22nd May 2024

Viral infection

Enteroviruses, herpes and arboviruses are the most common viral causative organisms. Herpesviruses encompass a wide array of viruses including HSV type 1 and 2, VZV (varicella zoster), CMV, EBV and HHV (human herpesvirus) 6,7 and 8. HSV encephalitis, usually caused by HSV1, can be a fatal infection as opposed to aseptic meningitis caused by HSV2, which is self-limiting.

Enteroviruses account for 48-95% of cases of aseptic meningitis syndrome. In addition to meningitis, it can also cause acute flaccid paralysis (Guillain-Barre syndrome), encephalitis and myocarditis with the worst presentations occurring in infants. Older people have better clinical outcomes with enterovirus-related aseptic meningitis. Transmission is via the faecal-oral route.