The outbreak of swine flu has been mostly mild in the United States, with three deaths, the CDC said in a statement. On Sunday the CDC reported 2,532 cases.

Globally, the World Health Organization confirmed 4,694 infections in 30 countries with 53 deaths, all but four in Mexico.

While it is widespread across the United States, WHO said the new H1N1 virus shows no signs of sustained person-to-person spread outside of North America. "There are about 3,300 probable and confirmed cases in 46 states and the District of Columbia," the CDC's Dr. Anne Schuchat told a news briefing.

She said 94 patients with confirmed disease had needed hospital care and the latest new case become sick on May 5. More than 60 percent of cases are among children under the age of 18.

"These actual numbers really need to be interpreted with caution," Schuchat said. She said they are likely the tip of the iceberg and said many states would report weekend data on Monday, meaning the toll would likely jump on Tuesday.

Seasonal flu is still circulating, Schuchat added, and only 40 percent of people with influenza-positive tests had the new H1N1 strain.

"I think there a perception out there that we are winding down, that we are in a lull," Schuchat said.

"We know that this virus is present in our communities and it is actively circulating and we don't know what will happen come the fall."

Source : Reuters