A businessman who returned from China and began showing symptoms of a respiratory ailment remains in quarantine pending the outcome of further tests, Mexico’s federal government confirmed late Wednesday. The case marks the second of its kind this year along the U.S.-Mexico border–though the first case was eventually cleared.

In a daily update, Mexico’s Health Secretariat listed the new potential case from Nuevo Leon as the second pending case, with 13 previously ruled negative. The other possible case is in Guanajuato.

In Nuevo Leon, state health officials identified the patient in a prepared statement as a 45-year-old businessman who had returned from China on January 30 and began showing symptoms of a respiratory illness on February 10. The patient is being treated at the University Hospital in Monterrey where doctors await the results of blood work to determine if he has the 2019-NCOV strain. The patient’s family is also quarantined.

In late January, a college professor who spent the Christmas holidays in China became the first border state case to be listed as suspicious in nature. That case was ruled out days later after blood samples revealed he suffered from a common cold. The professor had traveled to the Wuhan Province, the current epicenter for the epidemic, that has led to a total of 45,171 confirmed cases and 1,115 fatalities worldwide, per Mexico’s Health Secretariat’s most recent statistics.