Possible Return of Swine Flu in Fall Has U.S. Health Officials on Alert

Biggest concern is emergence of more virulent, easily transmitted strain

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Possible Return of Swine Flu in Fall Has U.S. Health Officials on Alert

By
HealthDay Reporter

WEDNESDAY, May 27, 2009 (HealthDay News) -- As the H1N1 swine flu virus continues to wax and wane in different parts of the country, U.S. health officials said they were working as fast as possible to learn as much as they can about the novel pathogen before the return of the flu season in the fall.

The reason for the urgency: Some past pandemics were preceded by "herald waves" of a flu strain that surfaced at the end of one flu season, only to return with far greater consequences the next flu season.

"We are mindful that pandemics of influenza have sometimes come in waves," Dr. Anne Schuchat, the U.S. Centers for Disease Control and Prevention's interim deputy director for science and public health program, said during a Tuesday afternoon news conference. "The very severe 1918 pandemic had a moderate herald wave in the spring and a much more severe second wave in the fall. So that very terrible experience of 1918 is in our minds."

Some estimates have placed the worldwide death toll from the 1918 outbreak -- often referred to as the "Spanish Flu" -- as high as 40 million people.

"We are really on a fast track, over the next to eight to 10 weeks, to learn as much as we can as this virus heads to the Southern Hemisphere [where flu season is just beginning] and to strengthen our planning for the surge of illness that we expect to experience here in the fall," Schuchat added.

Scientists will be looking to see if the H1N1 swine flu virus mutates or becomes resistant to antiviral medications, or is more easily spread among people, she said.

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. "Whether it will dominate among the seasonal flu viruses or whether it will disappear is not predictable right now," she said.

To date there have been 7,927 confirmed and probable cases of infection in the United States, the CDC reported Wednesday. Most of the cases have been mild and patients have recovered quickly.

The CDC was reporting 11 deaths linked to the swine flu, and all of the victims had underlying health problems before they were infected.

The World Health Organization said Wednesday that 48 countries have reported 13,398 cases of infection, including 95 deaths, most of them in Mexico, where the outbreak began.

The CDC said last week that progress was being made toward the development of an H1N1 swine flu vaccine, with two promising candidate viruses for use in such a shot. And U.S. Department of Health and Human Services Secretary Kathleen Sebelius said Friday that the federal government was allocating $1 billion to the search for a swine flu vaccine.

In the United States, most cases of the swine flu continue to be no worse than seasonal flu. Testing has found that the swine flu virus remains susceptible to two common antiviral drugs, Tamiflu and Relenza, according to the CDC.

The CDC says some older people may have partial immunity to the H1N1 swine flu virus because of possible exposure to another H1N1 flu strain circulating prior to 1957. So far, 64 percent of cases of swine flu infection in the United States have been among people aged 5 to 24, while only 1 percent involves people over 65, officials said last week.

U.S. Human Cases of H1N1 Flu Infection
(As of May 27, 2009, 11:00 AM ET)
States # of
confirmed and
probable cases
Deaths
Alabama
67
 
Arkansas
12
 
Arizona
532
3 deaths
California
553
 
Colorado
68
 
Connecticut
102
 
Delaware
108
 
Florida
139
 
Georgia
28
 
Hawaii
44
 
Idaho
11
 
Illinois
927
 
Indiana
120
 
Iowa
71
 
Kansas
34
 
Kentucky**
38
 
Louisiana
86
 
Maine
9
 
Maryland
44
 
Massachusetts
286
 
Michigan
178
 
Minnesota
44
 
Mississippi
8
 
Missouri
24
1 deaths
Montana
12
 
Nebraska
35
 
Nevada
50
 
New Hampshire
27
 
New Jersey
29
 
New Mexico
97
 
New York
456
2 deaths
North Carolina
13
 
North Dakota
6
 
Ohio
15
 
Oklahoma
64
 
Oregon
120
 
Pennsylvania
95
 
Rhode Island
11
 
South Carolina
39
 
South Dakota
4
 
Tennessee
95
 
Texas
1358
3 deaths
Utah
122
1 deaths
Vermont
2
 
Virginia
25
 
Washington
575
1 death
Washington, D.C.
14
 
Wisconsin
1130
 
TOTAL*(48)
7,927 cases
11 deaths
*includes the District of Columbia
**One case is resident of Ky. but hospitalized in Ga.

Source: U.S. Centers for Disease Control and Prevention

More information

For more on swine flu, visit the U.S. Centers for Disease Control and Prevention.

SOURCES: May 26, 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 22, 2009, teleconference with Nancy Cox, Ph.D., chief of U.S. Centers for Disease Control and Prevention's Influenza Division; Associated Press

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