Viral Meningitis/Encephalitis Public Health Communicable Disease Control Unit
Communicable Disease Management Protocol
Manitoba Health Viral Meningitis/Encephalitis Public Health Communicable Disease Control Unit
Case Definition Etiology Clinically compatible illness and laboratory- Numerous viruses can cause this syndrome, but half confirmed virus identification using serologic or or more of cases have no demonstrable etiology. In isolation techniques. Canada, enteroviruses cause most cases of known etiology, particularly coxsackievirus and echovirus. Reporting Requirements In addition, arboviruses, measles, herpes simplex and varicella viruses, adenovirus and others are • Positive isolates or positive serologic tests for viral responsible for sporadic cases. meningitis/encephalitis are reportable by laboratory. Epidemiology • Clinical cases of viral meningitis/encephalitis Reservoir: Humans and probably certain birds, need not be reported by attending health care mammals and reptiles. professional, unless the case results in neurological sequelae or death. Transmission: Depends on specific virus, but for enteroviruses, generally directly by fecal-oral or • Meningitis/encephalitis due to Western Equine respiratory droplet contact with an infected person, Encephalitis, measles, mumps or rubella should or indirectly by contact with articles freshly soiled be reported under those diseases. with feces or throat discharges from an infected person. Western equine encephalitis is transferred Clinical Presentation/Natural History through bites by infected mosquitoes. Viral meningitis/encephalitis is a relatively common Occurrence: but rarely serious syndrome with multiple viral General: Some viruses have a worldwide etiologies. It usually appears as a sudden onset of distribution, others are localized. Cases may be fever, with headache, and other signs and sporadic or occur in epidemics. Seasonal symptoms of meningeal involvement and abnormal increases in late summer and early autumn are CSF findings. A rash resembling rubella due mainly to arboviruses and enteroviruses. characterizes certain types of viral meningitis caused by echoviruses and coxsackieviruses; vesicular and Manitoba: Between 1995 and 1999, 290 cases petechial rashes may also occur. Active illness of viral meningitis were reported in Manitoba seldom exceeds 10 days. Recovery is usually (Echo=153, Unspec=72, Entero=34, complete. GI and respiratory symptoms may be Coxsackie=26, Herpes simplex=5). Outbreaks associated with infection with enteroviruses. tend to occur in late summer or early autumn. Various diseases caused by non-viral agents may Incubation Period: Depends on the specific virus, mimic aseptic meningitis, such as inadequately but for enteroviruses, often three to five days. treated pyogenic meningitis, tuberculous and Susceptibility and Resistance: Susceptibility is cryptococcal meningitis, and post-vaccinal universal unless immunization has been given for reactions, including sequelae to measles, mumps, specific viral diseases, such as measles, Japanese varicella and post-rabies immunization. encephalitis or varicella. Illness is more frequent and more severe in infants, children and the elderly.
Communicable Disease Management Protocol – Viral Meningitis/Encephalitis November 2001 1 Communicable Disease Management Protocol
Period of Communicability: Depends on the Control specific virus, but for enteroviruses, generally during the acute stage of infection, although stool Management of Cases: may contain virus for several weeks. • Enteric precautions are indicated for seven days after onset, unless a non-enteroviral diagnosis is Diagnosis established. Under optimal conditions, specific identification Management of Contacts: can be made in about half of cases, using serologic • Investigation of contacts is not of practical value. and virus isolation techniques. Viral agents may be isolated in early stages from throat washings and Management of Outbreaks: stool, and occasionally from CSF and blood. Typical CSF findings include pleocytosis (usually • General notice to health professionals of the mononuclear but may be polymorphonuclear in presence of an epidemic and the necessity for early stages), increased protein, normal sugar and differentiation of cases from more serious absence of bacteria. medical or surgical emergencies. Preventive Measures: Key Investigations • Immunization is available for Japanese • CSF examination and viral isolation or serology. encephalitis.
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