U.S. Customs and Border Protection is monitoring all information and guidance concerning the outbreak of H1N1 flu. At this time all U.S. ports of entry are open and operating as normal with officers using risk based border screening. CBP officers and Border Patrol agents are responding to guidance from health officials from the Centers for Disease Control and Prevention. They are monitoring the health of incoming travelers and taking all appropriate precautions. CBP collaborates with CDC and local health officials to assess potential threats, including referring a person with symptoms to a CDC quarantine station or a local public health official for evaluation. CBP reminds U.S. citizens and those with plans to enter the United States from Mexico to monitor health information at the CDC Web site.