The San Diego County Health & Human Services Agency says it is now working with the state health department to respond to outbreaks of flu-like symptoms at Patrick Henry and Del Mar high schools this week.

Dr. Cameron Kaiser, the county’s deputy public health officer, said about 40% percent of students at those campuses stayed home on Wednesday, the most recent day for which he had data. Some preliminary tests on students were positive for influenza A.

“It is important to note, though, the state is already involved with this. We certainly reported it up to them. I’m sure they’re discussing it with their federal partners,” Kaiser said. “Right now, though, this is occurring against a baseline of something that we expected to happen, and that’s why we want people to be prepared.”

Kaiser warned that the current outbreak isn’t limited to these high schools, but said school outbreaks were more noticeable because administrators monitor attendance.

“If you’re going to see a large number of people sick out in a geographic area, you tend to see it hit the schools first,” he said, “not because it’s not occurring other places, but that’s simply those are the ones keeping the closest tabs on statistics.” 

The county says the flu is already spreading quickly in the community, and is only going to get worse. So officials are urging everyone to get their flu shot — especially people who are more vulnerable.

“Across the county we’re seeing a large number of influenza cases in some of the largest counts we’ve ever seen for October,” Kaiser said. “This is important for folks to realize that, if it walks like a duck, quacks like a duck, it probably is a duck, and we already expected that it was going to to be a bad flu season. And everything is clicking into place.”

Dr. Teresa Hardisty, a Sharp Rees-Stealy pediatrician, told KPBS that influenza A is particularly hard-hitting. She said that, after a couple of years of pandemic precautions, not everyone’s immune system is ready for it.

“The natural immunity in the population has gone down, and influenza has not really circulated that much,” Hardisty said. “And so people are coming in with high fevers, serious cough, feeling achy and low fevers. Usually with influenza the fevers last for four or five days, and they can be as high as 104 or 105, so people are very uncomfortable.” 

Hardisty said the flu vaccine gave the body a “prewarning,” so, if someone gets the flu, they have a milder case.

“[The flu] rages through the community, so I think that if you can decrease the level of illness by having the vaccine prior, I think that is an important critical way for you to protect yourself and also minimize the chance that you might spread influenza A to somebody who might has lower natural immunity,” Hardisty said.

She said she had seen the worst cases in medically fragile babies, children under the age of 1, and children with asthma and other conditions. She urges parents to get children vaccinated if they’re old enough. And, she said, “I would recommend to be more cautions with exposure in large indoor groups [and] in communities that have current outbreaks.”

When that’s not possible, she said masking was possible for older children, and advised parents to talk to their doctors about medications that can protect their children.

And for people who are sick, she said, plenty of rest and healthy foods are key to getting better.