As Global COVID-19 Total Passes 850,000, Study Shows 1.4% Fatality Rate

In Asia, Japan yesterday confirmed 87 more cases, 20 of them from airport quarantine, raising its total to 1,953 according to the country’s health ministry. Japan’s COVID-19 cases have risen slower than other countries, but it has been experiencing an uptick in cases in the Tokyo area.

South Korea yesterday reported 125 more cases, lifting its total to 9,786, according an update from the Korea Centers for Disease Control and Prevention. Of those, 29 were imported cases, mostly from Europe or the United States. Most international travelers are now required to self-quarantine before entering the country.

Singapore yesterday reported 47 new cases yesterday, 16 of them imported, and Hong Kong reported 32 new cases, 24 of them with a travel history.

New Fatality Rate Estimates
In research developments yesterday, scientists from the MRC Center for Global Infectious Disease Analysis at Imperial College London estimated that symptom onset to death is 18 days and that the case-fatality rate (CFR) in and outside of China is 1.4 percent, but declined to 0.66 after adjusting for undiagnosed cases. The team, which based its findings on case data from people who died from COVID-19, published its findings yesterday in The Lancet Infectious Diseases.

The hospitalization rate was 8.2 percent for people in their 50s, but rose to 18.4 percent for people ages 80 and older.

In a related commentary in the same issue, Shigui Ruan, PhD, with the mathematics department at the University of Miami in Florida, wrote that estimating the CFR in real time is challenging, but it’s an important piece of information to guide the outbreak response. He added that estimates might vary country to country based on several factors, including differences in prevention, control, preparedness, healthcare availability, and mitigation policies, and because the CFR is substantially affected by the preparedness and availability of healthcare.

Michael T. Osterholm, PhD, MPH, said one problem with the study’s conclusions is that it doesn’t factor in comorbidity risk factors, especially obesity, which is rare in China but much more common in the United States, where 45 percent of men and woman are moderately to severely obese.

He said his conversations with medical colleagues in New York City reveal that the number one risk factor for severe disease and death there is obesity. Osterholm is directory of the University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP), which publishes CIDRAP News.

The study’s authors acknowledge that reality. They write, “Mortality can also be expected to vary with the underlying health of specific populations, given that the risks associated with COVID-19 will be heavily influenced by the presence of underlying comorbidities.”

Different Infection Patterns in Korea
In the other study, researchers from the United States and Korea found differences in illness and death patterns by age and gender when they compared data from South Korea with data from China. They published their findings yesterday in Clinical Infectious Diseases.

In China, illness levels were greatest in people ages 50 to 59, but in South Korea, illnesses showed peaks in two different groups: they were highest in those ages 20 to 29 and second-highest in those ages 50 to 59. China’s cases trended slightly male, while South Korea’s patients were female by a 2:1 ratio. The CFR in South Korean males, however, was twice as high as in female Korean patients.

The researchers said the younger tilt in South Korea’s cases may reflect lower rates of physical distancing and compliance with quarantine measures in younger people.