US COVID activity continued to decline in many areas, the Centers for Disease Control and Prevention (CDC) said today in its latest updates.

Test positivity for COVID was 13.5% last week, down from 14.9% the week before.

Hospitalizations continue to decline but remain highest in seniors, followed by adults ages 50 to 64 and children younger than age 4 years. 

Emergency department visits dropped about 19% compared to the previous week and are now at low levels across much of the country. 

Deaths held steady, and provisional data show that the CDC received reports of 563 COVID deaths for the week ending September 14.

Detections of SARS-CoV-2 in wastewater are still high nationally, according to CDC tacking. The highest levels remain in the West, followed by the Midwest and the South. However, all regions show downward trends.

The latest data from WastewaterSCAN, a national wastewater monitoring system based at Stanford University in partnership with Emory University, show that detections are still high nationally and in the Midwest, with no significant up or down trend over the past 3 weeks.

Very low uptake of COVID, flu vaccines in adults

In its updates today, the CDC also had some respiratory virus vaccine uptake estimates. So far, about 2.8% of adults have received the updated COVID vaccine, and 6.8% have received a seasonal flu vaccine.

Among adults ages 75 and older, 33.1% have reported ever receiving a respiratory syncytial virus (RSV) vaccine.

The Minnesota Department of Health has reported two variant H3N2 (H3N2v) flu infections, both involving young people who visited agricultural fairs, where they were exposed to pigs, the US Centers for Disease Control and Prevention (CDC) said today in its latest weekly flu update.

Both patients sought care the week ending September 7, and neither were hospitalized. Both have recovered from their infections. The cases raise the nation's variant flu case total to nine for the season. 

Investigators found that the patients were not contacts of each other but had attended the same agricultural fair. One child had indirect contact with pigs, and the other had direct contact. 

One family member had COVID

The probe into the first case found that that all household members became ill the day after attending the fair. One household member tested positive for COVID, and all recovered, including the first patient. Soon afterward, the first patient got sick with new symptoms and was tested for influenza A, which was further identified as H3N2v. No related illnesses were found among the first patient's contact.

The investigation into the second case found no related illnesses among contacts. "No human-to-human transmission of influenza A(H3N2)v associated with either case was identified" the CDC said.

The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed 6 more H5N1 avian flu outbreaks in California dairy herds, raising the state's total to 16 since the virus was first found in the state's Central Valley dairy farms in the middle of August.

The detections push the national total of dairy farm outbreaks to 214 across 14 states.

In another avian flu development, the USDA confirmed highly pathogenic avian flu at a commercial turkey farm in California. The California Department of Food and Agriculture said the detection at the turkey farm is the state's first in domestic poultry since the state was declared free of the virus at the end of June.

Though Merced County is part of California's Central Valley, it's not clear if the turkey farm has any connection to the cattle outbreaks in that part of the state.

FDA advisers to discuss human H5 vaccines

Meanwhile, the Food and Drug Administration vaccine advisory group will discuss the composition of human H5 vaccines as part of preparedness for highly pathogenic as one of three topics at its upcoming meeting on October 10. The other topics on the Vaccines and Related Biological Products Advisory Committee (VRBPAC) agenda are recommendations on strain selection for seasonal flu vaccines for the Southern Hemisphere's 2025 season and research programs regarding departments that study viral diseases.

• The number of measles cases reported in the United States this year has risen to 262, up 11 from a week ago, the Centers for Disease Control and Prevention reported today in an update. Of the patients, 107 (41%) have been hospitalized, with the highest percentage of hospitalizations seen in children under 5 (52%). Eighty-eight percent of the case-patients are either unvaccinated or have unknown vaccination status. A total of 13 measles outbreaks have been reported in 2024, compared with 4 reported in all of 2023, and 70% of cases are outbreak-associated. Thirty-two jurisdictions have reported measles cases, including Minnesota, which now has 51 cases from an outbreak that began in May.
• Three countries reported new polio cases this week, according to an update from the Global Polio Eradication Initiative (GPEI). Afghanistan reported one case of wild poliovirus type 1 (WPV1) in Kandahar province, bringing its total number of cases for 2024 to 19. Cameroon reported two cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) from Est province, its first two this year. In Nigeria, 4 cVDPV2 cases were reported from Yobe province, bringing its total number of cases this year to 53. GPEI also reported that the first round of an emergency polio vaccination campaign in Gaza was completed on September 12, with novel oral polio vaccine type 2 provided to an estimated 560,000 children under 10.