MERS virus: CDC advises an 'abundance of caution'

Doctors and health care workers should err on the side of caution with a patient possibly infected with Middle East Respiratory Syndrome Coronavirus (MERS-CoV), said infectious disease experts at the Centers for Disease Control and Prevention (CDC) in a June 11 webcast to health care providers.

Only two confirmed cases of MERS-CoV have been reported in the United States—and both of those occurred last year. But in light of the current viral outbreak in the Republic of Korea, the CDC updated its evaluation guidelines. Red flags for patients who may be infected include:

• Fever and/or upper respiratory illness
• A history of travel to Korea or the Arabian peninsula
• Exposure to a health care facility

Other signs and symptoms of acute illness are chills/rigors, headache, non-productive cough, dyspnea, and myalgia. Additional symptoms can include sore throat, coryza, sputum production, dizziness, nausea, vomiting, diarrhea, and abdominal pain. But these characteristics are not exhaustive, and there are many unknowns. All patients should be evaluated on a case-by-case basis, said CDC experts.

If the patient’s clinical presentation or exposure history is uncertain, then “in an abundance of caution, I would recommend at this time to call public health authorities” for further guidance, said CDC’s Susan Gerber, MD, Team Lead of the Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.

The CDC update coincides with news from Korea of an eleventh death from the virus. At this time, Korea now has 125 confirmed cases, which is the largest outbreak of MERS-CoV outside the Arabian Peninsula, where the virus was first identified in 2012, according to the World Health Organization (WHO). Investigators using genetic sequencing have traced the virus to dromedary camels, the likely primary source of MERS-CoV, the WHO reported.

Person-to-person spread usually involves close contact, particularly in hospitals and health care settings, the CDC said. Researchers have not detected that MERS-CoV is spreading in the community.

For any patient who has the likely signs, symptoms and history, evaluation and testing should be performed immediately. “Our recommendation right now for acute infection is to collect multiple specimens,” Dr. Gerber said. “If available, lower respiratory tract specimens are still the preferred specimen to detect MERS-CoV. In addition, we do request nasopharyngeal/oropharyngeal swabs plus serum for acute PCR [assay].” Also, patients should be questioned about when their illness or symptoms began.

Additional CDC guidelines recommend precautions for contact with “patients under investigation” to minimize exposure. “When scheduling appointments, instruct patients and those who accompany them to call ahead or inform personnel on arrival if they have respiratory symptoms,” said CDC’s David Kuhar, MD, Medical Officer in the National Center for Emerging and Zoonotic Infectious Diseases.

For health care workers and staff, “ensure that all who enter the patient care area adhere to standard contact and airborne precautions,” he added. “Hand hygiene should be performed before and after all patient contact, contact with potentially infectious material, and before putting on and removal of personal protective equipment.” Recommended equipment includes gowns, gloves, respirator (NIOSH-certified disposable N95 respirators or equivalent) and eye protection.

“Rapid triage and isolation of patients at risk for infection of MRS is critical,” Dr. Kuhar said. Such patients should be immediately isolated in an airborne-infection isolation room. For medical offices and outpatient clinics without such a room, “placing them in a standard patient room with a facemask on for source control and with the door closed could be a sufficient temporizing measure. After that, they should be transferred to a facility with an airborne-infection isolation room as soon as possible,” he said.

The latest guidelines for health care professionals are posted on a dedicated page about MERS on the CDC website. Dr. Gerber noted that these are only guidelines, and they will be changing.

Most importantly, if you think you’re dealing with an infected patient, “please call local and state health department authorities immediately,” she concluded. “I can’t emphasize enough that state and local public health departments need to be part of the process and decision making.”