Commentary.

[Ann Emerg Med. 2013;62:270-271.]

Acute respiratory tract infection is a common reason prompting an emergency department (ED) visit. Although these illnesses are almost always caused by known respiratory pathogens, emergency physicians should recognize the risk of novel pathogens and be familiar with current recommendations for evaluating patients who may be infected with emerging pathogens from specific geographic areas. This report of a new coronavirus (now referred to as Middle East respiratory syndrome coronavirus, or MERS-CoV) identified in patients in the United Kingdom after travel to the Arabian Peninsula illustrates some important points about identifying infections with novel pathogens and implementing infection control procedures when specific transmission risk may be unknown. The 3 confirmed cases demonstrate that the virus has the capability of human-to-human transmission and coinfection with another pathogen (influenza A). Subsequent clusters of disease confirm that the novel coronavirus can spread from person to person, including from patients to health care workers. Although MERS-CoV has a different genetic sequence than the virus that caused SARS, the implications for emergency medicine are similar.

Health care providers, hospital administrators, and global health organizations learned many important lessons during the 2003 SARS outbreak. The subsequent improvement in infection control measures is especially important for the ED in the event of infectious outbreaks with new pathogens. Transmission in the health care setting to a large number of health care workers and other patients was a notable feature of the SARS coronavirus. The greatest risk of transmission was to individuals who had close contact with infected subjects and who were not properly trained in the use of protective equipment. Exposure of health care providers to procedures that aerosolized droplets such as nebulizers, suctioning, and intubation was another source of virus transmission. N95 respirators may offer protection to individuals involved in high-risk procedures.

CDC recommendations for respiratory hygiene/cough etiquette evolved during the SARS outbreak. These concepts have since been incorporated into CDC planning documents for SARS and pandemic influenza. Although basic precautions such as hand washing are intended for health care workers associated with direct patient contact, respiratory hygiene/cough etiquette applies to everyone in the hospital setting: providers, patients, and visitors. This concept was developed in response to observations that visitors and patients without diagnoses were contributing to hospital transmission. Recommendations included posted signs in different languages about containment of respiratory secretions, convenient hand sanitizers and tissue receptacles, and sitting at least 3 feet apart if coughing. Screening patients with respiratory symptoms for recent travel, placing a mask, and isolation from others in the waiting room/ED are important for early detection and prevention. For pathogens that emerge in specified geographic areas, risk assessment is based on where the organism is currently circulating, ie, within the local community, limited geographic areas, or not actively circulating anywhere in the world. If transmission is occurring only in limited areas (as with the coronavirus in this report), screening should focus on travel from those areas.

Emergency physicians are often the first health care providers evaluating patients presenting with symptoms compatible with an emerging pathogen. When outbreaks are widely reported in the media, EDs are often faced with large numbers of concerned patients. In these situations, it is important to be aware of risk assessment criteria and recommended diagnostic testing strategies. The CDC is a good source of current information and has guidelines for reporting patients to state and local health departments. For example, recommendations for evaluation of suspected infection with this coronavirus were based on travel within 10 days to the Arabian Peninsula or neighboring countries or close contact with a symptomatic traveler. The CDC has similar recommendations for newly emerging viruses such as avian influenza A (H7N9), a virus that has been recently identified in humans in China. There are no specific guidelines for admission or treatment if MERS-CoV is suspected. During the 2003 SARS outbreak, individuals who were discharged home were told to limit interactions with others and not return to work, school, or public areas until 10 days after resolution of fever. Updated recommendations are available at the CDC coronavirus Web site (http://www.cdc.gov/coronavirus/index.html).

As of May 31, 2013, 50 confirmed cases of MERS-CoV have been reported, and 27 individuals have died. Although the SARS coronavirus had a much larger global influence, application of the resulting infection control recommendations could limit the spread of this new coronavirus. Early screening for cases among patients and health care workers, limiting access to hospitals by visitors, and availability of adequate supplies and staffing were shown to be most beneficial in controlling the SARS coronavirus. Simple infection control measures such as these can be applied in EDs to limit outbreaks and minimize transmission of more common infections such as influenza.