Back in mid-March, when the US and Europe were really starting to feel the tremors of the COVID-19 pandemic, a widely shared meme was pushed around Facebook saying: “Who got sick in November or December and it lasted 10 to 14 days, with the worst cough that wouldn’t go away?
“If you can answer, yes, then you probably had the coronavirus,” it added. “Quit letting the media control you.”
They weren’t the only people on social media to speculate the nasty cold they experienced earlier in the winter was COVID-19. Pro soccer player Carli Lloyd, as just one example, tweeted on March 20: “I think my husband and I had the Coronavirus back in mid-February. A sickness we have never felt before.”
So, could you have caught COVID-19 as far back as January, December, or November and not even realized? It’s a tough question to answer, not least because the world's knowledge of this disease is constantly evolving and developing. However, here’s what we know so far.
A Cough In The Winter Months
First of all, self-diagnosing yourself based on symptoms alone is a slippery business. That’s especially true for COVID-19, a disease that the world's scientists and medical experts are still only just getting to grips with understanding.
COVID-19 is typically associated with a dry cough and a high fever, although the severity of symptoms can range from mild to severe. Many people are asymptomatic (although still contagious), others are bed-ridden for days, a considerable number are hospitalized, and some people die. The spectrum of severity means it’s easy to attach the label of many respiratory illnesses, including COVID-19, but that doesn’t necessarily mean you have it.
The only way to truly know is by having an antibody test, which looks for antibodies in your blood that indicate your body has come into contact with SARS-CoV-2 – the coronavirus responsible for COVID-19 – and fought off the infection. While the Centers for Disease Control and Prevention (CDC) has started to roll out antibody tests to get a more precise count of undetected COVID-19 cases, they are currently focusing on the nation’s high-risk hotspots.
Undetected Cases Circulating In The US
By looking at both vast banks of data and microscopic genomes, researchers have unveiled evidence that suggests cases of COVID-19 may have been circulating in the US before the dates shown in the official data.
As it currently stands, the first confirmed case of COVID-19 was reported on December 1, 2019, in an elderly man living in the Chinese city of Wuhan, although there have also been unverified reports suggesting the first infection occurred in November 2019. By January 20, the first confirmed COVID-19 case in the US was identified in a 35-year-old man in Washington State who had just returned from Wuhan. The earliest confirmed case within the US with no known exposure to the coronavirus through travel was a person in California on February 26.
The genome of SARS-CoV-2 helps to fill in some of the gaps in between. New research – which has not yet been peer-reviewed – by Icahn School of Medicine at Mount Sinai sequenced 90 genomes of SARS-CoV-2 taken across New York City and neighboring Westchester County. By looking at the changes seen in these genomes, the team concluded that COVID-19 began to circulate in the New York area by mid-February after being brought over by travelers from Europe, not Asia.
Taken all together, we can assume that COVID-19 was circulating in select parts of the US by mid-February, although it currently appears that numbers of undetected cases before this time were not significant.
Nicholas Reich, a biostatistician from the University of Massachusetts Amherst who leads the CDC’s flu forecasting team, looked into the number of non-flu-related influenza-like illnesses across the US this year. The team suspected there might have been a sharp rise of these mystery respiratory illnesses in the 2019-2020 flu season, indicating that undetected COVID-19 cases were spreading across the US from around the new year.
However, the lab’s report concluded there were no truly significant increases in mystery respiratory illnesses compared to previous years. In other words, not that many people in the US were sick with an unknown respiratory illness in December or January that could potentially have been COVID-19.
Dr Georges Benjamin, executive director of the American Public Health Association, told USA Today he also believes it’s unlikely that a significant number of people in the US had COVID-19 before the end of 2019, although it's not impossible.
"I believe at the end of this, when we do look back – and we will – we will probably find that this disease was here earlier than we thought,” before adding that it’s "plausible but not likely" that COVID-19 was circulated in the US before January 2020.
Given what we currently know, there appears to be a very slim chance you had COVID-19 in the US in November or December 2019, unless you were traveling to and from Central China at the time. The chances are higher if you fell sick between January and mid-February, but this would be mere speculation at the moment.
Infected Or Not, Stay Vigilant
Despite your suspicions and hunches, it’s important to act like you have not been infected. If you believe you were infected with COVID-19 earlier this year or before, it might be tempting to think you're safe from the infection. Unconsciously or otherwise, you might start to relax on social distancing measures under the pretense you have recovered from the illness, which would put you and many others at risk.
So, regardless of the cough you experienced around Christmas, experts recommend you stay inside whenever possible, regularly wash your hands, and be sure to follow the advice given by your national health authorities.