ATLANTA – The number of confirmed swine flu cases in the United States has jumped to 64, federal officials said Tuesday, and states reported at least four more.

The U.S. Centers for Disease Control and Prevention said the new count includes "a number of hospitalizations." CDC officials had previously said just one person had been hospitalized.

The CDC said there were 17 new cases in New York City, four more in Texas and three additional cases in California. That brings the total numbers of cases confirmed by federal officials to 45 in New York City, 10 in California, six in Texas, two in Kansas and one in Ohio.

State health officials in California have confirmed three other cases, and Indiana authorities have confirmed one.

The increase is not surprising. For days, CDC officials have said they expected to see more confirmed cases — and more severe illnesses. Health officials across the country have stepped up efforts to look for cases, especially among people with flu-like illness who had traveled to Mexico.

CDC officials also warned that updates in the number of confirmed cases would at time be disjointed, as different states announce new information before the CDC's national count is updated.