"Four new patients have been detected and they are being treated at their respective homes," Chief Medical Officer SNS Yadav said.
He said that only three patients are admitted, which included two at Sanjay Gandhi Post Graduate Institute of Medical Sciences and one at King George Medical University.
With this, a total of 40 swine flu patients have been detected in Lucknow so far, he said.
A retired army officer died of H1N1 virus on January 9, while the wife of a retired jawan died on January 13 in the state capital.