Q&A: Why MERS matters
An outbreak of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has recently been reported in South Korea and China. Frightening, given that nearly thirty percent of those that contract the virus die and that in this age of air travel, any person – and the viruses he or she is carrying – can move across the world in a matter of hours. With no known cure or vaccine, many wonder if the SARS (Severe Acute Respiratory Syndrome) cousin poses a public health threat to the United States. To find out more about the possibility of a global health concern, we sat down with Gerald Parker, D.V.M., Ph.D., vice president of public health preparedness and response at Texas A&M Health Science Center, who recently visited the impacted area as he addressed the Institute Pasteur Korea to share recent experience with Ebola in Texas.
Q: What is MERS?
A: MERS-CoV, or Middle East Respiratory Syndrome, first found in the Arabian Peninsula in 2012, is a coronavirus – the same group of viruses that cause the common cold and SARS, or Severe Acute Respiratory Syndrome that was identified in 2003. MERS-CoV attacks the respiratory system. The virus manifests in humans with flu-like symptoms including fever, cough and shortness of breath and can lead to severe symptoms like pneumonia and kidney failure.
Q: Who is at greatest risk?
A: All existing cases of MERS-CoV have been traced back to the Middle East, specifically the Arabian Peninsula, except one recent case of an individual that traveled from South Korea to China; however, even this case does have origins in the Middle East. Traveling to or from the Arabian Peninsula and South Korea and having close contact with an ill person from these areas puts people at greater risk for contracting the disease. People at greatest risk have been health care workers who have close contact with MERS-CoV patients.
While it’s still unknown how people initially became infected with MERS-CoV, the virus has been found in camels and bats, and it is possible initial cases were a spillover event from animals carrying the virus.
According to the World Health Organization (WHO), some people are also more at risk for developing severe MERS. These groups include people with:
- Kidney failure
- Chronic lung diseases
- Weakened immune systems
Q: What are the symptoms?
A: The common symptoms of MERS-CoV include fever, cough and shortness of breath. Some people also suffer from gastrointestinal symptoms such as diarrhea, nausea and vomiting. Severe complications can include pneumonia and kidney failure.
Q: How is MERS transmitted?
A: MERS-CoV has spread from ill people to others through close contact, such as caring for or living with an infected person. Infected people have spread MERS-CoV to others in health care settings, such as hospitals. Sustained human-to-human spread of MERS-CoV in the community has not been reported. There have been a few cases in which someone contracted the virus after coming in close contact with an infected person who had recently traveled from the Arabian Peninsula. There is an ongoing serious outbreak in South Korea resulting from a traveler returning to Korea from the Middle East. MERS-CoV subsequently spread to China from a family member of a Korean MERS patient who defied orders not to travel from Korea.
Q: How did the current MERS outbreak in South Korea start?
A: The Korean Ministry of Health reported that a 68-year-old man was diagnosed with MERS on March 20, 2015.
The individual arrived at Inchon International Airport on May 4, following a two-week business trip to Bahrain. He did not show any symptoms upon his return to South Korea. The patient presented with fever and a cough beginning on May 11 and visited two clinics and two hospitals in the ensuing days. He was treated symptomatically and sent home each time. A sputum sample was submitted for MERS-CoV laboratory testing on May 19 with a confirmed diagnosis coming the following day.
Doctors at the clinics and hospitals did not isolate the man initially because he did not report his travel history and possible exposure to MERS. It is not clear whether or not the two clinics and hospitals asked the patient about his travel history. Before his diagnosis, he potentially exposed a number of medical staff and hospital patients, as well as their family members and visitors and they, in turn, exposed others.
As soon as the Korean Centers for Disease Control and Prevention became aware of a laboratory confirmed case of MERS, an epidemiologic investigation to identify contacts and contain the outbreak was initiated. The same day, the patient was hospitalized at a designated hospital for isolation and treatment.
During the initial investigation, the patient reported that he was not in contact with common sources for the infection, such as camels or patients with similar respiratory symptoms, during his stay in Bahrain or while returning to Korea through Qatar.
Bahrain had no reported cases of MERS to date and Qatar, where the patient made a brief stop for a plane change, reported no cases of MERS for the past two months. Officials subsequently learned that the patient also traveled to Saudi Arabia and United Arab Emirates, where there are active cases. The World Health Organization is working with public health authorities in the Middle Eastern countries to determine how the South Korean index patient was exposed to the virus.
Q: How did MERS spread to China?
A: A family member of a Korean MERS patient departed, against doctor’s orders, for China traveling through Hong Kong to Guangdong Province for business on May 26.
As soon as the Korean Ministry of Health became aware that the man disobeyed an order not to travel, they immediately notified the public health authorities in China so they could take action to find and isolate the patient, identify potential contacts, and institute strict infection control. The man tested positive for MERS three days later, and he was hospitalized and isolated in China. To date, no new MERS-CoV cases have occurred in China. This is the first time that an imported case resulted in a secondary transmission affecting another country.
Q: What is the current status in South Korea?
A: To date, 150 people have tested positive for MERS in South Korea, with 16 deaths. All confirmed cases are due to exposure in health care facilities.
Fifty of the 150 patients are age 50 and below, and were in relatively good health before contracting MERS-CoV. Some of the younger patients are now in critical condition. To date, the deaths have occurred in older patients with pre-existing medical conditions. Seventeen percent of the 150 patients are medical staff at MERS-hit hospitals or clinics; approximately 50 percent are patients who were receiving treatment for other conditions at a MERS-hit hospital or clinic; and the remaining are family members of MERS patients.
More than 5,200 contacts are under quarantine at government-designated facilities or in their homes. The Korean Ministry of Health recently indicated the number in quarantine could increase by several thousand. This is the largest MERS-CoV outbreak outside of the Arabian Peninsula.
The public has been critical of the government’s handling of the outbreak, particularly for lack of transparency and not rapidly sharing information about the outbreak. As a result, thousands of schools have closed due to public fear. The government lowered interest rates to mitigate potential economic impacts, and the country’s current administration has suffered in public opinion polls. Some MERS-hit hospitals have suspended service or temporarily closed, leading to cascading effects limiting access to health care.
Q: Will more MERS cases occur in Korea?
A: The World Health Organization (WHO) recently completed a visit to South Korea for a joint review of the outbreak with the Korean government, and reported that because the outbreak is so large and complex more Korean MERS cases are expected in people who had close contact with infected patients. The WHO also reported there are currently no signs that the virus is behaving differently than in previous outbreaks and there is no sustained person-to-person transmission. Viral sequencing also revealed there are no significant genetic changes in the virus.
Q: How did the South Korean outbreak reach this level?
A: The original patient, or index case, visited four health care settings before diagnosis, leading to exposure of a large number of people during the period from May 11 – 20, 2015. Although the Korean public health authorities acted quickly upon receipt of laboratory confirmation on May 20, the index patient had already exposed a large number of people, and initial infection control procedures were not sufficiently stringent to control further spread in hospital settings. The WHO cited South Korean frontline doctors’ unfamiliarity with MERS, “doctor shopping,” crowded emergency rooms and hospital wards, together with the custom of family and friends staying with patients without proper infection control and isolation procedures in place as contributing factors. Also, several medical staff were not included on monitoring lists early on, despite being in close contact with patients before diagnosis.
But there is good news. The joint WHO and Korean review panel reported that the rate of new infections is decreasing as South Korean officials and hospitals have improved their communications with the public and carried out stronger infection-control measures.
Although the outbreak in Korea is alarming, the quick action of the Korean public health authorities, once they became aware of the first laboratory confirmed case, as well as the rapid notification to China and the WHO have so far limited the impact of what could have been much worse.
Q: What is the threat to the United States?
A: There have already been two travel-related MERS cases in the United States. Both cases were health care workers who lived and worked in Saudi Arabia. Prompt action to identify, isolate and institute stringent infection control procedures in these two individuals, as well as prompt identification of close contacts, prevented further spread.
Since it is difficult to identify MERS-CoV infections early, health facilities everywhere should have standard infection prevention and control practices in place to guard against a range of infectious diseases, including MERS-CoV. It is not a surprise that MERS-CoV spread around the world to South Korea. It could have spread to anywhere just as easily as it spread to South Korea. The question is where will it occur next, and will front-line health care providers suspect MERS-CoV and act promptly? Just like Ebola came to Texas last fall, MERS-CoV could arrive again in the U.S., too. Health care workers everywhere must remain on high alert for potential MERS-CoV infections, especially in travelers returning from the Arabian Peninsula or South Korea.