A Yuen Long market stall where a cholera victim bought shrimps has been ordered to close after cholera bacteria was found in its fish tank. Tests were carried out on the tank, at Stall M79, Tai Kiu Market in Kin Lok Square, by the Food and Environmental Hygiene Department. 'The water and shrimp samples were taken from the market stall on September 16. Test results confirmed the presence of Vibrio cholerae,' a department spokesman said last night. 'The market stall will remain closed until we are satisfied that it has been properly disinfected.' It is the fourth food outlet to have been closed this year because of cholera. A total of 36 people have been diagnosed with the disease since January. It is also the first time this year that cholera bacteria have been found in food. The 45-year-old woman was diagnosed with cholera on September 16. She was treated at Princess Margaret Hospital and discharged yesterday. The woman, who had been out of Hong Kong for part of the incubation period, told the Department of Health she had bought shrimps from the now-closed market stall. Of the 36 cases reported, 21 were locally contracted and 13 imported. Two people are still being treated at Princess Margaret Hospital.