Flu continues hasty retreat in US; COVID, RSV markers fall

Seniors in quiet waiting room

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After an early and brisk surge, US flu activity last week declined to near-baseline levels, with trends for other respiratory viruses also dropping, the US Centers for Disease Control and Prevention (CDC) said in its latest updates.

The fall in COVID-19 cases is occurring despite steady increases in the proportions of the more transmissible Omicron XBB.1.5 subvariant, the agency said.

Flu levels sink toward baseline

Six of the nation's regions are below their baseline level for flulike illness outpatient visits, and, as a whole, the level declined to 2.6%, just above the national baseline of 2.5%.

Only three jurisdictions—New York City, New Mexico, and Puerto Rico—reported high flu activity, a metric that also tracks outpatient visits for flulike illness.

At clinical labs, only 3% of respiratory specimens tested positive for flu, and, of those, 96% were influenza A. Of subtyped influenza A viruses at public health labs, 73.2% were the H3N2 strain and 26.8% were 2009 H1N1.

Hospitalizations continued to decline, as did outbreaks in nursing homes.

One marker that rose, however, was pediatric deaths. The CDC received reports of 6 more, bringing the season's total to 91. The latest deaths in kids occurred between the week leading up to Christmas and the week ending Jan 21. All involved influenza A, and, of four subtyped viruses, three were H3N2 and one was H1N1.

COVID, RSV activity ebbs

COVID-19 cases and hospitalizations have been falling over the past few weeks, and, after a stubborn rise, deaths are now also declining, according to the CDC's latest data. The 7-day average for new daily cases as of Jan 25 is 42,163, down 11.3% compared to week before. By a similar measure, hospitalizations declined 13.9%.

The nation is now averaging 564 deaths per day, down 4.9% from the week before.

In updated variant proportions, Omicron XBB.1.5 is now dominant, making up an estimated 60% of sequenced samples, up from just under 50% the previous week. The subvariant is now dominant in southeastern states, alongside regions in the Eastern Seaboard, where it was already dominant. However, the proportion increased in all US regions.

In its other respiratory virus tracking systems, the CDC said emergency department (ED) visits for flu and COVID-19 are declining steadily. And though there are fewer visits for respiratory syncytial virus (RSV), which peaked in the middle of November, those ED visits are gradually trailing off. A similar system the CDC uses to track hospitalizations for the viruses shows a similar trend.

In other US COVID-19 developments, the Food and Drug Administration (FDA) yesterday announced that it pulled its emergency use authorization for Evusheld, a monoclonal antibody combination used to prevent COVID-19 in high-risk groups. It said data show the drug isn't likely to be active against certain SARS-CoV-2 subvariants that are currently responsible for 90% of infections in the United States.

The move narrows the treatment options to Paxlovid (nirmatrelvir and ritonavir), Veklury (remdesivir), and Lagevrio (molnupiravir).

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