LONDON, ENGLAND - JULY 30:  A woman wearing a surgical mask to prevent the transmission of airborne infection walks in Westminster on July 30, 2009 in London, England. Figures released by the Health Protection Agency show that by July 19, an estimated 100,000 Britons have been infected with swine flu and there have been 26 deaths in England linked to the disease. Over 700 people worldwide have died after contracting swine flu which is spreading faster than any other flu pandemic.  (Photo by Oli Scarff/Getty Images)
Oli Scarff/Getty Images
LONDON, ENGLAND - JULY 30: A woman wearing a surgical mask to prevent the transmission of airborne infection walks in Westminster on July 30, 2009 in London, England. Figures released by the Health Protection Agency show that by July 19, an estimated 100,000 Britons have been infected with swine flu and there have been 26 deaths in England linked to the disease. Over 700 people worldwide have died after contracting swine flu which is spreading faster than any other flu pandemic. (Photo by Oli Scarff/Getty Images)
Now playing
01:39
4 ways the flu turns deadly
Kenneth Copeland Ministries/Facebook
Now playing
01:27
Minister: Jesus is your flu shot
KNXV
Now playing
00:46
Flu diagnosis ends up being flesh-eating disease
WPXI
Now playing
00:45
21-year-old dies from flu complications
CDC
Now playing
01:46
Seasonal flu: What you need to know
deadly flu virus could doctors do more_00002629.jpg
deadly flu virus could doctors do more_00002629.jpg
Now playing
02:23
Deadly flu virus: Could doctors do more?
8 year old dies from flu despite flu shot sot_00000505.jpg
KARK
8 year old dies from flu despite flu shot sot_00000505.jpg
Now playing
00:50
8-year-old dies of flu despite flu shot
SAN FRANCISCO, CA - JANUARY 22:  Simone Groper receives a flu shot at a Walgreens phramacy on January 22, 2018 in San Francisco, California. A strong strain of H3N2 influenza has claimed the lives of 74 Californians under the age of 65 since the flu season began in October of last year. People are being encouraged to get flu shots even through the vaccine has been only 30% effective in combating the influenza. (Photo by Justin Sullivan/Getty Images)
Justin Sullivan/Getty Images North America/Getty Images
SAN FRANCISCO, CA - JANUARY 22: Simone Groper receives a flu shot at a Walgreens phramacy on January 22, 2018 in San Francisco, California. A strong strain of H3N2 influenza has claimed the lives of 74 Californians under the age of 65 since the flu season began in October of last year. People are being encouraged to get flu shots even through the vaccine has been only 30% effective in combating the influenza. (Photo by Justin Sullivan/Getty Images)
Now playing
02:21
CDC: Flu virus will be around many more weeks
LOS ANGELES, CA - OCTOBER 26:  Emily Moore administers an inoculation as free flu shots are given to people over 50 by the Los Angeles County Department of Health Services on October 26, 2005 in Los Angeles, California. An estimated 60 million flu shots will be given in the United States this season.  (Photo by David McNew/Getty Images)
David McNew/Getty Images North America/Getty Images
LOS ANGELES, CA - OCTOBER 26: Emily Moore administers an inoculation as free flu shots are given to people over 50 by the Los Angeles County Department of Health Services on October 26, 2005 in Los Angeles, California. An estimated 60 million flu shots will be given in the United States this season. (Photo by David McNew/Getty Images)
Now playing
01:29
How the flu spreads
lead elizabeth cohen flu live jake tapper_00003823.jpg
lead elizabeth cohen flu live jake tapper_00003823.jpg
Now playing
01:22
CDC: Deadly flu season will likely get worse
Getty Images
Now playing
01:13
Know when and where the flu will hit
Getty Images
Now playing
01:21
Don't believe this about the flu
Flu shot
CNN
Flu shot
Now playing
00:51
CDC reports 10 more pediatric flu deaths
Government shutdown could halt CDC flu program nr_00000000.jpg
Government shutdown could halt CDC flu program nr_00000000.jpg
Now playing
01:04
Government shutdown could halt CDC flu program

Story highlights

About 4% of people who visited doctors complained of flu-like illness last week

Pediatric flu-related deaths now total 119 for the season

A total of 24,644 confirmed flu-related hospitalizations have been reported for the season

(CNN) —  

The number of people sick with flu has continued to decrease across the nation, but experts warn that the season is not over yet. New York City and 21 states continued to experience high activity of flu-like illness during the week ending March 3, the US Centers for Disease Control and Prevention said Friday in its weekly surveillance report.

Looking at the data for recent weeks, CDC spokeswoman Kristen Nordlund said, “we’re still continuing to see a decline in influenza-like activity. Even though It looks like all signs point to decreasing influenza activity, we’re still in what we normally think of as flu season.”

Caused by viruses, flu is a contagious respiratory illness with mild to severe symptoms that can sometimes lead to death.

The CDC confirmed 6,856 new infections for the week ending March 3, bringing the season total to 230,038 since October.

The states still experiencing high activity are Alaska, Arizona, Arkansas, Georgia, Indiana, Kansas, Kentucky, Massachusetts, Michigan, Missouri, Nebraska, New Jersey, New Mexico, New York, Pennsylvania, South Carolina, South Dakota, Texas, Vermont, Virginia and Wyoming.

In addition, there was moderate flu-like illness in 15 states; the District of Columbia, Puerto Rico and 14 states experienced either low or minimal activity during the week ending March 3.

Regional hotspots

“We’re certainly seeing less states with high influenza-like illness activity, and it seems like things are easing up a little bit on the East Coast and in the Midwest,” Nordlund said. “There’s a cluster of states in the South having high activity.”

Overall, flu activity is going down, she said – while urging caution. “If people aren’t feeling well and think they might have flu, there’s still a chance they could have it.”

The CDC also reported five additional flu-related deaths in children, increasing the total number of pediatric deaths for the season to 119 as of March 3.

According to the report, 3.7% of people who visited their doctors complained of flu-like illness for the week ending March 3. Though that’s above the expected level of 2.2% for the week, the percentage has gone down from the previous week, when the rate was 5%.

A total of 24,644 confirmed flu-related hospitalizations were reported between October 1 and March 3, according to the CDC.

The cumulative rate of flu-related hospitalizations rose to nearly 86 people out of every 100,000 in the ninth week of 2018, an uptick from about 82 out of every 100,000 last week, the surveillance report estimated.

Examining the laboratory evidence, the CDC found that circulating flu strains this season are a mix of H3N2, H1N1 and B viruses. H3N2 strains continued to be dominant as they have throughout the season, but the proportion of influenza B viruses increased for the week. H3N2 commonly leads to more severe illness and more hospitalizations, according to the CDC.

For example, the majority of hospitalizations, just over 80%, were the result of type A flu virus infections, and most of those were H3N2, during the ninth week of the year.

Among adults, the proportion of pneumonia- and flu-related deaths decreased to 8.8% of all deaths reported during the seventh week of the year, the CDC reported, noting that these data are always two weeks delayed.

In a Thursday hearing on Capitol Hill on flu preparedness before the US House Committee on Energy and Commerce, Rick Bright, director of the Biomedical Advanced Research and Development Authority, addressed the development of new flu treatments.

Medications

“We have not had a new class of antivirals for 20 years,” Bright told the members, adding that the influenza virus continues to change and so can develop “high levels of resistance” against the current Food and Drug Administration-approved antiviral medicine, oseltamivir (Tamiflu). In particular, H7N9, seen primarily in China but not in the US, is most resistant, he said.

Nordlund said the CDC is not concerned about this. “We work very closely with the Chinese and the countries that border China. We monitor the situation going on there,” she said.

Follow CNN Health on Facebook and Twitter

  • See the latest news and share your comments with CNN Health on Facebook and Twitter.

And the numbers support the lack of concern. The CDC found 8% resistance among H1N1 influenza A virus strains against oseltamivir, but the more severe H3N2 strains showed no resistance against the popular drug.

Nordlund concluded with a recommendation for people who have not done so to get a flu shot.

“As along as flu is circulating, people should – if they have not already – still get their flu vaccine,” she said. People most at risk of developing serious complications include the elderly, young children, pregnant women and people with underlying medical conditions. Anyone at higher risk should see their doctors if they feel ill, the CDC recommends.