In 2003, masks became a symbol of terror as the world dealt with its first pandemic of the 21st Century — SARS, or severe acute respiratory syndrome.
It began with a businessman who fell ill in Foshan, China. He had pneumonia-like symptoms, but the people who treated him quickly fell sick, too.
It's thought that he caught the SARS virus from a wet market in southern Guangdong Province.
By February 9, 305 people had contracted SARS in the region, and five people had died from it.
next slide will load in 15 secondsSkip AdSkip AdDoctors had never seen the virus before. What was confusing and prompted doubts was that, at the beginning, SARS looked like pneumonia.
The symptoms were similar — coughing, fever, body aches, difficulty breathing, fatigue. SARS spread through the air, by coughing or sneezing.
It was also, as CNN described, a "super spreader," meaning one person could infect many others. And, worryingly, there was no known cure.
To the world, it seemed like SARS came out of nowhere, but that wasn't entirely true. China had an information blackout, and waited until February to disclose cases of SARS to the World Health Organization. In the coming months, China would be criticized for failing to be open about the virus.
There were a number of reasons for the delay. But the economy was a major one. Cholera in the early 1990s cost Peru $770 million, while India lost about $1 billion in tourism when it had a bout of the plague. China didn't want its economy to take a hit.
next slide will load in 15 secondsSkip AdSkip AdIn late February, an unusual case in Vietnam stumped a local doctor. He had heard about the outbreak in China, but wasn't sure he was dealing with the same thing. Then, 10 staff members contracted the virus, and his "doubts would balloon into dread," the Wall Street Journal wrote.
On February 21, SARS went global, after an infected doctor working in Guangdong province checked into Hong Kong's Metropole Hotel. The virus spread to 16 other guests, who then dispersed around the world. Room 911, where he stayed, became a museum after the outbreak, and the building was renamed Room 911.
Having SARS in an international hub like Hong Kong was an infectious disease expert's "worst nightmare," The New York Times wrote at the time.
International travel made it difficult to contain SARS. Infected people could get through customs, and into another country, before they presented symptoms of the virus.
On March 15, SARS was finally taken seriously. The WHO labeled it a worldwide health threat, describing it as an unnamed virus spreading through Asia. There were concerns it could be as serious and deadly as the influenza pandemic of 1918-19.
next slide will load in 15 secondsSkip AdSkip AdBy April, SARS had spread from China to 25 other countries, including Canada, Hong Kong, and India, infecting nearly 3,500 people and killing 182.
Yet it still wasn't clear, according to The New York Times, whether it would turn into "a global wildfire, or cool down."
A clearer picture of the virus began to emerge in April when whistleblower Jiang Yanyong, a prominent doctor in Beijing, sent a letter to international media, informing them that at least 100 people were being treated for SARS in Beijing.
On April 20, the Chinese government admitted there were 10 times as many SARS cases as reported in Beijing — 339 cases, rather than 37. To make amends, China's health minister and the mayor of Beijing were both dismissed.
The announcement caused panic. Thousands left Beijing, just a day after the WHO advised against traveling to Beijing or Shanxi province.
next slide will load in 15 secondsSkip AdSkip AdOne Beijing resident named Shi Chuanquan told The New York Times, "This virus is invisible and untouchable, which makes it really scary."
Schools were closed down. More than 1.7 million students in Beijing were sent home.
Measures at airports increased, including random temperature checks.
Because SARS was spread through coughing and sneezing, surfaces like the insides of planes were wiped down. Beijing's council also closed public spaces like swimming pools and movie theaters, where the virus could easily spread.
Quarantines became a staple. In Beijing, crime-scene tape was wrapped around an entire block, keeping 2,000 health employees contained and cut off.
next slide will load in 15 secondsSkip AdSkip AdPeople stocked up on basic household goods like cooking oil and rice, as well as masks.
Even though Beijing had about 14 million people, meaning the number of infected people was comparably low, it was taken seriously, and the impact was felt everywhere.
The news continued to be grim. In Hong Kong, SARS spread through an apartment building by way of bathroom drainpipes. According to the Washington Post, it was a "disturbing new confirmation of the microbe's versatility."
Quarantines popped up in other countries. Here, a nurse talks to her relatives through a webcam in Taiwan in late April. Taiwan was the third worst hit country, with 83 deaths.
Patrick Dixon, an expert on global trends, told The Guardian that unless SARS mutated into a less serious virus, "the only hope we have is to mount an immediate aggressive global response at the highest levels against SARS, something we've not yet seen."
next slide will load in 15 secondsSkip AdSkip AdAlso in April, scientists cracked the genetic code of SARS. With that in hand, drugs and vaccines could be made. Yet it wouldn't be for another 20 months before a vaccine was ready to be used by humans.
Headlines around the world continued to question how bad SARS would get. Newsweek's cover read, "SARS Can it be stopped?"
On May 15, the Chinese government increased measures to beat SARS. It threatened to execute anyone who intentionally broke quarantine. About 11,000 people were confined to their homes or hospitals.
In Singapore, those who were suspected of being infected with SARS were monitored at home. Electronic bracelets alerted the police if they tried to leave.
All of the prohibitive measures began to pay off. In June, SARS started to slow down. WHO Director General Gro Harlem Brundtland said, "We have seen SARS stopped dead in its tracks."
next slide will load in 15 secondsSkip AdSkip AdBy early July, the WHO declared the outbreak was contained. In total, more than 8,000 people were infected and 774 died. It was stopped by isolating cases, good hygiene practices, as well as summer warmth and humidity.
Of those who died, China had 349 deaths out of its 5,327 cases.
In the United States, only eight people were infected, and no one died. This was partly due to the country being in a heightened state of alert after September 11, and the anthrax postal attacks. Another reason, according to The New York Times, was "sheer good luck."
Toronto, Canada, wasn't so lucky. The city was declared SARS-free in May, but later cases emerged. In the end, 375 people were infected and 44 people died. Up to 80% of small Asian-owned businesses' income was estimated to be lost because of racist boycotting.
But in relative terms, Hong Kong got it the worst. Along with a recession due to the city coming to a standstill, 1,755 people were infected, and 299 people died.
next slide will load in 15 secondsSkip AdSkip AdSince 2004, there have been no reported cases of SARS.
The final death toll was relatively low, considering the thousands who die from influenza every year. Yet SARS terrified the world — it was invisible, unknown, and the first pandemic of the globalized world.