Features of viral meningitis
Epidemiology, pathogenesis, clinical features, diagnostic approach, and differential diagnosis of viral meningitis.
| Epidemiology | Enterovirus: MCC, immunocompetent, hypogammaglobulinemia Arbovirus: immunocompetent, blood donors, organ transplant (WNV) LCM: mice/hamster owners/handlers EBV: oral secretions, allogeneic bone marrow transplant |
| Pathogenesis | Enterovirus: fecal–oral contamination → replication in intestinal lining → viremia and seeding of CNS. Clearance by antibody mechanism Arbovirus: mosquito/tick bite → local replication in tissues and lymph nodes → viremia and seeding of CNS HSV: inoculation during time of genital infection → latent infection in sacral DRG → reactivation of genital lesions, radiculitis, and meningitis |
| Clinical features | Fever, frontal/retro-orbital headache, pain on extraocular movements, photophobia, neck stiffness, maculopapular erythematous rash from face to trunk. Focal deficits and seizure not seen |
| Diagnosis, CSF studies | Lymphocytic pleocytosis, normal-mildly decreased (enterovirus, HSV-2, VZV) glucose, normal-mildly increased protein Enterovirus: RT-PCR, throat/stool culture (presumptive diagnosis) Arbovirus: antibody titer in serum, IgM antibody in CSF PCR: WNV, HSV, EBV, HIV |
| Differential diagnosis | Fungal (MCC: cryptococcal), Mycobacterium tuberculosis , and Lyme disease |
DRG , Dorsal root ganglion; WNV , West Nile virus; LCM , lymphocytic choriomeningitis; MCC , most common cause; EBV , Epstein–Barr virus; CNS , central nervous system; HSV , herpes simplex virus; VZV , varicella zoster virus; RT-PCR , reverse transcription polymerase chain reaction; CSF , cerebrospinal fluid; HIV , human immunodeficiency virus.
