Flu-like activity has been reported as high or very high in more than half of the country, according to the latest update by the U.S. Centers for Disease Control and Prevention.In California, levels were reported as “high” for the week that ended on Dec. 20. That was a change from “moderate” the prior week. It comes as the busy holiday travel season is still underway. The CDC estimates that there have been at least 7.5 million illnesses, 81,000 hospitalizations and 3,100 deaths so far this season. There have been at least eight child deaths, according to the CDC. One child flu-related death was recently reported in Sacramento County. KCRA 3 is trying to learn if that case was included in the national tally. California’s Department of Public Health reports that seasonal flu activity is increasing in all regions of the state with a notable rise in test positivity among children. Hospitalizations are low but expected to increase, according to the state. A variant known as “subclade K” is believed to be driving the latest increase in flu cases. Subclade K is a variant of the H3N2 strain. That strain can lead to more severe cases in older adults. It’s not clear if subclade K is just spread more easily or is also more dangerous, the AP reported. The flu is particularly dangerous for people 65 and older, pregnant women, young children and those with chronic health problems, including asthma, diabetes, heart disease and weak immune systems.The CDC and most medical societies recommend that people ages 6 months and older get a flu shot. The Associated Press reported that the flu vaccine isn’t a perfect match to subclade K but that health experts still believe it could offer at least partial protection. About 42% of adults and children have gotten a flu shot so far this year, according to the CDC. Below are the symptoms one can feel if they have the flu:FeverCoughSore throatRunny or stuffy noseMuscle or body achesHeadachesFatigue (tiredness)Vomiting and diarrheaThe following steps can also be taken to reduce the likelihood of contracting the flu and other respiratory illnesses:Wash hands thoroughly and frequently.Cover coughs and sneezes.Stay home from work or school when sick.Consider indoor masking in crowded places.Improve ventilation by opening windows or moving events outdoors.Disinfect frequently used surfaces. See more information on flu activity by state in the chart below. –Jonathan Ayestas and The Associated Press contributed to this story. See more coverage of top California stories here | Download our app | Subscribe to our morning newsletter | Find us on YouTube here and subscribe to our channelPHNjcmlwdCB0eXBlPSJ0ZXh0L2phdmFzY3JpcHQiPiFmdW5jdGlvbigpeyJ1c2Ugc3RyaWN0Ijt3aW5kb3cuYWRkRXZlbnRMaXN0ZW5lcigibWVzc2FnZSIsKGZ1bmN0aW9uKGUpe2lmKHZvaWQgMCE9PWUuZGF0YVsiZGF0YXdyYXBwZXItaGVpZ2h0Il0pe3ZhciB0PWRvY3VtZW50LnF1ZXJ5U2VsZWN0b3JBbGwoImlmcmFtZSIpO2Zvcih2YXIgYSBpbiBlLmRhdGFbImRhdGF3cmFwcGVyLWhlaWdodCJdKWZvcih2YXIgcj0wO3I8dC5sZW5ndGg7cisrKXtpZih0W3JdLmNvbnRlbnRXaW5kb3c9PT1lLnNvdXJjZSl0W3JdLnN0eWxlLmhlaWdodD1lLmRhdGFbImRhdGF3cmFwcGVyLWhlaWdodCJdW2FdKyJweCJ9fX0pKX0oKTs8L3NjcmlwdD4=

Flu-like activity has been reported as high or very high in more than half of the country, according to the latest update by the U.S. Centers for Disease Control and Prevention.

In California, levels were reported as “high” for the week that ended on Dec. 20. That was a change from “moderate” the prior week. It comes as the busy holiday travel season is still underway.

The CDC estimates that there have been at least 7.5 million illnesses, 81,000 hospitalizations and 3,100 deaths so far this season. There have been at least eight child deaths, according to the CDC. One child flu-related death was recently reported in Sacramento County. KCRA 3 is trying to learn if that case was included in the national tally.

California’s Department of Public Health reports that seasonal flu activity is increasing in all regions of the state with a notable rise in test positivity among children. Hospitalizations are low but expected to increase, according to the state.

A variant known as “subclade K” is believed to be driving the latest increase in flu cases.

Subclade K is a variant of the H3N2 strain. That strain can lead to more severe cases in older adults. It’s not clear if subclade K is just spread more easily or is also more dangerous, the AP reported.

The flu is particularly dangerous for people 65 and older, pregnant women, young children and those with chronic health problems, including asthma, diabetes, heart disease and weak immune systems.

The CDC and most medical societies recommend that people ages 6 months and older get a flu shot.

The Associated Press reported that the flu vaccine isn’t a perfect match to subclade K but that health experts still believe it could offer at least partial protection. About 42% of adults and children have gotten a flu shot so far this year, according to the CDC.

Below are the symptoms one can feel if they have the flu:

FeverCoughSore throatRunny or stuffy noseMuscle or body achesHeadachesFatigue (tiredness)Vomiting and diarrhea

The following steps can also be taken to reduce the likelihood of contracting the flu and other respiratory illnesses:

Wash hands thoroughly and frequently.Cover coughs and sneezes.Stay home from work or school when sick.Consider indoor masking in crowded places.Improve ventilation by opening windows or moving events outdoors.Disinfect frequently used surfaces.

See more information on flu activity by state in the chart below.

–Jonathan Ayestas and The Associated Press contributed to this story.

See more coverage of top California stories here | Download our app | Subscribe to our morning newsletter | Find us on YouTube here and subscribe to our channel