October 15, 2015
2 min read

MERS remains viable in hospital room after patient discharge

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SAN DIEGO — Researchers from South Korea reported that a majority of the touchable surfaces in the hospital rooms of patients with Middle East respiratory syndrome, or MERS, coronavirus were contaminated even after the patients had recovered from their illness, suggesting the need for stricter environmental disinfection practices to prevent the spread of disease in the hospital setting.

“Middle East respiratory syndrome has caused several health care-associated outbreaks,” Hye Won Jeong, MD, PhD, from the department of internal medicine at Chungbuk National University College of Medicine, said during her presentation at IDWeek 2015. “In South Korea, human-to-human transmission in health care facilities was the main route of outbreak expansion. At present, the detailed mode of transmission and the period of virus shedding from infected patients are still poorly understood.”

The MERS coronavirus (MERS CoV) outbreak in South Korea began in May. To date, there have been 186 confirmed cases, including 33 deaths, although no new cases have been reported in the country since July, according to WHO. Researchers have found no genetic differences between the viruses affecting South Korea and those affecting the Middle East, where the disease originated. Hospitals have emerged as the epicenter of MERS transmission in both regions.

Jeong and colleagues investigated the contribution of environmental contamination to the spread of MERS CoV in the hospital setting and the length of time in which patients continued to shed the virus and potentially spread illness to others.

They enrolled four female patients (median age, 68 years) in airborne isolation at two hospitals with laboratory-confirmed MERS CoV, and their rooms — three at Chungbuk National University Hospital and one at Hallym University Kangnam Sacred Heart Hospital — were analyzed in an environmental study. All four patients had pneumonia, and one patient died.

The researchers collected and cultured respiratory specimens and environmental samples from each patient during the later stages of clinical disease, and they continued to collect and test environmental samples via culture and PCR for up to 120 hours after discharge.

Results of their analysis suggested that most surfaces — including many frequently touched by patients and health care workers such as bedsheets, bedrails and IV fluid hangers — were contaminated by MERS CoV, even after patients’ respiratory specimens were PCR-negative. The virus also was found in the air ventilation system located on the ceiling of the isolation rooms. In addition, Jeong and colleagues detected MERS CoV on anteroom desks and floors, suggesting viable virus could potentially escape the isolation room and spread to the corridor via health care personnel and medical equipment.

Viable virus was found up to 4 days after patient discharge, Jeong said. During the late clinical stages of MERS-CoV infection, the virus was isolated from three patients between days 18 and 25 after symptom onset.

“In a MERS outbreak, we need to isolate patients for a sufficient time period to limit virus spread based on laboratory results rather than rely solely on clinical symptoms,” Jeong said. – by John Schoen


Jeong HW, et al. Abstract 1978a. Presented at: IDWeek; Oct. 7-11, 2015; San Diego.

WHO. Archive of MERS-CoV cases in the Republic of Korea. www.who.int/csr/disease/coronavirus_infections/archive-cases/en/. Accessed October 14, 2015.

WHO. Middle East respiratory syndrome coronavirus (MERS-CoV) – Republic of Korea. www.who.int/csr/don/07-july-2015-mers-korea/en/. Accessed October 14, 2015.

Disclosure: The study was supported in part by the Republic of Korea’s Ministry of Health and Welfare and the Ministry of Science. Jeong reports no relevant financial disclosures.