Coronavirus has ‘pandemic potential’ – but what is a pandemic?

Coronavirus is not a pandemic, at least not yet. That was the message from the World Health Organization’s Director General Dr Tedros Adhanom Ghebreyesus in a briefing today.

“We should not be too eager to declare a pandemic without a careful and clear-minded analysis of the facts,” he said, noting appeals for a declaration from some politicians and journalists.

His remarks beg one key question: What does it take for experts to label a disease a pandemic?

A pandemic is a new disease that has spread globally, according to the WHO. As most people are not immune to this new disease, it can spread beyond expectation.

Pandemics, as some experts have explained, don’t speak to the severity of a disease, only its geographic reach.

Transition from local epidemics to a global pandemic, according to the WHO, “may occur quickly or gradually as indicated by the global risk assessment, principally based on virological, epidemiological and clinical data.”

At the moment, however, WHO says the coronavirus has not caused a “sustained and intensive community transmission” or large-scale casualties.

China has fewer than 80,000 cases in a population of 1.4 billion people, explained WHO. In the rest of the world, there are 2,790 cases in a population of 6.3 billion.

Are we already there?

Some disagree. Professor Jimmy Whitworth of the London School of Hygiene and Tropical Medicine, told the BBC: “I think many people would consider the current situation a pandemic, we have ongoing transmission in multiple regions of the world.”

Cases of the virus have now been reported on every continent apart from Antarctica, with Brazil and Greece the latest countries to confirm outbreaks.

Dr Nathalie MacDermott of the UK National Institute for Health Research told the BBC she was most worried about the ability of countries with weakened healthcare systems to cope with the virus.

“I think we are teetering on the balance of a pandemic, in the next week or two we’re likely to see it pop up in lots of places and if it’s on several different continents then we’d be approaching a pandemic.”

Still, cases in China peaked at the end of January and have since declined. As the Director General explained, measures taken in China have helped stem the spread of the disease and “have averted a significant number of cases.”

He said: “The key message that should give all countries hope, courage and confidence is that this virus can be contained.”

Looking ahead

Ultimately, the decision to declare a pandemic rests with the WHO’s Director General. His decision will be based on a range of factors including how fast the disease is spreading, which groups of people are most at risk and the effectiveness of treatments.

The list also includes an assessment of symptoms and complications, how many people become ill and the impact on health workers and the ability of the global health system to cope. There are no hard and fast criteria – it’s a judgment call.

Caution has driven WHO’s reluctance to use the word “pandemic.” The word, the Director General explained, “has no tangible benefit, but it does have significant risk in terms of amplifying unnecessary and unjustified fear and stigma, and paralyzing systems.”

That caution could stem, in part, from WHO’s handling of the H1N1 swine fever outbreak in 2009. Using criteria since abandoned, the WHO declared a pandemic. Later, when the disease proved less deadly than first feared, some accused the WHO of overreacting.

Preventing unnecessary panic, of course, is key. The word pandemic “may also signal that we can no longer contain the virus, which is not true,” said the Director General. “We are in a fight that can be won if we do the right things.”

He added that WHO would not hesitate to use the word pandemic if it becomes “an accurate description of the situation.”

Still, the Director General was keen to stress today that coronavirus has “pandemic potential” and that preparation would be crucial.

“Do not mistake me,” he said. “I am not downplaying the seriousness of the situation.”