Contagiousness of MERS

The recent outbreak of MERS - Middle East respiratory syndrome virus - has infected at least 36 people in South Korea.  As a result, the outbreak has been a source of concern for epidemiologists around the world.  Efforts to quarantine people and camels have followed in an attempt to squash the outbreak.

Perhaps surprisingly, however, the MERS virus is not highly contagious; previous studies have found that its R0 is 2-3, meaning that the average infected person only infects two to three other people.  In fact, MERS is thought to be spread primarily zoonotically (from camels to humans).

It is important to note that while the MERS virus is not highly contagious, it is still important to monitor the outbreak and prevent it from growing any larger.  One issue commonly found in reports on the contagiousness of viruses is that there is an implication that less contagious viruses cannot manifest into epidemics and that they are less serious than highly contagious viruses.  However, with HIV - a virus that is relatively low in contagion (e.g. exposure to the virus via an infected needlestick seldom leads to infection) - we see that it can still lead to a deadly epidemic.  More recently, Ebola, a virus with an R0 if 1.5-2.5 manifested itself into the huge Ebola outbreak in West Africa.

Thus, articles reporting on the contagiousness of viruses should be taken just as a presentation of the facts, or as one of many indicators of the epidemic potential of a virus.

Source: http://abcnews.go.com/Health/infectious-mers-virus-compared-viruses/story?id=31535945

--Andrew Duong