U.S. public health officials said Wednesday that ten U.S. states have reported confirmed cases of swine flu, as the first confirmed death from the virus in the United States was announced. Dr. Richard Besser, the acting chief of the Centers for Disease Control and Prevention, told reporters in Atlanta that 51 cases have been confirmed in New York, 16 in Texas and 14 in California. Two cases have been confirmed in Kansas, Massachusetts and Michigan. Individual cases have been confirmed in Arizona, Indiana, Nevada and Ohio. Elsewhere, officials in Maine said laboratory tests had confirmed three cases in that state but the new cases were not included in the CDC count. A possible further outbreak was being investigated in southern California at a Marine Corps base. The commandant of the Marine Corps told reporters that 39 Marines were being confined at the base until test results were received. Homeland Security Secretary Janet Napolitano held a joint press conference with newly-confirmed Health and Human Services Secretary Kathleen Sebelius to address the new cases and the government response. Napolitano addressed statements from a number of congressmen who have called for the United States to close its border with Mexico. “First of all, it is important to know that we are making all of our decisions based on the science and the epidemiology,” Napolitano said. “The CDC, the public health community and the World Health Organization all have said that closing our nation's border is not merited here.” “We are following those recommendations now,” she said. Napolitano said border patrol will continue to “actively monitor” travelers coming across the border, adding that 49 individuals have been referred for testing, of whom 41 were clear of the disease. Test results are pending for the remaining eight. Sebelius warned that influenza outbreaks of all kinds, including the yearly seasonal flu, result in deaths such as that of a 23-month-old toddler who became the first confirmed victim of the swine flu in the United States. “Today was the first confirmed death. Unfortunately there will be more. And we don't want people to think this is a sign of things going out of control. This is what happens with a flu virus,” she said.