A new document from China’s Centers for Disease Control and Prevention (CCDC) reveals that most cases of coronavirus are mild, and that older adults and people with other conditions are at increased risk.

CCDC’s new coronavirus pneumonia emergency response epidemiology team has conducted a study analyzing all confirmed cases of coronavirus, effective February 11, 2020.

Experts have recently named the new coronavirus SARS-CoV-2. The disease that causes infection with the virus is called COVID-19.

In the new study, the CCDC team extracted all cases of COVID-19 that the China Infectious Disease Information System had recorded.

In their analysis, scientists included:

  • “summary of patient characteristics”
  • An analysis of viral spread by age and sex.
  • a calculation of deaths and the “lethality rate”
  • An analysis of viral spread over time and geographic space
  • epidemiological curve or visual visualization of the outbreak
  • an analysis of subgroups of cases outside China’s Hubei province and “all cases among health workers across the country”

Less deadly than SARS

Importantly, the study found that the fatality rate increases with age. Specifically, up to the age of 39, the mortality rate is 0.2%, at the age of 40, it is 0.4%, 1.3% for people aged 50, 3.6% for people aged 60 and finally, 8% for those in their 70s.

By comparison, Severe Acute Respiratory Syndrome (SARS), which health experts have compared coronavirus with fewer people affected in 2002-2003, but the mortality rate was 14-15%, according to the World Health Organization (WHO).

They add that this suggests “that perhaps the isolation of entire cities, the transmission of critical information (e.g., promoting handwashing, masking and seeking attention) with high frequency across multiple channels, and the mobilization o[a]f multisector rapid response teams helping to curb the epidemic.”

However, the authors warn that a “bounce” of the epidemic is still possible:

The COVID-19 epidemic has spread very rapidly, taking only 30 days to expand from Hubei to the rest of mainland China. With many people returning from a long vacation, China needs to prepare for the possible uptick in the epidemic.”

The study also found that “a total of 1,716 health workers have been infected and 5 have died (0.3%)”.

However, “the percentage of severe cases among Wuhan medical staff has gradually declined from 38.9% at peak (January 28) to 12.7% in early February.”