Flu cases have been staying steady or rising in the region and the country during a particularly bad season.

According to data from the Virginia Department of Health, there were around 240 positive laboratory tests in the state last week. That’s significantly higher than last year around this time, when there were between 80 and 100 positive tests each year.

Meanwhile, emergency department visits for influenza-like illnesses are at their highest rates since the 2009-10 flu season, according to data from the Centers for Disease Control and Prevention.

Colin Greene, the director of the Lord Fairfax District of the Virginia Department of Health, said that the 2009-10 influenza season, when the H1N1 virus struck the country, was a so-called “novel” flu season, occurring outside of the normal winter season. This, Greene said, is a particularly bad winter flu season.

“Of the seasonal flus, this is the worst one in quite some time, as far as the numbers of people getting sick,” Greene said.

In northwestern Virginia, as with the rest of the state and country, emergency-department flu visits have continued to climb. Last week, around five percent of all emergency-department visits in the region were for influenza-like illnesses—a high for this flu season.

Greene said that he was unaware of any deaths occurring in the region. So far, the CDC has reported that 37 children have died of influenza this  season.

But people may have died from the flu in the region, he said, because flu cases frequently are not reported.

Under Virginia Department of Health regulations, laboratories have to report all cases of the flu and physicians are required to report weekly statistics. But individual cases of the flu do not have to be reported unless a person under the age of 18 has died from the flu or the case was a “novel” case of the flu.

That can cause cases of the flu to go underreported.

“Particularly, if a death occurred in an elderly person, it might not be reported as well,” Greene said.

Meanwhile, people with milder cases of the flu will often stay at home, rather than go to a physician to seek treatment.

“That’s exactly what we’d like them to do, if they have a milder case,” Greene said. “Stay home and don’t share your germs.”

Greene added that milder cases of the flu often can’t be distinguished from cases of the common cold without laboratory test results.

“And there’s no point in [conducting laboratory tests] if the symptoms are not severe,” Greene said.

Greene added that it is not too late for people to receive the flu vaccine.

Health departments in the Lord Fairfax District of the Virginia Department of Health have walk-in hours on Mondays and Fridays when people can receive the flu vaccine, Greene said. Meanwhile, local pharmacies continue to carry the vaccine, he added.

Greene added that people who have severe symptoms influenza-like symptoms or who are particularly at-risk, because of a chronic illness or because of their age, should see a physician.

Correction: This article has been corrected to reflect that 37 children have died of the flu, according to data from the Centers for Disease Control and Prevention.