This involves inflammatory cells in the subarachnoid space, its boundary membranes, and its extensions. Acute meningitis may be divided into septic due to bacteria and aseptic due to viruses. There are over 10,000 cases of viral aseptic meningitis cases reported each year in the country with the peak incidence in summer and early fall. The clinical syndrome involves abrupt onset of fever, headache, stiffness of the neck, with or without vomiting, irritability, and lethargy. Cerebral spinal fluid shows a mononuclear pleocytosis with a normal spinal glucose level and a mildly increased protein.
Viral meningitis causes acute discomfort that last several days.
Recovery is seen within weeks and the prognosis is excellent with virtually no mortality or morbidity. The major viral meningitis agents are enteroviruses, mumps, herpes simplex type I, HIV I, lymphocytic coreomeningitis virus, and arvoviruses. The enteroviruses are ubiquitous RNA viruses. There are over 70 serotypes including coxsackie A and B viruses, echoviruses, polioviruses, and some newer enteroviruses. Most enteroviral infections are clinically silent or nonspecific involving fever, gastrointestinal or upper respiratory infection.