Epidemic Disease- MERS
The outbreak of the Middle East Respiratory Syndrome (MERS) aroused tremendous amount of fear and panic in South Korea last May and June as more and more people contracted the disease, with some infected patients dying as a result of MERS. We can illustrate this epidemic disease as a contact network with a “patient zero” who started the spread.
The “patient zero” for the spread of MERS in South Korea was a 68-year-old South Korean man who ran a farm equipment company in Bahrain, a country that is not considered a MERS danger zone. However, he had also visited Saudi Arabia and United Arab Emirates during his trip to the Middle East, which are countries with the most known MERS cases. When he returned back to South Korea, he developed a cough and fever, which made him visit four hospitals. His visit to the four facilities was the cause of the spread of the disease, as more than half of the infections have been traced back to a hospital in the city of Pyeongtaek, in which the patient zero shared a room with another patient. That patient’s son also contracted the disease, as he visited his father at the hospital. The patient zero further spread the disease in the hospital by going out of the room for check ups and sneezing and coughing in the hallway. Others became infected through the other hospitals the patient zero had visited.
The MERS outbreak, starting with the patient zero, demonstrates a contact network that spreads as the the first node visits four hospitals and creates more nodes of people that have the potential for direct transmission of the disease. The image below illustrates the actual contact network that formed through this patient zero:
Like discussed in class, public health measures were carried out to decrease R=pk, the expected number of new cases caused by one exisitng case. One such measure was shutting down the hospital at Pyeongtaek and quarantining the staff at the hospital. This is equivalent to reducing k in the equation, or the number of people that have the potential for direct transmission of the disease. Sanitization measures were also taken, such as hand-washing before and after contacting each patient and wearing medical mask, gloves, gown, and eye protection when treating MERS cases. This approach reduced p in the equation, or the probability of the disease being transmitted. Through these public health measures, South Korea was able to finally control the MERS outbreak and end the epidemic run.
Sources:
http://www.reuters.com/article/2015/06/03/southkorea-mers-patient-idUSL3N0YP17T20150603
http://www.wpro.who.int/mediacentre/releases/2015/20150728/en/
Image Source:
http://virologydownunder.blogspot.com/2015/06/tracing-mers-cov-cases-in-south-korea.html