Roast Peking duck restaurants have seen a sharp drop in business because of the ongoing bird flu scare.

DaDong Food & Beverage Investment Co Ltd has seen its business fall 15 percent since the bird flu outbreak last month, said Dong Zhenxiang, Da Dong Peking Roast Duck Restaurant owner.

But he said the restaurants are not worried because duck dishes are only part of the menu, and the reduction of orders for duck will not affect their business on a large scale.

Also, he said, Da Dong sources its ducks from Beijing Golden Star Duck Center, and he trusts the safety of ducks provided by the company based on his experience working with it in past years.

"Their quarantine and epidemic prevention management are rather mature," Dong said.

Beijing Golden Star Duck Center also provides ducks to such large roast duck restaurants as China Quanjude Group and Duck King.

After dealing with long lines at the DaDong Peking Roast Duck Restaurant in the past, Zhu Hong and her family were surprised to find one of its upmarket restaurants in the downtown Wangfujing area only half-full on Wednesday. "The VIP rooms are almost empty," Zhu said.

Meanwhile, shares of Quanjude, a brand with 136 years experience in making roast duck, have plummeted 17.05 percent in 12 trading days, despite company assurances that the safety of its ducks is guaranteed.

Feng Zijian, director of the health emergency center of the Chinese Center for Disease Control and Prevention, told the Beijing Times there is no proof that processed and cooked chicken and eggs can lead to infection with the H7N9 virus.

Catering industry leaders have been more optimistic about the effect of the spreading influenza caused by poultry.

"We haven't seen much of a negative impact on the catering business as a result of bird flu," said Bian Jiang, assistant director of the China Cuisine Association.

Government transparency on bird flu infection cases has eased public worries about the outbreak, Bian said.

Bian said the loss of business at some high-end restaurants is more due to the government's new rules that ban spending at luxury restaurants with public funds.

The drop in sales at high-end restaurants shows the rules have been effective in curbing consumption by officials, said Sheng Laiyun, spokesman for the National Bureau of Statistics, on Monday.

In the first two months of this year, Quanjude's revenue was down 3 percent. According to Quanjude's annual report in 2012, the company's profits rose 12.73 percent year-on-year to 216 million yuan ($34.9 million). The number of customers grew only 1.22 percent, to 7.56 million.

To reduce the risk from bird flu, the China Cuisine Association has asked restaurants to pay attention to product hygiene during purchasing and production.

It is important to increase cooking time and raise boiling temperatures, Bian said. Adjusting the percentage of poultry dishes on the menu also will reduce the risk, he added.

For roast-duck lovers like Zhu Hong, bird flu is not a worry.

"I don't think the H7N9 virus can survive the high temperature in the hot oven," said Zhu, who ordered a roast duck.