The number of people confirmed to have fallen ill after eating raw or half-cooked snails contaminated with parasites at a Beijing restaurant chain has risen from 70 to 87, the Beijing Health Bureau reported on Wednesday.

Patients were diagnosed with a type of angiostrongyliasis, a disease caused by parasites that affects the brain and spinal cord, and can lead to meningitis, the bureau said.

In the past few days, the Tropical Diseases Department of the Beijing Friendship Hospital, which specializes in treating the disease, has been crowded with people complaining of headaches or stiff necks, including some who hadn't even eaten raw or half-cooked snails or other river or seafood.

The hospital has opened three more clinics and extended consultation hours to cater for the influx of patients. Although each doctor sees nearly 100 people a day, they're still finding it hard to cope, a hospital spokesman said.

After two to three weeks' treatment, most of the first group of patients the Friendship Hospital received are now in stable condition, and some of them will be discharged from hospital this week, the spokesman added.

Because the disease could produce sequelae such as headaches and dementia, the hospital will conduct follow-up checks to ensure complete recovery.

Dr. Yin Chenghong, an expert with the hospital's Tropical Medicine Institute, urged citizens not to panic, saying that if they hadn't eaten raw or half-cooked snails or other aquatic food, there was no exposure to the disease.

"There's no need for the public to panic, they should go to a clinic first if they have a fever or headache," he said.

The Friendship Hospital's first case of meningitis was reported on June 24 when a 34-year-old man was admitted suffering from violent headaches and nausea after having eaten a dish of cold snail meat at one of the Shuguo Yanyi Restaurant outlets.

The restaurant that sold parasite-contaminated snails made an official apology to customers on Wednesday.

Qu Chuangang, spokesman for Shuguoyanyi Restaurant, which serves Sichuan-style food, said they will assume responsibility for the incident and try their best to deal with the problems caused.

"All 390 staff members of our restaurant feel deeply sorry about the incident. We hope we can do something to make up for it," Qu said.

The restaurant admitted that the snails had not been processed correctly, which was the main reason customers had taken ill.

The restaurant has formed a team to cooperate with the Beijing Health Bureau in investigations.

The spokesman said his restaurant is ready to compensate those who fell ill after eating the snails.

He said patients can bring them their restaurant bill and those who do not have a restaurant bill can also be compensated because Shuguoyanyi can confirm their visit by tracking dining records.

According to the Beijing Health Bureau, treatment for each patient will cost at least 3,000 yuan (about US$375).

A patient surnamed Zhang said that he has spent 20,000 yuan (US$2,500) on medical treatment. He wants compensation for physical and mental suffering.

To date, no deaths have been reported.

Among the patients, the youngest was 13 years old and the oldest 51. All had eaten raw or undercooked Amazonian snails two to four weeks ago at Shuguo Yanyi Restaurant outlets, according to the health Bureau.

The bureau confirmed in its earlier report that infections were as a result of processing problems at the restaurant, which failed to eradicate eel worms on the snails.

The restaurant was ordered to stop selling the snail dishes on August 8.

The Beijing health monitoring department posted an urgent notice on Monday, asking that all restaurants in the city stop serving undercooked snails.

The municipal food safety office ordered on Tuesday that all agricultural markets, supermarkets, department stores and restaurants must stop buying, selling and processing Amazonian snails.

Beijing citizens have also been spreading the word by SMS.

According to Yin Quanxi, director of the emergency center of the health monitoring department, the snails are edible if they are cooked at 90 degrees Celsius or above for more than two minutes.

The health bureau is trying to trace the suppliers of the snails that were contaminated with eel worms.

The bureau has also demanded that the city's disease control and health monitoring departments, together with the restaurant chain, file daily reports.

Amazonian snails originated in South America and were introduced to China in the 1980s as a delicacy. The first case of a person falling ill after eating the snails was reported in Guangzhou in south China's Guangdong Province.

The large, black snails were a popular dish in big Chinese cities like Beijing.

(Xinhua News Agency August 24, 2006)