The number of reported cases of the coronavirus surpassed 1 million last week, marking a grim milestone that is expected to be matched within days, rather than weeks or months, as the deadly pandemic quickens its spread across the globe.
But as health researchers monitor case counts submitted by nations to better model patterns and projections of the fast-moving disease, the reported number of infections is looking increasingly like a flawed metric for calculating the extent of the outbreak.
Figures support the World Health Organization conclusion that the United States and Western Europe have become the epicenters of the virus’ spread. But they also raise questions about the extent of its presence in places like China, Russia and Mexico. In all those places, issues about accuracy of reporting have emerged.
Photos: The Global Coronavirus Outbreak
“It’s all to do with how difficult it is to have surveillance during an outbreak of a highly transmissible disease, especially with the characteristics of COVID,” says Timothy Russell, a research fellow at the London School of Hygiene and Tropical Medicine who co-authored a new study suggesting only a small fraction of countries may have accurately reported the number of cases of the virus. “People are transmitting while they’re walking around and don’t know it. It quickly overburdens every health care system.”
The number of deaths from the coronavirus is perhaps less prone to misreporting and manipulation than tallies of reported cases and may ultimately prove to be the statistic that defines where around the globe the virus has had the most severe effects. However, that data has limits as the number of deaths only provides a snapshot of the damage caused by the virus at a point in the past.
On Saturday, Deborah Birx, the coordinator of the White House’s coronavirus task force, and Anthony Fauci, the leading infectious diseases expert at the National Institutes of Health, noted that the subsequent days would become some of the worst in terms of deaths since the virus first began spreading. But they added that the case count would be particularly important to watch.
“There are going to be deaths that are going to continue to go up,” Fauci said, citing the “cascading events” of the spread of the virus marked by instances of new cases, hospitalizations, transfers to intensive care units and, in some cases, deaths. “As we may be seeing an increase in deaths, we want to focus on the effect of mitigation. It’s really the number of new cases, and that’s what we’re going to be thinking about.”
Even a country like the U.S., in which reporting appears to be largely transparent, concerns remain about the availability of testing, the time lag to get results from those tests and the accuracy of them.
The picture is complicated in other countries for other reasons.
In China, where public health experts believe the virus originated, government officials revealed last week that they had not been reporting the number of asymptomatic cases, or cases in which people tested positive although they showed no symptoms of the virus. Though officials began including that measure, the true number of asymptomatic infections since the outbreak began in December may forever remain a mystery and leave a massive hole in the data tracking the disease’s spread. In addition to that, Bloomberg News reported last week that a U.S. intelligence assessment indicated China had actively concealed the extent of its infections.
The speed of the virus’ spread is also becoming increasingly apparent in Russia, and even some government officials are uncertain that the country knows how widespread it is. At a televised meeting last month on the handling of the coronavirus, Moscow Mayor Sergey Sobyanin urged Russian President Vladimir Putin to intensify the country’s response, saying the “testing volume is very low and the real picture – no one in the world knows.”
In Mexico, coronavirus czar Hugo Lopez-Gatell recently acknowledged to The Washington Post that his country relies on its own modelling regarding the disease, rather than tests, to determine the spread of the virus and how it should respond. The decision perhaps accounts for the massive disparity between that country’s 2,143 reported cases and the much higher numbers across the border in the U.S. Lopez-Gatell says it represents “a bet that’s technically sound,” shortly after his government decided to leave airports, government offices and stores open even after its neighbors instituted widespread lockdowns.
According to the University of London study that Russell co-authored, Australia, Israel, Norway and Chile have possibly reported 100 percent of the known cases of the virus as of this week, while others, such as China, may have only documented as little as a third. For countries such as Iran, Italy, Spain and the U.K. that number could be lower than 10 percent.
Some governments may be more accurate in reporting the true number of cases because they have been more proactive, have a smaller population or have a greater availability of coronavirus test kits.
Other countries with overwhelmed hospitals, such as the U.K. and U.S., or with underdeveloped public health systems may not have the ability to test for COVID-19 accurately or keep up with the speed of its spread – four days after reaching the 1 million case mark, the number of cases globally grew again by almost a quarter.
The study authors employed calculations based on what they considered the best available estimates for the likelihood of dying after contracting the disease – a 1-1.5 percent chance – and compared them with data each country has reported.
Several other factors contribute to a particular country’s reporting its case numbers inaccurately in the months since the pandemic seized global attention. To begin with, COVID-19 possesses an unusually long incubation period, or time it takes for an infected person to show symptoms – as long as 14 days, delaying countries’ ability to track the virus as it spreads.
Elderly populations are particularly vulnerable, skewing data for countries with a higher number of senior citizens. And widespread lack of testing in some countries makes it difficult to understand how frequently people may carry the disease and pass it on to others without ever showing symptoms themselves – a factor that Russell says would account for “an enormous amount of cases not to be included in the numbers.”
“The virus is not discriminating,” Russell says. “In a way, it’s good to know there’s nothing special about where you are. It’s also worrying because it is spreading quickly everywhere.”