Key points
- Lymphocytic choriomeningitis, or LCM, is a disease caused by a virus and spread by the common house mouse, Mus musculus.
- Healthy people with LCM usually recover.
- LCM can result in serious illness for people who are pregnant or have a weakened immune system.
- LCM can occur wherever infected rodents are found.
- Some studies show 2 to 5 percent of people living in urban areas have had a past LCM infection.
What it is
LCM is caused by the lymphocytic choriomeningitis virus. LCM has been reported in Europe, the Americas, Australia, and Japan, and may occur wherever infected rodents are found. LCM is underreported, making it difficult to determine how common it is and where else it is found.
Signs and symptoms
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People who do get symptoms are usually sick for about a week and may experience:
- Fever
- Fatigue
- Lack of appetite
- Muscle aches
- Headaches
- Nausea
- Vomiting
Less common symptoms include sore throat, cough, and pain in the chest, testicles, or glands in the mouth.
After a few days of recovery, a second, more serious phase of illness may occur. This phase involves neurologic distress like a buildup of fluid on the brain and inflammation of the brain, its membranes, and the spinal cord.
Neurologic symptoms can include:
- Fever
- Headache
- Stiff neck
- Drowsiness
- Confusion
- Inability to move
- Muscle weakness
How long it takes for signs to show
People with LCM start showing signs of the disease about 8-13 days after being infected with the virus.
Possible complications
Most people with LCM survive. Less than 1 percent of people pass away from the disease.
Even most patients who experience more severe brain symptoms survive. However, temporary or permanent nerve damage is possible. After recovering, some people develop deafness, arthritis, or swelling of the heart.
People who get LCM during pregnancy may pass the infection on to their fetus. Infections in the first trimester may result in miscarriage. Infections in the second and third trimesters can cause serious birth defects.
Risk factors
Fact
Other people at risk:
- Owners of pet mice and hamsters if their pets came from infected colonies or are infected by wild mice.
- Laboratory workers who work with the virus or handle infected animals.
Risk factors for severe disease:
- Immunocompromised people, including organ transplant recipients, are at a higher risk of experiencing fatal hemorrhagic fever-like disease.
- 70 percent of immunocompromised people infected with LCM will die.
- Pregnant people with LCM are at a higher risk for miscarriage.
- It is also possible to pass the infection onto the fetus.
- Infected newborns can have build-up of fluid deep in the brain, abnormal deposits of calcium in the brain, or swelling in the eye.
- 70 percent of newborns with these birth defects die. Around 35 percent of all newborns with LCM die.
How it spreads
Someone can get LCM when they are exposed to fresh urine, droppings, saliva, or nesting materials from infected rodents.
Except for transmission to the fetus during pregnancy, spread between people has not been reported. Rarely, someone may contract LCM if they receive an organ transplant from an infected person.
Prevention
You can protect yourself from LCM by avoiding contact with wild mice. Take precautions when handling pet rodents like mice, hamsters, or guinea pigs.
Testing and diagnosis
Healthcare providers diagnose LCM by testing for the virus or its antibodies in a patient's blood or spinal fluid.
Treatment and recovery
LCM has no treatment. Although some studies have shown the drug ribavirin may be effective against LCM, there is not enough evidence to support its use in all cases.
People who develop neurological symptoms require hospitalization. They may receive anti-inflammatory drugs, like corticosteroids.
- Albarino CG, Palacios G, Khristova ML, et al. High diversity and ancient common ancestry of lymphocytic choriomeningitis virus. Emerging Infectious Diseases. 2010;16(7):1093-1100.
- Amman BR, Pavlin BI, Albarińo CG, et al. Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients. Emerging Infectious Diseases. 2007;3(5):719-25.
- Armstrong C and Lillie RD. Experimental lymphocytic choriomeningitis of monkeys and mice produced by a virus encountered in studies of the 1933 St. Louis encephalitis epidemic. Public Health Reports. 1934;49:1019-27.
- Centers for Disease Control. Update: Interim Guidance for Minimizing Risk for Human Lymphocytic Choriomeningitis Virus Infection Associated with Pet Rodents. Morbidity Mortality Weekly Report. 2005;54(32):799-801.
- Fischer SA, Graham MB, Kuehnert MJ, et al. Transmission of Lymphocytic Choriomeningitis Virus by Organ Transplantation. New England Journal of Medicine. 2006;354(21):2235-49.
- Jahrling PB and Peters CJ. Lymphocytic choriomeningitis virus. A neglected pathogen of man. Archives of Pathology & Laboratory Medicine. 1992;116(5):486-8.
- Knust B, Stroeher U, Edison L, et al. Lymphocytic choriomeningitis virus in employees and mice at multipremises feeder-rodent operation, United States, 2012. Emerging Infectious Diseases. 2014;20(2):240-7.
- Macneil A, Stroeher U, Farnon E, et al. Solid Organ Transplant-associated Lymphocytic Choriomeningitis, United States, 2011. Emerging Infectious Diseases. 2012;18(8):1256-62.
- Mets MB and Chhabra MS. Eye manifestations of intrauterine infections and their impact on childhood blindness. Survey of Ophthalmology. 2008;53(2):95-111.
- Park JY, Peters CJ, Rollin PE, et al. Age distribution of lymphocytic choriomeningitis virus serum antibody in Birmingham, Alabama: Evidence of a decreased risk of infection. American Journal of Tropical Medicine and Hygiene. 1997;57(1):37-41.
- Peters CJ. Arenaviruses. Richman, Douglas D.; Whitley, Richard J., and Hayden, Frederick G., eds. Clinical virology. Second ed. 2002; pp. 949-69.
- Schafer IJ, Miller R, Stroeher U, et al. A Cluster of Lymphocytic Choriomeningitis Virus Infections Transmitted Through Organ Transplantation Iowa, 2013. Morbidity and Mortality Weekly Report. 2014;63(11):249.
- Yama IN, Cazaux B, Britton-Davidian J, et al. Isolation and characterization of a new strain of lymphocytic choriomeningitis virus from rodents in southwestern France. Vector Borne and Zoonotic Diseases. 2012;12(10):893-903.