A sample collected from a wet market in Hong Kong has tested positive for bird flu H9, days after a two-year-old boy who visited the venue contracted a mild strain of the infectious disease.

But the Centre for Health Protection (CHP) said on Monday that the risk of a serious bird flu outbreak was low.

The boy, who lives in Sha Tin, became ill after visiting Wo Che Market in the district and was later confirmed to be infected with H9N2 avian influenza, the centre said.

He was now in a stable condition, and six of his household contacts remained asymptomatic, according to authorities.

The centre’s Public Health Laboratory Services Branch conducted whole genome sequencing and analysis of the virus infecting the boy, confirming it was the low-pathogenic H9N2 strain with no significant genetic variations.

Seventeen environmental samples were collected from the boy’s home, the fresh provision shop at Wo Che Market he had visited and a park at Fung Wo Estate, all within Sha Tin.