The full-body ache. The persistent fever. That feeling of just wanting to crawl under the covers and moan "uncle."
It's spelled f-l-u, and Boulder County is not exempt from the national spike in influenza that, for many, is taking the glow off the start of the new year.
"I just saw one (patient) with the flu five minutes ago," said Dr. Howie Wolf, of Community Medical Associates of Lafayette. "We're seeing more flu this month than we did in November and December put together."
Boulder County hospitals have admitted 16 people with influenza this flu season, according to Boulder County Public Health, and five of those have come this week. Through Jan. 5, the Colorado Department of Public Health and Environment counted 506 hospitalizations and two child deaths statewide since the start of the season Oct. 7.
"Last year we were lucky, and it was a milder year," said state epidemiologist Dr. Lisa Miller. "We didn't have any deaths among children, and we only had about 540 hospitalizations for the entire season.
"This year is clearly not mild. We already have over 500 hospitalizations, so we know this is going to be a more moderate, or severe, year. On average, the past several years, we have had about 750."
In the most severe flu season in recent years, 2009-10, Colorado saw 2,041 hospitalizations, Miller said.
Miller said that in the past week, Colorado has seen a shift from a statistical predominance of Type B strains to an increase in Type A, which includes the H3N2 subset, a strain that kills about 36,000 people in the United States each year.
However, Miller said, "If someone is ill, you can't tell the difference" between strains. "Influenza is influenza."
And it has Boulder County singing the flu blues.
"It's definitely a flu spike," said Dr. Brea Bond, clinic medical director at People's Clinic in Boulder. "Is it worse than other seasons? It's hard to say. It's certainly not as bad as it was 2009-10."
Bond added: "Last year, we had a flu spike very late in the season, April-May, which was unusual. So we don't know what the rest of this season is going to be like."
The increase in flu cases has hit the county at a time when flu vaccines are not immediately available everywhere. Both Boulder Walgreens stores on Thursday were out of the vaccine but expected their supply to be replenished Friday.
"I can say nationally that there are select locations that may experience shortages in supply of flu vaccine, but we're working on it, and we're able to distribute vaccine to those stores and do so very quickly," said Jim Graham, a Walgreens spokesman in Deerfield, Ill.
"In a situation like Boulder, where both those pharmacies are experiencing a shortage, you can call ahead and ask whether we've got vaccine in."
Kaiser Permanente in Colorado expected to have a renewed stock of flu shots available at its clinics by late Thursday, according to a spokeswoman. Kaiser recommends that its patients call its flu hotline at 303-344-7600 to check on availability in their area.
The five clinics in Boulder and Adams counties that comprise the Clinica Family Health Services network, serving primarily the uninsured, Medicaid and Medicare patients, remain well stocked.
"I know we still have flu vaccine available; we have not run out yet," Bond said. "We've really been promoting the vaccine for our patients. That's a very good preventive health measure, so even though we've been vaccinating a lot of our patients, we still have a lot of vaccine available."
At Longmont United Hospital, there have been 50 confirmed cases of flu since October, but only two of those patients have been hospitalized.
As for the vaccine, said hospital spokeswoman Karen Logan, "I know that we have enough for our employees and our patients. We try to catch our patients when they're getting discharged to make sure that they have flu shots, and if not, then we offer it."
Carol Helwig, communicable disease control program coordinator for Boulder County Public Health, said, "If any places or medical providers have been running low or running out (of the vaccine), they will easily be able to restock because there is no shortage nationwide."
Beth Reasoner, director of organizational excellence for Boulder Community Hospital, said BCH has admitted 12 people for flu since Dec. 1 and that 144 patients have tested positive for flu in that time. However, she said, there were certainly more people with the flu who were not tested and therefore not reflected in statistics.
"Not every patient with influenza is necessarily tested for influenza," Reasoner said. "If they are presenting with symptoms, sometimes it's just so clear that it (the lack of confirmation through testing) doesn't change the course of treatment."
Reasoner said 3,068 flu shots have so far been administered to physicians, employees and volunteers at BCH facilities. The 94 BCH personnel who have not elected to receive one have signed contracts pledging to wear masks throughout their work shifts.
With the winter holiday break just concluded, it's too soon to know whether the flu is taking a toll on local schools.
"At this point in time we have not had reports of any issues, but they are just back," said Susan Rowley, health services coordinator for the Boulder Valley School District.
Chana Goussetis, spokeswoman for Boulder County Public Health, said those who suspect they have the flu should not head to a hospital emergency room for initial treatment without first consulting their family doctor.
"Our primary message," Goussetis said, "is stay home if you're sick, and it's not too late to get the vaccine through your doctor or Walgreens ... and obviously other things, like, cover your cough and wash your hands often."
For a map showing locations where flu shots are available, see http://flushot.healthmap.org.
The Denver Post contributed to this report.
Contact Camera Staff Writer Charlie Brennan at 303-473-1327 or email@example.com.