Flu activity continued to drop in most areas but still remains high, the Centers for Disease Control and Prevention (CDC) said in its weekly update on Dec 30, which covers the week ending Dec 24.

Forty-four states reported very high (25) or high (19) flu activity, a marker that reflects outpatient visits for flulike illness, down from 48 the week before. Activity in a few states—including Minnesota and Vermont—are back into green "minimal" category on the CDC's flu map (below).

Levels appear to be easing, especially in some southeastern and southwestern states.

Hospital admissions for flu declined for the third week in a row. And though hospitalizations at this point in the season are higher than for the same time in previous years going back to the 2010-11 season, overall levels are still lower than end-of-season hospitalization rates for all but 4 years going back to 2010-11.

Of respiratory samples tested at public health labs, nearly all were influenza A. And, of subtyped influenza A viruses, 83.1% were the H3N2 strain. The CDC said most circulating viruses tested are similar to the viruses included in this season's flu vaccines.

One marker that rose sharply is the number of pediatric flu deaths, with 14 more deaths reported, which puts the season's total at 51. The deaths occurred between the end of November and the end of December. All were due to influenza A, and, of 6 subtyped samples, 1 was a H3N2/H1N1 coinfection and 5 involved H3N2.

A Salmonella Typhimurium outbreak linked to alfalfa sprouts from Nebraska-based SunSprout Enterprises has so far sickened 15 people in three states, the US Centers for Disease Control and Prevention (CDC) said in a Dec 30 announcement.

Illness-onset dates range from Dec 2 to Dec 13. Patient ages range from 19 to 78 years old, and, of 14 people with available information, 2 were hospitalized. No deaths have been reported. Affected states are Nebraska (8 cases), South Dakota (6), and Oklahoma (1).

Interviews with sick people found that all 12 had eaten alfalfa sprouts before their symptoms began. Genetic data from the CDC's PulseNet system show that the bacteria from the sick people were closely related, suggesting that they got sick from the same source.

Trace-back information from the Food and Drug Administration suggests that restaurants and grocery stores involved in the outbreak received their sprouts from SunSprout Enterprises. Two patients also confirmed that they bought SunSprouts brand alfalfa sprouts from their local grocery stores.

On Dec 29, the company recalled four lots of its raw sprouts, which were distributed in Nebraska, Kansas, and Iowa. The products were sold in clear, plastic clam shell containers and in 2.5-pound packages. The best-by dates range from Dec 10, 2022, to Jan 7, 2023.

The CDC urged consumers to throw away or return the recalled sprouts and to wash surfaces that may have touched the recalled product.

Raw and undercooked sprouts are a known source of foodborne illnesses and outbreaks, and the CDC urges consumers, restaurants, and other retailers to follow safe food practices to prevent illnesses.

People who have COVID-19–related loss of smell may benefit from visual-olfactory training using patient-preferred essential oils, according to a clinical trial published late last week in JAMA Otolaryngology-Head & Neck Surgery.

Washington University researchers in St. Louis randomly assigned 275 adults aged 18 to 71 years who reported post-COVID loss of smell to undergo either unimodal olfactory training using four physician-assigned essential oils or bimodal visual-olfactory training using four patient-chosen scents.

Participants sniffed the essential oils for 15 seconds each, with a 15-second rest in between, for 3 months. Bimodal patients were also shown images of their chosen oils. A control group was used to compare the efficacy of the trainings with simple monitoring.

Before and after the trainings, participants completed the University of Pennsylvania Smell Identification Test (UPSIT), the Clinical Global Impressions-Improvement (CGI-I) scale, and the Olfactory Dysfunction Outcomes Rating (ODOR) questionnaire.

Loss of smell was defined as an UPSIT score of less than 34 for men and 35 for women for 3 months or longer. Participants enrolled from Feb 1 to May 27, 2021.

No significant differences

Five (24%) participants in the control group saw clinical improvement on UPSIT, compared with 18 (53%) in the bimodal arm (difference, 29 percentage points). Four (19%) controls reported improvement on the CGI-I, compared with 12 (35%) in the bimodal arm (difference, 16 percentage points). The average change in ODOR score from before to after the intervention was a clinically unimportant 11.6 points.

There were no differences between arms, the authors said, "but when exploring within-patient change in UPSIT as well as self-reported impression of improvement, active interventions were associated with larger improvement than controls with a potential advantage of bimodal intervention."

Active interventions were associated with larger improvement than controls.

Carol Yan, MD, of the University of California San Diego, said in a related commentary that while the study was inconclusive, olfactory training could be considered in individual patient treatment plans. "Ultimately, patients' belief and satisfaction in their therapeutic plan can have substantial placebo-effect benefits that are not to be ignored," she wrote.

Infections caused by Clostridioides difficile and methicillin-resistant Staphylococcus aureus (MRSA) resulted in 1,743 premature deaths in Canada in 2019 and cost Canadian hospitals more than $91 million, according to a new study published in the Canada Communicable Disease Report.

To estimate the mortality, hospital costs, and value of lost production associated with MRSA and C difficile, researchers with Health Canada and the University of Ottawa analyzed data from the Discharge Abstract Database, which contains administrative data on hospital discharges, diagnoses, and patient characteristics from facilities in all Canadian provinces except Quebec.

Using a two-step process, they estimated the number of cases for each diagnosis from 2010 through 2019 (dividing MRSA cases into bloodstream and non-bloodstream infections [BSIs]) and mortality associated with those cases. They then derived the average cost per case, hospital-related costs, and total economic costs.

There were a total of 16,070 and 9,889 cases of C difficile  and MRSA infections, respectively, in Canada in 2019. Although C difficile fell during the study period, MRSA BSIs more than doubled. After adjusting for sex and number of comorbidities, the number of deaths attributable to C difficile, MRSA non-BSIs, and MRSA BSIs was 1,309, 257, and 177, respectively. Most cases occurred in older age-groups, with 70% of deaths occurring in patients aged 75 and older.

The annual hospital-related costs attributable to C difficile and MRSA infections in 2019 were over $125 million in Canadian dollars (US $91.5 million), while the value of lost production was estimated to be between $18.8 and $146.9 million (Canadian). Total economic costs were estimated to be between $143.8 and $272 million (Canadian).

"Given the assumptions employed and noting that only two types of antimicrobial-resistant infections were incorporated in the analysis, these results can be considered lower values of the economic burden of antimicrobial-resistant infections in Canada," the study authors wrote.