Infection with MERS-CoV - shown here in lung tissue - leads to severe acute respiratory illness, including fever, cough and shortness of breath.
On Thursday, Thailand's public health minister Rajata Rajatanavin told the press that a 75-year-old man from the Middle East, who had recently traveled to the kingdom with his family, has tested positive for Middle East respiratory syndrome (MERS).
On Friday, South Korea's Ministry of Health and Welfare announced the country's 166th confirmed case of MERS in a family member of a patient being treated at the Samsung Medical Center in the capital Seoul.
MERS is a respiratory illness caused by infection with the Middle East respiratory syndrome coronavirus (MERS-CoV). It first appeared in humans in Saudi Arabia in 2012 and has since spread to several other countries, including the US.
People who become infected with MERS-CoV develop severe acute respiratory illness, including fever, cough and shortness of breath. About 36% of patients confirmed with MERS-CoV infection have died.
Nobody knows where MERS-CoV comes from, but there is evidence that it likely arose in animals. MERS-CoV has been found in camels in several countries, and there is also genetic evidence that MERS may have started in bats in Saudi Arabia.
WHO say MERS not a 'Public Health Emergency of International Concern'
The case in Thailand brings to 16 the total number of countries outside the Arabian Peninsula to have reported confirmed cases of MERS. The other countries include: Austria, China, Egypt, France, Germany, Greece, Italy, Malaysia, Netherlands, Philippines, South Korea, Tunisia, Turkey, the UK and the US.
As well as Saudi Arabia, countries in or near the Arabian Peninsula with MERS cases include: Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, United Arab Emirates and Yemen.
The new patient in Thailand is thought to have traveled from Oman.
MERS has spread most alarmingly in South Korea, where since it was first reported there in May 2015, it has claimed 24 lives. Most of the patients who died were older, high-risk, patients with underlying medical conditions such as cardio- cerebrovascular disease, cancer and chronic respiratory disease.
Meanwhile, following an emergency meeting to discuss MERS-CoV, the World Health Organization (WHO) say while they consider the MERS outbreak to be "a wake-up call," they conclude that the conditions for a Public Health Emergency of International Concern (PHEIC) have not been met.
WHO say that in a highly mobile world, all countries should be ready for unexpected outbreaks of this nature and that the current situation highlights "the need to strengthen collaboration between health and other key sectors, such as aviation, and to enhance communication processes."
A recent joint mission between WHO and the Korean authorities concluded a number of factors contributed to the spread of MERS in South Korea. These include: lack of awareness among health workers and the public, inadequate infection control in hospitals, crowded emergency rooms and multibed rooms in hospitals, the custom of visitors staying with infected patients, and the practice of "doctor shopping" where patients seek care at multiple hospitals.
Meanwhile, the Centers for Disease Control and Prevention do not recommend that Americans change their travel plans because of MERS. The current CDC travel notice remains at Watch Level 1, and the federal agency website lists precautions travelers can take to prevent MERS.