Bird Flu’s Latest Talons Force Fresh Defense

A surprise attack by a new strain of the bird flu virus has forced Chinese authorities into the trenches for a two-pronged defense against unseen enemies.

The primary threat is the deadly virus that scientists identified as a new strain of H7N9. It first surfaced in February in Shanghai and, as of April 16, had infected sixty-six people in six provinces and municipalities nationwide, claiming fourteen lives.

Meanwhile, authorities have been defending social order against a rumor mill they say has at times come close to triggering panic over unfounded reports about avian influenza’s spread.

The straight facts confirmed by health officials need no embellishment to generate fear: Although the virus has killed only a few birds so far, the death rate among infected humans has been unusually high.

And death comes quickly. The virus invades and grips the lungs so rapidly that an infected person can plunge from coughing and common flu symptoms to full-blown pneumonia within a week.

That’s what happened to three members of the Li family who were diagnosed February 19 with severe pneumonia at the Fifth People’s Hospital in Shanghai. Two—a woman with the last name Li, 87, and her youngest son, 57—died from what doctors said were the compound effects of bird flu and other causes.

Officials have so far confirmed that flu infections were found in Shanghai and in nearby Anhui, Zhejiang, and Jiangsu provinces, as well as Beijing.

A week after members of the Li family were admitted to hospital, doctors began suspecting an outbreak of type A bird flu. Hospital administrators invited experts from the Ministry of Health’s Center for Disease Control (CDC) to join the vice director of Shanghai’s Municipal Public Health Center, Lu Hongzhou, for a study of the family’s case.

Lab tests were conducted, and Lu raised the possibility of a new virus within the type A bird flu family. “This may very well be a big fish,” he told colleagues at the time.

Meanwhile, a twenty-seven-year-old butcher named Wu Liangliang who lived near the Li family’s home sought treatment March 3 at the same hospital for fever and coughing. He died a week later.

On March 31, the health ministry’s National Health and Family Planning Commission reported that the virus that had killed Wu and infected the Li family was a new form of H7N9.

The commission’s fast, conclusive research stood in sharp contrast to the five-month lag between the outbreak of a deadly respiratory disease ten years ago in China and its identification as SARS. Officials credit transparency and experience for the speedy response to the latest H7N9.

After the virus was identified as a mutated form of avian flu, health officials were able to treat infected patients. That fact, coupled with the fact that the disease does not appear to spread from person to person, but rather from birds to people, has led authorities to conclude that China is unlikely to experience a large-scale epidemic.

Networking Fear

Nevertheless, fears about the outbreak’s possible effects have been fueled via private reports transmitted through China’s vast online network of social media outlets.

Police have arrested an unknown number of people on charges of spreading rumors about the disease on the Internet and through microblogs. Various rumors have forced government officials in Beijing, Shanghai, Xi’an, Kunming, and other cities to post official replies, usually denying the presence of H7N9.

On April 2, for example, the Internet started buzzing with reports that a patient had been diagnosed with the virus at the Infectious Diseases Office at Beijing Traditional Chinese Medicine University’s Dongzhimen Hospital.

Officials denied the reports. On April 13 they confirmed Beijing’s first case of avian flu. The victim was a seven-year-old girl diagnosed in Shunyi district and, as of mid-April, was recovering.

Taiwan and Hong Kong officials have also been on high alert for the virus as well as rumors, all of which have been discounted. So far, the virus has only been found on the mainland.

Taiwan media, though, has reported falling local prices for chicken and other domestic fowl. And since April 11, Hong Kong officials have stepped up fowl testing. Hong Kong Health Bureau Director Ko Wing-man said a single infection’s discovery would prompt an immediate extermination of all chickens in the area.

The first rumor surfaced March 7 on a Weibo [microblog] account. “Some deaths from unknown causes have occurred at Shanghai Fifth People’s Hospital. The initial diagnosis was flu, and the deceased had difficulty breathing. We hope the hospital will tell the truth.” Authorities quickly deleted the post.

Shanghai Municipal Health Bureau officials used their public Weibo account to refute the rumor. It said the hospital was treating three members of the same family, and that doctors after conducting epidemiological and lab tests had excluded SARS, human-avian flu, novel coronavirus, type A influenza, and other ailments.

The official blog post did not mention the fact that health authorities were indeed investigating whether the Li family members might have been infected by a previously unknown strain of bird flu.

Intense Tests

New virus strains in China are officially identified by CDC after testing at laboratories that carry a so-called P3 biological hazard security designation. (Only P4 labs are more secure.) And P3 testing must be pre-approved by the central government, which indeed happened following a Shanghai public health agency request.

Lu told Caixin that by March 19 officials had reached a preliminary conclusion that the new strain of H7N9, so named for combining two protein fragments identified as H7 and N9, had been discovered. The discovery was reported by CDC officials two days later.

The “H” in the virus’ title refers to a glycoprotein called influenza hemagglutinin (HA) which unlocks a host cell so that the “N,” or viral neuraminidase (NA), can destroy a cell’s receptors and help the virus propagate.

Viruses may periodically self-mutate, which is how H7N9 emerged. Occasionally, two sub-strains of a single virus may swap genetic material, structurally changing a virus.

The latest H7N9 strain is apparently unlike the H7N9 virus found among Czech Republic geese in 2009 and the H7N9 strain that infected wild ducks in South Korea in 2008.

Researchers at the Chinese Academy of Science’s Laboratory of Pathogenic Microbiology and Immunology found out that this new strain’s genetic mix involves migratory birds from South Korea and domestic ducks and chickens. Scientists have been trying to determine how the latest H7N9 jumped from birds to people—a sleuthing task assigned to the Ministry of Agriculture, which is responsible for managing animal disease outbreaks.

Bird flu viruses, regardless of how serious they are among birds, rarely infect people. The human respiratory tract usually kills these viruses before they cause trouble.

But avian flu is highly susceptible to mutation. A virus that harmlessly circulates among birds for a long time might suddenly mutate after passing through a separate host, such as a pig. Or a virus can suddenly directly infect people.

Investigators have focused on birds living around the homes of people infected with the new H7N9 strain. They’re also studying pigs as potential intermediary hosts for the virus.

Agriculture officials have dispatched eight groups to infected regions to test live fowl markets, fowl farms, and wild birds. More than 10,000 samples had been collected as of mid-April.

The agriculture ministry announced April 4 that samples from pigeons sold at the Huhuai Agricultural Market in Shanghai’s Songjiang District were infected with H7N9, leading some to theorize that the strain may have come from pigeons.

The pigeon theory, however, has been discounted by many researchers, including Guan Yi, an expert at the University of Hong Kong. “It is very unlikely that the bird flu virus would appear in a pigeon,” he said.

Experts at the Chinese Academy of Sciences, Chinese Academy of Agricultural Sciences, and other institutions agree with Guan.

“It is highly likely that a pigeon may be infected by the H7N9 virus,” said another expert, “but not that a pigeon would directly infect human beings with the virus.”

What’s most likely, the experts said, is that the virus jumped to humans from chickens or ducks.

Agriculture officials, who some say may have blamed pigeons in hopes of preventing a plunge in poultry demand, later revised their conclusions to match the opinions of Guan and other researchers. They said more than half of the nineteen samples from birds that tested positive for bird flu came from chickens.

At the same time, the ministry declared a bird flu epidemic closed and decontaminated the live fowl section of the Huhuai Market, and slaughtered all its birds.

Solving Riddles

Meanwhile, health officials have been unlocking riddles of the virus’ human infections and high mortality rate. They’ve also made progress in the areas of detection and treatment.

Speaking to Caixin, Lu blamed the steep fatality rate on the fact that H7N9 patients seldom sought treatment before it was too late.

A doctor who treated one victim said early-on it’s usually hard to identify the virus as anything more than common flu. But the new bird flu spreads rapidly, and common flu treatments have proven ineffective.

Science academy researchers have also linked H7N9’s mortality rate to a virus mutation, which they said shows up as a shortened N9 fragment that makes it easier to unlock human cell receptors and, thus, leads to infection.

Since April 5, doctors through local governments have had access to H7N9 detection reagents that can determine whether a patient is infected with the new strain within six hours. On the same day, the government approved a new injection drug for treating flu called peramivir sodium chloride.

Testing for a single patient’s infection can cost 2,000 yuan, the deputy director of Jiangsu province’s CDC recently announced at a press conference. The leader of a family planning commission group in charge of controlling H7N9, Liang Wannian, recently told reporters “we should resolutely refuse to deny prompt treatment because of cost-related issues.”

Some researchers have wondered aloud about the agriculture ministry’s supervision of the poultry industry, and questioned why the virus was not traced to birds before it jumped to people.

Guan has raised questions about China’s system of vaccinating chickens and testing birds at fixed sites.

“Most countries don’t use vaccines to prevent bird flu,” he said. “If every chicken in the country were vaccinated, bird flu could not be eradicated, nor tested.”

Guan added that “by protecting the lives of the chickens” through the agriculture ministry’s bird-flu fighting procedures “they’re ensuring that people will continue to be infected.”

Guan thinks vaccines should be used on a large number of chickens in China through a system that leaves some “sentinel chickens” unvaccinated. A sentinel that falls signals trouble.

But another senior researcher defended the agriculture ministry, noting the new strain of H7N9 is far more difficult to detect in birds than other forms of avian flu. A form potentially more contagious to humans, H5N1, is easier to spot because it’s marked by high morbidity rates among infected birds.