The nation's COVID activity remains high, but there are more signs of decline in many areas, the Centers for Disease Control and Prevention (CDC) said today in its latest updates.

Wastewater SARS-CoV-2 detections are still high, especially in the West, but are dropping in all regions except for the Midwest, according to the CDC's latest tracking. 

Test positivity showed another small decline and is at 16.4% nationally, but is higher in the Midwest and Middle Atlantic. Emergency department visits declined 10.2% from the previous week, but are still at the moderate level in some of the southeastern states.

Hospitalizations are still elevated, especially in seniors and children younger than 2 years old, but are also showing downward trends. 

Deaths up from previous week

One metric that rose last week was deaths, which were up 18.2% compared to the previous week, with COVID making up 2.6% of US deaths. For the week ending August 31, 663 people died from COVID-19, according to the CDC's provisional data. During August, COVID deaths averaged roughly 900 per week, the highest since March.

In a recent seasonal outlook, the CDC said it expects that the upcoming fall and winter virus season will have similar or lower peak numbers of hospitalization from COVID, flu, and respiratory syncytial virus (RSV) as last year. 

However, it noted that peak will likely be higher than the years before COVID emerged, the group said in its update that covers the main three respiratory viruses. "COVID-19 activity this fall and winter will be dependent on the progression of the ongoing summer COVID-19 wave."

A study today of 1,296 pediatric Italian COVID-19 patients who underwent multiple follow-ups over 2 years shows decreasing rates of long COVID over time. The study is published in eClinicalMedicine and is one of the longest studies conducted on kids with long COVID. 

The findings are based on outcomes seen at a single clinic in Rome from January 2020 through February 2024. During follow-up appointments at 3, 6, 12, 18, and 24 months after a confirmed COVID-19 infection, 23.2%, 13.2%, 7.9%, 6.1%, and 7.1%, were diagnosed as having long COVID, respectively. 

During initial COVID infection, 8.6% (114) were asymptomatic and 88.6% (1,169) had mild, 2.2% (29) had moderate, and 0.2% (2) had severe COVID-19. Most children were diagnosed as having COVID-19 when the Omicron variant was prevalent (939, 71.2%). More than three fourths of children (79.6%) were not vaccinated before the infection, while, respectively, 6.2%, 12.6%, and 5.2% of children had received one, two, and three doses of COVID-19 vaccine.

Older age associated with long COVID 

Two factors were associated with increased risk of long COVID diagnosis through 18 months: age of 12 years or older (odds ratio [OR], 9.37; 95% confidence interval [CI], 1.58 to 8.64) and being infected with the original strain of the virus (OR, 3.52; 95% CI, 1.32 to 8.64) or the Alpha strain (OR, 4.09; 95% CI, 2.01 to 8.30).

Older age and original and Alpha infection were associated with long COVID at 3 months, as was female sex and comorbidities. 

Long-COVID diagnosis was considered after continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection. 

COVID-19 vaccines were associated with a lower risk of developing Long Covid particularly in adolescents.

"COVID-19 vaccines were associated with a lower risk of developing Long Covid particularly in adolescents, while re-infections had a minimal burden on most patients, although one case of Long Covid following re-infection was identified," the authors wrote. 

UK public health officials have determined that the likely source of a 2022 outbreak of Shiga toxin–producing Escherichia coli (STEC) O157:H7 was lettuce contaminated by sheep feces washed to the field by heavy rainfall and flooding related to climate change.

The investigation findings, published yesterday in Eurosurveillance, detail how consumption of the tainted lettuce sickened 259 people, 75 of them requiring hospitalization, in August and September 2022. No deaths were reported.

The UK Health Security Agency–led research team conducted whole-genome sequencing, interviewed patients, analyzed patient questionnaires, traced the lettuce back through the supply chain, and used new methods to determine rainfall and temperature before the outbreak, how the affected land was used, and the location of the sheep suspected to be the source of the feces.

"The gastrointestinal tract of ruminants is the ecological niche of STEC, with cattle and sheep being the main animal reservoirs," the investigators wrote. "Food items frequently associated with food-borne outbreaks of STEC O157 include raw or undercooked beef or lamb meat products, unpasteurised dairy products, and fresh produce exposed to rainwater run-off, floodwater, or irrigation water containing animal faeces."

Climate change expected to fuel more outbreaks

The 19 patients interviewed reported exposures such as restaurant dining and eating chicken, salad, or beef. A frequency-matched study involving 41 patients and 206 controls linked the illness to consumption of chicken or salad. Loyalty-card data and supply-chain investigations tied a single lettuce grower to all food service establishments or retailers of interest.

Our new techniques could help to predict and prevent future outbreaks and inform risk assessments and risk management for farmers growing fresh produce for people to eat.

The investigators identified no failures by the lettuce grower, but a geospatial analysis independently identified the grower as the probable outbreak source. An analysis of epidemiologic factors, the food chain, and weather data suggested that floodwater carried STEC-contaminated sheep feces to the lettuce crops.

"Climate change will have increasing impacts on our health and food security," the authors wrote. "Our new techniques could help to predict and prevent future outbreaks and inform risk assessments and risk management for farmers growing fresh produce for people to eat."

• Over the past week the Minnesota Department of Health (MDH) reported 10 more measles cases, raising the state's outbreak total to 40. The outbreak is concentrated in unvaccinated children in the Twin Cities, largely in the Somali community. Eleven people were hospitalized. Of the cases, 23 involved children younger than 5 years old, and 16 occurred in those ages 5 to 19. One patient is an adult age 20 or older. The Centers for Disease Control and Prevention (CDC) in its latest two weekly updates has reported 20 more measles cases, raising the total for the year to 247 in 29 jurisdictions, of which 70% (173) were part of 13 outbreaks. Cases are tracking well above the 2023 total and are part of a global rise in measles infections.
• Five countries reported more polio cases this week, including Afghanistan, with another wild poliovirus type 1 (WPV1) case, and Indonesia, with three circulating vaccine-derived poliovirus type 2 (cVDPV2) cases, according to the latest weekly update from the Global Polio Eradication Initiative. Afghanistan’s WPV1 case is in Hilmand province and raises the country's total to 18 for the year. Indonesia's cVDPV2 cases were in three provinces and put the country's number at seven for 2024. Elsewhere, three African countries reported more cases, all involving cVDPV2. They are the Democratic Republic of the Congo (DRC), Niger, and Nigeria. The DRC's 2 cases add to its 2023 total, which has reached 120. Niger had 2 new cases, lifting its total to 9 for the year, and Nigeria reported 7 more cases in five locations, putting its 2024 total at 49.