In one of the largest outbreaks of suspected foodborne illness in Philadelphia, nearly 100 lawyers and law students were sickened last month after attending a banquet celebrating the Lunar New Year in Chinatown.
But even though the restaurant has a history of food-safety problems stretching back several years, the city Health Department says it cannot publicly discuss details of its investigation, citing a 1955 state law.
That law hasn't silenced the outbreak's victims.
About 250 people attended the feast Feb. 27 at Joy Tsin Lau, the venerable dim sum restaurant at 10th and Race Streets. Dozens of the diners reported that they felt the first symptoms two mornings later.
Chi Mabel Chan, who has owned Joy Tsin Lau for more than 30 years, denied that the diners had suffered food poisoning from the banquet.
"It was not a problem with my restaurant," she said, theorizing that chilly weather or festivities at a karaoke bar after the dinner might be to blame.
"Maybe they got cold or drank too much," she said of the victims.
The eight-course dinner - well-documented on social media - was a fund-raiser for a group of Temple University law students, the Asian Pacific American Law Student Association.
"This was the worst case of food poisoning I've ever witnessed," Antima Chakraborty, a Philadelphia assistant district attorney, wrote on Yelp, a restaurant review site. "Many individuals had to go to the ER."
City inspection reports show that Joy Tsin Lau has long had a problem maintaining food-safety standards.
Just 17 days before the banquet, a Health Department sanitarian was at Joy Tsin Lau to check back on an earlier problem. In a report dated Feb. 10, Kyria Weng wrote "that current management practices have allowed unacceptable public health or food-safety conditions."
An Inquirer analysis of city inspection reports found that the average eat-in restaurant in Philadelphia last year had 2.3 risk factors for foodborne illness, the more serious of the two main categories defined by the Food and Drug Administration.
Weng cited Joy Tsin Lau for five such risk factors. Several of those - dumplings held at a bacteria-friendly 57 degrees, and a lack of soap and paper towels in the employee restroom - were noted as repeat violations. Weng also found nine lesser violations, called "lack of good retail practices."
But that was an improvement over Weng's Dec. 22 visit, when she cited the restaurant for seven risk factors for foodborne illness (including a chicken held at unsafe temperatures) and 13 lesser violations.
Back in 2010, the city Health Department filed suit against Joy Tsin Lau after deeming it a "public nuisance" and issued a cease-and-desist order for "failure to ensure that public-health standards for a safe and sanitary operation . . . are being maintained."
City legal officials did not respond to questions asking if the city ever acted on the order or if the restaurant ever was forced to close.
David S. Haase, a Center City lawyer, said he began to feel nauseated about 30 hours after the banquet. Contrary to Chan's theory, he said he was warmly dressed and did not go to the karaoke bar.
A combination of nonstop puking and explosive diarrhea kept him bedridden for four days.
"It was freaking terrible," Haase said. "I'd crawl back into bed and curl up into a ball, moaning like a child with the cramps."
Organizers, in a post-banquet e-mail to attendees, said multiple guests had sought medical attention.
Thursday, nearly four weeks after the banquet, Health Department spokesman Jeff Moran would say only that a "food source" had been identified for the outbreak.
"We are not permitted, by law, to publicly release the findings of outbreak investigations," Moran said.
He cited the Pennsylvania Disease Prevention and Control Law of 1955, which prohibits health authorities from disclosing reports or records of diseases. Though the law primarily addresses patients with venereal diseases and tuberculosis, its confidentiality clause keeps secret the details of all health investigations.
Most states have similar laws, according to Scott Burris, the codirector at Temple University's Center for Health Law, Policy, and Practice.
"It's pretty typical," Burris said. "Pennsylvania is not an outlier."
Investigators need some secrecy to collect sensitive information, he said, but the laws may go too far when it comes to alerting the public of potential threats.
"That's a price we pay," Burris said of secrecy laws. "It's probably worth working on our privacy laws to see if we can find an approach that lowers that price."
But there is no law silencing the sickened.
"If you enjoy being on your back for the 48 hours post-dinner writhing in pain, burning up, and exploding out of all orifices, then this is the restaurant for you," wrote Jack Jiang, a University of Pennsylvania researcher who attended the banquet with his girlfriend.
In an e-mail to a reporter, Jiang said he had been bedridden for three days and suffered lingering effects through the end of the week.
Haase, who missed his daughter's championship track meet due to the illness, said he had contacted a Health Department coordinator, who told him the outbreak was likely brought on by norovirus.
Norovirus, the most common cause of foodborne illness, sickens about 20 million people a year in the United States, according to the Centers for Disease Control and Prevention. The pathogen is often spread by contact with an infected person or by ingesting food or water contaminated by fecal matter. Acute gastroenteritis strikes usually between 24 and 48 hours after exposure to norovirus.
Caroline Johnson, director of the city's division of disease control, said she couldn't talk specifics, but in general said the goal of investigations "is to find out what happened, correct that problem, and move on."
As for the secrecy, she said, "We don't want to drive underground the facts we want to uncover."
Her agency told Haase about the norovirus because "we feel that by telling them, they won't need to have the wrong antibiotic prescribed to them or have unnecessary testing. It's the right medical thing to do. I wouldn't withhold information from them because it might have medical significance to their situation."
Foodborne illness outbreaks in Philadelphia are relatively uncommon - about 10 a year - and when they do occur, they usually strike fewer than 20 people, Johnson said.
"They're not always as impressive as this one," she said.
"These foodborne outbreaks can happen to the finest of restaurants and it doesn't necessarily mean that the restaurant did anything wrong," Johnson said.
None of the lawyers or the Temple group said they were planning to sue Joy Tsin Lau. They have two years before the statute of limitations runs out.
Haase, whose law firm sponsors a table at the banquet each year, said he would continue attending under one condition.
"It will have to be at a different place," he said.
In the meantime, Haase said he won't collect the two raffle prizes he won at this year's banquet: two dim sum dinners at Joy Tsin Lau.
Full menu for Temple APALSA's 8th Annual Lunar Banquet, Feb. 27, at Joy Tsin Lau:
Chicken sweet corn soup
Stir-fry beef celery
Deep-fried fish Hunan
Veg fried rice
Veg spring rolls
Sautéed string beans
Black bean eggplant
Braised bean curd
5-spice bean curd bean sprouts
Kung pao vegetables
Chinese vegetable with hearts of greens in light gravy