Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea

Yeong Jun Song, Jeong-Sun Yang, Hee Jung Yoon, Hae-Sung Nam, Soon Young Lee, Hae Kwan Cheong, Woo Jung Park, Sung-Han Park, Bo Youl Choi, Sung Soon Kim, Moran Ki

OBJECTIVES The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

2018

Asymptomatic infection, Epidemiology, Middle East respiratory syndrome coronavirus, nosocomial infections, Outbreak, Enzyme-linked immunespecific assay

DOI: 10.4178/epih.e2018014

Epidemiology and Health

Korean Society of Epidemiology

Medicine

EN