Reports of deadly disease caused by food bacteria more than double in Hong Kong

Reports of a deadly food-borne disease are soaring as people switch to a lifestyle in which they eat more prepackaged food, doctors say.

Cases of the bacterial infection listeriosis have risen more than twofold in the past two years alone, the Centre for Food Safety said. But rising awareness of the disease and doctors' growing tendency to report suspected cases might have contributed to the increase, it added.

The bacteria that causes the disease, , often grows quickly in ready-to-eat food with a shelf life of more than five days that needs to be refrigerated.

Last year, 26 cases of the infection - which has a 20 per cent mortality rate - were reported in Hong Kong, more than twice the annual average of 11 in the previous three years. Sixteen cases have already been reported in the first seven months of the year.

"There are a number of factors," said Dr Samuel Yeung Tze-kiu, the centre's principal medical officer for risk and communication. "One is the increase in reporting and people's awareness about the disease; the other is that people have changed their diets … As prepackaged food becomes more popular, the risk has increased."

Listeriosis can lead to miscarriage, stillbirth, blood infection and brain infection among pregnant women, newborns, elderly and people with a weak immune system. The centre had tested 100 prepackaged food samples, including cheese, smoked seafood, processed meat and salad, and found all satisfactory in regard to listeria bacteria level.