AlHijjah 19, 1435, Oct 13, 2014, SPA -- Every U.S. hospital must know how to diagnose Ebola in people who have been to West Africa and be ready to isolate a suspected case, the director of the Centers for Disease Control and Prevention (CDC) said Monday. Tom Frieden told reporters that the CDC is working to improve protections for hospital workers after a nurse caring for an Ebola patient in Dallas, Texas, became the first person to become infected with the disease inside the country. "We have to rethink the way we address Ebola infection control because even a single infection is unacceptable," Frieden said. The CDC is scrambling to interview all staff of the Dallas hospital who could have been exposed to the patient, a Liberian man who became sick after traveling to the United States and died at the hospital. Anyone at risk will be monitored, the director said. "We need to consider the possibility that there could be additional cases, particularly among the health care workers who cared for the index patient (the Liberian man) when he was so ill," Frieden said.