Lymphocytic choriomeningitis is a flu-like disorder caused by an arenavirus and often followed by meningitis. It occurs when the tissues covering the brain and spinal cord become inflamed.

• Rodents can transmit the virus to people through contaminated dust or food.
• The infection may cause no symptoms, a flu-like illness, or meningitis.
• If symptoms suggest meningitis, a spinal tap is done.
• Treatment aims to relieve symptoms.
• Most people recover completely.

The arenavirus that causes lymphocytic choriomeningitis is commonly present in rodents, especially gray house mice and hamsters. These animals are usually infected by the virus for life and excrete it in urine, feces, semen, and nasal secretions. Most often, exposure to dust or food contaminated by these waste products causes the disorder in people. The disorder usually occurs in autumn and winter when wild rodents seek shelter indoors.

Symptoms

Most people have no symptoms or very mild symptoms. Symptoms, if they develop, often occur in two phases.

First, flu-like symptoms develop 5 to 10 days after exposure to the virus. Typically, people have a fever of about 101 to 104° F (38.3 to 40° C), sometimes accompanied by shaking. People may feel generally ill (malaise), nauseated, light-headed, and weak. They may have muscle pains, a headache behind the eyes worsened by bright light, and a poor appetite. The throat may become sore. After 5 days to 3 weeks, the flu-like symptoms may subside for 1 or 2 days.

In the second phase, flu-like symptoms recur and other symptoms develop. Knuckle and finger joints may become painful and swollen, and the testes may become inflamed, swollen, and painful. People may lose their hair or vomit. Meningitis may develop, causing a headache and stiff neck, but it tends to be less severe than in acute bacterial meningitis.

Most people who develop meningitis recover completely. However, headaches and fever may recur periodically for months.

Diagnosis

At first, the disorder appears to be the flu, so usually no tests are done.

If symptoms suggest meningitis, a spinal tap (lumbar puncture) is done to obtain a sample of the cerebrospinal fluid. If lymphocytic choriomeningitis is present, the cerebrospinal fluid usually contains many white blood cells, mostly lymphocytes. A sample of blood is also obtained.

The disorder is diagnosed by identifying the virus or by detecting antibodies to the virus in blood or cerebrospinal fluid.

Treatment

No specific treatment is available. Doctors try to relieve the symptoms until the disorder subsides—in about 1 to 2 weeks.

Last full review/revision May 2008 by Michael Jacewicz, MD