Perhaps with those pitfalls in mind, the United States Centers for Disease Control and Prevention (CDC) has been ramping up its advice to clinicians to be aware of the possibility of patients in the U.S. presenting with MERS, which was first identified in Saudi Arabia in 2012, and to expedite diagnoses. The difficulty is that the initial symptoms of the often-deadly disease are much like those of less serious respiratory ailments. Questions need to be asked about the recent travel history of patients with respiratory symptoms. MERS cases have originated in several countries in or near the Arabian Peninsula: Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, United Arab Emirates (UAE), and Yemen. In addition to South Korea, among the countries to which it has travelled are Austria, China, Egypt, France, Germany, Greece, Italy, Malaysia, the Netherlands, the Philippines, Tunisia, Turkey, and the United Kingdom.
The CDC has alerted clinicians as follows:
“Limited data on the clinical presentation of MERS are available; most published clinical information to date is from critically ill patients. At hospital admission, common signs and symptoms include fever, chills/rigors, headache, non-productive cough, dyspnea, and myalgia. Other symptoms can include sore throat, coryza, sputum production, dizziness, nausea and vomiting, diarrhea, and abdominal pain. Atypical presentations, including mild respiratory illness without fever and diarrheal illness preceding development of pneumonia, have been reported. Clinical judgment should be used to guide testing of patients for MERS-CoV infection.”
Recognizing that the clinical lab plays a crucial role in the timely diagnostics that are required, the CDC has provided guidance to laboratories as well:
“To date, limited information is available on the pathogenic potential and transmission dynamics of MERS-CoV. To increase the likelihood of detecting MERS-CoV infection, CDC recommends collecting multiple specimens from different sites at different times after symptom onset.
“In a PUI [Person Under Investigation], CDC strongly recommends testing a lower respiratory specimen (e.g., sputum, broncheoalveolar lavage fluid, or tracheal aspirate), a nasopharygeal/oropharygeal swab, and serum, via the CDC MERS-CoV rRT-PCR assay. If symptom onset was more than 14 days prior, CDC also strongly recommends additional testing of a serum specimen via the CDC MERS-CoV serologic assay.
“Most state laboratories are approved to test for Middle East Respiratory Syndrome Coronavirus (MERS-CoV) using CDC’s rRT-PCR assay. However, they should coordinate with CDC for specimen testing since widely available diagnostic tests are not suitable.
“FDA issued an Emergency Use Authorization (EUA) on June 5, 2013, to authorize use of CDC’s 2012 real-time reverse transcription–PCR assay to test for MERS-CoV in clinical respiratory, blood, and stool specimens. CDC has distributed this device to qualified laboratories in the United States and around the world….The Emergency Use Authorization was recently expanded to allow use for testing asymptomatic contacts.”
It is very unlikely that an epidemic of MERS will occur in the U.S. It is quite possible that the Korean outbreak, the largest on record outside of the Middle East, will result in some cases. Procedures to address this eventuality are in place, and must be followed.