“Bao’s life signs are stable: normal temperature, alleviated symptoms, lighter coughing after three days’ medication and care by medical workers from the Health Ministry, Sichuan Province and Chengdu City,” He said at a news briefing held by Chengdu City Government Tuesday.

Bao was also relieved of anxiety through psychological intervention and counseling, and was in a healthy mood, said He.

Bao’s father and girlfriend, both of whom had close contact with the patient and were requested to receive medical observation at Chengdu Infectious Diseases Hospital, the same hospital where Bao is kept, were transferred to the centralized observation camp of Chengdu City Tuesday afternoon.

Bao, 30, who had been studying at an American university, arrived in Beijing on board the Northwest Airlines flight NW029 May 9, after making a transfer in Tokyo from St Louis, Missouri, and St. Paul, Minnesota in the United States. His body temperature was normal when entering China. He then flew from Beijing to Chengdu on Sichuan Airlines flight 3U8882 the same day.

Bao was found to have a fever on the flight from Beijing to Chengdu accompanied by a sore throat, coughing, a stuffy nose and sneezing.

He went to the Sichuan People’s Hospital after getting off the plane, and was tested “weakly positive” to A/H1N1 virus twice by the Sichuan Center for Disease Control and Prevention Sunday. He was then transferred to the Chengdu Infectious Disease Hospital. The Ministry of Health said Monday morning he tested positive for A/H1N1 influenza.

To prevent A/H1N1 flu from spreading in the Chinese mainland, Sichuan Province is seeking passengers who were on the same flight3U8882 with Bao and other people with close contacts with these passengers.

A total of 125 people were put under quarantine in Chengdu, capital of Sichuan Province, as of midday Tuesday, including 94 passengers and 31 other people with contact with the passengers, said He.

There were 150 passengers on flight 3U882. The crew were put under quarantine.

Chengdu didn’t received reports about new confirmed or suspected A/H1N1 cases as of 4 p.m. Tuesday.

In the meantime, Chengdu City Center for Disease Control and Prevention has dispatched five groups down to different urban districts to guide and supervise A/H1N1 disease prevention efforts there.

Northwards, Beijing opened a second venue for quarantine purpose near the Capital Airport Monday, said Yu Debin, deputy chief of Beijing Municipal Tourism Administration who is appointed as commander-in-chief of medical observation venues for A/H1N1 flu.

The first venue used for quarantine is Guomenlu Hotel near the airport. This hotel, with only 188 rooms, which was used to quarantine people in an earlier flu case involving a Mexican national who ended up in Hong Kong, keeps 163 people under quarantine.

And the second venue, Jinglin Mansion, is at the south of the Capital Airport and has 191 guestrooms. Yu didn’t give an exact number of people being kept under quarantine at Jinglin Mansion at the moment.

There were altogether 233 passengers on flight NW029, including106 foreign nationals, said Xu Xiaoyuan, deputy chief of the infectious disease section with the No.1 Hospital affiliated to Peking University, at a press conference held by the Chinese Health Ministry in Beijing Monday afternoon.

The health ministry confirmed that most of the passengers from the flight had already been tracked down and isolated at local health institutions in 21 provinces, municipalities and autonomous regions.

The efforts to track down those who had contact with Bao turn out to be arduous.

In Beijing, for instance, the municipal health department had contacted 121 out of the 147 people on flight NW029, and were still looking for 26 other passengers as of 2 p.m. Monday, including 24 foreign nationals, said Deng Ying, chief of Beijing Center for Disease Control and Prevention.

According to Deng, Bao stayed for more than nine hours at Xinhanglv Hotel in Shunyi district before he caught flight 3U8882.All 103 people around the hotel, including nine foreign nationals, were therefore told to keep a week-long observation at the hotel.

None had shown fever symptoms, said Deng.

Deng said the municipal health department had also informed concerned localities to seek 10 other people who took the same van from the hotel to the airport together with Bao.

Bao was the second confirmed case of A/H1N1 influenza in China. A 25-year-old male Mexican was confirmed on May 1 in Hong Kong to be infected with influenza A/H1N1, and those who were in close contact with him were put under quarantine in 19 mainland regions.

Two crewmembers aboard Royal Caribbean’s 90,090-ton, 2,112-passenger Serenade of the Seas, currently sailing in Alaska, have recovered from flu-like symptoms, according to a cruise line statement.

Though both tested positive in shipboard testing for influenza A, samples have been submitted to the Centers for Disease Control and Prevention to confirm whether the H1N1 strain — also known as swine flu — was indeed present. No other crewmembers or passengers have tested positive for influenza A.

The two affected crewmembers were isolated on May 1 and May 4, respectively, after becoming ill — standard procedure regarding any flu illness outbreak, according to the statement. The statement further says that both individuals were treated with Tamiflu, are fully recovered and can no longer be a source of an influenza infection.

In addition to treatment and isolation, other measures being taken to reduce the risk of the spread of influenza include the screening of all crew and passengers pre-boarding, and the placement of hand sanitizers throughout the ship. Passengers are encouraged through daily notices to contact the medical facility onboard should they experience flu-like symptoms.

The ship departed San Juan on April 18 for a Panama Canal transit that concluded in San Francisco on May 2. The ship called on Huatulco, Mexico, on April 26, and Acapulco, Mexico, on April 27. On April 28 — one day after U.S. officials suggested restricting non-essential travel to Mexico — Royal Caribbean suspended port calls in Mexico.

Serenade of the Seas is currently sailing a 14-night Alaska cruise, which departed San Francisco on May 2 and ends in Vancouver on May 16. Interestingly, the Seattle Times reports that the state of Alaska conducted its own testing on a sample taken from the ship when it arrived in Ketchikan, but the sample was negative for influenza A — likely because of the effectiveness of the Tamiflu medication being administered.

The United Nations agency’s guidelines state that as soon as the virus starts spreading freely in two regions of the world, its six-point pandemic alert should be raised to the top notch.

With infection numbers rising in Europe, public health experts are struggling to decide whether it is worth sounding the full alarm over H1N1, which is treatable with existing drugs and appears less severe than seasonal flu in most cases.

“It is a judgement call,” one WHO official said when asked about whether the global alert needs to hit its top rung.

WHO Director-General Margaret Chan raised it to level 5 — signalling a pandemic was “imminent” — last week after the flu strain that killed young adults in Mexico emerged in the United States and Canada and spread from schools to communities there.

Under the rules, just one country outside the Americas needs to have a community-level outbreak of the new strain to trigger a Phase 6 designation indicating a global pandemic is under way.

Chan has sought to prepare the public for the declaration of a full pandemic of H1N1, which is widely known as “swine flu” and also contains pieces of human and bird viruses.

“Level 6 does not mean, in any way, that we are facing the end of the world,” she told the Spanish daily El Pais this week. She stressed that the alert ladder indicates how likely the virus is to spread around the world, not how dangerous it is.

The WHO’s recommendations about how to respond to a pandemic are virtually the same for alert levels 5 and 6.

In both cases, countries with outbreaks are told to consider closing schools and cancelling public events, and to distribute drugs and procure vaccines as means allow, while “countries not yet affected” are urged to prepare themselves for the virus.

“The best way would be to describe them as a continuum of actions that countries will take at different points of time, depending on their particular circumstances,” WHO spokesman Thomas Abraham said of the top two alert phases.

BRITAIN AND SPAIN IN FOCUS

The H1N1 flu has hit Mexico hardest, killing 42 people there and infecting nearly 1,000.

While Mexican authorities have said their outbreak has peaked, raising hopes the public health scare is over, officials at the WHO are continuing to pore over data about the spread of the virus around the globe.

Almost all the people with confirmed infections outside the Americas region to date had travelled to Mexico or had close contact with people who did.

But some experts believe Britain is especially vulnerable to a community-wide outbreak, given the flu strain is propagating inside some schools. Spain also has a relatively large cluster of infections, with 73 according to the latest WHO tally.

Chan, who fought SARS (Severe Acute Respiratory Syndrome) and bird flu as Hong Kong’s health director, has warned such cases should not be taken lightly.

“It is true that the number is small, but because of that I would say that we have not seen the full situation or the whole picture of what is happening,” she told El Pais.

No one country, however, is likely to want to be seen as tipping the scale towards a pandemic declaration, especially with discontent rising about whether public health experts have exaggerated the risks of the H1N1 strain.

That leaves the WHO in a difficult spot, given many disease experts anticipate the new virus could rebound with a vengeance later this year when winter temperatures conducive to the spread of flu return to the populated northern hemisphere.

WHO spokesman Gregory Hartl summed up the quandary Monday when asked why international health experts remain on edge about future risks from the flu. “The world really would not forgive us if we did not continue to be vigilant,” he said.

Health officials told lawmakers Wednesday it took only two weeks to identify the genetic characteristics of swine flu, and they are in good position to quickly produce a vaccine if the flu takes a turn for the worse.

At the same time, the officials cautioned members of a House Foreign Affairs subcommittee that there are still elements of what they called the novel 2009 H1N1 influenza virus that they don’t understand, and it was not time for complacency.

Dr. Dennis Carroll, special adviser on pandemic flu to the U.S. Agency for International Development, noted that the 1918-1919 flu pandemic also began in the spring and was initially mild, but a much more lethal version hit six months later and the virus eventually killed 50 million worldwide.

Dr. Anne Schuchat, acting deputy director for science and program at the Centers for Disease Control and Prevention, also urged caution, saying they expected to see more people get sick and more serious cases. One factor, she said, is that the Southern Hemisphere is now moving into its flu season.

But she also stressed that “at no time in our history have we been more prepared to face this challenge.”

She said the CDC moved rapidly to determine that the virus circulating in the U.S. and around the world contains genetic pieces from four different virus sources and that within two weeks it was able to understand its complete genetic characteristics.

“We have isolated and identified the virus and discussions are under way so that, should we need to manufacture a vaccine, we can work towards that goal very quickly,” she said.

Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases, said the CDC is currently at the stage of processing vaccine seed virus. If the need arises, they can coordinate with manufacturers on clinical trials, verifying the safety, efficacy and right dosages of the vaccine, and then move to mass production.

Hundreds of guests and staff were under quarantine at a hotel in China on Saturday after a guest there contracted the H1N1 virus.

About 200 hotel guests and 100 staff members were ordered to stay in the Metro Park Hotel in Hong Kong for seven days to stop the spread of the virus commonly known as swine flu, a government spokesman said.

The quarantine was ordered after a 25-year-old Mexican man stayed in the hotel and became sick. The man flew from Mexico to Shanghai on April 30 and then went to Hong Kong. He was taken to a hospital and tests confirmed that he had the virus, said York Chow, the secretary for food and health.

Chow said officials would isolate the hotel and that “relevant people” would be quarantined for seven days and treated with an anti-viral medication, commonly known as Tamiflu.

This was the first confirmed case of the virus in Hong Kong, local medical officials said.

The World Health Organization has also confirmed the case in Hong Kong. It is among the agency’s 615 confirmed cases worldwide. None of the cases have been confirmed in mainland China.

South Korean officials on Saturday confirmed their first case — a 51-year-old nun who recently traveled to Mexico for volunteer work. Several other countries were investigating hundreds of other probable cases of the virus.