Lymphocytic Choriomeningitis virus (LCMV) – 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 serology and PCR testing information on Lymphocytic Choriomeningitis virus (LCMV) through Public Health Ontario (PHO).

Lymphocytic Choriomeningitis Virus (LCMV) is a zoonotic RNA virus in the Arenaviridae family that can cause severe neuroinvasive or hemorrhagic fever-like disease¹.
Human infection occurs primarily through exposure to rodent excreta (e.g., feces, urine), secretions (e.g., saliva) or contaminated nesting materials. LCMV can be carried asymptomatically in the house mouse (Mus musculus) and some other rodents². Other routes of transmission (e.g. laboratory exposure, vertical transmission) are also possible³.
Serology and molecular (PCR) testing for LCMV infection are available at the National Microbiology Laboratory (NML)

Updates
As of July 2, 2025 the Vector-borne and Zoonotic Virus Testing Intake Form must now be submitted when submitting LCMV test requests.

*Uncontrolled print copy. Valid only on day of print: 03 July 2025.

Testing Indications

Note: A clinical risk assessment for LCMV infection is recommended prior to submitting a test request. Due to laboratory biosafety concerns, testing for other infectious diseases will not be performed at PHO until LCMV testing has been completed by the NML.

LCMV testing is performed at the NML. All requests require approval by a PHO Microbiologist. A review of the individual’s clinical status, exposure history and consideration of alternative diagnoses should be performed prior to requesting LCMV testing. This information will be required for the approval process.

The following individuals may be considered for LCMV testing:

New onset of compatible symptoms following recent exposure to rodents, their excretions or secretions, or contaminated bedding/nesting materials
Symptoms of an acute febrile illness or neuroinvasive disease are possible. The incubation period for LCMV infection is between 1 to 4 weeks post-exposure⁴.

Symptomatic individuals with risk factors for severe disease and relevant exposures
Severe disease can occur in individuals that are immune compromised, and infants born to mothers infected during pregnancy^1,2,4.

Other clinical situations where LCMV testing may impact patient management.
Situations not identified above require discussion with a PHO Microbiologist.

Serology is the preferred method for LCMV testing. Requests for LCMV PCR in the setting of an acute infection should be accompanied by a parallel request for LCMV serology. Testing is not recommended for asymptomatic individuals. Test requests with insufficient justification based on the indications above may be cancelled.

Acceptance/Rejection Criteria

Specimens received without the appropriate forms (See: Submission and Collection Notes) are subject to cancellation.

Specimen Collection and Handling

Specimen Requirements

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

It is MANDATORY to provide the clinical information, relevant travel(s), and relevant exposures for Zoonotic viruses requested on the Vector-borne and Zoonotic Virus Testing Intake Form. Test requests that are submitted without the appropriate mandatory information are subject to cancellation.

Testing for LCMV is not routinely performed and must be approved 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.

If additional infectious disease testing is required, requests for LCMV testing require the submission of a separate tube of blood. If testing for other infectious diseases is required at the same time, ensure that the LCMV collection is made in a separate tube. Notify laboratory staff, both at your local microbiology laboratory and PHO that the patient is under investigation for LCMV. All tests (LCMV and non- LCMV tests) can be listed on one PHO requisition.

Timing of Specimen Collection

Serology:
Acute and convalescent sera should be collected for serologic testing from individuals with clinical symptoms. 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, unless otherwise indicated via discussion with a PHO Microbiologist.

Limitations

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

Storage and Transport

Specimens should be transported according to TDG guidelines for Category B pathogens (UN 3373 packaging).

All clinical specimens must be shipped in accordance with the Transportation of Dangerous Goods Act/Regulations.

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. 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 is not needed and should be avoided.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

LCMV serology and molecular (PCR) testing is referred out to the National Microbiology Laboratory (NML).

Turnaround time is up to 28 business days from receipt at PHO.

Test Methods

Serology:
Lymphocytic choriomeningitis virus (LCMV) is performed at the NML by enzyme linked immunosorbent assay (ELISA).

Molecular (PCR):
Molecular testing is performed at the NML by PCR amplification of specific regions of the LCMV virus genome.

Algorithm

The NML offers Serology and PCR testing for LCMV. The tests performed will depend on the patient’s clinical presentation and epidemiological risk factors indicated at the time of submission. Testing for supplemental targets may be necessary.

Interpretation

LCMV Testing is conducted at the NML. The NML indicates that some components of their testing
(laboratory-developed or in vitro diagnostic tests) may not be fully validated/verified. All results
should be interpreted in the context of the clinical and epidemiological information available.

The following tables provide possible test results with associated interpretations:

LCMV Serology*

IgM ELISA Result	IgG ELISA Result	Possible Interpretation and Recommendations
Negative	Negative	LCMV antibodies were not detected. This does not rule out infection. Submit an additional specimen if clinically indicated unless PCR has also been performed, and the result is negative or not detected.
Positive	Negative	Suggests an acute/recent infection. Cross-reactivity with other arenaviruses (especially Old World Arenaviruses) may be possible. Submit a convalescent specimen for testing.
Negative	Positive	Suggestive of a past LCMV infection or potential cross-reactivity with other arenaviruses (especially Old World Arenaviruses) is possible. Submit a second specimen for testing if clinically indicated.
Positive	Positive	Suggestive of an acute or recent infection. Submit a convalescent specimen for testing.
Equivocal	Equivocal	Unable to determine if anti-LCMV antibodies were present. Submit an additional specimen for testing if clinically indicated.

LCMV PCR*

Probe PCR Assay Result	Possible Interpretation and Recommendations
Negative	LCMV nucleic acids were not detected. This does not exclude infection. Submit an additional specimen if clinically indicated, including CSF if neuroinvasive disease suspected.
Positive	LCMV nucleic acids were detected. This suggests an acute infection. Submit a convalescent specimen for testing.
Invalid	Unable to determine if LCMV nucleic acids were present. Submit an additional specimen for testing if clinically indicated.

*Reviewed in collaboration with 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.

References

Rollin PE, Knust B, Nichol S. 2014. Lymphocytic choriomeningitis. In: Heymann. 2022. Control of Communicable Diseases Manual (21st ed). American Public Health Association. Washington DC, USA. 383-385.
Public Health Agency of Canada (PHAC). 2011. Pathogen Safety Data Sheets: Infectious Substances – Lymphocytic choriomeningitis virus. Available from: Pathogen Safety Data Sheets: Infectious Substances – Lymphocytic choriomeningitis virus - Canada.ca
Caron L, Delisle JS, Strong JE, Deschambault Y, Lombard-Vadnais F, Labbe AC et al. 2023. Armstrong strain lymphocytic choriomeningitis virus infection after accidental laboratory exposure. Virology Journal. 20: 294.
Centers for Disease Prevention and Control (CDC). Lymphocytic Choriomeningitis. Available from: https://www.cdc.gov/lymphocytic-choriomeningitis/about/index.html

*Uncontrolled print copy. Valid only on day of print: 03 July 2025.

Contact Laboratory Customer Service

Microbiology and Laboratory Services

customerservicecentre@oahpp.ca

Updated 2 July 2025