Abstract

"BACKGROUND: Encephalitis is an acute inflammatory process affecting the brain. Viral infection is the most common and important cause, with over 100 viruses implicated worldwide. Viral encephalitis is an important cause of mortality and morbidity in children. The etiological agents are varied, it may be sporadic like herpes simplex encephalitis (HSE) or epidemic such as Japanese B encephalitis (JE). Pediatricians who treat these children should be aware of when to suspect encephalitis, how to manage a child with suspected encephalitis, as specific antiviral therapy is lifesaving in some diseases like Herpes encephalitis and these should be diagnosed without delay. For some cases of encephalitis like JE, effective vaccine is available. Moreover, optimum supportive care is of paramount importance in the management of suspected encephalitis due to any etiology for optimum outcome in the affected children. There is no Indian data on the incidence of encephalitis due to various viral agents. There are numerous lacunae in our knowledge, problems in epidemiological investigations, lack of diagnostic facilities, as well as difficulties in managing these critically ill children in smaller centers in our country resulting in high mortality and morbidity with permanent neurological sequelae in the surviving children. Japanese encephalitis (JE) is the main cause of epidemic viral encephalitis in many countries of Asia including India with nearly 68 000 clinical cases every year. The disease in Southern India affects children below 15 yr of age whereas in Northern India, all age groups are affected. Although symptomatic JE is rare, the case-fatality rate among those with encephalitis can be as high as 30%. Permanent neurologic or psychiatric sequelae can occur in 30%–50% of those with encephalitis. There is no cure for the disease. Treatment is focused on relieving severe clinical signs and supporting the patient to overcome the infection. Safe and effective vaccines are available to prevent JE. WHO recommends JE vaccination in all regions where the disease is a recognised public health problem. Since there is no data available from our area regarding the incidence and severity of vaccine preventable cases of JE, inspite of several cases of encephalitis getting admitted every year, we undertook this observational study to determine the incidence, clinical features & severity of viral encephalitis and the contribution of JE to the burden of encephalitis in our region so that effective preventive steps by various strategies including vaccination for JE can be undertaken to control this devastating disease which is having a long lasting effect on the neuro-motor system of children in their formative years of growth & development. MATERIALS AND METHODS: Type of Study: It was an observational hospital based study. Inclusion Criteria: All the children who were admitted in Pediatric ward, GGH/Guntur Over a period of 1 year with clinical features of fever, seizures, altered sensorium were included in the study. Exclusion Criteria: Cases which turned out to be positive for Bacterial / TB Meningoencephalitis, febrile seizures were excluded from study. Investigations: CSF analysis, Fundus examination, Monteux test, Chest X - ray, CT Brain, MRI Brain, EEG, Virological studies at VBRI, Hyderabad.RESULTS: Total of 105 cases of viral encephalitis were studied which were admitted in the Pediatric Department, GGH/Guntur from October 2009 – January 2011. Out of 105 cases, 52.38 % were males and 47.62 % were females. Very few cases were seen in infancy, predominant age group being 05 – 08 yrs. Out of 105 cases, 75 cases were seen from the months of September – November (71.42%), youngest age being admitted was 6 months old child. Majority of cases were reported from rural areas accounting for 86.66 % of cases when compared to urban areas. Among presenting features, fever was present in all cases (100 %), altered sensorium and seizures were next common presenting features. CSF analysis was done in 90 cases, pleocytosis was seen in 75.58 %, elevated protein levels was seen in 70.93% and globulins was positive in 11.42 %. CT Brain was done in all cases which was reported normal except for 12 cases which showed diffuse cerebral oedema. MRI Brain showed bilateral thalamic hyper intensities in T2 weighted images in 10 cases, out of which two cases were also sero-positive for Japanese Encephalitis. Two cases showed temporal lobe involvement characteristic of herpes encephalitis.CONCLUSIONS&RECOMMENDATIONS:Vulnerable areas for viral encephalitis in our district especially for epidemic cases of JE, the predominant age groups affected with viral encephalitis, most common season for occurrence of viral encephalitis due to JE epidemics and the predominant clinical features of suspected viral encephalitis were determined and these would be an aid to pediatricians in the evaluation and management of children with suspected viral encephalitis admitted in the hospital and assist the public health authorities in acute encephalitis surveillance so that appropriate steps can be undertaken to minimize the burden of this neurological disease in the vulnerable pediatric population. "

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