Feeling like everyone around you is sick? California public health officials said that cases of flu and hospitalizations are rising in the state as they confirmed a second pediatric death associated with it this season.

Nationwide, that figure is 17 pediatric deaths for the season, according to the Centers for Disease Control and Prevention.

The CDC recently said that flu activity is expected to remain elevated in the United States for several weeks.

A strain of one influenza virus, H3N2 subclade K, has been detected within the state, the California Department of Public Health said on Jan. 13. This strain has been referred to as a “super flu,” and CDPH said it’s the reason seasonal flu activity is elevated in the state.

CDPH is recommending people get the flu vaccine, with the CDC saying the flu vaccination “has been shown to reduce the risk of flu and its potentially serious complications.”

Is flu rising in Southern California? What to know about ‘super flu’

Test positivity for flu began to rise in December in Southern California, including Los Angeles, according to data from the CDPH.

For these combined regions, the test positivity for flu is considered to be moderate, based on data from early January. For context, the latest test positivity figure for these regions is lower than last year’s at the same time.

In December, the World Health Organization said that the current data don’t “indicate an increase in disease severity” regarding the flu variant circulating.

One expert told Stanford Medicine that the term super flu is “made up.” Another expert told Axios that it “doesn’t really have any medical meaning.”

What’s the latest with COVID and RSV in Southern California?

Here’s what to know about two other respiratory viruses that have similar symptoms, according to data available from the CDPH.

• COVID-19: COVID-19 activity “remains very low statewide,” according to the CDPH as of Jan. 9. For Southern California and Los Angeles combined, test positivity is considered very low as of data from early January.

• RSV: The test positivity for respiratory syncytial virus — a common respiratory virus — in Southern California and Los Angeles combined is considered moderate, according to early January data. However, Los Angeles County Department of Public Health reported that while the percentage of positive tests for RSV is low, based on figures as of early January, it was an increase compared to the previous week. This is based on preliminary surveillance data.

In San Bernardino County, health officials noted another issue: a surge in whooping cough compared to last year, the Victorville Daily-Press reported.

When am I not contagious with the flu?

The time period during which you could potentially infect someone else varies. For some otherwise healthy adults, they can spread the flu a day before symptoms develop and up to 5 to 7 days after becoming sick, according to the CDC. However, others, including young children and people with weakened immune systems, may be contagious for longer, the CDC said.

“People with the flu are most contagious during the first three days of their illness,” according to the CDC.

Is it COVID or is it the flu? What to know about symptoms

For those wondering whether they have the flu or COVID-19, the CDPH said it’s often difficult to identify the type of respiratory infection someone has based on symptoms alone, noting that only testing for these viruses can confirm the diagnosis. Both the flu and COVID-19 can cause similar symptoms, said the CDPH. It echoes what the CDC said in 2024, in that you can’t tell the difference between the two by symptoms alone.

Paris Barraza is a reporter covering Los Angeles and Southern California for the USA TODAY Network. Reach her at [email protected].

This article originally appeared on USA TODAY: Is it flu, COVID? What to know if you're sick in Southern California