As far back as late November, U.S. intelligence officials were warning that a contagion was sweeping through China's Wuhan region, changing the patterns of life and business and posing a threat to the population, according to four sources briefed on the secret reporting.Concerns about what is now known to be the novel coronavirus pandemic were detailed in a November intelligence report by the military's National Center for Medical Intelligence (NCMI), according to two officials familiar with the document's contents.The report was the result of analysis of wire and computer intercepts, coupled with satellite images. It raised alarms because an out-of-control disease would pose a serious threat to U.S. forces in Asia -- forces that depend on the NCMI's work. And it paints a picture of an American government that could have ramped up mitigation and containment efforts far earlier to prepare for a crisis poised to come home."Analysts concluded it could be a cataclysmic event," one of the sources said of the NCMI's report. "It was then briefed multiple times to" the Defense Intelligence Agency, the Pentagon's Joint Staff and the White House.From that warning in November, the sources described repeated briefings through December for policy-makers and decision-makers across the federal government as well as the National Security Council at the White House. All of that culminated with a detailed explanation of the problem that appeared in the President's Daily Brief of intelligence matters in early January, the sources said. For something to have appeared in the PDB, it would have had to go through weeks of vetting and analysis, according to people who have worked on presidential briefings in both Republican and Democratic administrations."The timeline of the intel side of this may be further back than we're discussing," the source said of preliminary reports from Wuhan. "But this was definitely being briefed beginning at the end of November as something the military needed to take a posture on."Read more of this story on ABCNews.com