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Middle East Respiratory Syndrome (MERS) Quicksheet

COVID Control Branch

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Quicksheet

Background

Middle East respiratory syndrome (MERS) is an illness caused by a distinctive coronavirus (MERS-CoV).  
Typical symptoms include fever, cough, chills, and shortness of breath, although certain patients with compromised immune systems might not mount a fever. Some cases have had head and body aches, sore throat, abdominal pain, diarrhea, nausea, or vomiting. Other cases have been asymptomatic.  
Complications include severe pneumonia, acute respiratory distress syndrome, and organ failure. Approximately 35% of confirmed cases have died. Most severe cases of MERS have had underlying chronic medical conditions.  
Zoonotic transmission from infected dromedary (single-hump) camels to human caretakers is the primary mode of virus transmission.  
Limited human-to-human transmission of MERS-CoV has occurred in family members and healthcare workers exposed to cases. To date, there is no evidence of sustained transmission in the community. 
There is no specific antiviral treatment for MERS-CoV infection; management is supportive.

Suspect MERS Case Definition 

People that meet the following MERS criteria should be evaluated and tested for MERS-CoV infection.  

Severe Illness and Epidemiologic Risk Criteria: A person with fever (≥ 38°C, 100.4°F) AND pneumonia or acute respiratory distress syndrome (based on clinical or radiological evidence) with no other more likely alternative diagnosis; AND EITHER 

History of travel from countries in or near the Arabian Peninsula¹ within 14 days before symptom onset; OR 
Close contact with a symptomatic person who developed fever and acute respiratory illness within 14 days of residing in or traveling from countries in or near the Arabian Peninsula¹; OR 
History of direct or indirect physical contact² with camels in North, West, or East Africa³ within 14 days before symptom onset; OR 
A member of a cluster of patients with severe acute respiratory illness (e.g., fever and pneumonia requiring hospitalization) of unknown etiology; OR 
High risk occupational exposure to MERS-CoV, such as laboratory or research personnel⁴.

Milder Illness and Epidemiologic Risk Criteria: A person with fever OR symptoms of respiratory illness (not necessarily pneumonia; e.g. cough, shortness of breath) with no other more likely alternative diagnosis; AND EITHER 

History of being in a healthcare facility (as a patient, worker, or visitor) within 14 days before symptom onset in a country or territory in or near the Arabian Peninsula in which recent healthcare associated cases of MERS have been identified; OR 
History of direct or indirect physical contact² with camels in or near the Arabian Peninsula¹; OR 
Close contact⁵ with a confirmed MERS case while the case was ill; OR 
High risk occupational exposure to MERS-CoV, such as laboratory or research personnel⁴.

MERS Infectious Period  

The infectious period for MERS-CoV is not clearly established but typically, patients with more severe disease shed virus longer than laboratory confirmed cases with mild or no symptoms.  

MERS Incubation Period  

Most patients develop symptoms approximately 5 days after an exposure to an infected person or camel, but the incubation period can range from 2 to 14 days. 

¹Includes Bahrain, Iraq, Iran, Israel, the West Bank and Gaza, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, the United Arab Emirates (UAE), and Yemen.

²Direct physical contact could include touching, riding, hugging, kissing, grooming, racing, shepherding, pageant showing, working in an abattoir, or exposure to camel respiratory secretions. Indirect contact can include consumption of raw camel milk, undercooked camel meat or use of camel urine.

³Consider MERS evaluation for travelers coming from North, West, or East Africa regions who develop severe respiratory illness within 14 days of direct or indirect physical camel contact.

⁴Laboratory exposure can occur through contact with infected animals and viral specimens without proper precautions and personal protective equipment (PPE)

⁵Close contact is defined as: a) being within approximately 6 feet (2 meters), or within the room or care area, of a confirmed MERS patient for a prolonged period of time (such as caring for, living with, visiting, or sharing a healthcare waiting area or room with, a confirmed MERS patient) while not wearing recommended PPE (e.g., gowns, gloves, NIOSH-certified disposable N95 respirator, eye protection); or b) having direct contact with infectious secretions of a confirmed MERS patient (e.g., being coughed on) while not wearing recommended PPE.

Public Health Reporting

Local health departments should immediately notify CDPH of suspect MERS cases by first creating a MERS-CoV incident report in CalREDIE.  LHDs should additionally notify the Coronavirus Control Branch at CDPH via email at (coronavirusclinical@cdph.ca.gov and COVIDepi@cdph.ca.gov) and, if after hours, contact the CDPH Duty Officer (916) 328-3605.  

The CDPH MERS investigation team will work with local health departments to determine if testing is indicated, and if so, how to proceed.  

Testing Considerations when considering a MERS diagnosis 

A full differential diagnosis should be taken into account when considering MERS testing. Pathogen-specific testing should be ordered based on the most likely etiology for the patient’s clinical presentation. In most scenarios in the United States, testing for other more common pathogens should be done before testing for MERS-CoV.  

Consider testing for common viral respiratory pathogens, including SARS-CoV-2, influenza A, influenza B, respiratory syncytial virus (RSV), human metapneumovirus, human parainfluenza viruses, seasonal human coronaviruses, adenovirus, enterovirus/rhinovirus, and other respiratory viruses. Also, test for other common bacterial pathogens including Streptococcus pneumoniae, Chlamydia pneumophila, Legionella pneumophila, Mycoplasma pneumoniae, and other bacterial pathogens that cause severe lower respiratory infections.  

If there is strong suspicion that an individual is infected with MERS-CoV, simultaneous testing for MERS-CoV along with other possible pathogens should be considered. 

MERS-CoV Specimen Collection and Testing 

Polymerase chain reaction (PCR) testing for MERS-CoV is available at the CDPH Viral and Rickettsial Disease Laboratory (VRDL). This is a presumptive assay, confirmation of MERS-CoV is performed at the CDC.

Prior approval is required to ship samples for MERS-CoV testing. Local health departments should 1.) Obtain approval from CDPH and then 2.) Contact VRDL at 510-307-8585 or at VRDL.submittal@cdph.ca.gov to arrange shipping. VRDL will not test specimens for MERS-CoV that are received without prior approval, coordination, and tracking information.

Collect and priority ship specimens. Acceptable types:

Lower respiratory tract specimens have the highest yield in patients with MERS-CoV pneumonia. Whenever possible collect one or more of: bronchoalveolar lavage fluid, tracheal aspirate, pleural fluid, or sputum.
Upper respiratory tract specimens: Obtain nasopharyngeal and oropharyngeal (throat) with swabs made of synthetic fiber (NOT cotton) with plastic shafts may be submitted in viral or universal transport medium. Swabs must have a Dacron or synthetic tip with aluminum or plastic shaft. Do not use calcium alginate or wooden shaft swabs as they may contain substances that inactivate some viruses and inhibit PCR testing.
Serum and/or stool may be submitted with respiratory specimens.

Send respiratory samples in 2-3 mL of Universal or Viral Transport Medium.

For additional specimen collection information, see VRDL Test Page - MERS-CoV PCR.

Specimens must be accompanied with a hard copy of the completed VRDL General Purpose Specimen Submittal Form (PDF) (one for each specimen) or a form generated in the VRDL Lab Web Portal.:

Include CalREDIE incident ID number for Individual’s Epidemiologic and Clinical information.
Samples should be packaged according to instructions for Biological Substance – Category B (UN 3373) shipment. Submitters must coordinate deliveries with VRDL (VRDL.submittal@cdph.ca.gov) before shipping.
VRDL accepts sample deliveries 7 days/week, but for sample deliveries after business hours, or on weekends or holidays, specific consultation with VRDL is required and can be discussed on a case-by case basis. For consultation, please contact VRDL via email at VRDL.submittal@cdph.ca.gov.

Laboratories should NOT attempt to perform viral culture on specimens from patients with suspected or laboratory-confirmed MERS infection.  

Infection Control

Hospital Isolation

Suspect or confirmed MERS cases who are ill enough to be hospitalized should be placed in an airborne infection (negative-pressure) isolation room with Airborne, Contact, and Standard precautions, including eye protection. Isolation should continue until the patient is asymptomatic and has two consecutive upper respiratory tract samples (e.g. nasopharyngeal l [NP] and/or oropharyngeal [OP] swabs) taken at least 24 hours apart test negative on RT-PCR. See updated CDC and WHO hospital infection control guidance for more information. 

Home Isolation 

Persons with suspect or confirmed MERS infection who are not ill enough to require hospitalization should:  

Stay home: Restrict activities outside the home, except for getting medical care and not go to work, school, or public areas, or use public transportation.  
Separate themselves from other people in the home: Stay in a different room from other people in the home as much as possible and use a separate bathroom, if available.  
Call ahead before visiting the doctor: Before a medical appointment, notify the healthcare provider about the possibility of MERS infection.  
Wear a facemask: Wear a facemask when in the same room with other people and when visiting a healthcare provider. If a facemask cannot be worn, persons in the home should wear one while in the same room with the patient. 
Cover coughs and sneezes: Cover mouth and nose with a tissue when coughing or sneezing, or cough or sneeze into a sleeve. Throw used tissues in a lined trash can, and immediately wash hands with soap and water.  
Keep hands clean: Wash hands often and thoroughly with soap and water. Use alcohol-based hand sanitizer if soap and water are not available and if hands are not visibly dirty. Avoid touching eyes, nose, and mouth with unwashed hands.  
Avoid sharing household items: Do not share dishes, drinking glasses, cups, eating utensils, towels, bedding, or other items with other people in the home.  These items should be washed thoroughly after use with soap and warm water.

These recommendations should be followed until symptoms are resolved based on either clinical and/or laboratory findings (two negative RT-PCR tests at least 24 hours apart).  

MERS Close Contact Definition 

Any person who was: 

Within approx. 6 feet or within the room or care area for a prolonged period of time (e.g., healthcare personnel, household members) while not wearing recommended personal protective equipment (i.e., gowns, gloves, respirator, eye protection).

In direct contact with infectious secretions (e.g., being coughed on) while not wearing recommended personal protective equipment.

At this time, brief interactions, such as walking by a person, are considered low risk and do not constitute close contact. If an exposure occurs in a venue in which individual contacts cannot be identified, local healthcare providers should be notified to be on the alert for possible cases. 

Management of Contacts 

Close contacts of suspect or confirmed MERS cases should monitor their health for 14 days, starting from the day they were last exposed to the ill person. 

Symptom monitoring includes temperature checks twice daily and self-observation for: 

Fever (≥ 38°C/100.4°F) 
Coughing 
Shortness of breath 
Any other symptoms such as chills, body aches, sore throat, headache, runny nose, abdominal pain, diarrhea, nausea or vomiting.

Close contacts should alert their local health department immediately if they develop symptoms; the local health department should arrange for evaluation and testing in a healthcare setting that can provide appropriate isolation and infection control. 

While being evaluated, symptomatic contacts should stay home other than for medical care and follow other recommendations for persons under home quarantine. 