First Human-transmitted MERS Case Detected in U.S.

CDC Resources Can Guide Physicians in Evaluating, Managing Possible Cases

May 20, 2014 12:28 pm News Staff

(Editor's Note: On May 28, the CDC announced that after additional testing, the agency has determined that the Illinois man believed to have contracted Middle East respiratory syndrome coronavirus (MERS-CoV) infection from contact with the first U.S. patient diagnosed with MERS-CoV infection was not actually infected.)

Just five days after the CDC confirmed a second imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in an individual who had recently traveled to the United States from Saudi Arabia, a third case has been reported( This time, CDC officials have identified a clear face-to-face connection between the latest person infected with the virus and the nation's very first case of imported MERS-CoV infection reported on May 2.

[Man with herd of camels in desert]

Unlike the first two patients infected, the third individual -- an Illinois resident -- never became ill and sought no medical treatment. Still, people should continue to take common-sense precautions to avoid possible exposure to the virus, said one CDC official.

"This latest development does not change CDC's current recommendations to prevent the spread of MERS," said David Swerdlow, M.D., who is leading the agency's response to the MERS-CoV case reports. "It's possible that as the investigation continues, others may also test positive for MERS-CoV infection but not get sick.

"Along with state and local health experts, CDC will investigate those initial cases and if new information is learned that requires us to change our prevention recommendations, we can do so."

Among those recommendations for preventing spread of the illness are the following:

Story highlights
  • A third case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection has been confirmed in the United States.
  • The most recent case is thought to have been caused by close, extended contact with the patient who first imported MERS-CoV into the country.
  • The CDC has released a number of interim guidance resources on MERS-CoV for physicians and other health care professionals.
  • For the general public: Although health experts do not yet know exactly how the virus is spread, CDC officials routinely advise people to take the initiative in protecting themselves from respiratory illnesses through preventive activities such as frequently washing their hands, avoiding touching their face with unwashed hands, avoiding contact with people who appear ill and disinfecting frequently touched surfaces.
  • For travelers: The CDC currently does not recommend that U.S. residents change their travel plans. For individuals who travel to countries in or near the Arabian Peninsula, however, the agency recommends that they pay close attention to their health during and after their trip. The CDC travel notice for MERS-CoV advises people traveling to the Arabian Peninsula for health care work to follow the agency's recommendations for infection control and cautions other travelers to the Arabian Peninsula to take general steps to protect their health.
  • For physicians and other health care professionals: Patients who should be evaluated for MERS-CoV infection are those with fever and pneumonia or acute respiratory distress syndrome who have an appropriate travel history or a history of close contact with a symptomatic person who traveled in or near the Arabian Peninsula within 14 days before symptom onset. In addition, any person who is part of a cluster of patients with severe acute respiratory illness of unknown etiology in which MERS-CoV is being evaluated should also be assessed for the viral infection.

Following each case report, public health officials have reached out to health care professionals, family members and others who had close contact with the patient to offer guidance on monitoring their health and to recommend evaluation by a physician. Officials also have worked with airlines to identify and notify U.S. travelers who may have been in close contact with an infected patient on any transcontinental or domestic flight.

MERS-CoV infection was first reported in Saudi Arabia in 2012. As of May 16, 572 laboratory-confirmed cases of MERS had been reported in 15 countries, according to the news release. Most patients developed severe acute respiratory illness, with fever, cough and shortness of breath, and 173 people died of the disease. As previously noted, officials do not know where the virus came from or exactly how it spreads, although camels have been implicated in outbreaks in Egypt, Saudi Arabia and nearby areas. There is no available vaccine or specific treatment recommended for the virus.

The CDC has released a number of interim guidance resources on MERS-CoV for physicians( and other health care professionals, such as information about clinical features of the disease, and guidance on evaluating and managing close contacts of a confirmed or probable case, specimen collection and laboratory testing, and infection control. Information about specific case definitions(, checklists to help health care professionals( and facilities enhance infection control preparedness, interim guidance regarding home care and patient isolation( and interim recommendations( for managing hospitalized patients with the infection also are available from the CDC website.

Additional Resources
Call Transcript: May 6 CDC Update for Clinicians on Middle East Respiratory Syndrome Coronavirus (MERS-CoV)(

Emerging Infectious Diseases Dispatch: MERS Coronaviruses in Dromedary Camels, Egypt(
(June 2014)

Emerging Infectious Diseases Research: Antibodies against MERS Coronavirus in Dromedary Camels, United Arab Emirates, 2003 and 2013(
(April 2014)