The mortality rate associated with COVID-19 may be "considerably less than 1%," instead of the 2% reported by some groups, write Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, and colleagues in an editorial published February 28 in the New England Journal of Medicine.

The editorial appeared alongside a report by Wei-jie Guan, PhD, and colleagues, that characterized 1099 patients with laboratory-confirmed COVID-19 from 552 hospitals in China through January 29, 2020. Guan is with the Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University in China,

"Guan et al report mortality of 1.4% among 1099 patients with laboratory-confirmed Covid-19; these patients had a wide spectrum of disease severity. If one assumes that the number of asymptomatic or minimally symptomatic cases is several times as high as the number of reported cases, the case fatality rate may be considerably less than 1%," Fauci and colleagues write.

"This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza (which has a case fatality rate of approximately 0.1%) or a pandemic influenza (similar to those in 1957 and 1968) rather than a disease similar to SARS or MERS, which have had case fatality rates of 9 to 10% and 36%, respectively."

Fauci and colleagues also said research is in full swing to develop a vaccine and they write that the NIH expects the first patients will enter phase 1 trials by early spring.

Characteristics of the Chinese Cohort

In the 1099-patient cohort, the average age was 47 years and 41.9% were female, Guan and colleagues report.

Overall, 67 (6.1%) patients experienced a composite endpoint event, which included admission to an intensive care unit, use of a mechanical ventilator, or death. When the events were analyzed individually, 5% of patients were admitted to the ICU, 2.3% placed on a ventilator, and 1.4% died.

Among 173 patients with severe disease, 43 patients (24.9%) met the composite endpoint.

The researchers calculated the cumulative risk of the composite endpoint among all patients as 3.6%; for those with severe disease, the cumulative risk was 20.6%.

The authors point out that patients often presented without fever and many did not have abnormal imaging results.

Among 877 patients with nonsevere disease, 157 (17.9%) had no radiographic or computed tomography (CT) abnormality detected. Among the those with severe disease, the percentage with normal radiographic and CT results was substantially lower at 2.9%.

Of those with abnormal radiographic findings, "the most common patterns on chest CT were ground-glass opacity (56.4%) and bilateral patchy shadowing (51.8%)," write Guan and colleagues.

Most Common Symptoms

Fever was the most common symptom, the authors write. It was present in only 43.8% of the patients at admission, but 88.7% had or developed fever while in the hospital.

The second most common was cough (67.8%). Nausea, vomiting, and diarrhea were uncommon (found in 5% or less of patients). Nearly 1 in 4 had "at least one coexisting illness (eg, hypertension and chronic obstructive pulmonary disease)," the authors write.

"Lymphocytopenia was present in 83.2% of the patients on admission," they note.

Demographic Characteristics

Overall, 38 (3.5%) of the patients were healthcare workers, and 483 patients (43.9%) were residents of Wuhan, China, the authors write. Only 1.9% of the patients had come into direct contact with wildlife.

Among those who lived outside Wuhan, 72.3% had contact with people who lived there. More than a quarter (25.9%) of nonresidents had neither visited the city nor had contact with Wuhan residents.

On admission, 926 in the cohort had nonsevere disease and 173 were categorized as having severe disease.

The average time in the hospital was 12 days.

"During hospital admission, most of the patients received a diagnosis of pneumonia from a physician (91.1%), followed by [acute respiratory distress syndrome] (3.4%) and shock (1.1%). Patients with severe disease had a higher incidence of physician-diagnosed pneumonia than those with non-severe disease (99.4% vs. 89.5%)," the authors write.

Those who had severe disease in the cohort overall tended to be older by an average of 7 years.

The research was funded by the National Health Commission of China, the National Natural Science Foundation, and the Department of Science and Technology of Guangdong Province.

New Engl J Med. Published online February 28, 2020. Full text, Editorial

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