Current Threat in COVID-19. Asymptomatic Carriers

ABSTRACT

BACKGROUND/AIM: Asymptomatic infections are not low in their inability to spread the virus and have no special clinical signs. Consequently, the detection of asymptomatic infections is the central issue for early prevention and control of the coronavirus disease-2019 (COVID-19) around the world. This study aimed to assess the demographic, clinical, and laboratory findings of symptomatic and asymptomatic patients with a diagnosis of COVID-19. MATERIALS AND METHODS: In this retrospective single-center study, 165 laboratory-confirmed COVID-19 patients who were asymptomatic or symptomatic and followed up at home or in the hospital between March 15, 2020, and May 23, 2020, were included. RESULTS: Among all 165 patients, 21 (12.7%) were asymptomatic and 144 (87.2%) were symptomatic. The median age of the symptomatic patients was higher than the asymptomatic patients, and there were no asymptomatic patients over 65 years older. Twenty-one patients were asymptomatic at admission, but four of them (19%) developed symptoms in the follow-up. Although the white blood cell (WBC) and lymphocyte counts were within the normal range for all patients, the asymptomatic patients had a significantly higher WBC and lymphocyte count than the symptomatic patients. The symptomatic patients had higher median C-reactive protein levels than the asymptomatic patients. For the typical CT findings for COVID-19, there were fewer in the asymptomatic infections (12 cases, 57.1%) than those in the symptomatic infections (103 cases, 71.5%). There were 17 (10%) patients in need of intensive care and the mortality rate was 6.1%. CONCLUSION: Asymptomatic infections spread silently in COVID-19. More importance should be given to the identification and quarantine of asymptomatic patients to eliminate COVID-19 transmission and to allow for the early diagnosis of pre-symptomatic patients.