Greenville, SC (Liv Osby, Greenville News) --As 2013 comes to a close, flu season is picking up across South Carolina. And the most prevalent strain both here and across the nation is the H1N1 virus, which typically hits younger people hardest.
The state's first case of flu was reported in October, but the volume didn't start to pick up until the week before Christmas, according to the state Department of Health and Environmental Control.
"Last year, it seemed like it started right around Thanksgiving and we were extremely busy thereafter with flu," said Dr. Jim Ellis, medical director of MD 360, Greenville Health System's urgent care centers.
"This year, it picked up pretty dramatically the week before Christmas with similar volumes," he said.
MD 360's four locations see about 250 to 300 patients on an average day, he said. But on Thursday, there were 385 patients - a 25 percent increase - and one day last week there were 400 patients, he said.
Some of the volume can be attributed to doctors' offices being closed over the holidays, but the majority is related to the flu, Ellis said.
Since Sept. 29, 401 people have been hospitalized for the flu - 67 in the week ending Dec. 21, DHEC reports. And there have been six deaths from flu so far this season in Berkeley, Charleston, Dorchester and Richland counties.
The U.S. Centers for Disease Control and Prevention reported this week that the predominant strain is influenza A-H1N1, also called the swine flu.
Since it appeared in 2009, H1N1 has caused more illness in children and young adults - some leading to intensive care hospitalizations - than older adults, who are typically at higher risk, according to the CDC.
Though the illness so far this season is fairly typical, if H1N1 continues to dominate, young and middle-aged adults may be disproportionately affected, the CDC reports. Scientists theorize the H1N1 virus is more severe in younger people because they don't have the immunity that older people have from being exposed to related viruses years ago.
The flu is a contagious respiratory illness that can cause mild to severe symptoms that include a sudden onset of fever, dry cough, headache, muscle aches, fatigue, sore throat and nasal congestion. The very young, elderly, pregnant women and those with chronic illnesses are most at risk, according to DHEC.
Though flu is still classified as regional in South Carolina, the CDC reports that other parts of the country, including Texas, Louisiana, Mississippi and Alabama, are experiencing high levels of the virus, and incidence is expected to increase in the coming weeks.
Vaccination is recommended for everyone six months old and older. But only about four in 10 people 64 and younger had been vaccinated by early November, according to the CDC. About 61 percent of those over 65 had had a flu shot.
And while vaccination of health-care workers has been shown to reduce the spread of illness, only about 63 percent had been vaccinated, even though the CDC recommends flu shots for all health-care workers. Vaccination rates were highest in hospitals - 79 percent - and lowest in long-term care facilities, 52.6 percent, the CDC reports.
In the last two flu seasons, immunization rates had increased 3 percent to 9 percent by the end of the season, according to the CDC.
While flu season generally runs from October to March in South Carolina, it typically peaks in February. Health officials say it's not too late to be inoculated, and H1N1 is covered in this year's vaccine.
Ellis said the majority of MD 360 patients with the flu have been adults who hadn't had a flu shot.
"People still should go ahead and get immunized," he said. "I don't think we've reached the peak yet. Especially with it starting later this year, we anticipate it lasting a little longer."
Along with a flu shot, Ellis says the best way to keep from getting the virus is frequent hand-washing and avoiding contact with people who are sick because the flu is typically transmitted through respiratory droplets.
"We've had a lot of people recently who've been at family gatherings over Christmas and it was caught that way, by people coughing a lot," he said.
"We've seen a number of families come in with two or three people in the family having it because it spread. And when they come in here, we put a mask on them immediately."
The flu killed 46 South Carolinians and hospitalized 1,721 from Sept. 30, 2012, to Sept. 21, 2013, according to DHEC.
Officials say those who are sick should stay home from work and school to avoid infecting others, and cough or sneeze into the elbow or a tissue.
To learn more and to find flu clinics near you, go to www.scdhec.gov/flu.