Flu continues to rise in some US regions as COVID markers decline


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Respiratory virus activity remains high across the United States, with flu activity up, especially in three regions, and COVID-19 and respiratory syncytial virus (RSV) markers continuing to drop from high levels, the Centers for Disease Control and Prevention (CDC) said today in its latest updates.

Overall, 27 jurisdictions reported high or very high respiratory virus activity last week, an increase from 25 the previous week, the CDC said in its weekly snapshot.

Flu B linked to regional rises

In the first weeks of the near year, flu activity ebbed a bit but is rebounding in some regions, partly due to increasing proportions of influenza B.

Overall, most markers held steady last week compared to the week before, but flu deaths declined, the CDC said in its weekly FluView report.

Activity increased in the upper and central Midwestern regions, as well as in Middle Atlantic states.

Test positivity remained stable, but influenza A proportions fell slightly while influenza B detections rose, mainly due to activity in the regional hot spots. Influenza B circulation often rises in the latter part of the US flu season. Of respiratory samples that were positive for flu at US public health labs, nearly 77% were influenza A and 23% were influenza B, about the same as the week before. Of subtyped influenza A viruses, 59% were 2009 H1N1, which has been the dominant strain, and 41% were H3N2.

The CDC said it received reports of 8 more pediatric flu deaths, raising the season's total to 82. The deaths occurred between late January and early February. Five involved influenza B, and 3 were due to influenza A. Of two subtyped influenza A viruses, one was the H1N1 strain and the other was H3N2.

COVID wastewater levels highest in South

For COVID, the CDC's main severity indicators—hospitalizations and deaths—showed a mixed picture. Hospitalizations were up slightly, by 0.8% compared to the previous week, with deaths down 6.9%.

Early indicators continued a downward trend, with emergency department (ED) visits down 5.3%. ED visits are still highest in infants and older adults. Test positivity is at 9.3% nationally, down 0.6% from the week before. Test positivity is higher across the South than in other parts of the country.

The CDC still classified wastewater SARS-CoV-2 detections as high, and in its respiratory virus snapshot, it said levels are highest in the South but are falling.

Also today, the CDC released its latest variant projections, which shows a further rise of JN.1, which now makes up 96.4% of samples.

RSV test positivity, hospitalizations decline

For RSV, activity is declining in many areas, and hospitalization levels are trending downward—though still elevated—for both young children and seniors.

Similar to COVID, test positivity for RSV is also declining.

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