Eleven people who had contact with the Philippines’ first confirmed case of Middle East Respiratory Syndrome coronavirus (MERS-CoV) are also showing symptoms, the World Health Organization says.

The patient, a 32-year-old nurse, returned from Saudi Arabia on Feb 1 and was hospitalized the next day. The Philippines Health Ministry said on Wednesday she had tested positive for the disease, which has been linked to camels.

The World Health Organization is still trying to track down more than half the people who were on the same Saudia airline flight from Riyadh to Manila.