The outbreak of pig-to-human Streptococcus suis has led to a sharp fall in pork sales and live-pig exports in Southwest China's Sichuan Province, according to provincial officials.

The disease, which causes symptoms such as high fever, listlessness, vomiting and internal bleeding, broke out in Ziyang, Sichuan, and has killed at least 39 people and sparked public panic.

Many urban residents are shunning pork and sales have dropped by 20 to 30 per cent in affected areas. On average, pork prices are down around 10 per cent.

Stagnant sales have led to the temporary closure of many slaughterhouses.

Liu Jingming, a 42-year-old butcher in Deyuan Township, Pixian, a county under the jurisdiction of Chengdu, provincial capital of Sichuan, told China Daily he had been on "vacation" for nearly 20 days.

"Only a small number of people are eating pork, so the boss has closed the slaughterhouse where I work. I'm afraid it won't reopen for a month," he said.

Many provinces and cities have restricted imports of pork from Sichuan. In neighbouring Chongqing, 12 checkpoints have been set up to examine live pigs going in.

Sichuan rears the highest number of pigs in the country and exports can touch as many as 20 million animals in a good year.

According to the provincial animal husbandry association, Sichuan exported 150,000 tons of live pigs last year. In the first half of this year the province exported 75,000 tons.

Live pig exports would have been excellent this year if not for the outbreak of the disease, it said.