Seasonal flu is spreading earlier than usual in much of the United States. In its Nov. 13 surveillance report, the Centers for Disease Control and Prevention said 11.3% of respiratory samples tested by reporting clinical labs were positive for flu in the week ending Nov. 7, up from 9.1% the previous week. Seven states reported high or very high levels of outpatient visits for flu-like illness, up from two a week earlier.
The CDC also received reports of two more flu-associated deaths in children that occurred during the current season, bringing its preliminary total to five. One of those two deaths occurred in October and one in the week ending Nov. 7. A separate death reported in the same bulletin occurred last season. The CDC says it can take weeks for pediatric flu deaths to be reported.
Where activity is higher
The CDC's high or very high group included California, Louisiana, Oregon, South Carolina, Tennessee, Texas and Washington. Most jurisdictions were still in the low or minimal categories. These levels reflect how often people seek outpatient care for symptoms such as fever with cough or sore throat, compared with what is typical for the reporting area. Other infections can cause the same symptoms. The CDC national map and state links show how activity differs across the country.
Nationally, flu-like illness accounted for 3.2% of visits in the reporting outpatient network, above its 2.9% baseline. The lab positivity figure tracks a different group: respiratory specimens tested by participating clinical labs. Neither figure measures the percentage of all Americans with flu. Hospital admissions rose as well. Among the 460 influenza A samples that public health labs subtyped that week, 455 were H1N1. That breakdown describes the samples those labs tested.
What the hospital numbers show
Hospitals reported 9,584 admissions associated with laboratory-confirmed flu for the week ending Nov. 7. The reported weekly admission rate was highest among adults 65 and older, at 8.6 per 100,000 people, followed by children under 5, at 3.2 per 100,000. Both rates increased from the prior week.
Separately, the CDC estimates at least 2.6 million illnesses, 36,000 hospitalizations and 2,100 deaths from flu so far this season. Those are cumulative estimates, which include illnesses that may never have been confirmed by a lab. The previous weekly report estimated at least 1.7 million illnesses. Revisions to earlier estimates and gaps in reporting mean the difference should not be read as an exact count of people who got sick in one week.
The CDC still rates early-season severity as low across age groups. Its hospital admissions forecast expects admissions to rise nationally through the week ending Nov. 28, with a range of 8,300 to 34,400 laboratory-confirmed admissions reported for that week. Many jurisdictions had incomplete hospital reporting for the latest observation. The range leaves room for the pace of admissions to change before Thanksgiving.
What to do before holiday travel
The CDC recommends a flu vaccine each season for most people age 6 months and older. It generally takes about two weeks for protection to develop. A child who needs two doses has to get them at least four weeks apart, according to CDC guidance. A pediatrician or pharmacist can confirm which schedule applies. The CDC's risk guidance includes adults 65 and older, young children, pregnant people and people with conditions such as asthma, diabetes or heart disease.
If someone at higher risk develops flu symptoms, the CDC advises contacting a health care provider promptly. Prescription antiviral medicines work best when started within two days of symptoms, and a clinician may recommend them later for severe illness or people at higher risk. If you are planning to visit an older relative or a household with a young child, check the local activity numbers as well as the national figures. The CDC report lists different activity levels for neighboring states, and those levels can change week to week.
