How Infectious the MERS Virus Is Compared to Other Viruses

At least 1,179 people have been infected with MERS, according to WHO.

ByABC News
June 4, 2015, 6:03 PM
Hospital workers and visitors wearing masks pass by a precaution against the MERS, Middle East Respiratory Syndrome, virus at a quarantine tent for people who could be infected with the virus at Seoul National University Hospital in Seoul, June 3, 2015.
Hospital workers and visitors wearing masks pass by a precaution against the MERS, Middle East Respiratory Syndrome, virus at a quarantine tent for people who could be infected with the virus at Seoul National University Hospital in Seoul, June 3, 2015.
Ahn Young-joon/AP Photo

— -- News that an outbreak of coronavirus.htm" id="ramplink_MERS_" target="_blank">MERS has infected at least 36 in South Korea has lead the country to quarantine more than 1,600 and even 17 camels in the hope of stopping virus, according to local authorities.

But just how contagious is the Middle East respiratory syndrome virus?

Far less than many other viruses, including SARS or measles, according to early studies of the disease.

A 2014 study found that in Saudi Arabia, where the virus was first identified, the virus' reproductive rate -- often called the R0 -- was estimated at approximately two to three people, meaning two to three people were infected by one infectious person. The study published in PLOS clarified that data -- a total of 707 cases -- was from a short period of time when an outbreak of the virus hit certain areas of the country.

The virus has thought to mainly be transmitted from animals -- mainly camels -- to humans, who then rarely pass it along to another human. The R0 of the virus could end up being lower, the study authors said, and the R0 values can change in different outbreaks.

However, even if further studies find that the R0 of the virus remains at two to three people, its communicability will remain far lower than other viruses that are more common.

Measles is one of the most infectious viruses in existence, and according to a report from the U.S. Centers of Disease Control and Prevention, a single infected person can sicken between 12 to 18 others. In fact, someone with measles can be so infectious that if that person passed through a crowded room, the person can sicken nine out of 10 people who lack immunity to the disease, according to the CDC.

The SARS virus, which is a coronavirus like MERS, was found to have an R0 of approximately three, according to a 2006 study. In that disease, those sickened with the virus were most contagious when they exhibited the most symptoms, meaning those in close contact and health care workers were the most at risk.

Mumps, which can cause fever and the salivary glands to expand, has an R0 of approximately four to seven people for every one person affected by the virus, according to the CDC.

The frightening Ebola virus was found to have an R0 of approximately 1.4 to 2.7 in recent outbreaks, depending on the site of the outbreak, according to a 2014 report from the World Health Organization.

ABC News' Jan Diehm and Kathleen Dooling contributed to this report.