Ten people in California have died so far this winter from influenza, evidence that health professionals' warnings are valid: this flu is hitting harder and earlier than it has in years. The virus has hospitalized scores of people, leaving the state to contend with widespread outbreaks and, locally, a dwindling supply of antiviral medications.

Health providers say they are experiencing some of the busiest emergency departments they’ve seen in a long time — something they attribute to an early flu season, a less-effective vaccine and poor local air quality that exacerbates symptoms.

Every county in the state has seen elevated flu activity, outbreaks and hospitalizations, according to the California Department of Public Health.

“Data is indicating that we’re in the midst of a flu season that is potentially taking early,” said Michelle Corson, spokeswoman for the Kern County Public Health Services Department. “It’s highly contagious, so people really need to stay home when they’re sick. This flu is to be taken seriously.”

The flu is a contagious respiratory virus. Its symptoms include fever, coughing and fatigue, and can result in severe illness and sometimes death. Last year, it was associated with two deaths in Kern County and sent four to intensive care units.

This year, 13 people have died of influenza across the nation, according to the U.S. Centers for Disease Control and Prevention.

Locally, no deaths had been reported as of Thursday, but Kern County health providers have seen three severe influenza cases that have sent patients to intensive care units, Corson said.

Those numbers, however, could be much higher. Only cases among those 64 and younger are reportable at the local level, but elderly people are at a higher risk of falling ill to the flu, health experts said.

Many attribute the surge to the ineffectiveness of this year’s vaccine to fight a common and virulent strain of influenza, H3N2. Researchers say it’s the result of a mutation in the strain as the vaccine was being developed, making it anywhere from 15 percent to 30 percent effective against the strain. This year's vaccines reduce the risk of getting other strains of the flu by between 40 percent and 60 percent, according to the CDC.

“The flu shots just didn’t have the coverage this year, and we’re having a bad flu season as a result,” said Jenny Wilson, director of nursing operations at Bakersfield Memorial Hospital.

The surge in cases has been flooding local emergency rooms with respiratory-related ailments, several doctors, nurses and health administrators said. Memorial Hospital, Kern Medical and Adventist Health Bakersfield have all reported upticks.

Memorial’s emergency department has seen an increase of 100 adult patients and an additional 75 children per day over the last few weeks, said Dignity Health spokeswoman Jessica Neeley.

The emergency department averaged about 246 patients in December. The week of the new year — which was marked with unhealthy air thanks to a lingering high-pressure system that trapped smog in the valley — Wilson said she averaged 315 patients per day.

“I’ve been director of this emergency department for seven years, and this is the worst I’ve ever seen it,” Wilson said. “It’s the perfect storm of the vaccine not working real well and the poor air quality.”

Meanwhile, as emergency rooms, clinics and urgent care centers are overwhelmed with flu patients, the local supply of antiviral medications is dwindling, said Dr. Shakti Srivastava, who practices family medicine at Kern Medical’s Sage Brush Clinic.

Those antiviral medications are used to decrease symptoms and the duration of the flu by days, Srivastava said.

“We are facing some serious shortages,” Srivastava said. “A lot of pharmacies are running out.”

That means physicians could be inclined to begin prescribing those medications only to those in high-risk groups, including the elderly, young children, pregnant women, those with asthma and chronic obstructive pulmonary disease, and anyone with a compromised immune system, Srivastava said.

Those groups of people are generally at a higher risk for developing complications than healthy adults.

“The complications are to the point where you wake up in the morning and you’re in severe distress, to the point of it being life-threatening,” Srivastava said.

Even though the flu seems to be hitting harder and earlier, health professionals say that it’s being treated no differently than in past years.

That means people should be getting vaccinated, staying hydrated, practicing good hygiene and washing their hands often. If somebody is infected, they should steer clear of others. The virus is contagious from up to 6 feet away.

“The message of how to prevent the flu never changes,” Corson said.

But this year it has an exclamation point.

Harold Pierce covers education and health for The Californian. He can be reached at 661-395-7404. Follow him on Twitter @RoldyPierce