Fifteen years ago, Sars spread through Hong Kong like wildfire. With ever-denser populations and rising antibiotic resistance how many cities are prepared for a viral or bacterial outbreak?

It has been 15 years since an outbreak of severe acute respiratory syndrome (Sars) in Hong Kong killed 299 people and infected 1,755. The wildfire spread of the deadly virus through densely packed housing estates stunned the city’s health authorities and traumatised residents. Now the city’s top microbiologist thinks more deaths are on the way.

“It’s very likely we’ll see an epidemic on the scale of Sars,” says Professor KY Yuen, chair of infectious diseases at the University of Hong Kong. He cites two key reasons for this, both applicable to cities around the world. The first is population density. “Our population is increasing. The number of people living in subdivided flats is now at least 200,000, maybe as high as 600,000,” says Yuen.

The second is the rise of antibiotic-resistant superbugs. One new superbug infection is reported every 18 minutes in the city’s public hospitals. “The level of antimicrobial resistance in Hong Kong far exceeds that in other developed countries, with resistance to some antibiotics over 20 times higher than in the UK or Sweden,” says Yuen.

Facebook Twitter Pinterest Children attend a ballet lesson during Hong Kong’s Sars outbreak in 2003. Photograph: Vincent Yu/AP

That situation is “very likely to get worse” without urgent action to tackle overuse of antibiotics, he says. A government survey revealed half of Hongkongers had taken antibiotics in the past year, with 2% admitting sourcing them illegally. Some argue that pressure to free up hospital bed space leads to oversubscription of antibiotics, as doctors try to shift patients out the door.

A 2016 report backed by the British government found that drug-resistant infections cause 700,000 deaths globally each year. The same report projected that death toll could rise to 10 million a year by 2050 – more people than die annually from cancer. The authors put the economic cost of such a catastrophe at $100tn (£75tn). The World Health Organisation (WHO) has described rising resistance levels to antibiotics as a “global crisis”, while England’s chief medical officer has warned of a coming “post-antibiotic apocalypse”.



An airborne virus could pass from an infected individual to 25,000 others in a week, and more than 700,000 in the first month Dr Jonathan D Quick, Harvard Medical School

Cities, in particular the world’s growing megacities, are especially vulnerable. Densely populated urban areas make ideal incubators for new epidemics. A high concentration of people means a greater risk of exposure to bacteria and a higher likelihood that infectious diseases will spread.

“Once transmitted to a human, an airborne virus could pass from that one infected individual to 25,000 others within a week, and to more than 700,000 within the first month,” Dr Jonathan D Quick, chair of the Harvard Medical School’s global health council, warned this year. “Within three months, it could spread to every major urban centre in the world. And by six months, it could infect more than 300 million people and kill more than 30 million.”

The Cityscape: get the best of Guardian Cities delivered to you every week, with just-released data, features and on-the-ground reports from all over the world

Last year a university in London found traces of nine of the world’s most threatening superbugs on the city’s transport network. India’s megacities are reported to have some of the worst antibiotic-resistance rates in the world, while the Nigerian government has described anti-microbial resistance rates both in Lagos and nationwide as “untenably high”. Between 2000 and 2015 antibiotic consumption increased 79% in mainland China.

For Sylvie Briand, director of infectious hazards management at WHO, the next major influenza outbreak in cities around the world is inevitable. “This is a certainty. The only thing we don’t know is when,” she says.

Facebook Twitter Pinterest Health workers taking part in a simulation. Following the Sars outbreak, Hong Kong’s Centre for Disease Prevention holds regular preparedness exercises. Photograph: Courtesy: CHP

“Urban areas are growing fast, but facilities aren’t necessarily growing at the same pace,” she says. “We try to push certain cities to go through this preparedness planning, because we know the risks and vulnerabilities and they will most likely be the first responders.”

Briand recommends big cities have at least three preparedness plans, ranging from worst-case to best-case scenario. “It’s vitally important for cities to work out their plan of action before a crisis occurs. During a crisis you always find a way, but it’s not necessarily the best way or the most cost effective way.”

A resilient healthcare system is also key. “When we had the plague in Madagascar last year, the laboratory was used to dealing with 10 samples a week. I said to them: what would you do if you have 2,000 samples a week? What is your plan?

It’s not the usual business, or maybe twice the usual business. Cities have to imagine a scenario that is a thousand times worse Sylvie Briand, WHO

“This is the kind of scenario that cities need to get prepared for. It’s not the usual business, or maybe twice the usual business. They have to imagine a scenario that is a thousand times worse.”

In response to the Sars crisis, Hong Kong established the Centre for Health Protection (CHP) in 2004, tasked with preventing and managing outbreaks. A three-tier alert system was established to respond to outbreaks of infectious diseases. At the highest level of alert, triggered by confirmation of human-to-human transfer of a deadly virus, the city would be put on lockdown with enforced closure of public schools and places, a ban on all public gatherings, and the closure or diversion of transportation routes.

The CHP stages regular training exercises in public spaces to prepare for outbreak emergencies. In one such scenario a passenger infected with a dangerous disease is discovered on a flight leaving Hong Kong airport. Another simulates an influenza epidemic, with hordes of patients arriving at public hospitals across the city.

“Compared with the days when we were facing Sars, we are definitely better prepared,” says Dr Dominic Tsang, chief infection control officer for the city’s Hospital Authority. But he accepts that catching an outbreak early is vital. “The strategy for prevention of an outbreak has to be early detection and isolation of infected patients,” says Tsang. “Otherwise, it will spread like wildfire in the community and to control it will be immensely difficult.”



In China, a single plague death means an entire city quarantined Read more

In July the city launched a five-year action plan for tackling antimicrobial resistance, hoping to crack down on antibiotic overuse. Easing the strain on public hospitals will be key to that effort. “The fact is, Hong Kong’s hospitals are crowded,” says Tsang. “We need to build more hospitals and find ways to unload the patient area.” Yuen, the microbiologist, argues that improved monitoring of superbug activity, as wells education about antibiotic overuse, are both urgently needed to avert disaster.

“There are no magic bullets, but the way for megacities to reduce their risk is to invest in all public health capabilities and to strive hard to improve access for all to modern medical care,” says Richard Hatchett, head of the Coalition for Epidemic Preparedness Innovations (CEPI), a global public-private group that supports the development of vaccines.

“We cannot prevent every death from every emerging disease,” says Hatchett. “But we can prevent epidemics and we can prevent such diseases from becoming global security threats. It’s not whether we can – it’s whether we will.”

Follow Guardian Cities on Twitter, Facebook and Instagram to join the discussion, and explore our archive here