First Confirmed Cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infection in the United States

Updated Information on the Epidemiology of MERS-CoV Infection, and Guidance for the Public, Clinicians, and Public Health Authorities -- May 2014

Stephanie R. Bialek, MD; Donna Allen, MS; Francisco Alvarado-Ramy, MD; Ray Arthur, PhD; Arunmozhi Balajee, PhD; David Bell, MD; Susan Best, DO; Carina Blackmore, DVM, PhD; Lucy Breakwell, PhD; Andrew Cannons, PhD; Clive Brown, MD; Martin Cetron, MD; Nora Chea, MD; Christina Chommanard, MPH; Nicole Cohen, MD; Craig Conover, MD; Antonio Crespo, MD; Jeanean Creviston; Aaron T. Curns, MPH; Rebecca Dahl, MPH; Stephanie Dearth, MS; Alfred DeMaria, Jr, MD; Fred Echols, MD; Dean D. Erdman, DrPH; Daniel Feikin, MD; Mabel Frias, MPH; Susan I. Gerber, MD; Reena Gulati, MD; Christa Hale, DVM; Lia M. Haynes, PhD; Lea Heberlein-Larson, MPH; Kelly Holton; Kashef Ijaz, MD; Minal Kapoor, MD; Katrin Kohl, MD; David T. Kuhar, MD; Alan M. Kumar, MD; Marianne Kundich; Susan Lippold, MD; Lixia Liu, PhD; Judith C. Lovchik, PhD; Larry Madoff, MD; Sandra Martell, DNP; Sarah Matthews, MPH; Jessica Moore, MPH; Linda R. Murray, MD; Shauna Onofrey, MPH; Mark A. Pallansch, PhD; Nicki Pesik, MD; Huong Pham, MPH; Satish Pillai, MD; Pam Pontones, MA; Sarah Poser; Kimberly Pringle, MD; Scott Pritchard, MPH; Sonja Rasmussen, MD; Shawn Richards; Michelle Sandoval, MPH; Eileen Schneider, MD; Anne Schuchat, MD; Kristine Sheedy, PhD; Kevin Sherin, MD; David L. Swerdlow, MD; Jordan W. Tappero, MD; Michael O. Vernon, DrPH; Sharon Watkins, PhD; John Watson, MD


Morbidity and Mortality Weekly Report. 2014;63(19):431-436. 

In This Article


This report describes the first two cases of MERS identified in the United States. These cases highlight the critical role that health-care providers play in considering a diagnosis of MERS-CoV infection in persons who develop respiratory symptoms within 14 days after traveling from countries in or near the Arabian Peninsula. Recent travelers might seek medical care distant from cities served by international air connections and all HCP need to be vigilant, including those outside of cities with the highest number of arriving travelers from the Arabian Peninsula. Health-care providers and health departments throughout the United States should be prepared to consider, detect, and manage cases of MERS.

Recommendations might change as additional data become available. Guidance on evaluation of patients for MERS, infection control, interim home care and isolation, and collection and testing of clinical specimens for MERS-CoV infection is summarized below and is available on CDC's MERS website ( No specific treatment for MERS-CoV infection is currently available. WHO has posted guidance for clinical management of MERS patients at

Evaluating Patients

CDC's Interim Guidance for Health Professionals was updated on May 9, 2014, to include additional guidance on evaluation of patients and close contacts. Health-care professionals should evaluate for MERS-CoV infection in patients in the United States who meet the following criteria: A) fever and pneumonia or acute respiratory distress syndrome (based on clinical or radiologic evidence) and either 1) a history of travel from countries in or near the Arabian Peninsula within 14 days before symptom onset or 2) close contact with a symptomatic traveler who developed fever and acute respiratory illness (not necessarily pneumonia) within 14 days after traveling from countries in or near the Arabian Peninsula, or 3) is a member of a cluster of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) of unknown etiology in which MERS is being evaluated in consultation with a state or local health department; or B) close contact with a confirmed or probable case of MERS while the affected person was ill. Additional guidance for health-care providers is available at Health-care providers should immediately report any person being evaluated for MERS-CoV infection who meets the criteria of a patient under investigation to their state or local health department. States will then notify CDC. Case definitions are available at Health-care providers should contact their state or local health department if they have any questions.

Infection Control

HCP should adhere to recommended infection-control measures, including standard, contact, and airborne precautions (including eye protection), while managing symptomatic contacts and patients who are patients under investigation or who have probable or confirmed MERS-CoV infections. Additional CDC guidance on MERS-CoV infection control in health-care settings is available at

Interim Home Care and Isolation

Ill persons who are being evaluated for MERS and do not require hospitalization for medical reasons may be cared for and isolated in their home. Health-care providers should contact their state or local health department to determine whether home isolation or additional measures are indicated because recommendations might be modified as more data become available. Isolation is defined as the separation or restriction of activities of an ill person with a contagious disease from those who are well. Additional information on home care and isolation guidance is available at

Collecting and Testing Clinical Specimens for MERS-CoV Infection

To increase the likelihood of detecting MERS-CoV infection, CDC recommends collecting multiple specimens from different sites at different times after symptom onset. For suspected MERS cases, health-care providers should collect the following specimens for submission to CDC or the appropriate public health laboratory: nasopharyngeal swab, oropharyngeal swab (which can be placed in the same tube of viral transport medium as nasopharyngeal swabs), sputum, serum, and stool/rectal swab. In addition to nasopharyngeal/oropharyngeal specimens, collection of lower respiratory specimens (e.g., sputum or bronchoalveolar lavage) is recommended because MERS-CoV infection has been confirmed in sputum of patients who tested negative by PCR for MERS-CoV in nasopharyngeal/oropharyngeal specimens. Personnel collecting specimens should wear recommended personal protective equipment (i.e., gloves, gowns, eye protection, and respiratory protection), and recommended infection control precautions should be used when collecting specimens. Health-care providers should notify their state or local health departments if they suspect MERS-CoV infection in a person. State or local health departments should notify CDC of patients under investigation and any positive MERS-CoV test. Additional information is available at

Travel Guidance

In response to the recent increase in cases of MERS in countries in and near the Arabian Peninsula, CDC updated its advice for travelers. CDC's travel notice has been upgraded to a Level 2 Alert,§§ which includes enhanced precautions for travelers to countries in or near the Arabian Peninsula who plan to work in health-care settings. These travelers should review CDC's recommendations for infection control for confirmed or suspected MERS patients before they depart, practice these precautions while in the area, and monitor their health closely during and after their travel.

CDC continues to recommend that all U.S. travelers to countries in or near the Arabian Peninsula protect themselves from respiratory diseases, including MERS, by washing their hands often and avoiding contact with persons who are ill. If travelers to the region have onset of fever with cough or shortness of breath during their trip or within 14 days of returning to the United States, they should seek medical care. They should call ahead to their health-care provider and mention their recent travel so that appropriate isolation measures can be taken in the health-care setting.

More detailed travel recommendations related to MERS are available at In addition to the Travelers' Health website, CDC is using partner distribution lists, e-mail subscription channels, social media, and airport messages to alert U.S. travelers and clinicians about precautions for MERS.

§§A Level 2 Alert includes recommendations for travelers to follow new or enhanced precautions for the affected destination because of the increased health risk. Additional information available at