News Scan for Sep 15, 2022

News brief

E coli outbreak linked to ground beef in Hello Fresh meal kits

The Centers for Disease Control and Prevention (CDC) yesterday reported an Escherichia coli O157:H7 outbreak tied to Hello Fresh meal kits that contained contaminated ground beef.

So far, health officials have identified seven infections from six states. Six people were hospitalized, and none of them developed hemolytic uremic syndrome (HUS), a potentially fatal kidney complication of E coli infection. No deaths have been reported.

The meals containing the contaminated ground beef were shipped between Jul 2 and 21. The latest illness onset was Aug 17. Of six people interviewed, all reported eating ground beef from Hello Fresh meal kits before they became ill. The traceback investigation found that for multiple patients, the ground beef came from the same establishment. US Department of Agriculture (USDA) investigators are still tracking the materials used to produce the ground beef.

The CDC urged people to check their freezers to see if they have any of the affected beef from the meal kits, which would have "EST. 46841" inside the USDA inspection mark. It added that officials are also working to determine whether other ground beef products may be contaminated.
Sep 14 CDC outbreak notice

Study examines inpatient antibiotic use in Japanese hospitals

A point-prevalence study conducted at five hospitals in Japan found that fewer than 30% of patients were prescribed an antibiotic on the survey date, but more than half of the antibiotics prescribed were broad spectrum, researchers reported yesterday in Antimicrobial Stewardship & Healthcare Epidemiology.

To better understand inpatient antibiotic use and the uptake of antimicrobial stewardship programs (ASPs) in the prefecture of Okinawa, a team of Japanese and US researchers assessed the proportion of total eligible hospitalized patients who received an antibiotic at five community hospitals on Oct 1, 2020. They also categorized antibiotics according to indication, drug class, and World Health Organization AWaRE (Access, Watch and Reserve) classification. Each hospital has one physician ASP champion, and three have an infectious diseases–trained physician as ASP champion.

Across the five hospitals, 504 of 1,728 (29%) unique patients received at least one antibiotic, with 51 (10%) receiving two antibiotics and 2 (0.4%) receiving 3 antibiotics. Of the patients who received antibiotics, 114 (23%) received them for prophylaxis (prevention) and 390 (77%) received them for treatment. Of the 390 patients who received antibiotics for treatment, 385 (98.7%) had a documented infection.

Overall, 241 (43.9%) of all 559 antibiotics prescribed were categorized as Access drugs, 304 (54.4%) were Watch drugs, and 12 (2.1%) were Reserve drugs. Cephalosporins were the most prescribed antibiotic class (56%), followed by beta-lactam/beta-lactamase inhibitors (19%), and narrow-spectrum penicillins (8.2%).

The study authors say that while the proportion of patients who received an antibiotic is lower than has been reported in many international studies, the high proportion of Watch antibiotics is a concern.

"Antibiotics in this classification may be more likely to cause resistance compared to Access antibiotics," they wrote. "Focusing on antimicrobial stewardship strategies (eg, selection of antibiotics for national or institutional guideline recommendations) that consider risk of antimicrobial resistance could be effective and beneficial."
Sep 14 Antimicrob Steward Hosp Epidemiol study

H5N6 avian flu hospitalizes Chinese girl

China reported another H5N6 avian flu infection, which involves a 6-year-old girl whose symptoms began in late July and who was admitted to the hospital on Aug 3.

In a statement today, Hong Kong's Centre for Health Protection (CHP) said the girl is from Guangxi province, which is in the southern part of the country. An investigation into her illness found that she had been exposed to market poultry before she got sick. She is listed in serious condition.

The case is China's first since the end of June, which involved an individual from Jiangxi province. It marks the 16th case of the year and the 80th since the virus was first detected in humans in 2014.

H5N6 infections are often severe or fatal in humans. The virus is known to circulate in poultry in some Asian countries, but China and Laos are the only ones that have reported human cases.
Sep 15 CHP statement

Avian flu outbreaks strike more turkey farms in 2 US states

Two states—Minnesota and Utah—reported more highly pathogenic avian influenza outbreaks in poultry, affecting commercial turkey farms in both states, according to the latest updates from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).

In Minnesota, new outbreaks were reported at a turkey farm in Brown County that houses 44,000 birds and one in Stearns County that has 72,700 birds. The virus was also detected in a backyard flock in Freeborn County.

Utah reported an outbreak at a turkey farm in Sanpete County, which affected a flock of 5,700 birds.

Outbreaks involving the Eurasian H5N1 strain started in early February and have so far led to the loss of more than 44 million birds in 39 states. Activity in poultry slowed over the summer but has increased over the past few weeks. Virus detections in wild birds have persisted over the summer across several US regions.
USDA APHIS poultry avian flu updates

COVID-19 Scan for Sep 15, 2022

News brief

Efficacy of monovalent COVID-19 booster began waning by 3 or 4 months

South African researchers report waning monovalent (single-strain) COVID-19 vaccine booster effectiveness against the Omicron subvariants, with estimated efficacy falling to 50% against the BA.1/BA.2 and 47% against BA.4/BA.5 as early as 3 or 4 months after vaccination.

In the study, published yesterday in the New England Journal of Medicine (NEJM), the research team estimated the effectiveness of two and three doses of the monovalent Pfizer/BioNTech vaccine against COVID-19 hospitalization among 32,883 patients hospitalized for any cause and tested for COVID-19 from Nov 15, 2021, to Jun 24, 2022.

They used a test-negative design to estimate the odds of vaccination among patients who tested positive for COVID-19.

The study was conducted before the Aug 31 US Food and Drug Administration (FDA) authorization of the updated bivalent (two-strain) boosters designed to protect against BA.4/BA.5, in addition to the wild-type virus (BA.4/BA.5 has superseded BA.1/BA.2). The new Pfizer booster is authorized for ages 12 and older, while the Moderna booster is authorized only for adults. The older booster is no longer in use.

From Nov 15, 2021, to Feb 28, 2022 (BA.1/BA.2-dominant period) and Apr 15 to Jun 24, 2022 (BA.4/BA.5-dominant period), 18% of patients tested positive for COVID-19. During both periods, two-dose effectiveness against hospitalization began waning as early as 3 or 4 months after vaccination.

Estimated vaccine effectiveness was 56.3% (95% confidence interval [CI], 51.6% to 60.5%) during BA.1/BA.2 dominance and 47.4% (95% CI, 19.9% to 65.5%) amid BA.4/BA.5. A third dose remained effective against severe infections with all four subvariants at 1 or 2 months, but effectiveness fell by 3 or 4 months to 50% (95% CI, 4.4% to 73.9%) amid BA.1/BA.2 dominance and 46.8% (95% CI, 35.3% to 56.2%) during the BA.4/BA.5 period.

"The evidence of rapid waning of durability indicates the need for regular boosting as early as 4 months after the last dose or the need for vaccines to incorporate variants of concern to maintain protection," the authors concluded.
Sep 14 NEJM research letter

Later Omicron period associated with fewer COVID-19 hospital deaths

Today Centers for Disease Control and Prevention (CDC) researchers published new data in Morbidity and Mortality Weekly Report showing that the risk of death among hospitalized COVID-19 patients was substantially lower during the later Omicron period than during the earlier Omicron period or the Delta period, even though more elderly patients were hospitalized during the later Omicron period.

The authors used a large US hospital database composed of 678 hospitals to look at in-hospital mortality risk during the Delta (July–October 2021), early Omicron (January–March 2022), and later Omicron (April–June 2022) variant periods among patients hospitalized primarily for COVID-19.

From April 2020 to June 2022, a total of 1,072,106 COVID-19 hospitalizations and 128,517 in-hospital deaths were reported.

Before the Omicron variant emerged as the dominant strain in the United States, COVID-19 hospitalizations identified as primarily for COVID-19 were 83.8%, (95% confidence interval [CI], 83.7% to 83.9%) and fell during the Omicron period to 62.8% (95% CI, 62.6% to 63.0%). Among patients hospitalized primarily for COVID-19 during the Delta, early Omicron, and later Omicron periods, patients aged 65 years or older constituted 15.1%, 22.9%, and 28.9% of all COVID patients, respectively.

The authors found the crude mortality risk (cMR, recorded as deaths per 100 patients hospitalized primarily for COVID-19) was lower during the early Omicron (13.1) and later Omicron (4.9) periods than during the Delta (15.1) period.

"During the later Omicron period, 81.9% of in-hospital deaths occurred among adults aged ≥65 years and 73.4% occurred among persons with three or more underlying medical conditions," the authors wrote. "Vaccination, early treatment, and appropriate nonpharmaceutical interventions remain important public health priorities for preventing COVID-19 deaths, especially among persons most at risk."
Sep 16 MMWR study