— Seven people died of the flu in North Carolina last week, bringing the total number of flu-related deaths statewide to 20 since the beginning of October, public health officials said Thursday.

The seven deaths in the week ending Dec. 30 were almost double the previous weekly high this season and included the second child to die of the flu, officials said.

The Centers for Disease Control and Prevention said up to half of all children who die as a result of the flu have no known medical condition that put them at higher risk for complications of the illness.

"Most people who have flu either don't ever get diagnosed, or if they do get diagnosed, they don't get reported. So, we know there's a lot more serious illness and death than what we hear about," State Epidemiologist Dr. Zack Moore said.

The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness and at times can lead to death. The elderly, young children and people with chronic medical conditions or weakened immune systems are at high risk for serious flu complications. The best way to prevent the flu is by getting vaccinated each year.

Last flu season, the vaccine proved to be only about 50 percent effective. Moore said that, although it is difficult to determine the value of the vaccine this early, it can save lives even at 50 percent effectiveness.

"If you could cut your risk of dying from a heart attack in half, you would do it," he said. "Even when you have vaccines that are order of 30 to 40 percent effective, that's millions of illnesses that you can prevent and tens of thousands of hospitalizations that you can prevent.

"We all wish we had a 100 percent effective vaccine that you only needed to get once in your life, but it's the best that we have in terms of protecting yourself and your family," he added.

The pattern of flu cases is similar to last season in that the predominant strain involves the H3N2 virus.

"When we see H3N2 as the predominant virus, we know that people who are over 65 are going to be hit especially hard," Moore said.

Flu symptoms include:

A 100 degree or higher fever or feeling feverish (not everyone with the flu has a fever)

A cough and/or sore throat

A runny or stuffy nose

Headaches and/or body aches

Chills

Fatigue

Nausea, vomiting, and/or diarrhea (most common in children)