June 1 (HealthDay News) -- Swine flu cases have now been reported in all 50 states, with the total number of people infected probably surpassing 200,000, U.S. health officials said Monday.
"It's accurate to say that there are probably several hundred thousand people that have been impacted by this flu," said Tom Skinner, a spokesman for the U.S. Centers for Disease Control and Prevention. "But that's in line with what we would see with seasonal influenza if we had the number of cases we are reporting right now."
And while the outbreak continues to wane, new cases will continue to emerge, Skinner said.
On Monday, the CDC was reporting a total of 10,053 cases in all 50 states and the District of Columbia, including 17 deaths. The agency has said in the past that confirmed cases of H1N1 swine flu represent about one in 20 of actual cases, bringing the total number of cases to about 200,000.
Infections with the H1N1 swine flu virus continue to be mild and recovery is fairly quick, as is the case with seasonal flu, officials said. Testing has found that the virus remains susceptible to two common antiviral drugs, Tamiflu and Relenza, according to the CDC.
What has been different about the swine flu outbreak, Skinner said, is that activity picked up late in the typical flu season. "What was unusual was that in late March into April and late May we saw activity at a higher-than-expected level," he said.
Dr. Anne Schuchat, the CDC's interim deputy director for science and public health program, said last week that the newly identified H1N1 swine flu virus continues to behave much like seasonal H1N1 viruses, which may partly explain why this flu strain affects more younger people. "Seasonal H1N1 often causes more disease in younger people, compared with the other strains that can be more common in older people," she said.
Some older people may have partial immunity to the H1N1 swine flu virus because of possible exposure to another H1N1 flu strain that circulated prior to 1957.
Schuchat said a vaccine for the swine flu virus could be ready in October, if research and testing proceed on pace this summer. Candidate viruses have been shipped to vaccine manufacturers, she said.
It's still not clear whether a swine flu vaccine is needed, Schuchat said. Any decision to move forward would be based on several factors, including the severity and spread of the virus and whether there's a safe and effective vaccine, she said.
During the next few months, scientists will be looking to see if the swine flu virus mutates or becomes resistant to antiviral medications, or is more easily spread among people, Schuchat said. The flu season is winding down in the Northern Hemisphere but is just beginning in the Southern Hemisphere.
Schuchat said there's no way to tell now if the H1N1 virus will be more virulent when -- and if -- it returns to the Northern Hemisphere with the approach of winter.
The World Health Organization said Monday that 53 countries have reported 15,510 cases of H1N1 swine flu, including 99 deaths, most of them in Mexico, where the outbreak began.
SOURCES: Tom Skinner, spokesman, U.S. Centers for Disease Control and Prevention; May 28, 2009, teleconference with Anne Schuchat, M.D., interim deputy director for science and public health program, U.S. Centers for Disease Control and Prevention