The emergence of a SARS-like virus in China is the last thing Hong Kong's struggling economy needs, analysts say, as the city reels from the twin storms of the global trade war and months of political unrest.
The semi-autonomous financial hub is currently on high alert for any appearance of the new coronavirus, which first surfaced in the Chinese city of Wuhan and has since spread to the United States and around Asia.
In 2003, nearly 300 people were killed in Hong Kong during an outbreak of Severe Acute Respiratory Syndrome (SARS), which also began on the mainland and hammered the city's economy as tourists arrivals plunged.
"We are on extreme high alert and preparing for the worst," chief secretary Matthew Cheung told reporters on Tuesday. "We have not lowered our guard."
The timing could hardly be worse.
Hong Kong has been tipped into a recession by the US-China trade war and months of seething pro-democracy protests that have upended its reputation for stability.
On Monday, Moody's downgraded Hong Kong's credit rating, saying the government had failed to respond to the economic and political demands of protesters and that China's increased influence was undermining the city's once-vaunted institutions.
A disease outbreak in the densely packed city would only add to current economic woes.
"This is definitely the last thing Hong Kong people want to see," said Jackson Wong, an asset management director at Amber Hill Capital Ltd. "The current situation will definitely remind investors about what we suffered in 2003 during the SARS outbreak in Hong Kong," he added.
'Salt in wounds'
Hong Kong's stock market sank on Tuesday -- with tourism-linked stocks leading the losses -- after a top Chinese scientist said the Wuhan virus has now been found to pass between humans.
The brewing crisis comes days before the Lunar New Year holiday, which sees hundreds of millions of people travel across China and overseas.
The number of mainland Chinese travelling to Hong Kong has dropped dramatically since the anti-government protests began last summer, and there are fears the Wuhan virus will only make things worse for the battered tourist industry.
"Hotel, catering and tourism have borne the brunt of the recession and now this situation is like rubbing salt into the wounds," Dickie Wong, executive director of research at Kingston Securities, told AFP.
"It will deal a heavy blow to the city's economic atmosphere. The impact of the political unrest sparked by the extradition bill (protests) has not yet ended."
Hong Kong's health authorities are taking few chances in a bid to stave off a repeat of the SARS epidemic.
Monitoring for people with fevers has been ramped up at the airport and local hospitals to include anyone coming from Hubei province, not just its capital city Wuhan.
More than 100 people who have come back from the region and reported flu-like symptoms have been isolated and treated, although none have yet tested positive for the new strain.
More prepared than SARS
But the spread of confirmed cases in multiple Chinese cities, including neighbouring Shenzhen, has put Hong Kong on edge with face masks rapidly selling out.
Isolation wards and doctors are on standby.
The SARS outbreak dramatically transformed Hong Kong into a place where the population is now far more conscious of contagion and hygiene standards.
Door handles and lift buttons in the city's myriad skyscrapers are routinely sterilised multiple times a day, while an unguarded sneeze on the crowded subway can cause neighbouring commuters to scramble for distance.
Surgical face masks are ubiquitous, not just in the winter flu season.
Hong Kong's difficulties in battling SARS were compounded by the veil of secrecy that surrounded the outbreak on the authoritarian mainland.
But specialists who are prepping the city for any new outbreak say they have been encouraged by the transparency Chinese authorities have shown following the Wuhan outbreak.
"The timescale of recognising, characterising, releasing and reporting information is a vast improvement from the time of SARS," Gabriel Leung, dean of the University of Hong Kong's medical school told reporters on Tuesday.
"What did take months during the time of SARS is now compressed into a matter of weeks or days," he added.