April 18, 2016
3 min read

Inconsistent infection control, isolation fuels hospital MERS outbreak

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Recently published data indicate a 2014 outbreak of Middle East respiratory syndrome coronavirus, or MERS-CoV, that affected 78 people at a Saudi hospital was propelled by overcrowding, poor infection control and inconsistent separation of suspected cases.

Further analysis found the risk for transmission was similar within the hospital’s ED, inpatient areas and dialysis units, despite previously reported data implicating the dialysis units as a substantial risk factor for MERS infection.

“MERS-CoV, like other CoVs, is thought to spread through respiratory secretions; however, the precise ways the virus spreads are not well-understood,” the researchers wrote. “Most documented symptomatic infections have resulted from human-to-human transmission. Transmission among health care workers (HCWs), hospital inpatients, dialysis patients and families has been implicated in previous clusters.”

Exposure risk similar between ED, inpatient areas, dialysis units

From a cohort of reverse transcription PCR-confirmed MERS cases identified through a previous study in Jeddah, Saudi Arabia, the researchers investigated a subset of cases who may have been exposed at the King Fahd General Hospital. Patients, visitors and HCWs were included in analysis if their period of exposure (estimated as 2 weeks before symptom onset) fell within a pre-specified time period. Patient exposures were determined through analysis of electronic records. The investigators interviewed administrative, infection control and clinical personnel and conducted a facility walk-through to evaluate the hospital’s infection control program. Along with determining the probable setting and time of MERS-CoV transmission, the researchers calculated and compared incidence rates for each setting.

Seventy-eight symptomatic MERS patients were believed to have been exposed at the hospital and were investigated. These included 53 hospital patients, 16 HCWs and nine hospital visitors. The overall MERS incidence during the outbreak period was 6.1 cases per 10,000 patient-days. While cases were most often associated with ED exposures, incidence and estimated risk for exposure were similar between the hospital’s ED, inpatient areas and dialysis unit. Although the investigators only were able to directly track transmission for five cases, acquisition within the hospital was strongly suggested due to the duration of these patients’ care, the researchers wrote. Investigation also revealed crowding within the ED early during the outbreak and no system for triaging or isolating available. When ED and dialysis infection control were improved and a MERS unit was established in a separate building, disease transmission declined, the researchers wrote.

“Heightened awareness of MERS, aggressive triaging of patients, prompt isolation and strict infection control measures were associated with a rapid decrease in transmission,” the researchers wrote. “Continued vigilance and consistent adherence to infection control precautions is necessary to prevent future health care-acquired MERS outbreaks.”

‘Intense’ outbreak forces closure of Riyadh hospital’s ED

ED overcrowding and poor infection control also were implicated in a 2015 outbreak that affected 130 people at a tertiary care hospital in Riyadh, Saudi Arabia.

According to 2016 data published in MMWR, the outbreak was traced to a man aged 67 years admitted with a history of fever and cough and confirmed MERS-CoV. After a second case was confirmed 3 weeks later, the hospital’s infection control program initiated an investigation to identify risk factors and exposures.

There were 81 confirmed and 49 probable cases identified during about 2 months, one-third of whom were HCWs. Nearly all cases were linked to the hospital’s ED, and 53% resulted in death.

During the outbreak, the hospital initiated a pre-existing Infectious Disease Epidemic Plan developed from CDC and WHO guidelines. Despite strict enforcement of infection control practices, including hand hygiene and isolation of cases, more patients and HCWs continued to be infected. This led the hospital to close its ED, postpone elective surgical procedures and suspend all outpatient appointments and visits. These measures were associated with a rapid decline in new cases, and subsequently led to the outbreak’s conclusion.

“Although data are still limited, this occurrence is considered a more intense transmission than has been previously described in similar outbreaks,” the researchers wrote. “Early recognition of cases and rapid implementation of infection control guidance is necessary to prevent health care facility-associated outbreaks of MERS-CoV.” – by Dave Muoio

Disclosure: The researchers report no relevant financial disclosures.