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Canine Culls and Feral Feasts: China Still No Closer to Ending Its Rabies Problem

Without surveillance and a vaccination strategy, China won't be able to conquer the horrific--but preventable--rabies virus, experts say



KYLE AND KELLEY ADAMS/FLICKR

When a boy and his grandfather were bitten by a rabid dog several years ago in one of China's poorest provinces, the family had to make a tough choice. Without treatment, the disease kills nearly everyone it infects in a horrific progression: from fever and itching to hallucinations and seizures to paralysis, ending in an agonizing death.  "The price was too expensive, and only the grandson got the vaccine," says Xianfu Wu of the U.S. Centers for Disease Control and Prevention (CDC), "The grandfather took the risk...and eventually died."

The case was not unusual. According to a survey conducted by the Chinese Center for Disease Control and Prevention, out of 21 rabies cases that occurred over a two-month period in 2004 in Anlong County, Guizhou Province, only three individuals were properly vaccinated in time. Other estimates suggest that 73 percent of individuals bit by rabid dogs fail to receive vaccinations in rural China.

The country has never had easy access to human rabies vaccines, but the disease has soared in recent years: from fewer than 200 cases in the 1990s to 3,302 in 2007, and such official estimates are likely to be an undercount. That makes rabies the third-biggest infectious disease killer in China after AIDS and tuberculosis.

What's causing the outbreak? Money, for one, says Charles Rupprecht, head of rabies research at the CDC. Dogs are prized in some areas of China both as a delicacy and as personal protection. Many families have enough income to raise semiferal animals but not enough to cover complete veterinary care. The country is now home to 200 million dogs, less than 10 percent of which are vaccinated for rabies. Pampered pets, they are not.

Although China's Ministry of Agriculture is in charge of annual rabies vaccination campaign, scientists say local governments periodically skip the program to save money. And even if they were diligent in their efforts, a 2008 study showed that two locally produced vaccines were so weak they only conferred protection to 10 to 20 percent of animals. Rabies vaccine expert Zhen Fang Fu of the University of Georgia in Athens says the live attenuated vaccines (created from the weakened virus) still used in China have been banned in many other countries.

Not only is it possible to get rabies from bites and scratches, but a 2007 study documented the spread of rabies from the consumption of canine meat in Vietnam. In dog slaughterhouses in China's Guangxi province, researchers have reported rabies incidence as high as 6.4 percent.

Lacking an effective animal vaccination program, in 2006 China began enforcing a one-dog per family policy and in a June crackdown one city culled 37,000 dogs in hopes of quelling an outbreak. Instead, officials only angered animal rights activists in China and abroad, while leaving U.S. epidemiologists scratching their heads in bemusement. "Beating dogs to death—that's just not a 21st century way of going about stopping rabies," Rupprecht says.

He says the government needs to set up a routine surveillance system for rabies, such as the one in place now in the U.S. for reporting and sampling suspect rabid animals. When Rupprecht conducts rabies genetic research in China, he finds it is easier to sample brain tissue from deceased humans than from animals. "The fact that you have to focus on people to get a handle on the disease in nature speaks volumes on the epidemic." He believes that China needs to get serious about producing animal vaccines to create "herd immunity."

The final piece of the puzzle is producing a safe, widely available, and effective rabies vaccine for people like the grandfather in Guizhou. A promising sign, Fu says, is that at least 15 companies are now producing human rabies vaccines for as low as $15 per dose through modern techniques. (Earlier vaccines sometimes caused such diseases as encephalitis.) The new inoculation series requires an injection of human or horse immunoglobulin, which is in short supply in developing countries, but the University of Massachusetts Medical School in Boston is currently testing a strategy in India that uses monoclonal antibodies that could one day be easily manufactured in China.

Whether the development of safer, more affordable vaccines can stop the rise of rabies is unclear. Recent studies have shown that locally made Chinese vaccines are less effective than imported versions, which cost five to 10 times as much. "What does it say about what our priorities are," Rupprecht asks, "when [one of] the major economic powers still has the worst rabies problem on the planet?"

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