Britain's chief medical officer called for urgent action to reduce use of antibiotics and improve hospital hygiene to prevent resistant bacteria from spreading. Sally Davies, who previously warned bacteria becoming resistant to drugs is a threat equal to that of terrorism, said immediate action is needed to address antibiotic resistance. She said the problem is matter of "national concern" after a report by Public Health England documented a rise in the group of infections involving carbapenemase-producing Enterobacteriaceae from five cases in 2006 to 600 cases in 2013, the Daily Telegraph reported. These infections are resistant even to antibiotics that are normally given as a "last resort" because nothing else works. Patients may sometimes respond to other drugs, but it can be difficult to find the right treatment in time, the report said. Medical staff need to be trained so they are more aware of the risks of prescribing unnecessary antibiotics, and to improve hygiene to ensure cases of CPE did not spread, the report said. Medical staff need to be alert to the increased risk of infection from patients from high-risk overseas countries, which include Bangladesh, China, Cyprus, Greece, India, Italy, Malta, Pakistan, Taiwan, Turkey, the United States and all countries in North Africa and the Middle East. "We need to act swiftly to avoid getting into the situation which has been seen in some other countries, such as Greece, Israel and the United States, where there is significant resistance," Dr. Paul Cosford, medical director of PHE, told the Telegraph.