Officials are telling the Chinese a traditional herb called ban lag gen can prevent H7N9 infections. With no scientific study to back it up, the recommendation has made the root an overnight sensation, selling out at many stores across the country. (William Wan/The Washington Post)

Amid growing panic over a new strain of bird flu in China, some officials have prescribed a surprising solution: hot brews of a root called ban lan gen.

With more Chinese cities closing their poultry markets, U.S. scientists rushing to produce a vaccine and the death toll reaching nine on Tuesday, the herb has flown off pharmacy shelves during the past week. Many stores from Shanghai to Guangzhou are sold out. Prices have shot up.

The suggestion from several provincial authorities that people turn to the herb has garnered ridicule online and sparked debate among China’s scientific community.

It has also generated some reflection here about the Chinese tendency toward panic buys, which have become an almost-standard reaction to disaster. The easy sway of suggestion and rumor, some say, shows how much is uncertain in modern society and how little — from tainted milk powder to copycat Apple stores — can be trusted.

After the 2011 meltdown at a nuclear plant in Japan, hordes of Chinese rushed to buy personal mountains of salt on the mistaken belief that it would help mitigate radiation. (It might have, experts later pointed out, but one would die first from the amount required.)

Bottles of vinegar were must-haves in Guangdong during the 2003 SARS epidemic, for its supposed ability to prevent respiratory illness. Then came floods in Beijing last year, in which a man drowned after being trapped in his car. A sudden run on emergency hammers to smash car windows ensued, followed just months later with a run on candles amid worries of darkness during a predicted doomsday.

Root of the bedlam

The most recent run began with a public advisory issued by Jiangsu province, just north of Shanghai, where most cases of the new H7N9 strain have appeared. The memo, published last Wednesday on the local government’s Web site, carried a tinge of nationalism, urging experts to “explore and develop the role of Chinese medicine” in treating the new bird flu. It suggested a long list of herbs for treating infected patients, including ginseng, bamboo, licorice and powder made from bear bile.

But what caught most people’s attention was the assertion, unsupported by scientific evidence, that ban lan gen could prevent infection in the first place. The next day, after Shanghai authorities made their own plug for the root at a news conference, shop owners in the region sold out almost instantly. China’s equivalent of eBay lit up with orders.

Authorities in nearby Nanjing were so incensed at the bedlam in stores there that they issued two advisories last weekend banning increases in ban lan gen prices and forbidding public suggestions that it can prevent bird flu.

Curiously, on the same day as the Jiangsu memo, the western province of Gansu issued a memo suggesting that facial massages of key acupuncture pressure points could prevent H7N9 infections. (Alas, no panicked runs on facial massages have been reported — perhaps because Gansu health officials have been mocked before for their medical advice, notably pushing pig’s feet in recent years as a cure-all.)

Ban lan gen

Ban lan gen, however, has been a particular favorite for China’s panic buyers. It caught public attention during the 2003 epidemic of severe acute respiratory syndrome, then resurfaced during the 2009 H1N1 swine flu pandemic and previous H5N1 avian flu outbreaks.

Derived from the root of a flowering plant called woad, or Isatis tinctoria, ban lan gen has a certain logical appeal as a cure-all for many in China, where it is widely used to combat the common cold. In the parlance of traditional Chinese medicine — focused on balancing yin and yang, hot and cold, in the body — ban lan gen is valued for its antiviral properties as a “clear heat,” said Yang Liteng of Southern Medical University in Guangzhou.

The view of Yang, an expert in integrating Chinese and Western medicine for respiratory diseases, reflects the vast majority of China’s medical community — that ban lan gen may have proved helpful for viruses in the past but lacks proof as a treatment for H7N9.

“In the first 24 hours of the common cold, ban lan gen can restrain the virus and is helpful,” Yang said. In the case of H7N9, however, Yang said it’s too soon to tell, calling the Jiangsu advisory irresponsible because “there is no scientific evidence showing that it is helpful.”

But with relatively mild side effects, the herb would be harmful only to those with weak constitutions, Yang said.

Diplomacy and skepticism

For the most part, central health authorities have avoided weighing in on the ban lan gen debate.

The World Health Organization, the lead international agency in the crisis, has been similarly diplomatic. “The main recommendation in our clinical guidelines for treatment is the prompt administration of neuraminidase inhibitors,” a type of anti-influenza drug, WHO spokesman Gregory Hartl said in an e-mail. “We do not have enough evidence to comment on the efficacy of traditional medicines, although we know there have been reports of their efficacy.”

But some people have had a field day with the conflicting government advisories on the root remedy, especially online, one of the rare places where criticism of Chinese officials is possible. In one especially popular Internet meme, bloggers have been tweeting traditional poems but replacing key words with “ban lan gen” in mock praise of its good-for-any-situation properties.

Although skepticism abounds, there are many other steps that Chinese and WHO experts agree the public should be taking, such as eating only fully cooked poultry, avoiding contact with birds and washing hands frequently.

Perhaps sensing a rare opening for unsolicited public health advice, Yang, the medical professor, did not hesitate to tack on a few precautions that never hurt anyone: “Adopt a clean living style and a healthier diet. And do some physical exercise.”

Li Qi contributed to this report.