[1] ESI PGIMSR, Dept Pathol, Kolkata 7000054, W Bengal, India
[2] NRS Med Coll & Hosp, Dept Chest Med, Kolkata, W Bengal, India
[3] North Bengal Med Coll & Hosp, Dept Pathol, Darjeeling, W Bengal, India
[4] Burdwan Med Coll & Hosp, Dept Med, Burdwan, W Bengal, India
[5] RG Kar Med Coll, Dept Pathol, Kolkata, W Bengal, India