Though it may not cause symptoms for everyone, preventing the spread of lymphocytic choriomeningitis (LCM) is important to keeping everyone in our community safe.

A mouse, carriers of lymphocytic choriomeningitis, sitting on someone's shoe. Share on Pinterest
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Lymphocytic choriomeningitis (LCM) is a viral infection. When humans contract this virus, it can lead to symptoms such as fever, malaise, and pain.

Rarely, serious infections with LCMV can lead to inflammation of the spinal cord and paralysis.

Keep reading to learn about how this virus is spread and how to prevent it in your home.

The lymphocytic choriomeningitis virus (LCMV) causes lymphocytic choriomeningitis (LCM). Rodents and house mice most commonly carry the virus.

Infections can occur when a human comes in contact with fresh droppings, urine, saliva, or nesting material from a rodent that carries the virus.

It’s also possible for transmission to happen if any of these materials comes in contact with broken skin, the eyes, the nose, the mouth, or through a rodent’s bite.

About 5% of house mice in the United States carry LCMV. Mice can carry LCMV throughout their lives without ever showing signs of infection.

Other types of rodents, including those kept as pets, can also carry LCMV if a house mouse spreads it to them.

Humans most often catch LCMV through contact with house mice, but sometimes transmission can happen through contact with pets and other rodents.

LCMV transmission can happen in the womb during pregnancy and via organ transplant, but there aren’t any other reports of human-to-human transmission.

It’s common for people who catch LCMV to have no symptoms at all. When symptoms do develop, they typically begin about 5–13 days after exposure to the virus.

Common symptoms of LCM include:

Sometimes, a second phase of infection happens after a few days of recovery. In this phase, symptoms can include:

Rarely, LCMV can cause serious and complex symptoms such as:

  • spinal inflammation
  • paralysis
  • muscle weakness
  • changes to body sensation

It’s rare for LCMV to cause any symptoms. People with compromised immune systems, along with pregnant people and people who’ve had organ transplants, are at higher risk of developing an LCM infection that leads to symptoms.

Many people with LCM never experience symptoms and never need treatment. When treatment is necessary, the exact treatment plan will depend on the severity of the infection and symptoms.

For instance, corticosteroids and other anti-inflammatory drugs can sometimes reduce inflammation and relieve symptoms.

If an LCM infection is severe, hospitalization might be necessary during treatment. Your doctor will be able to design a treatment plan that takes your symptoms and overall health into account.

Is lymphocytic choriomeningitis curable?

LCM is curable.

Most people who develop LCM survive and recover, and its general fatality rate is less than 1%. Still, it’s possible for severe LCM to lead to lasting complications, such as neurological damage.

Also, LCM infections during the first trimester of pregnancy share a link to fetal death.

Infections during the second and third trimesters have an association with serious birth defects such as visual difficulties, intellectual disabilities, and hydrocephaly.

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Some steps you can take you can take to reduce your risk of LCM and help prevent the spread of LCMV in your community include:

  • always practicing good hand hygiene, especially after handling rodents or their cages
  • if you have pet rodents, keeping cages clean and changing bedding often
  • cleaning rodent cages in a well-ventilated area
  • avoiding contact with wild rodents
  • avoiding holding any rodent close to your face
  • if you’re pregnant, avoiding contact with any rodents, including pets
  • sealing any holes in your home that could allow for rodent entry with caulk or steel wool
  • removing any foods, packaging, or nesting materials that can attract rodents to your home
  • if a wild rodent enters your home, trapping and removing it as quickly as possible
  • wearing gloves if using frozen “feeder” rodents for snakes and other pets

LCM is a viral infection carried by rodents. Transmission happens through human contact with the droppings, urine, saliva, and nesting material of common house mice.

LCM often causes no symptoms at all but can lead to fever, pain, malaise, nausea, and other unpleasant symptoms. In serious cases, LCM can cause swelling in the nervous system and might require hospitalization.