LOS ANGELES, CA — Flu-related illnesses and deaths spiked the week of Jan. 18 across California, recording the deadliest week of the season with another 44 deaths statewide.

There were 15 million cases nationwide as health officials from the Centers for Disease Control reported an additional 1,400 deaths since last week — 15 of which were of children.

Influenza B — which tends to affect children and young people more — continued to dominate among tested cases, but the H1N1 also surged, according to the California Department Of Public Health. That means that some people will get the flu twice this season, acquiring both viruses before flu season ends in the spring. Across California six children have died from the flu this season.

The flu virus continues to affect young people at an alarming rate. More than 50 percent of reported cases this flu season are in children and young adults under age 25. So far, 54 pediatric deaths have been recorded nationwide this flu season.

Nationally, according to the CDC's influenza report for the week ending Jan. 18, the percentage of virus specimens testing positive for influenza increased from 23.3 percent for the week ending Jan. 11 to 25.6 percent this week.

The CDC estimates that, so far this season, there have been at least 15 million illnesses, 140,000 hospitalizations and 6,600 deaths from the flu.

The latest data from the agency shows that the virus has been widespread in nearly all states, including California, which has suffered through 52 outbreaks.

The CDC's surveillance of influenza-like illness measures the level of flu activity within a state. According to the latest data, flu activity is high California

The groups most at risk of the flu are older adults, very young children, pregnant women and those with certain chronic medical conditions, according to the CDC.

According to the CDC, symptoms of the flu include:

    Fever or feeling feverish/chills (though not everyone with flu will have a fever)
    Cough
    Sore throat
    Runny or stuffy nose
    Muscle or body aches
    Headaches
    Fatigue
    Some people may have vomiting and diarrhea, though this is more common in children than adults.

The flu is a highly contagious illness, which is why the CDC urges everyone to take the following steps to protect themselves and others: