until hantavirus testing has been completed by the NML.

Timing of Specimen Collection

Serology:
Acute and convalescent sera should be collected for serologic testing. The convalescent serum specimen should be collected at least 2 to 3 weeks after the initial specimen.

Molecular (PCR):
Specimens submitted for molecular testing (PCR) should be collected ASAP after the onset of symptoms (within 3 to 10 days⁶).

Limitations

Haemolysed, icteric, lipemic or microbial contaminated sera or plasma are not recommended for testing.

Storage and Transport

Specimens should be transported in accordance with Transportation of Dangerous Goods Act/Regulations for Category A pathogens (UN2814 packaging).

Place each specimen type in an individual biohazard bag and seal. Insert the corresponding requisition in the pocket on the outside of each sealed biohazard bag.
Clotted blood/serum specimens should be stored at 2-8°C following collection and shipped to PHO on ice packs.
Ship refrigerated specimens (e.g., clotted blood, serum, CSF) on ice packs, and frozen specimens (e.g., serum, CSF, tissues) on dry ice. Do not ship clotted blood, EDTA/ heparin/citrated whole blood on dry ice.

All specimens submitted for molecular testing should be stored at 2-8°C following collection and shipped to PHO on ice packs. For CSF and serum, if a delay in transport to PHO is anticipated (more than 72 hours), specimens should be frozen (at -80°C if possible) and shipped on dry ice.

Centrifugation of serum tubes should be avoided.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Hantavirus serology and molecular (PCR) testing is referred out to the National Microbiology Laboratory (NML), with a TAT of up to 28 business days from receipt at PHO.

Testing for Andes virus is initiated only after the decision to proceed is made during the provincial health systems partners coordination call.

Test Methods

Hantavirus testing at the NML may be performed by a method that is not fully validated/verified. Refer to NML-Guide to Services for further information. The testing approach may vary depending on the patient’s clinical presentation and the epidemiological risk factors for specific hantaviruses associated with HPS or HFRS indicated at the time of submission.

Serology:
Hantavirus serology (IgM/IgG) is performed at the NML by enzyme linked immunosorbent assay (ELISA) or strip immunoassay for select HPS or HFRS-associated viruses (e.g. Sin Nombre, Andes virus or Seoul virus).

Molecular (PCR):
Molecular testing is performed at the NML by PCR (quantitative and gel-based). Positive results may be confirmed by Sanger sequencing.

Interpretation

All results should be interpreted in the context of the clinical and epidemiological information available.

Serology*

IgM ELISA Result	IgG ELISA Result	Possible Interpretation and Recommendations
Negative	Negative	Anti-hantaviral antibodies not detected. This does not rule out infection. Submit a second specimen for testing if clinically indicated unless a PCR test has also been performed and the result for the hantavirus gene targets are negative or not detected.
Positive	Negative	Anti-hantaviral IgM antibodies detected. This suggests an acute/recent infection. Cross-reactivity with other viral agents may be possible. Submit a convalescent specimen for testing.
Negative	Positive	Anti-hantaviral IgG antibodies detected. This suggests a past hantavirus infection or potential cross-reactivity. Submit a second specimen for testing if clinically indicated.
Positive	Positive	Anti-hantaviral IgM and IgG antibodies detected. Suggestive of an acute or recent infection. Submit a convalescent specimen for testing.
Equivocal	Equivocal	Unable to determine if anti-hantaviral antibodies were present. Submit an additional specimen for testing within 2 to 3 weeks of the initial specimen collection date.

Molecular (PCR)*

PCR Result	Possible Interpretation and Recommendations
Negative	Hantavirus nucleic acids not detected. This does not exclude infection. Serology testing is recommended if there is a strong clinical suspicion of hantavirus infection.
Positive	Hantavirus nucleic acids detected. This suggests an acute infection.
Equivocal	Unable to determine the presence of hantavirus nucleic acids in the specimen. This may represent an acute infection (low level viremia) or a false positive. Submit an additional specimen for testing.
Invalid	Testing unable to be completed due to a quality issue. Submit an additional specimen for testing if clinically indicated.

* Reviewed in collaboration with the NML

Reporting

Results are reported to the ordering physician, authorized health care provider (General O. Reg 45/22, s.18) or submitter as indicated on the requisition.

Positive results are also reported to the Medical Officer of Health as per Health Protection and Promotion Act.

References

Bradfute, S. B., Calisher, C. H., Klempa, B., Klingström, J., Kuhn, J. H., Laenen, L., Tischler, N. D., & Maes, P. 2024. ICTV Virus Taxonomy Profile: Hantaviridae 2024, J. Gen. Virol. 105: 001975.
Warner BM, Dowhanik S, Audet J, Grolla A, Dick D, Strong JE et al. Hantavirus cardiopulmonary syndrome in Canada. 2020, Emerg. Infect. Dis. 26(12): 3020-3024.
Drebot MA, Jones S, Grolla A, Safronetz D, Strong JE, Kobinger G, et al. Hantavirus pulmonary syndrome in Canada: An overview of clinical features, diagnostics, epidemiology and prevention. 2015, CCDR. 41-6: 124-130.
Pan American Health Organization (PAHO). 1999. Hantavirus in the Americas: Guidelines for diagnosis, treatment, prevention and control (Technical paper No. 47). Washington DC, USA.
Kerins JL, Koske SE, Kazmierczak J, Austin C, Gowdy K, Dibernardo A et al. Outbreak of Seoul Virus Among Rats and Rat Owners — United States and Canada, 2017. 2018, MMWR. 67(4): 131-134.
Klena JD, Chiang CF, Whitmer SM, Wang YF, Shieh WJ. Hantaviruses. In: Carroll KC, et al. 2023. Manual of Clinical Microbiology (13th ed). ASM Press. Washington DC, USA. 1917-1931.
Martinez VP, Di Paola N, Alonso DO, Perez-Sautu U, Bellomo CM, Iglesias AA et al. “Super spreaders” and person-to-person transmission of Andes virus in Argentina. 2020, N Engl J Med. 383(23): 2230-2241.
Ortiz N, Pinotti JD, Andreo V, Gonzalez-Ittig RE, Gardenal CN. Orthohantavirus rodent hosts and genotypes in Southern South America: A narrative review. 2025, PLoS Negl Trop Dis. 19(9): e0013489.

*Uncontrolled print copy. Valid only on day of print: 09 May 2026.

Contact Laboratory Customer Service

Microbiology and Laboratory Services

customerservicecentre@oahpp.ca

Updated 8 May 2026