A newly published study from the Chinese Center for Disease Control and Prevention (CCDC) is offering a massive epidemiological insight into the ongoing novel coronavirus outbreak. The paper examines more than 44,000 confirmed patients, finding over 80 percent of cases are only mild in severity.
“These data give us a better understanding about the age range of people affected, the severity of the disease and the mortality rate,” says Director-General Tedros Adhanom Ghebreyesus “As such, they are very important in enabling WHO to provide good evidence-based advice to countries.”
The report covers 44,672 confirmed cases of Covid-19, with 1,023 deaths, signaling a fatality rate of 2.3 percent. The majority of fatalities occurred in patients over the age of 50. Although nearly 20,000 of the confirmed cases were in patients aged 49 and under, only 64 of those patients died.
No deaths were noted in children up to the age of nine despite 416 confirmed cases, whereas the fatality rate in patients over the age of 80 is 14.8 percent.
One of the prevailing mysteries surrounding this outbreak is why infection rates have been so low in children. Experts are still unsure of the reasons behind this, and while there may be a physiological reason why children are less likely to contract the virus, it is also just as likely these low infection rates are due to effective quarantine measures.
In terms of disease severity, over 80 percent of confirmed cases were classified as mild. This means the vast majority of people contracting the virus are only suffering mild symptoms and not progressing to pneumonia-like conditions.
However, as previously suggested, patients with comorbid conditions seem at the greatest risk of suffering the worst of the disease. The fatality rate of the disease in patients with no other additional conditions is only 0.9 percent, however, fatality rates were higher for those also suffering cardiovascular disease (10.5 percent), diabetes (7.3 percent), chronic respiratory disease (6.3 percent), or hypertension (6 percent).
The new report also identifies a downward trend in new cases suggesting a possible wane in the epidemic, but Director-General Tedros Adhanom Ghebreyesus warns against interpreting this downward trend as the end of the problem.
“This trend must be interpreted very cautiously,” he says. “Trends can change as new populations are affected. It’s too early to tell if this reported decline will continue. Every scenario is still on the table,”
The report, produced by The Novel Coronavirus Pneumonia Emergency Response Epidemiology Team, optimistically notes the downward trend in the epidemic curve may be an early indication the measures taken by the Chinese government over the last few weeks have been successful in curbing the virus spread.
“… the downward trend in the overall epidemic curve suggest that perhaps isolation of whole cities, broadcast of critical information (e.g., promoting hand washing, mask wearing, and care seeking) with high frequency through multiple channels, and mobilization of multi-sector rapid response teams is helping to curb the epidemic,” the team writes in the paper.
The team does warn of a possible rebound in the epidemic as quarantine measures inevitably loosen and large numbers of people return to daily activities.
“Although the epidemic appears to be in decline in the lead up to February 11, 2020, we may yet face more challenges. Huge numbers of people will soon be returned to work and school after the extended New Year holiday. We need to prepare for a possible rebound of the Covid-19 epidemic in the coming weeks and months,” the team concludes.