Respiratory virus activity continued to decline last week, and though COVID-19 indicators continue to decline, estimates of new variant proportions show some notable shifts in SARS-CoV-2, the Centers for Disease Control and Prevention (CDC) said in its weekly updates today.

In its weekly snapshot for flu, COVID-19, and respiratory syncytial virus (RSV), the CDC said no states are reporting high activity. Only one—North Dakota—is reporting moderate activity.

Flu markers continue to tail off

Flu activity continues to decline, with levels below baselines in all but 1 of 10 regions. Region 1, which includes six northeastern states, is at its regional baseline, the CDC said in its weekly FluView update. 

Test positivity declined, and all three seasonal flu viruses continue to circulate, with influenza A making up 62.7% of positive samples at public health laboratories.

Hospitalizations declined, and overall deaths held steady. The CDC received reports of 6 more pediatric flu deaths, raising the season's total to 148. The deaths occurred from November 2023 to early this month. Three were due to influenza A, and three were linked to influenza B.

COVID trends decline, despite rise in FLiRT proportions

In its latest COVID data updates, the CDC reported further declines in its severity markers (hospitalizations and deaths), as well as its early indicators (test positivity and emergency department visits). Wastewater SARS-CoV-2 detections, another early indicator, remained at the minimal level and are at their lowest level since July 2023.

In its variant proportion update today, the CDC reported an ongoing decline in JN.1 variant detections and a steady rise in its spinoffs that have two added spike mutations, nicknamed the FLiRT (F for L at position 456 and R for T at position 346). The most notable rise was for KP.2, which edged above JN.1 and is now at 24.9%. Also, the proportion of another FLiRT subtype, called KP.1.1, rose from 3.1% to 7.5% over the past 2 weeks. 

So far it's not clear if the FLiRT subtypes will trigger another rise in COVID activity.

The US Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) announced that it has finalized a policy to declare Salmonella an adulterant in raw breaded chicken products, which have been linked to 14 foodborne illness outbreaks that have sickened at least 200 people since 1998.

In its statement, the USDA said Salmonella would be considered an adulterant in the products if it exceeds a certain microbiologic threshold.

The step is part of a plan the agency proposed in 2022 to reduce Salmonella contamination in raw poultry products. FSIS added that it will address contamination in other raw poultry products later this year.

USDA Secretary Tom Vilsack said the final determination marks the first time Salmonella has been declared an adulterant in a class of raw poultry products. "This policy change is important because it will allow us to stop the sale of these products when we find levels of Salmonella contamination that could make people sick," he said.

It will allow us to stop the sale of these products when we find levels of Salmonella contamination that could make people sick.

FSIS said it would carry out testing procedures on the raw incoming chicken component prior to stuffing and breading to ensure that producers are controlling Salmonella in the products. It said the rule will go into effect 12 months after it is published in the Federal Register.

Raw breaded products present unique challenges

Though the raw breaded chicken products make up less than 0.15% of the domestic chicken market, they account for about 5% of all chicken-related foodborne illness outbreaks. 

The products are problematic for consumers because they appear pre-browned and cooked. They are often cooked from a frozen state, which increases the chance that the raw chicken component may not reach the internal temperature needed to kill the Salmonella.

The Texas Parks and Wildlife Department (TPWD) and Texas Animal Health Commission (TAHC) yesterday announced the first detection of two cases of chronic wasting disease (CWD) in Edwards County, and further investigation revealed three more cases.

Two 2-year-old does in a deer-breeding facility tested positive at the Texas A&M Veterinary Medical Diagnostic Laboratory, and the National Veterinary Services Laboratory in Ames, Iowa, confirmed the finding. Subsequent testing of deer penned with the positive deer and other testing yielded three more cases.

CWD has been identified in Texas captive and free-ranging while-tailed deer, mule deer, red deer, and elk since it was first found in the state in 2012.

Infectious prion disease in cervids

Found in deer and other cervids such as moose and elk, the infectious illness is caused by misfolded proteins known as prions. The disease poses an ongoing threat to cervids, given that CWD can spread from animal to animal and through environmental contamination. 

No human cases have been reported, but health officials urge against eating the meat of infected animals and to take precautions when field-dressing or butchering cervids.

The incidence of uveitis in the year after COVID-19 was 17% among nearly 474,000 Korean adults with a history of the inflammatory eye condition, according to a report in JAMA Ophthalmology.

Researchers at the Hanyang University College of Medicine in Seoul mined the Korean National Health Insurance Service and Korea Disease Control and Prevention Agency databases for information on 473,934 patients diagnosed as having uveitis from January 2015 to February 2021. 

The patients had previously had uveitis and had received at least one dose of an mRNA (Pfizer/BioNTech or Moderna) or adenovirus vector–based (AstraZeneca or Johnson & Johnson) COVID-19 vaccine. The average patient age was 58.9 years, 51.3% were women, and none tested positive for COVID-19 during the study period. 

Uveitis is a potentially serious inflammation of the eye's middle layer of tissue that can cause symptoms such as pain, redness, and blurry vision.

Risk was elevated or all 4 vaccines

The incidence of uveitis was 8.6% at 3 months, 12.5% at 6 months, and 16.8% at 1 year. The odds of uveitis were increased among recipients of all four vaccines, including Pfizer (hazard ratio [HR], 1.68), Moderna (HR, 1.51), AstraZeneca (HR, 1.60), and Johnson & Johnson (HR, 2.07). The risk was highest in the first 30 days after vaccination and peaked between the first and second doses (HR, 1.64).

These results emphasize the importance of vigilance and monitoring for uveitis in the context of vaccinations, including COVID-19 vaccinations, particularly in individuals with a history of uveitis.

"Although uveitis following vaccination is rare, our findings support an increased risk after COVID-19 vaccination, particularly in the early postvaccination period," the study authors wrote. "These results emphasize the importance of vigilance and monitoring for uveitis in the context of vaccinations, including COVID-19 vaccinations, particularly in individuals with a history of uveitis."

In a related commentary, Anika Kumar and Nisha Acharya, MD, said it's important to weigh the risk of uveitis with that of remaining unvaccinated against COVID-19. "Indeed, other investigations of postvaccine NIU [noninfectious uveitis] that similarly identified increased risks of NIU after vaccination noted that effect sizes were small and attributable risks were low; thus, the findings should not preclude individuals from receiving a vaccination," they wrote.