Lymphocytic Choriomeningitis

Key Features

• Lymphocytic choriomeningitis (LCM) is an arenavirus infection of CNS

• Main reservoir is house mouse, but other animals may harbor virus

• Prevalence varies regionally and correlates with the expansion of rodents

• LCM virus is spread from animal to human by infected oronasal secretions, urine, or feces

• Person-to-person spread is rare

• However, vertical transmission is reported, and LCM is considered to be an underrecognized teratogen

Clinical Findings

• Incubation period

  • 8–13 days to the appearance of systemic manifestations

  • 15–21 days to the appearance of meningeal symptoms

• Symptoms are biphasic with a prodromal phase followed by a meningeal phase

• Fever, chills, headache, myalgia, cough, and vomiting, occasionally with lymphadenopathy and maculopapular rash in prodromal phase

• Headache, vomiting, lethargy, and variably present meningeal signs in the meningeal phase

• Transverse myelitis, deafness, Guillain-Barré syndrome, and transient and permanent hydrocephalus are reported

• Arthralgias can develop late

• LCM infection is a well-known, albeit underrecognized, cause of congenital infection frequently complicated with obstructive hydrocephalus, intracerebral calcifications, and chorioretinitis

• Differential diagnosis

  • Other aseptic meningitides

  • Bacterial and granulomatous meningitis

Diagnosis

• Leukocytosis or leukopenia

• Cerebrospinal fluid lymphocytic pleocytosis common

• Complement-fixing antibodies appear during second week of infection and may aid in diagnosis

• In fetuses and newborns with ventriculomegaly or other abnormal neuroimaging findings, screening for congenital LCM may be considered; mothers are asymptomatic half the time

Treatment

• No specific antiviral therapy

• Supportive measures