<prompt> Most common cause of meningo encephalitis in children is:Arbo virusEntero virusHSVPolio virus  <response>: Ans. b i.e. Enterovirus Ref. Nelson 18r, n 2521 Viral Meningoencephalitis An acute inflammatory process involving the meninges and to a variable extent brain tissue. Etiology: Enterovirus MC, Arbovirus, HSV-1, Mumps in regions where mumps vaccine is not used, EBV, CMV Clinical features - Headache most common, usually frontal or generalized. In adoloscent retrobulbar pain is frequent - Fever, nausea, vomiting Lab finding CSF shows mild mononuclear pleocytosis with absence of bacteremia Detection of viral RNA or DNA by PCR is diagnostic Treatment - Symptomatic in all cases except in HSV meningoencephalitis where acyclovur is beneficial Note: -- Enterovoirus is the MC cause of viral meningitis in mumps immunized population -- Enterovirus meningitis is paicularly prevalent in infants 3 months of age. Frequently implicated serotypes include Enterovirus 70 71, coxsackie 4, 6, 7, 9, 11 