TABLE 2.
Summary of available diagnostic methods for viral meningitis and encephalitisa
| Virus | Effectivenessb of diagnosis by:
|
Other specimens | |||||||
|---|---|---|---|---|---|---|---|---|---|
| PCR
|
Serologyc
|
Culture of specimens
|
|||||||
| Serum | CSF | Serum | CSF | Throat | Rectal | Blood | CSF | ||
| Adenovirus | − | + | +/− | +/− | ++ | + | − | + | Conjunctival swab, stool electron microscopy |
| Arboviruses | +d | +d | ++ | ++ | − | − | ++ | +/− | |
| WNV | +d | +d | ++ | ++ | − | − | − | − | Serology preferable |
| Enteroviruses | |||||||||
| Nonpoliovirus | + | ++ | + | − | + | ++ | +/− | ++ | |
| Poliovirus | + | ++ | +e | − | + | ++ | − | − | Urine |
| Herpesviruses | |||||||||
| CMV | + | ++ | + | ++ | + | − | + | Rare | Urine |
| EBV | + | + | ++ | ++ | +/− | − | +/− | +/− | |
| HHV-6 | +/− | +/− | +/− | − | − | − | +d | +d | |
| HSV-1, and HSV-2 | − | ++ | +/− | + | − | − | − | − | Skin vesicle, brain tissuef |
| VZV | ++ | + | +e | ++ | − | − | − | + | Skin vesiclef |
| HIV | ++ | + | + | − | − | − | +/− | − | |
| Influenza virus | − | − | +/− | − | ++f | − | − | − | |
| JCV | − | ++ | − | − | − | − | − | − | |
| Lymphocytic chorlomen- ingitis virus | − | + | ++ | ++ | +/− | − | + | ++ | Urine |
| Mumps virus | − | − | +e | + | ++ | − | +/− | ++ | Urine, saliva |
| Measles virus | − | +d | +e | + | + | − | + | − | Urine |
| Parainfluenza virus | − | − | +/− | − | ++ | − | − | − | |
| Parvovirus | ++ | − | + | − | − | − | − | − | |
| Rabies virus | − | + | ++ | ++ | − | − | − | + | Saliva, brain tissue, nuchal skin biopsy, corneal impressionsf |
Reprinted with permission from the American Academy of Neurology (65a).
++, extremely effective for diagnosis; +, effective for diagnosis; +/−, variable effectiveness; −, not useful.
Serologic indexing which compares CSF- to serum-specific antibody levels in reference to total CSF and serum albumin or total immunoglobulin may be required for definitive diagnosis. A fourfold rise in IgG from acute- and convalescent-phase specimens or a single positive IgM may also be diagnostic.
Test not widely available but can be sent to research labs.
Serology may be difficult to interpret for vaccinated patients or in a postviral setting. In these patients, the presence of IgM indicates active or reactivated viral disease rather than past immunity.
Direct fluorescent-antibody test (DFA) on tissues or secretions is more rapid and may be more sensitive than culture methods. The direct-fluorescent-antibody test has replaced Tzanck prep, which is less sensitive and specific.