Rao, CKaur, HGupta, NSabeena, SPAmbica, RJain, AYadav, ADwibedi, BMalhotra, BKakru, DKBiswas, DSavargaonkar, DGanesan, MSabat, JDhingra, KLalitha, SValecha, NMadhavilatha, PBarde, PVJoshi, PDSharma, PGupta, RRatho, R KSidhu, SShrivastava, SSDutta, SShantala, G BImtiaz, SSethi, SKalawat, UVijayachari, PRaj, VVijay, NBorkakoty, BBarua, PMajumdar, TArunkumar, G2020-04-102020-04-102019-04Rao C, Kaur H, Gupta N, Sabeena SP, Ambica R, Jain A, Yadav A, Dwibedi B, Malhotra B, Kakru DK, Biswas D, Savargaonkar D, Ganesan M, Sabat J, Dhingra K, Lalitha S, Valecha N, Madhavilatha P, Barde PV, Joshi PD, Sharma P, Gupta R, Ratho R K, Sidhu S, Shrivastava SS, Dutta S, Shantala G B, Imtiaz S, Sethi S, Kalawat U, Vijayachari P, Raj V, Vijay N, Borkakoty B, Barua P, Majumdar T, Arunkumar G. Geographical distribution of primary & secondary dengue cases in India – 2017: A cross-sectional multicentric study. Indian Journal of Medical Research. 2019 Apr; 149(4): 548-5530971-59160975-9174http://imsear.searo.who.int/handle/123456789/195852Background & objectives: Dengue virus infection is endemic in India with all the four serotypes of dengue virus in circulation. This study was aimed to determine the geographic distribution of the primary and secondary dengue cases in India. Methods: A multicentre cross-sectional study was conducted at Department of Health Research / Indian Council of Medical Research (DHR)/(ICMR) viral research and diagnostic laboratories (VRDLs) and selected ICMR institutes located in India. Only laboratory-confirmed dengue cases with date of onset of illness less than or equal to seven days were included between September and October 2017. Dengue NS1 antigen ELISA and anti-dengue IgM capture ELISA were used to diagnose dengue cases while anti-dengue IgG capture ELISA was used for identifying the secondary dengue cases. Results: Of the 1372 dengue cases, 897 (65%) were classified as primary dengue and 475 (35%) as secondary dengue cases. However, the proportion varied widely geographically, with Theni, Tamil Nadu; Tirupati, Andhra Pradesh and Udupi-Manipal, Karnataka reporting more than 65 per cent secondary dengue cases while Srinagar, Jammu and Kashmir reporting as low as 10 per cent of the same. The median age of primary dengue cases was 25 yr [interquartile range (IQR 17-35] while that of secondary dengue cases was 23 yr (IQR 13.5-34). Secondary dengue was around 50 per cent among the children belonging to the age group 6-10 yr while it ranged between 20-43 per cent among other age groups. Interpretation & conclusions: Our findings showed a wide geographical variation in the distribution of primary and secondary dengue cases in India. It would prove beneficial to include primary and secondary dengue differentiation protocol in the national dengue surveillance programme.Denguegeographic variationIndiaprimarysecondaryviral research and diagnostic laboratoriesJournal ArticleIndiaManipal Centre for Virus Research, Manipal Academy of Higher Education (Deemed to be University), Manipal, IndiaIndian Council of Medical Research, Department of Health Research, Ministry of Health & Family Welfare, Government of India, Bengaluru, IndiaDepartment of Microbiology, Bangalore Medical College and Research Institute, Bengaluru, IndiaDepartment of Microbiology, King George's Medical University, Lucknow, IndiaDepartment of Microbiology, All India Institute of Medical Sciences, Bhopal, IndiaICMR-Regional Medical Research Centre, Bhubaneshwar, IndiaDepartment of Microbiology, Sawai Man Singh Medical College and Attached Hospitals, Jaipur, IndiaDepartment of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, IndiaICMR-National Institute of Malaria Research, New Delhi, IndiaDepartment of Microbiology, Government Theni Medical College, Theni, IndiaDepartment of Microbiology, Government Medical College, Amritsar, IndiaDepartment of Microbiology, Sri Venkateswara Institute of Medical Sciences, Tirupati, IndiaNational Institute for Research in Tribal Health, Jabalpur, IndiaICMR-National Institute of Cholera & Enteric Diseases, Kolkata, IndiaDepartment of Virology, Postgraduate Institute of Medical Education and Research, Chandigarh, IndiaICMR-Regional Medical Research Centre, Port Blair, IndiaICMR-Regional Medical Research Centre, North East Region, Dibrugarh, IndiaDepartment of Microbiology, Jorhat Medical College, Jorhat, IndiaDepartment of Microbiology, Agartala Government Medical College, Agartala, India