Two months into the epidemic, the coronavirus has not proven to be as deadly as the SARS virus. That, however, may also help explain why it’s spreading so quickly. It has an incubation period of up to two weeks, which enables the virus to spread through person-to-person contact.
The coronavirus, a highly contagious, pneumonia-causing illness that infects the respiratory tract, was responsible for 259 deaths in China, with 46 new deaths reported in the previous 24-hour period, and 11,791 infections worldwide, according to the latest figures released by China’s National Health Commission on Saturday (late Friday, EST).
SARS, or severe acute respiratory syndrome, infected 8,096 people worldwide with approximately 774 official SARS-related deaths; most of those infections occurred during a nine-month period from 2002 to 2003. Even with 43 new fatalities reported over 24 hours, the fatality rate remains steady.
SARS had a fatality rate of 9.6%[1] compared to the fatality rate of 2.2% for this new 2019-nCoV strain of coronavirus, which has remained steady for the last several weeks. However, that death toll could rise as the weeks progress, and drug companies scramble to come up with a vaccine for the virus. Whether the fatality rate remains steady has yet to be determined.
Assuming an incubation period of up to 14 days, with an average of 7 days, before a person presents with symptoms of the virus and succumbs to the illness within the first week of diagnosis, the current fatality rate may yet underestimate the eventual rate. The current fatality rate of 259 based on the total number of cases reported four days ago (4,600) equates to a fatality rate of closer to 5.6%.
If, on the other hand, the number of infections is as vastly underestimated, even more so than the fatality rate, that 2.2% coronavirus fatality rate could fall, which would be good news for those who have contracted the illness. (The World Health Organization has declared a global health emergency.)
Maciej Boni, an associate professor of biology, at Pennsylvania State University, said the 2009 H1N1 flu pandemic initially overestimated the final fatality rate, while the SARS fatality rate rose as the virus spread.
Boni wrote on the online science magazine LiveScience[2], “During the 2009 influenza pandemic, the earliest reports listed 59 deaths from approximately 850 suspected cases, which suggested an extremely high case fatality of 7%. However, the initially reported information of 850 cases was a gross underestimate. This was simply due to a much larger number of mild cases that did not report to any health system and were not counted.”
“After several months — when pandemic data had been collected from many countries experiencing an epidemic wave — the 2009 influenza turned out to be much milder than was thought in the initial weeks. Its case fatality was lower than 0.1% and in line with other known human influenza viruses,” he added.
But even...