Here is a snapshot of flu activity in all 50 states and the District of Columbia:
Like many states, Alabama is having an earlier and busier flu season than a year ago -- though not as bad as the 2009 pandemic. The state Department of Public Health doesn't tally statewide flu cases but emergency departments have been busy treating patients with flu symptoms. Hospitals have been able to handle the load without using tents or other unusual measures.
Flu in Alaska is widespread and occurring throughout the state, though not at the high levels being reported in some other states. There is no vaccine shortage and no flu deaths have been reported in children.
Flu cases are increasing in Arizona but authorities aren't calling it a worse-than-usual season so far. Plenty of vaccine remains. Like many states, Arizona only tallies flu deaths in children; none have been reported so far this season.
The Centers for Disease Control and Prevention said Friday that Arkansas is among a few states in the southeast in which flu cases spread less rapidly in the past week, but a state Health Department spokesman said it's too early to say cases have peaked there. Nine people have died from the flu so far in Arkansas, including one child,
Flu activity is on the rise in California, but the increase is not unexpected, state health officials said Friday. The nation's most populous state typically sees a surge in flu cases in late December or early January, peaking in February or March. Four flu-related deaths have been reported this year. Officials said there is no vaccine shortage and urged residents to get vaccinated.
At least two children have died from flu-related complications in Colorado. Several providers have reported temporary vaccine shortages, and one large health group, Kaiser Permanente, stopped offering flu shots this week but expected to resume vaccinations with new shipments expected by this weekend.
There were 1,680 confirmed cases of flu in Connecticut as of Jan. 5, an increase over the past two years. Three flu deaths have occurred, all in people older than 65. Vaccine supplies are adequate.
Flu activity is widespread in Delaware, and the number of cases is higher than at this time in recent years. No flu deaths have been reported and vaccine supplies are adequate.
District of Columbia
Washington, D.C. has seen a big spike in flu cases this year -- 310 since the season began on Sept. 30, an increase of more than 300 percent over the entire 2011-2012 flu season. There have been no reported deaths. Health officials are still urging residents to get vaccinated, and there have been no reports of shortages.
Most Florida counties are reporting mild or moderate flu activity. There has been an increase in flu-like illness treated in emergency rooms and doctors' offices, and two children have died. Vaccine demand is up but flu shots are readily available.
State authorities said Friday that flu has reached epidemic levels in Georgia. Although activity has declined a bit, it's uncertain if cases have peaked. Two adult, flu-related deaths, have been reported.
Flu in Hawaii is at a low, steady level normal for the state this time of year, and there is plenty of vaccine available. There have been no pediatric deaths or uptick in adult deaths related to the flu.
In Idaho, eight older adults have died from flu-related illness and doctors are seeing an increase in patients with flu-like symptoms. "It's definitely shaping up to be a more serious flu season than we've seen in the past several years," said spokeswoman Nikki Forbing-Orr of Idaho's Department of Health and Welfare. There have been no runs on flu vaccine and the state's supply is in good shape.
Intensive care unit hospitalizations and flu-related deaths surpass previous years and continue to climb, with 27 adult deaths so far. Eight Chicago-area hospitals turned away ambulances earlier this week because of a surge of patients with flu-like symptoms but that situation eased. Chicago's health department encouraged vaccinations and held a flu chat Friday on Twitter; Mayor Rahm Emanuel tweeted a photo of himself holding a sign that said, "Any advice for people who shake a ton of hands? (hash)FluChicago."
Flu is widespread in Indiana and deaths have climbed to 15 during what health officials call a "moderately severe" flu season. During the same period last year, no flu deaths were reported; two years ago there were two deaths. During the pandemic of the 2009-2010 flu season, there were 21 deaths by this time of the year. Two of this season's deaths were in children younger than 18.
Flu problems are increasing in Iowa and are worse than in recent years. Some locations have run out of vaccine, partly because clinics ordered fewer doses because of recent mild flu seasons. Iowa doesn't track flu deaths.
The Kansas Department of Health and Environment has reported one child flu death. Flu is widespread but vaccine supplies have mostly been adequate in Kansas.
Flu has been widespread in Kentucky for the past five weeks, which is earlier than usual. State authorities are not aware of any shortages and there have been no flu deaths in children.
High levels of flu-like illness are reported in Louisiana but no child deaths and so far emergency rooms have not had to turn away other patients to accommodate those with suspected flu. "This is going to be one of the very busy seasons," said Louisiana's state epidemiologist, Dr. Raoult Ratard.
Authorities say flu cases are increasing and reaching "epidemic proportions" with widespread illness throughout the state. Most hospitals are near capacity, and there have been some spot shortages of vaccine. Maine doesn't tally flu deaths but one school-aged child has died -- Maine's first flu-related death in a healthy child in years.
Flu cases are widespread and more numerous than expected in Maryland, but there are signs things may be stabilizing. Most patients are older than 65; no children's deaths have been reported. Emergency departments at several hospitals in the Baltimore-Washington area were at or near capacity for intensive- and critical-care patients but it wasn't clear to what extent flu was a factor.
Massachusetts has reported a high level of flu activity, with 18 deaths, none in children. The city of Boston declared a public health emergency on Wednesday and is working with health care centers to offer free flu vaccines. Ahead of weekend church services, the Roman Catholic Archdiocese of Boston advised priests they may want to encourage parishioners to avoid drinking from communion chalices and skip handshakes when exchanging signs of peace during services until the flu emergency subsides.
Health officials say the flu season is worse than previous ones, isn't slowing down, but has not reached an emergency level yet. Four Michigan children have died from flu-related illness. The hardest-hit regions are in the southwest, central and southeastern parts of the state. Some pharmacies are running out of vaccine, but enough is available on order.
Flu season has hit hard in Minnesota and many residents have gotten vaccinated. Some clinics have run out of vaccine and had to wait a day or two to get new supplies, but there have no serious shortages. There have been 27 deaths, most in elderly patients.
High levels of flu-like illness have been reported in Mississippi but no child deaths and so far emergency rooms have not had to turn away other patients to accommodate those with suspected flu.
Flu cases began in November in Missouri and authorities can't tell if the season has peaked yet. Illness is widespread, and the state health department recommends that residents seeking flu shots should call ahead to make sure supplies are available. There have been no reported flu deaths in children.
This flu season is shaping up as Montana's worst since 2009. Influenza is increasing with outbreaks occurring in at least half of the state. Increases are expected for at least another few weeks. There are no reported vaccine shortages. One elderly person has died from the flu.
One child and two adults have died from the flu in Nebraska, where cases are up this year compared with last year. There are some spot shortages of vaccines, but supplies are adequate in most places.
Confirmed flu cases are up 57 percent in Nevada from two weeks ago and the increase is continuing. Authorities say it is too soon to tell whether this will be a severe season.
Hospital emergency room visits by patients with flu-like symptoms in New Jersey are double the number seen at this time last year. Two children have died, both with underlying medical conditions that made them more vulnerable. Flu activity is highest in central and northeast portions of New Jersey.
The governor has declared a flu emergency. The order allows pharmacists give vaccines to anyone 6 months or older, suspending a state law that limits pharmacists to administering immunizing agents to those 18 or older. Flu has been reported in every county and has been widespread for seven weeks. Reported cases declined last week but hospitalizations for lab-confirmed flu were up. Two children and at least 10 New York City adults have died from flu-related illness. Statewide adult deaths aren't tracked.
Flu activity is earlier than usual but not abnormal; one death, in an elderly resident, has been reported.
There have been nearly 2,000 flu-related hospitalizations in Ohio since October, compared to 86 in last year's unusually mild flu season, and 175 the previous season. One child has died from flu complications; there were no child deaths last season and only one the previous year. The state Health Department says there are sufficient supplies of vaccine available around the state.
Flu is widespread and increasing in Oregon but authorities say it's not outside the normal range. No deaths in children have been reported.
The flu season is more severe in New Hampshire than in recent years, but the state public health director says it's not yet alarming. So far, 14 flu-related deaths in adults have occurred, an unusually high number this early in the season, but no child deaths. A Health Department spokeswoman said she was not aware of any vaccine shortages.
Flu has hit earlier and harder than usual in New Mexico. There have been no deaths but 88 New Mexicans have been hospitalized with flu-like illness compared with two cases at this time last year. Vaccine supply is ample.
Flu is prevalent in every county but declined slightly this past week; authorities say it's too soon to know if that's a trend. "This was a very early onset of the flu season and the proportion of medical visits that are due to flu-like illness has been higher than we've seen in the past decade," said health department spokesman Mark Van Sciver. As of Jan. 10, there were 17 reported flu deaths, including 14 people older than 65. Local public health departments had adequate vaccine supply.
Flu is widespread, with cases in at least half the state's regions. Of 23 flu-related deaths, one was an infant. Hospitals throughout Pennsylvania have reported an influx of cases; at least one hospital, to free up ER capacity and minimize flu transmission, has erected an outdoors MASH-like "surge tent." Other hospitals have mobile flu units.
Health Director Michael Fine says flu is "particularly severe" in Rhode Island and that it could be the worst season in years. The state has seen 5,568 emergency room visits for flu-like symptoms since Dec. 10, an average of about 180 a day. A Health Department spokeswoman says "people are sick everywhere." Many people are seeking vaccination and supplies are plentiful. No children have died from the flu.
Flu is widespread in South Carolina but hospitalizations have slightly decreased. Of 22 flu deaths, one was an infant, the rest adults older than 50. The State's Division of Health and Environmental Control has ample vaccine; whether there were any shortages elsewhere was unclear.
Flu activity is earlier and occurring at higher levels than usual in South Dakota. Nine people have died from flu-related illness, all older than 75.
Dr. Kelly Moore, the medical director of the Tennessee Immunization Program, says the flu season seems worse than in recent years but that clinic reporting is often disrupted over the holidays, so whether cases are increasing or not is uncertain. "We're not hearing reports of any hospitals being overwhelmed," she said. One child has died from flu-related illness.
Flu cases have been reported in more than half of Texas, and several county health departments say this season is worse than in past years. In the last week of December, nearly 12 percent of doctor visits were for flu-like symptoms, almost double the amount for that week in 2011. The number of cases dropped last week. In the Dallas area, many parents say their doctors don't have the pediatric vaccine so they've sought the shots at the county health department. At least six Texas children have died from flu-related illness since last fall.
Utah officials say flu cases spiked last week but dipped this week, and call it an early and active season. No deaths have been reported. Utah's vaccine supply is holding steady with no reports of shortages.
Flu cases appear to be on the rise in Vermont. Three adults have died, all in December. Vermont Health Department officials say flu rates are higher than other years but the number of deaths does not appear out of the ordinary. A total of 10 people died from the flu last year; seven in 2011 and none in 2010.
Virginia hit widespread influenza activity in December, a month or two early, which hasn't happened since the 2003-2004 season. Outbreaks have been reported in schools and nursing homes in all regions of the state but no children have died.
Flu has spread to more than half the communities in Washington state; that's not unusual but it appears to be increasing and authorities say is could be worse than recent mild seasons. There have been five lab-confirmed flu deaths in adults and one in a 12-year-old boy.
State public health officials say fewer than 1,400 cases of flu have been confirmed and flu-like symptoms are widespread. Public Health Commissioner Marian Swinker said Friday that more than 15,000 people have told doctors they were ill last month, with nearly 4,400 reporting they were sick so far this month. There have been no flu-related deaths in the state.
Flu-related hospitalizations in Wisconsin total more than 1,300, versus 389 for all of last year. One child has died. State officials believe they have an ample supply of vaccine and no shortages. In Milwaukee, hospital emergency department visits have tripled over the past few weeks due to patients with flu-like symptoms and ambulances were being diverted elsewhere, a city Health Department spokeswoman said Friday.
Flu activity is high in Wyoming. One county ran out of vaccine last week and the distributor won't have any more flu vaccine this season. Supplies are available from many doctors' offices and other providers, and thousands of people have already been vaccinated. There have been no reported deaths.
State health officials generally only keep track of children's flu deaths. Often the cause is pneumonia or related to frailty or other health problems so it is hard to draw conclusions about a flu season from state reports.