Asian outbreak sparks MERS concerns

On May 20, WHO was informed of a laboratory-confirmed case of Middle East respiratory syndrome coronavirus infection in South Korea.

The patient, a traveler from the Middle East, was asymptomatic upon his arrival on May 4. He developed symptoms a week later, was admitted to a hospital on May 15, and finally transferred to a nationally designated treatment facility after confirmation of a positive sputum sample.

Two more patients were confirmed with MERS coronavirus (MERS-CoV) the next day, and as of June 30 there have been 33 deaths and 182 cases of the disease in the country. One more case tied to this outbreak traveled to and has been isolated in China, while another unrelated case also has been identified in Thailand after international travel from Oman.

International response

On June 16, the International Health Regulations Emergency Committee convened to discuss the growing number of MERS cases in South Korea. After identifying major factors contributing to the spread of MERS and confirming no genetic differences between Korean and Middle Eastern viruses, the committee determined that the outbreak did not meet the conditions for a Public Health Emergency of International Concern.

“The Republic of Korea has strongly initiated actions to bring this outbreak under control,” the organization wrote in a statement. “WHO does not recommend the application of any travel or trade restrictions and considers screening at points of entry to be unnecessary at this time. Raising awareness about MERS and its symptoms among those traveling to and from affected areas is good public health practice.”

Limited transmission

Despite the larger number of cases in South Korea, recently published data concerning a MERS patient imported to the United States in 2014 suggests spread of the disease among close personal contacts could be infrequent.

The U.S. patient was a physician and Saudi Arabian resident who traveled by air to Chicago via London, then by bus to Indiana, researchers wrote in Emerging Infectious Diseases. From there, he stayed with his family for 4 days and interacted twice with a business associate before presenting for medical care at an Indiana hospital. Several health care personnel (HCP) came into contact with the patient during this time.

The researchers conducted a thorough contact investigation into the case to assess exposures in the household, community and hospital settings. Contacts were defined as all individuals who were possibly exposed to the case-patient before the introduction of airborne and contact precautions.

Respiratory and blood samples were collected from all contacts, and tested for MERS-CoV. The researchers also interviewed 56 of the case-patient’s 61 contacts.

Of the 45 HCP contacts, the most frequently exposed personnel were in the hospital’s ED (69%). Nurses had the most frequent hospital contact with the case-patient (47%).

Among household and community contacts, the exposure to the case-patient consisted of brief physical contact such as hugging. All laboratory test results were negative for MERS-CoV, and no secondary cases were identified.

“We conducted a thorough contact investigation into this MERS case,” the researchers wrote. “We documented the absence of transmission of MERS-CoV from the first identified imported case-patient in the United States despite his having multiple contacts at home and in the hospital before the implementation of appropriate infection-control procedures.”

As of June 30, WHO has been notified of 1,357 laboratory-confirmed cases of MERS-CoV infection and 486 related deaths globally. – by Jen Byrne and Dave Muoio

References :

Breakwell L, et al. Emerg Infect Dis. 2015;doi:10.3201/eid2107.150054.

Disclosure : The researchers report no relevant financial disclosures.