Meanwhile, another person who recently returned from Bangalore tested positive for H1N1 virus today. He was isolated immediately and was being treated at his residence.
Twenty-two-year-old William Lyngdoh is the sixth case of swine flu in the state. His family was also being treated as a precautionary measure.
State Director of Health Services K H Lakiang said four of the five persons, including the first swine flu case in the state were released from Shillong Civil Hospital.
"Doctors will monitor them for some time," Lakiang said.
Meanwhile, one of the patients, Mary Lyngdoh, was still undergoing treatment at the hospital and she too was improving.
Salwit Tongper, a 17-year-old footballer with the Sports Authority of India who had gone to England for coaching with Arsenal superstar club in Surrey, was the first swine flu patient in the state.
Four others also tested positive for H1N1 later. Three of them were suspected to have contracted the virus from Tongper.