1 Dept of Epidemiology, National Institute of Epidemiology, Indian Council of Medical Research, Chennai, Tamil Nadu, India. Electronic address: mmurhekar@gmail.com.
2 Dept of Pediatrics, Baba Raghav Das Medical College, Gorakhpur, Uttar Pradesh, India.
3 Dept of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India.
4 Dept of Medicine, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India.
5 Dept of Medicine, Baba Raghav Das Medical College, Gorakhpur, Uttar Pradesh, India.
6 Dept of Epidemiology, National Institute of Epidemiology, Indian Council of Medical Research, Chennai, Tamil Nadu, India.
7 Dept of Epidemiology and Communicable Diseases, Indian Council of Medical Research, New Delhi, India.
8 National Institute of Epidemiology, Indian Council of Medical Research, Chennai, Tamil Nadu, India.