Asymptomatic cases may play a role in COVID-19 transmission, features of these patients have not been well described. This study describes the characteristics of asymptomatic patients with SARS-CoV-2 infection in Jinan, Shandong province, China.

The authors examined the medical records of 47 patients with confirmed COVID-19 who were diagnosed between January 23 to March 10, 2020.

Among these patients, 11 (23.4%) were asymptomatic. Characteristics of asymptomatic patients included:

• 6 (54.5%) were men and 5  (45.5%) were women
• median age was 23 years (range 1 to 60 years);
• 5(45.5%) were children
• 7 (63.6%) had contact with confirmed cases.
• median time from admission to negative conversion of viral RNA was 10 days (range 3 to 34 days)
• median time of hospital stay was 14 days (range 10 to 30 days)

Compared with symptomatic patients, the hospital stay of asymptomatic patients was significantly shorter (14 days vs 22.5days, P=0.004). Creatine kinase-MB was also significantly higher in the asymptomatic group than in the symptomatic group (P=0.020), but there were no other statistically significant group differences in laboratory tests.

Comparing the characteristics of asymptomatic and symptomatic cases did not yield any indicators that would help with screening. Therefore authors suggest isolating symptomatic patients and quarantining their close contacts, especially family members.