Majority Of South Korean MERS Cases Hospital Acquired

While MERS does not appear to be spreading outside of hospitals in South Korea, quarantine measures have not been well enforced.

AsianScientist (Jun. 11, 2015) – Although many questions remain, officials say that most of the cases of Middle East Respiratory Syndrome (MERS) in the ongoing South Korean outbreak were hospital-acquired. These early findings suggest that it is unlikely that new infections will be community-acquired, despite the fear that has left streets and shopping malls empty.

Speaking yesterday at a press conference held at the World Conference of Science Journalists, Dr. Kim Sung-Han of the Asan Medical Center in Seoul acknowledged that a delay in obtaining a detailed travel history of the index patient led to the spread from St. Mary’s Hospital in Pyeongtaek to a second hospital, Samsung Medical Center in Seoul. The unnamed 68-year-old man—who returned to Seoul on May 4, 2015 after a business trip to Bahrain, the United Arab Emirates, Saudi Arabia and Qatar—went on to visit two more hospitals, possibly infecting dozens along the way.

The specter of SARS

The current outbreak of MERS has reminded many of the Severe Acute Respiratory Syndrome (SARS) epidemic that swept through various East Asian countries more than a decade ago. Between November 2002 and July 2003, there were 8,098 cases of SARS and 774 fatalities, according to World Health Organization data. In contrast, the latest figures on the South Korean outbreak are 95 cases and 7 fatalities.

Both MERS and SARS are caused by coronaviruses, single stranded RNA viruses that are believed to cause common colds. Indeed, at a high viral loads and in hospital settings, the fatality rate of MERS is about 30-40 percent, similar to that of SARS, said Kim. However, there are a number of key differences which make it unlikely that the current outbreak will become SARS version 2.0.

First of all, the MERS coronavirus (MERS-CoV) has a very different pattern of transmission. While SARS-CoV had a household transmission rate of 20 percent, none of the cases of the present outbreak were household transmitted, Kim said. The disease also appears to be transmissible only by very sick, bed-bound patients, making it unlikely to be spread by ambulant people in crowded areas.

Secondly, the fatality rate of MERS is lower than that of SARS, dropping to as low as 5-10 percent if healthcare workers are isolated and do not have any other co-morbidities. Based on a preliminary analysis of 45 cases, Kim said that the median age of those hospitalized for MERS is 50, a full decade older than the median age of patients affected by SARS.

Most importantly, unlike SARS-CoV which was completely new to science, both the genetic sequence and transmission patterns of the MERS-CoV are already known, meaning that health officials have diagnostic and predictive tools at their disposal.

A slow but over-reactionary response?

However, many South Koreans remain distrustful of the authorities, their confidence having been shaken by the way the Sewol Ferry Tragedy was handled. With MERS, the authorities have been criticized for being slow to release information to the public, only releasing a list of 24 affected hospitals on June 6, 2015. Also worrying is that at three cases of MERS were only diagnosed after death.

International critics have questioned measures such as school closures and the quarantine of camels in the zoo, calling them unnecessary and counter-productive. In fact, Professor Song Dae-sub of the Korea Research Institute of Bioscience and Biotechnology went so far as to say that the “quarantine of camels is meaningless from a medical aspect.”

At the press conference, Kim also conceded that face masks do not prevent MERS but that mask wearing was not dissuaded “so as not to stigmatize those with symptoms.”

However, taking unnecessary actions while not enforcing strict quarantines could send conflicting messages to the public on the severity of the condition and which preventive measures actually work. China’s first case of MERS was brought into Hong Kong by a 44-year-old man who broke quarantine and there have been reports of a MERS-positive doctor who also broke quarantine, even attending an event where more than 1,500 were gathered.


Copyright: Asian Scientist Magazine; Photo: Rebecca Tan.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Rebecca did her PhD at the National University of Singapore where she studied how macrophages integrate multiple signals from the toll-like receptor system. She was formerly the editor-in-chief of Asian Scientist Magazine.

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