London (CNN) -- A second case of the potentially deadly MERS virus has been identified in the Netherlands, a spokeswoman for the country's National Public Health Institute told CNN. It comes one day after authorities confirmed the first case.
The cases in the Netherlands involve two family members who had traveled together to Saudi Arabia.
It is one man and one woman who contracted the disease, said Harald Wychgel, spokesman for the Netherlands ministry of health.
The health ministry, citing privacy reasons, did not provide additional details except to say that the pair shared a room for two weeks in Saudi Arabia.
Officials do not know if one person infected the other or if both became infected at the same location. One of the two, however, had visited a camel farm. It is estimated that nearly 75% of dromedary -- or single-hump camels -- in Saudi Arabia have come into contact with the MERS virus, researchers said in February.
"It is also known that both patients have underlying conditions that make them probably more susceptible to infection with this virus," the health ministry said in a statement.
The announcement comes as the World Health Organization said the spread of the virus has become more urgent, but at least for now, is not calling it a global health emergency.
The first cases of Middle East Respiratory Syndrome were diagnosed in the Arabian Peninsula in 2012. MERS attacks the respiratory system, and symptoms can lead to pneumonia or kidney failure.
There have been over 570 confirmed cases of MERS, including 171 deaths, according to the World Health Organization.
Many of the cases are in Saudi Arabia and the United Arab Emirates.
Even without any official worldwide alert, Anne Schuchat, the head of the CDC's National Center for Immunization and Respiratory Diseases, acknowledges that "this is a relatively new virus that does have a high fatality rate," ample reason to pay attention. Authorities haven't pinned down all the details about how exactly it arose and how it spreads, though Schuchat said, "We don't have evidence right now that this is airborne ... the way the measles virus is."
Two cases have been confirmed in the United States. Both patients are health care providers who were working in Saudi Arabia. Those cases are in Indiana and Florida.
CNN's Miriam Falco contributed to this report.