NEW YORK, Jan. 23 (UPI) -- America's sometimes patchy health surveillance system may have led officials to expect a more serious H1N1 epidemic than actually materialized, experts say.
Last week the Centers for Disease Control and Prevention said about 55 million people in the United States have come down with H1N1 and about 11,000 have died so far, The Wall St. Journal reported Saturday.
The death toll is far smaller than a White House report last summer predicted. It projected a scenario where 60 million to 120 million people would become sick in fall and winter 2009 with a projected total of 30,000 to 90,000 dying, the newspaper noted.
The estimates were based on outbreaks such as the one at the University of Delaware. Many students who exhibited flu-like symptoms did not seek treatment, and many who did weren't confirmed by lab tests, the Journal said.
Delaware was chosen as a test case because it represented an isolated outbreak, and CDC investigators were on hand to help gather and analyze data. But a student population with on-campus health service might not behave like the general public.
Researchers said very large numbers were being projected from very small ones.
"For all of these steps, we used the data we had available to us," said David Swerdlow, a CDC epidemiologist.
Marc Lipsitch, co-author of last summer's report projecting up to 90,000 deaths from swine flu and an epidemiologist at the Harvard School of Public Health said, "the data were limited and misleading and confusing."