From the data on influenza-associated hospitalizations collected through CDC’s Emerging Infection Program (EIP), which conducts surveillance for laboratory-confirmed influenza-related hospitalizations in children and adults in 62 counties covering 13 metropolitan areas of 10 states, the estimation range of the total number of 2009 H1N1 cases, hospitalizations and deaths in US are following;

1. Between about 34 million and 67 million cases of 2009 H1N1 occurred between April and November 14, 2009. The mid-level in this range is about 47 million people infected with 2009 H1N1.

2. Between about 154,000 and 303,000 H1N1-related hospitalizations occurred between April and November 14, 2009. The mid-level in this range is about 213,000 people H1N1-related hospitalizations.

3. Between about 7,070 and 13,930 H1N1-related deaths occurred between April and November 14, 2009. The mid-level in this range about 9,820 peoples 2009 H1N1-related death.

Throughout the remainder of the 2009 H1N1 pandemic, Center for Disease Control and Prevention (CDC) will updated the range of estimated 2009 H1N1 cases, hospitalizations and deaths every three or four weeks.
While EIP data is reported weekly during influenza season, because the system is based on reviews of patients medical charts there are sometimes delays in reporting and it can take some time for all the data to fill in.