Former Himachal Pradesh chief minister Virbhadra Singh is suffering from swine flu and is undergoing treatment at Indira Gandhi Medical College and Hospital (IGMC) in Shimla, doctors said on Monday.
Singh was tested positive for swine flu Monday, they said.
He was admitted to the hospital on Sunday after he complaints of breathing problem.
21 patients have already tested positive for swine flu this season at IGMC, they said.
Four of them have succumbed to the virus at IGMC, whereas two swine flu patients from Himachal Pradesh's Una district died at PGI-Chandigarh, they added.
Two-year-old girl Priyanka of Bilaspur's Bamta village died on January 24, Jagdish, 64, of Mandi's Gagal village died due to the H1N1 virus on January 23, Padma Ram, 65, of Mandi's
Thandapani succumbed on January 14 and Chander Shekhar, 56, of Shimla's Chewda died on January 6 at IGMC, they added.