986. An Algorithmic Approach to Determine the Etiology of Acute Encephalitis Syndrome (AES) in India
Session: Poster Abstract Session: CNS Infection
Friday, October 9, 2015
Room: Poster Hall
Posters
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  • Background: In India, outbreaks of acute encephalitis syndrome (AES), defined as fever with altered mental status and/or seizures, involving thousands of patients are reported annually during the post monsoon season (July-November). While Japanese Encephalitis virus (JEV) is identified as the etiology in 5-35% of reported cases, the causative agents of the majority of AES in India remains unknown, and systematic testing is not routinely performed.

    Methods: We implemented a systematic algorithm to evaluate AES etiology across four referral laboratories in the heavily affected states of Uttar Pradesh, Assam, West Bengal, and Karnataka.  Serum and/or cerebrospinal fluid (CSF) specimens were collected from all AES patients admitted to participating hospitals between June and December 2014 and evaluated for JEV IgM antibodies.  JEV IgM negative serum samples were tested for scrub typhus IgM, dengue virus IgM, and West Nile Virus (WNV) IgM using commercially available kits. JEV IgM-negative CSF was tested for bacterial/viral nucleic acids for Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, herpes simplex virus type 1(HSV), enteroviruses and chikungunya virus, in that order of priority.

    Results: Of 1,253 AES patients evaluated, 617(49.48 %) were male and majority of the patients (59.48) wer below the age of 15years.   Paired CSF and serum samples were obtained from 639 (51%) patients; the rest had either CSF (352, 28%) or serum (262, 21%) submitted for evaluation. Of the 1,253 patients, JEV IgM was detected in 260 (21%). Among JEV-negative patients, evidence of another pathogen was identified in 237/993 (24%), including scrub typhus IgM (26%), dengue IgM (5%) and WNV IgM (2%) in serum.  Molecular testing of CSF indicated evidence of S. pneumoniae in 2%, H. influenzaein 1%, and HSV 1%.  Enterovirus was detected in only 1patient (0.2%) of patients.

    Conclusion: Among AES patients in India, JEV remains an important etiology of illness.  Employing a tiered, systematic diagnostic algorithm to AES evaluation enabled the identification of an etiologic agent in 40% of patients, and should be considered for broader implementation. The significance of high prevalence of serum IgM positivity for scrub typhus warrants further evaluation. eumoniae in 2%, H. influenzae in 1%, and HSV 1%.  Enterovirus was detected in only 1 patient(0.2%) of patients.

    Ravi Vasanthapuram, MBBS, MD1, Padmini Srikantaih, MD2, Vijayalakshmi Reddy, PhD1, Anita Desai, PhD1, Reeta Mani, MD1, Shah Hossain, MD3, Lahari Saikia, MD4, Amita Jain, MD5, Tapan Dhole, MD6, Sharon Daves, MPH RS3 and Kayla Laserson, ScD7, (1)Neurovirology, National Institute of Mental Health And Neuro Sciences, Banaglore, India, (2)CDC-India, Delhi, India, (3)CDC-INDIA, Delhi, India, (4)Assam Medical College, Dibrugarh, India, (5)King George Medical University, Lucknow, India, (6)Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India, (7)Centers for Disease Control-India, Delhi, GA, India

    Disclosures:

    R. Vasanthapuram, None

    P. Srikantaih, None

    V. Reddy, None

    A. Desai, None

    R. Mani, None

    S. Hossain, None

    L. Saikia, None

    A. Jain, None

    T. Dhole, None

    S. Daves, None

    K. Laserson, None

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