The State Department has evacuated more staff from China as a US medical team continued to screen Americans who work in the southern Chinese city of Guangzhou over fears they may have been hit by a mysterious illness that has struck US personnel in Cuba. The evacuations of the workers followed medical testing that revealed they might have been affected. State Department spokeswoman Heather Nauert said "a number of individuals" have been brought to the US but didnt say how many were affected or evacuated. One case in Guangzhou was disclosed last month after an American employee experienced strange sounds and was diagnosed with brain trauma. She said tests are being offered to "any personnel who have noted concerning symptoms or wanted baseline screening." There have been reports that the evacuated Americans are being taken for testing to the University of Pennsylvania. Thats where doctors have been treating and studying patients evacuated from the US Embassy in Havana. The preliminary findings of the medical reports on the 24 US Embassy personnel affected in Cuba showed they had sensory and memory problems similar to the brain dysfunction seen with concussions. Canada in April also ordered families of diplomatic staff in Cuba to return home after mysterious health symptoms were detected in 10 Canadians stationed on the island. The Chinese foreign ministry said Thursday that its investigation into the first case has not yielded any clues as to the cause of the incident. "As for the latest incident, my understanding is that the US side hasnt had any formal communication with the Chinese side about it," foreign ministry spokeswoman Hua Chunying said at a regular press briefing.