Roundup: Peak Influenza Season Sees Surge in Flu-Related U.S. Hospitalizations; and More News

Peak Flu Season Arrives as CDC Reports Surging Activity, Hospitalizations

The U.S. Centers for Disease Control and Prevention (CDC) reports that seasonal influenza activity is elevated and flu-related hospitalizations are surging nationwide. Historically, flu activity tends to peak in January and February.

Overall, the U.S. is experiencing its highest level of respiratory illness since at least the 1997-98 flu season, the CDC data shows.

According to the CDC’s most recent update for Week 52, ending Dec. 27, 2025, several key indicators point to continued and elevated flu activity:

• Very High Activity in Much of the Country: Out of all 55 U.S. jurisdictions (including all 50 states), 32 are currently experiencing "very high" levels of outpatient respiratory illness; another 16 states report "high" activity, according to CDC's activity measures.

• Increasing Hospital Admissions: During Week 52, 33,301 patients were admitted to hospitals with laboratory-confirmed influenza — the highest weekly tally thus far this season. Hospitalization rates have increased to 9.9 per 100,000 population for the week.

• Cumulative Impact: CDC estimates that, so far this season, there have been at least 11 million illnesses, 120,000 hospitalizations, and 5,000 deaths from influenza across the United States.

• Positivity Rate: Data from clinical laboratories show a 32.9 percent positivity rate for influenza (an increase from prior weeks), with a total of 23,271 positive specimens reported in Week 52.

• Predominant Strain: Influenza A(H3N2) viruses continue to be the most frequently reported this season, accounting for more than 90 percent of subtyped influenza A viruses reported by public health laboratories.

Pediatric influenza-associated deaths have also increased: the latest data show one new death reported in Week 52, bringing the total for the 2025–26 season to nine. All age groups are experiencing increased rates of illness and hospitalization, with the elderly and young children being most affected.

CDC officials indicate that the current elevated activity is expected to persist for several weeks. Indicators of severe disease, such as mortality rate and critical complications, remain low at this stage, but ongoing surveillance and precautions are recommended.

To mitigate the risk, the CDC continues to recommend annual influenza vaccination for all individuals aged six months and older who have not yet received it during the current flu season. More than 130 million doses of influenza vaccine have been distributed in the United States so far.

The CDC recommends the following measures for the public:

• Vaccination: It is not too late to get a flu vaccine. CDC maintains its recommendation that everyone aged six months and older receive their annual influenza vaccination if they have not done so already.

• Antivirals: Prescription flu antiviral medications are available, and early treatment is especially important for people at higher risk of complications.

• General Precautions: Good hygiene practices—such as frequent handwashing, covering coughs and sneezes, and avoiding close contact with people who are sick—remain effective in reducing the spread of influenza.

In addition to vaccination, the CDC advises individuals to monitor for flu symptoms, which include sudden onset of fever, cough, sore throat, and body aches. Prescription antiviral medications are available — but are most effective when started soon after symptom onset, especially for those considered at higher risk for flu-related complications.

Study Finds Opioid Use During Pregnancy Has Doubled in the Last Decade

A concerning new study reveals that the rate of opioid use during pregnancy has risen two-fold over the past 10 years. Researchers from Oregon Health & Science University (OHSU) highlight that this increase comes with significantly higher risks for both mothers and their babies, emphasizing an urgent need for better, more comprehensive support systems for pregnant women.

The findings were published recently in the Journal of Addiction Medicine. While the United States struggles with high rates of opioid use generally, previous data on how this specifically affects pregnancy has been limited or relied on international statistics. This new research offers a clearer picture of the domestic landscape by analyzing hospital data from more than 5.5 million patients in California between 2008 and 2020.

A Sharp Increase in Diagnosis

The study’s analysis showed that the prevalence of opioid-related diagnoses in pregnant patients jumped from 0.14 percent in 2008 to 0.33 percent in 2020. While these percentages may seem small, they represent a doubling of cases and mirror the national trend of increasing opioid dependence.

In a news release, Jamie Lo, M.D., the study’s lead author and an associate professor of obstetrics and gynecology at OHSU, noted the surprise at the lack of large-scale studies on such a critical issue. "Given the prevalence and seriousness of this issue, we were surprised to see the lack of large-scale studies available," Dr. Lo said.

Higher Risks for Mom and Baby

The research identified serious health complications associated with opioid use during pregnancy.

For infants, the risks include:

• Preterm birth: Being born too early, before 37 weeks of pregnancy.

• Respiratory distress: Breathing difficulties that often require medical intervention.

• NICU admission: Needing specialized care in the Neonatal Intensive Care Unit.

• Infant mortality: A higher risk of death shortly after birth.

For mothers, the study found a significantly higher chance of severe, unexpected complications, such as:

• Severe hypertension: dangerously high blood pressure.

• Hemorrhage: heavy, uncontrolled bleeding.

• Blood transfusions: needing donated blood to replace lost blood.

Barriers to Getting Help

One of the biggest hurdles to solving this problem is the fear of judgment. Dr. Lo explained that many people hesitate to ask for help because of stigma. The researchers argue that addiction should be treated with personalized medical care, not judgment.

Kristin Prewitt, M.D., a co-author of the study, pointed out that access to care is already difficult for many pregnant patients, but those with opioid-use disorders face even taller barriers. In Oregon, for example, only one in four residential treatment programs offers care for pregnant individuals.

The Need for a "Whole-Health" Approach

The study concludes that standard prenatal checkups aren't enough for patients struggling with addiction. Instead, there is a need for a "wraparound" or whole-health approach. This means a team of providers—including addiction specialists, primary care doctors, and pediatricians—working together.

"Evidence shows that linking patients to care earlier improves outcomes," said Dr. Prewitt in a news release. By identifying risks early, healthcare providers can ensure mothers and babies receive the support they need from pregnancy through to parenthood, the researchers said.

Is Marathon Running Bad for Your Heart? New Study Offers Reassuring Insights

For years, endurance athletes have heard whispers of concern about the long-term effects of strenuous exercise on the heart. Running a marathon pushes the body to its limits, and some have wondered if this intense effort could lead to lasting damage. A recent long-term study offers some welcome news for recreational runners, suggesting these fears may be unfounded.

The study focused on a key question: Does the temporary stress a marathon places on the heart lead to permanent changes?

To understand the findings, let's break down a few terms. Researchers looked at the "right ventricle," one of the heart's four chambers responsible for pumping blood to the lungs. They also measured "troponin T," a protein released into the bloodstream when the heart muscle is under stress, like during a heart attack or a grueling 26.2-mile run. A spike in troponin after a race is common, but scientists wanted to know if it signaled long-term problems.

What the Study Found

Researchers followed 152 male recreational marathon runners over a decade. They performed detailed heart scans and blood tests before a marathon, immediately after, a few days later, and then again 10 years down the road.

Immediately after the race, they noticed a temporary dip in the heart's pumping efficiency, specifically in the right ventricle. This was accompanied by that expected spike in troponin levels. However, this isn't the alarming part. Within just three days, the runners' heart function returned completely to normal.

Most importantly, when the researchers checked in 10 years later, the runners' hearts were still in great shape. The initial troponin spike after that one marathon had no connection to any negative changes or weakening of the heart muscle a decade later. While some minor, normal age-related changes were seen in the left side of the heart, all functions remained well within a healthy range.

What This Means for You

If you're a recreational runner who loves training for and competing in marathons, this study provides powerful reassurance. The temporary cardiac stress your body experiences during a race appears to be just that—temporary. Your heart is a resilient muscle that recovers quickly and doesn't seem to suffer long-term ill effects from the repetitive strain of endurance training.

The findings suggest that for most healthy individuals, the benefits of a running habit far outweigh the concerns about potential heart damage. So, you can feel confident lacing up your shoes for that next long run, knowing your heart is likely getting stronger, not weaker, with every mile.