The United Kingdom has confirmed its first human infection of a rare swine flu variant. The individual contracted the H1N1 swine flu variant, which contains the G4 gene, commonly found in Eurasian avian influenza and the H1N1 virus. The infected person has already recovered, but the UK health officials have issued an advisory to monitor any further cases and take necessary precautions. Experts say there is currently no evidence of sustained human-to-human transmission.