Lymphocytic Choriomeningitis Virus (LCMV)

Boston University
Research Occupational Health Program (ROHP)
617-358-7647

Agent

Lymphocytic choriomeningitis viruses (LCMV) are single-stranded RNA viruses of the family Arenaviridae, genus Arenavirus. ¹ They are pleiomorphic with a 110-130nm diameter and when observed under a microscope, granularities within the viral capsid resemble grains of sand. ²

Disease/Infection

LCMV infections can be divided into acquired and congenital infections.

Acquired: infections transmitted to immunocompetent adults are often asymptomatic or reflective of a self-limiting viral syndrome including upper respiratory and flu-like symptoms. Although the infection is typically non-fatal, symptoms may progress into neurological manifestations including meningitis or meningoencephalitis, even in immunocompetent hosts. ³

Congenital: transmission typically occurs in the setting of maternal LCMV viremia, and the effects of congenital LCMV are dependent on the developmental stage of the fetus. Spontaneous abortion, microcephaly, and various neurologic developmental deficits have been characterized. ²

Special Populations at Risk

• Immunocompromised populations, neonates.
• Women of childbearing age should be aware of risks posed by LCMV. Women who become infected with LCMV during pregnancy may pass the infection on to the fetus. Infections occurring during the first trimester may result in fetal death and pregnancy termination, while in the second and third trimesters, birth defects can develop. Infants infected in utero can have many serious and permanent birth defects, including vision problems, mental retardation, and hydrocephaly (water on the brain).

Biosafety Information

Risk Group/BSL
Biosafety level 2 (for laboratory-adapted strains)⁵
Biosafety level 3 (for strains found to be fatal in non-human primates)

Modes of Transmission

Human-to-human transmission is not considered a source of infection outside of transplacental cases. Hamsters and mice (Mus musculus) are vectors for LCMV and the virus is endemic in wild mouse populations. Transmission can occur through contact with contaminated rodent excretions and secretions. The virus enters the host through damaged skin, mucus membranes, ingestion of virally contaminated food, through respiration on dust, rodent bites, or fomite contact. Although LCMV has been isolated in arthropods, this vector is not considered to play a role in transmission. ⁶

Host Range/Reservoir
Wild mice carrying LCMV are thought to be endemic to all continents with the exception of Antarctica. ^1,3

Symptoms

If symptomatic, those with acquired active LCMV illness will likely present with non-specific viral syndromic symptoms. Fever, myalgias, malaise, headaches, upper respiratory symptoms (cough, sore throat, etc.), and gastrointestinal symptoms (nausea, vomiting) are likely presenting symptoms.

Progression of the infection can result in neurologic manifestations including meningitis, meningoencephalitis, motor paralysis, sensorineural hearing loss, and Guillain-Barre syndrome. ²

Congenital LCMV infections have a wide spectrum of possible effects, including hydrocephalus, chorioretinitis, and/or mental retardation. ³

Incubation Period

Symptomatic manifestations of acquired infections typically occur 1-2 weeks after exposure. Neurologic symptoms may take up to 3 weeks to appear. ⁸ Congenital manifestations usually appear at birth. ³

Survival Outside Host

LCMV does not survive well outside of the host in natural conditions. ¹

Information for Lab Workers

Laboratory PPE

Personal protective equipment includes but is not limited to gowns with tight wrists and ties in the back, disposable gloves, a combination safety glass and mask or a face shield. Street clothing and jewelry should be removed before potential contact with LCMV. Facilities for washing and changing clothing after work should be available. Eye protection should be used if there is a potential for splashes given possible transmission through mucus membranes.

Containment

Research should be conducted using Biosafety Level 2 practices, equipment, and facility design. Gloves and gowns should be worn when handling infected laboratory animals and when there is a likelihood of direct skin contact with infectious materials. BSL-3 practices, containment equipment, and facilities are recommended for activities using infected or potentially infected animals. These guidelines may not be reflective of individual strains but are a general recommendation for the species. ⁵

In Case of Exposure/Disease

• For injuries in the lab that are major medical emergencies (heart attacks, seizures, etc.…):
  • Medical Campus: call or have a coworker call the Control Center at 617-358-9090.
    You will be referred to or transported to the appropriate healthcare location by the emergency response team.
• For lab exposures (needle sticks, bite, cut, scratch, splash, etc.…) involving animals or infectious agents, or for unexplained symptoms or illness call the ROHP 24/7-hour number (1-617-358-ROHP (7647); or 8-ROHP (7647) if calling from an on-campus location) to be connected with the BU Research Occupational Health Program (ROHP) medical officer. ROHP will refer you to the appropriate healthcare location.
• Under any of these scenarios, always inform the physician of your work in the laboratory and the agent(s) that you work with.
• Provide the wallet-size agent ID card to the physician.

Vaccination

There is no immunization available for LCMV.

Information for First Responders/Medical Personnel

Public Health Issues

Human-to-human transmission outside of transplacental cases is not considered a method of transmission. Standard precautions can be used.

Diagnosis/Surveillance

Surveillance is done through symptom monitoring, given that infections are typically self-limiting, rarely fatal, and not typically transmissible to others.

Diagnosis may be confirmed using serologic testing, ELISA, RT-PCR, Western blot, immunohistochemical staining, neutralization assays, immunofluorescent antibody testing, and viral cultures (blood, cerebrospinal fluid). ⁹

First Aid/Post Exposure Prophylaxis

Perform one of the following actions:

There is no known effective LCMV prophylactic treatment.

Treatment

In vitro studies have shown Ribavirin to be efficacious in treating LCMV infections. Management is generally supportive care. ²

Reproductive Health

A confidential medical reproductive hazard consultation can be requested at any time by contacting ROHP. If accommodation in the work environment is being considered a consultation and referral to the Equal Opportunity Office can be made.

References

1. Armstrong, C., & Lillie, R. D. (1934). Experimental lymphocytic choriomeningitis of monkeys and mice produced by a virus encountered in studies of the 1933 St. Louis encephalitis epidemic. Pub. Health Rep., 49, 1019-1027.

2. Bonthius DJ. Lymphocytic choriomeningitis virus: an underrecognized cause of neurologic disease in the fetus, child, and adult. Semin Pediatr Neurol. 2012 Sep;19(3):89-95. doi: 10.1016/j.spen.2012.02.002. PMID: 22889536; PMCID: PMC4256959.

3. Jamieson, D. J., Kourtis, A. P., Bell, M., & Rasmussen, S. A. (2006). Lymphocytic choriomeningitis virus: An emerging obstetric pathogen? American Journal of Obstetrics and Gynecology, 194(6), 1532-1536.

4. Fischer, S. A., Graham, M. B., Kuehnert, M. J., Kotton, C. N., Srinivasan, A., Marty, F. M., Comer, J. A., Guarner, J., Paddock, C. D., DeMeo, D. L., Shieh, W. -., Erickson, B. R., Bandy, U., DeMaria Jr., A., Davis, J. P., Delmonico, F. L., Pavlin, B., Likos, A., Vincent, M. J., Sealy, T. K., Goldsmith, C. S., Jernigan, D. B., Rollin, P. E., Packard, M. M., Patel, M., Rowland, C., Helfand, R. F., Nichol, S. T., Fishman, J. A., Ksiazek, T., & Zaki, S. R. (2006). Transmission of lymphocytic choriomeningitis virus by organ transplantation. New England Journal of Medicine, 354(21), 2235-2249.

5. Biosafety in Microbiological and Biomedical Laboratories (BMBL), 6 th Ed. US Government Printing Office, Washington, 2020.

6. Childs JE, Glass GE, Korch GW, Ksiazek TG, Leduc JW. Lymphocytic choriomeningitis virus infection and house mouse (Mus musculus) distribution in urban Baltimore. Amer J Trop Med Hyg. 1992;47:27–34.

7. Jahrling PB and Peters CJ. Lymphocytic choriomeningitis virus. A neglected pathogen of man. Archives of Pathology & Laboratory
Medicine. 1992;116(5):486-8.

8. Rousseau, M. C., Saron, M. F., Brouqui, P., & Bourgeade, A. (1997). Lymphocytic choriomeningitis virus in southern France: Four case
reports and a review of the literature. European Journal of Epidemiology, 13(7), 817-823.

9. Acha, P. N., & Szyfres, B. (2003). In Pan American Health Organization (Ed.), Zoonoses and Communicable Diseases Common to Man and
Animals (3rd ed.). Washington DC: PAHO HQ library.

Rev. 2/14/23