Meningitis, Nonpolio Viral

Key Features

• Nonpolio enteroviruses cause over 80% of cases of aseptic meningitis at all ages, especially in the summer and fall

• Nosocomial outbreaks also occur

• Usual incubation period is 4–6 days

• Most infections are subclinical or not associated with central nervous system (CNS) symptoms, therefore a history of sick contact is unusual

• Neonates may acquire infection from maternal blood, vaginal secretions, or feces at birth; occasionally the mother has had a febrile illness just prior to delivery

Clinical Findings

• Sudden onset of fever, marked irritability, and lethargy in infants

• Older children also describe frontal headache, photophobia, and myalgia

• Abdominal pain, diarrhea, and projectile vomiting may occur

• Incidence of rash varies with the infecting strain; if rash develops,

  • Usually seen after several days of illness

  • Appears as diffuse, macular or maculopapular, occasionally petechial, but not purpuric

• Illness may be biphasic, with nonspecific symptoms and signs preceding those related to the CNS

• In older children, meningeal signs are more frequent, but seizures are unusual, and focal neurologic findings are rare, which should lead to a search for an alternative cause

Diagnosis

• Blood leukocyte counts are often normal

• Spinal fluid leukocyte count is 100–1000/μL with polymorphonuclear cells predominating early and shifting to mononuclear cells within 8–36 hours

• Culture of CSF may yield an enterovirus within a few days (< 70%)

• PCR is the most useful diagnostic method in many centers (sensitivity > 90%)

• Cerebral imaging is not often indicated

Treatment

• No specific antiviral therapy exists

• Infants are usually hospitalized, isolated, and treated with fluids and antipyretics

• Moderately to severely ill infants are given empiric antibiotics for bacterial pathogens until cultures are negative for 48–72 hours

• Codeine compounds or other strong analgesics may be needed