Earlier this week, Dr. Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases, said SARS-CoV-2 surprised him with “how rapidly it just took over the planet. . . . This took about a month to go around the world.”
Certainly between January 1 and January 31, the coronavirus changed from the subject of vague reports about a strange flu in Wuhan to an official World Health Organization “public health emergency of international concern,” with cases in 19 countries.
But when did the virus start going around the world? France has determined that a man who had not traveled out of the country caught it in December. In Washington state, two Snohomish County residents who have positive serology tests potentially linked to COVID-like illnesses dating back to December. Last week, ABC News offered more anecdotal evidence from satellite photography suggesting that residents of Wuhan knew some sort of serious health problem was brewing in October; one interpretation of the data suggests hospital visits started increasing as early as August 2019. Separately, an American couple described a Chinese cruise company rushing to get them out of Wuhan on November 1.
So this virus certainly commanded the world’s attention in a one-month span . . . but how likely is it that this virus spread around the world for two, three, or maybe even four months before the world realized the scale of the threat?
Medical researchers are trying to get a sense of just how many people catch the virus and remain asymptomatic — that is, they get it and remain contagious but suffer no symptoms. A recent study concluded that “the overall rate of asymptomatic infection is likely at least 30 percent and could be as high as 40 percent to 45 percent.” We can be frustrated that governments and doctors couldn’t mitigate the spread of this virus earlier, but it is really difficult for medical authorities to detect and contain infections when the patients themselves don’t realize that they’re infected.