ATLANTA -- The spread of the flu across the United States appears to have slowed with the number of cases falling off in portions of five states in the South and Southeast, a federal official told CNN early Friday.
The news came hours before the Centers for Disease Control and Prevention was due to release its flu advisory report for December 30 to January 5, which according to the official with knowledge of the findings will also show the number of flu-related deaths for children climbed by two last week.
That brings to 20 the number of deaths under the age of 18 since the outbreak of the flu. While the CDC does not count the number of adult deaths related to the flu, some states do and that data suggests dozens have died.
The number of cases, meanwhile, that dropped off in portions of the South and Southeast appear to have done so because that was where the flu season started earliest, said the official, who spoke on condition of anonymity. The official did not identify the five states where the flu activity has fallen off.
It's unclear from the official's comments if this means the traditional 12-week flu season has peaked. Traditionally, the season peaks in late January or early February.
This is only about week five in a 12-week flu season, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, told CNN's Wolf Blitzer on Thursday.
"Remember, once it peaks, you still have a considerable amount of time where there is a lot of flu activity, and right now it may have peaked in some places, but for the most part, it has not yet peaked," he said.
Early flu season
The flu season came early this season, and cases are more severe than last year, health officials say.
The Centers for Disease Control and Prevention flu advisory report issue last week, which covers the period of December 23 to 29, suggests that 41 states have widespread influenza activity, which was an increase of 31 states from the previous week. Of those states, a high level flu activity was reported in at least 24 states.
In Massachusetts, one of the 29 states that the CDC identified as having high activity of influenza-like illness, Boston Mayor Thomas Menino declared a public health emergency in the city Wednesday because of the flu.
Since October 1, there have been 700 confirmed influenza cases among Boston residents, according to Menino's office; that's 10 times more than were seen in all of last year's flu season.
There have been 18 flu-related deaths this season in Massachusetts, CNN affiliate WCVB reported. Hospitalization rates are higher than the last two years, Kevin Cranston of the state's Bureau of Infectious Diseases told WCVB. Most deaths have been in older patients, he said.
Menino is collaborating with the Boston Public Health Commission and community health centers to offer free vaccination clinics this weekend. The mayor urged residents to stay home from work or school if they are sick, and to get their flu shots.
"This is the worst flu season we've seen since 2009, and people should take the threat of flu seriously," Menino said in a statement. More than 4% of emergency department visits at Boston hospitals are from flu cases, up from 1% during non-flu season.
Massachusetts General Hospital has already counted 532 cases of flu among patients, which is more than the Boston hospital saw in any of the previous three flu seasons, spokeswoman Kristen Stanton said Wednesday.
Signs posted throughout the hospital discourage anyone from visiting who has a cough or fever, she said, and anyone who does visit with those symptoms must wear a mask and perform hand hygiene. All staff must wear a mask when providing care for possible flu cases. Any staff member who has not been vaccinated must wear a mask while caring for any patient.
Deaths in other states
The Oklahoma Department of Health said Thursday the state has had eight influenza-linked deaths since September 30, while the Minnesota Department of Health has recorded 27 flu-related deaths.
"We are clearly at a high level of influenza activity in the state," Minnesota Health Commissioner Dr. Edward Ehlinger said in a statement. "But it's important to keep this year in perspective: What is occurring has happened before."
The number of flu-related deaths elsewhere, according to state health officials:
-- Pennsylvania has had 22 deaths. Most of the deaths were among people older than 65.
-- Indiana has 13 confirmed adult deaths and two pediatric deaths.
-- Arkansas has seven confirmed flu fatalities.
-- South Carolina has counted 22 deaths.
-- In Illinois, there have been six deaths.
-- In Michigan, there have been four pediatric deaths.
Type of flu
The type of flu that is going around is called H3N2, which is often linked to more serious disease compared to other flu varieties, Fauci said.
That type of flu matches up well to the vaccine that
People may get more complications from this particular strain of H3N2, "which may make them ill for a longer period of time," Dr. Michael Jhung, medical epidemiologist in the influenza division at CDC, told CNN's Mary Snow.
Symptoms typically last up to seven days for a normal infection, he said.
CNN's Maggie Schneider and Elizabeth Landau contributed to this report.