Clinical spectrum of AES and a syndromic approach for its diagnosis

Background – Acute encephalitis syndrome (AES) is now being used for surveillance in all encephalitis endemic zones irrespective of the etiology. Numerous viral pathogens possess the ability to invade the CNS and produce neurologic dysfunction. Methods - We performed a hospital-based descriptive study between January 2019 to January 2020 in the Department of Microbiology, GMC, Thiruvananthapuram taking samples from 193 AES patients admitted under the Departments of Internal Medicine, Neurology & Paediatrics. The samples were proceeded with PCR/ELISA depending on the clinical history. Findings - A viral etiology was established in 48 cases (24.9%) & most were caused by EBV (5.7%). MRI revealed temporal lobe involvement in 9 patients. 20% cases had post-encephalitic sequelae - focal neurological deficits and persistent seizures. Interpretation – Most number of patients were found to have infected with Epstein- Barr virus. Identification of the causative agent is of great importance in AES, as rapid detection and confirmation of etiological agent will have a tremendous impact on the management of outbreaks as well as patient’s disease. Funding – Indian Council of Medical Research (ICMR)