May 9 (HealthDay News) -- The swine flu count in the United States now stands at 2,254 confirmed cases and 722 probable cases in 44 states, with 104 hospitalizations, federal health officials said Saturday.
"We had expected more cases and we are continuing to find them," Dr. Anne Schuchat, interim deputy director for science and public health program at the Centers for Disease Control and Prevention, said during a morning teleconference.
The jump in confirmed cases is partly due to the reduction in the backlog of testing for infections. But the number of confirmed cases is probably an underestimation of the total number of actual cases as the virus continues to spread, Schuchat said.
"Transmission here in the U.S. is ongoing. This is a very easily transmittable virus," she said. "Fortunately, the severity of illness that we're seeing, at this point, doesn't look as terrible as a category-five pandemic or the severely devastating impact some had feared. But influenza viruses are unpredictable and can change over time. Going forward, it's really important to us that we pay attention to how this virus may or may not change."
Because the new swine flu virus is a highly unusual genetic mix of bird, flu and human viruses, health officials worry that it could continue to mutate and return in a more virulent form for next winter's flu season.
And, while most of the infections continue to cause only mild illness, similar to the seasonal flu, and virtually all patients recover quickly and fully, federal officials warned Friday that the swine flu outbreak in the United States is far from over.
"I want to address an issue that's been concerning me, that has to do with a sense of having dodged a bullet, a sense that this is over," Dr. Richard Besser, the CDC's acting director, said during a Friday teleconference. "While we have seen a lot of encouraging news in terms of severity, we continue to see hundreds and hundreds of new cases each day," he said.
While the swine flu -- technically known as the H1N1 virus -- is similar to seasonal flu, there are some important differences, Besser said. "One thing we are seeing, unlike seasonal flu, a higher percentage seem to be having vomiting and diarrhea," he said.
Meanwhile, a new Harvard University survey found that many Americans have taken measures to protect themselves and family members from the disease.
For instance, 67 percent of those surveyed said they or someone in their home are washing their hands or using a hand sanitizer more frequently, and 55 percent said they've taken steps to stay at home if they or a family member get sick.
"This outbreak has permeated a lot of American life," Robert J. Blendon, a professor of health policy and political analysis at the Harvard School of Public Health/Kennedy School of Government, said during the Friday teleconference. "This is something that has really gotten into their lives. This is not something people are watching but not doing anything about. It's incredible when you see the list of things people are trying to do to avoid the situation."
Among those steps taken by people, according to the survey:
- About 25 percent report that they or a household member have avoided air travel or avoided public places where many people gather. About one-third said they personally have taken steps to avoid being near someone who has flu-like symptoms.
- 14 percent said they've stopped shaking hands with people, and 12 percent said they have stopped hugging and kissing close friends or relatives, even though 61 percent aren't concerned that they or someone in their immediate family may get sick from the swine flu in the next 12 months.
- 83 percent said they're satisfied with the way public health officials have managed the response to the outbreak, and 88 percent said they're satisfied with the information health officials have provided.
On Thursday, Besser said most new cases of swine flu in the United States are now caused by person-to-person transmission and not some link to Mexico, as was the case when the outbreak began more than two weeks ago. Mexico is believed to be the source of the outbreak.
Testing has found that the swine flu virus remains susceptible to two common antiviral drugs, Tamiflu and Relenza, according to the CDC.
The two U.S. deaths linked to swine flu occurred in individuals with multiple underlying health problems, according to a CDC report released Thursday by the New England Journal of Medicine.
The first victim -- a Mexican toddler named Miguel Tejada Vazquez who had been treated at a Houston hospital -- suffered from a chronic muscle disorder called myasthenia gravis, and also had a heart defect, low oxygen, and problems swallowing.
The second case involved 33-year-old schoolteacher Judy Trunnell, who suffered from asthma and rheumatoid arthritis and who was 35 weeks' pregnant and in a coma when she died in a Texas hospital on Tuesday. Doctors delivered her baby girl via Cesarean section.
On Friday, news reports said Canada had confirmed its first death linked to swine flu, a woman in her 30s living in northern Alberta. That woman also had other medical conditions, a provincial health officer noted.
U.S. health officials earlier this week said the outbreak of swine flu appears similar to the seasonal flu in its severity, so schools across the nation should remain open and any schools that did close should reopen.
On Saturday, the World Health Organization was reporting 3,440 confirmed cases of swine flu in 29 countries, with Canada, Spain and the United Kingdom having the most cases outside of Mexico and the United States.
Mexico has reported 1,364 confirmed cases of infection, including 45 deaths. The United States has reported 1,639 confirmed cases, including the two deaths. Canada has reported 242 confirmed cases, including one death, the WHO said.
Japan and Australia reported their first cases of swine flu on Saturday.
Meanwhile in Mexico, the country continued to emerge from a virtual shutdown designed to limit infections. High schools, universities, dance halls, movie theaters and bars have reopened, and primary schools are to reopen next week, the Associated Press reported.
Reports emerged Friday that the swine flu has extended its spread in the Southern hemisphere, where flu season is just beginning. Argentina and Brazil have now confirmed their first cases of swine flu, joining Colombia as South American nations reporting infections, the news service said.
SOURCES: May 9, 2009, teleconference with Anne Schuchat, M.D., interim deputy director for science and public health program, U.S. Centers for Disease Control and Prevention; May 8, 2009, teleconference with Richard Besser, M.D., acting director, U.S. Centers for Disease Control and Prevention, and Robert J. Blendon, Sc.D., professor of Health Policy and Political Analysis, Harvard School of Public Health/Kennedy School of Government; May 7, 2009, New England Journal of Medicine; Associated Press