A neonate who is febrile, presents with features of encephalitis. On examination, the baby is found to have vesicular skin lesions. Most probable causative organism is:

- Given features suggests the diagnosis of HSV encephalitis. As the question mentions Neonate, therefore answer is option 2 i.e. HSV-II. CNS infection by Herpes Simplex: In the neonatal period, HSV II (acquired from maternal genital lesions) is an impoant cause of encephalitis. Beyond the neonatal period, HSV encephalitis is almost always caused by HSV I. HSV encephalitis usually involves (most common) temporal frontal coex and the limbic system. HSV is a cause of aseptic meningitis and is the most common cause of recurrent aseptic meningitis (Mollaret meningitis). Fever is relatively uncommon and skin vesicles occur in only 60% of cases of HSV encephalitis Herpes simplex virus (HSV) type 1 is an impoant cause of severe, sporadic encephalitis in children and adults.Severe encephalitis with diffuse brain involvement is caused by HSV type 2 in neonates who usually contract the virus from their mothers at delivery.