With the recent news that two Californians died of COVID-19 in February, three weeks earlier than the United States' first known death from the disease, it has become clear that the coronavirus was spreading in the United States long before it was detected by testing. 

This fact might have you wondering if that weird cough or recurrent fever you had in late January or February was actually COVID-19. It's not impossible, experts say, but it's not necessarily likely, either. The virus was certainly circulating during that time. However, what is unknown is how prevalent it was, especially compared with the other respiratory viruses of winter. 

Epidemiologists in Colorado believe that the coronavirus landed in the Rocky Mountains somewhere between Jan. 20 and Jan. 30. The estimate comes from two different methods, Elizabeth Carlton, an epidemiologist at the University of Colorado School of Public Health, told Live Science. First, simple back-of-the-envelope calculations based on when the first detected cases in Colorado's outbreak reported symptoms suggest that those people got sick in that time frame. Second, the models that Carlton and her colleagues are using to track and forecast Colorado's cases fit the idea that the first cases in the state emerged between Jan. 20 and Jan. 30. (Colorado didn't report its first cases of the virus until March 4, according to Colorado Public Radio.) 

"It's ski season in Colorado in January, so it's not hard to imagine that someone from one of the West Coast states came to Colorado to go skiing and brought an infection," Carlton said. "That's just one of many possible routes."   

Read the full article at Live Science.

With the recent news that two Californians died of COVID-19 in February, three weeks earlier than the United States' first known death from the disease, it has become clear that the coronavirus was spreading in the United States long before it was detected by testing. 

This fact might have you wondering if that weird cough or recurrent fever you had in late January or February was actually COVID-19. It's not impossible, experts say, but it's not necessarily likely, either. The virus was certainly circulating during that time. However, what is unknown is how prevalent it was, especially compared with the other respiratory viruses of winter. 

Epidemiologists in Colorado believe that the coronavirus landed in the Rocky Mountains somewhere between Jan. 20 and Jan. 30. The estimate comes from two different methods, Elizabeth Carlton, an epidemiologist at the University of Colorado School of Public Health, told Live Science. First, simple back-of-the-envelope calculations based on when the first detected cases in Colorado's outbreak reported symptoms suggest that those people got sick in that time frame. Second, the models that Carlton and her colleagues are using to track and forecast Colorado's cases fit the idea that the first cases in the state emerged between Jan. 20 and Jan. 30. (Colorado didn't report its first cases of the virus until March 4, according to Colorado Public Radio.) 

"It's ski season in Colorado in January, so it's not hard to imagine that someone from one of the West Coast states came to Colorado to go skiing and brought an infection," Carlton said. "That's just one of many possible routes."   

Read the full article at Live Science.