Environmental Contamination and Viral Shedding in MERS Patients During MERS-CoV Outbreak in South Korea

Clin Infect Dis. 2016 Mar 15;62(6):755-60. doi: 10.1093/cid/civ1020. Epub 2015 Dec 17.


Background: Although Middle East Respiratory Syndrome coronavirus (MERS-CoV) is characterized by a risk of nosocomial transmission, the detailed mode of transmission and period of virus shedding from infected patients are poorly understood. The aims of this study were to investigate the potential role of environmental contamination by MERS-CoV in healthcare settings and to define the period of viable virus shedding from MERS patients.

Methods: We investigated environmental contamination from 4 patients in MERS-CoV units of 2 hospitals. MERS-CoV was detected by reverse transcription polymerase chain reaction (PCR) and viable virus was isolated by cultures.

Results: Many environmental surfaces of MERS patient rooms, including points frequently touched by patients or healthcare workers, were contaminated by MERS-CoV. Viral RNA was detected up to five days from environmental surfaces following the last positive PCR from patients' respiratory specimens. MERS-CoV RNA was detected in samples from anterooms, medical devices, and air-ventilating equipment. In addition, MERS-CoV was isolated from environmental objects such as bed sheets, bedrails, IV fluid hangers, and X-ray devices. During the late clinical phase of MERS, viable virus could be isolated in 3 of the 4 enrolled patients on day 18 to day 25 after symptom onset.

Conclusions: Most of touchable surfaces in MERS units were contaminated by patients and health care workers and the viable virus could shed through respiratory secretion from clinically fully recovered patients. These results emphasize the need for strict environmental surface hygiene practices, and sufficient isolation period based on laboratory results rather than solely on clinical symptoms.

Keywords: MERS-CoV; South Korea; environmental contamination; prolonged viral shedding; transmission mode.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Bedding and Linens / virology
  • Coronavirus Infections / drug therapy
  • Coronavirus Infections / epidemiology
  • Coronavirus Infections / transmission*
  • Coronavirus Infections / virology*
  • Cross Infection / drug therapy
  • Cross Infection / epidemiology
  • Cross Infection / virology
  • Disease Outbreaks / prevention & control
  • Equipment Contamination*
  • Equipment and Supplies, Hospital / virology*
  • Female
  • Fomites
  • Health Personnel
  • Humans
  • Middle Aged
  • Middle East Respiratory Syndrome Coronavirus / genetics
  • Middle East Respiratory Syndrome Coronavirus / isolation & purification*
  • RNA, Viral / isolation & purification
  • Real-Time Polymerase Chain Reaction
  • Republic of Korea / epidemiology
  • Sequence Analysis, DNA
  • Virus Shedding*


  • RNA, Viral