Incidence of influenza-associated hospitalization in rural communities in western and northern India, 2010e2012: A multi-site population-based study Siddhivinayak Hirve a,g , Anand Krishnan b,g , Fatimah S. Dawood c , Pallavi Lele a , Siddhartha Saha c , Sanjay Rai b , Vivek Gupta f , Kathryn E. Lafond c , Sanjay Juvekar a , Varsha Potdar d , Shobha Broor e , Renu B. Lal c , Mandeep Chadha d, * a Vadu Rural Health Program, King Edward Memorial Hospital Research Center, Pune, India b Centre for Community Medicine, All India Institute of Medical Sciences, New Delhi, India c Influenza Division, National Center for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, USA d National Institute of Virology, Indian Council of Medical Research, 20-A, Dr Ambedkar Road, Pune 411001, India e INCLEN Trust International, New Delhi, India f National Institute of Mental Health and Allied Sciences, Bangalore, India Accepted 5 August 2014 Available online --- KEYWORDS Influenza; Hospitalization; Health utilization survey; Burden; Seasonality Summary Background: The global burden of influenza is increasingly recognized, but data from India remain sparse. We conducted a multi-site population-based surveillance study to estimate and compare rates of influenza-associated hospitalization at two rural Indian health and demographic surveillance system (HDSS) sites at Ballabgarh and Vadu during 2010e2012. Methods: Prospective facility-based surveillance for all hospitalizations (excluding those for trauma, elective surgery and obstetric, ophthalmic or psychiatric reasons) was conducted at 72 health facilities. After collection of clinical details, patients had nasopharyngeal swabs taken and tested by reverse transcription polymerase chain reaction for influenza viruses. Annual healthcare utilization surveys (HUS) were conducted in HDSS households to identify proportion of hospitalizations occurring at non-study facilities to adjust for hospitalizations * Corresponding author. Tel.: þ91 20 26124386 (office); fax: þ91 20 26122669. E-mail address: mscniv@gmail.com (M. Chadha). g Joint 1st author with equal contribution. http://dx.doi.org/10.1016/j.jinf.2014.08.015 0163-4453/ª 2014 Published by Elsevier Ltd on behalf of The British Infection Association. www.elsevierhealth.com/journals/jinf Journal of Infection (2014) xx,1e11 Please cite this article in press as: Hirve S, et al., Incidence of influenza-associated hospitalization in rural communities in western and northern India, 2010e2012: A multi-site population-based study, J Infect (2014), http://dx.doi.org/10.1016/j.jinf.2014.08.015