News Scan for Oct 17, 2022

News brief

COVID-19 vaccines up protection from previous infection against Omicron

Previous non-Omicron SARS-CoV-2 infection was tied to a 44% lower risk of Omicron reinfection and 81% lower odds of related hospitalization, which was further improved by one, two, or three mRNA COVID-19 vaccine doses (86%, 94%, and 97%, respectively), according to a study published late last week in JAMA Network Open.

Canadian researchers conducted a test-negative case-control study of 224,007 infected participants and 472,432 uninfected controls aged 12 years and older tested for COVID-19 in Quebec from Dec 26, 2021, to Mar 12, 2022, before the emergence of the more highly contagious Omicron BA.4 and BA.5 subvariants.

In the respective cohorts, 62.2% and 63.9% of participants were female, 87.4% and 75.5% were aged 18 to 69 years, and 4.2% of infected participants and 6.3% of controls had been previously infected with a non-Omicron strain.

In unvaccinated participants, previous non-Omicron infection was linked to a 44% lower risk of Omicron infection; protection was 66% 3 to 5 months post-infection, falling to 35% at 9 to 11 months and to under 30% thereafter. Severe previous infection conferred the greatest protection.

Among previously infected participants, mRNA COVID-19 vaccination was associated with risk reductions in Omicron infection of 65% after one dose (vs 20% among the unvaccinated), 68% after two doses (vs 42%), and 83% after three doses (vs 73%).

Estimated protection against Omicron-related hospitalization among previously infected participants was 81%, rising to 86% after one vaccine dose, 94% after two doses, and 97% after three doses, with no evidence of waning.

The study authors noted that Omicron is the most highly transmissible and immune-evasive SARS-CoV-2 variant to date, and protection against Omicron infection and hospitalization from a previous infection was comparable to the protection provided by two mRNA vaccine doses.

"In the context of program goals to prevent severe outcomes and preserve health care system capacity, a third mRNA vaccine dose may add limited protection in twice-vaccinated individuals with prior SARS-CoV-2 infection," they concluded.
Oct 14 JAMA Netw Open study

Trauma patients with COVID-19 have more cardiac events, data show

Patients at trauma centers who test positive for COVID-19 have worse outcomes than COVID-negative trauma patients, even when they are asymptomatic, according to study results presented at the Scientific Forum of the American College of Surgeons Clinical Congress.

Trauma patients with COVID-19 have high rates of myocardial infarction and cardiac arrest and more intensive care unit (ICU) admissions and use more hospital resources than uninfected patients.

The study was based on outcomes seen at the LAC+USC Medical Center (Los Angeles) level 1 trauma center during the first 18 months of the pandemic (March 2020 to October 2021). The study authors excluded all COVID-positive trauma patients with symptoms and instead compared outcomes only among asymptomatic positive and negative patients.

A total of 185 asymptomatic COVID-positive patients were matched with 554 COVID-negative patients. The asymptomatic patients had higher rates of myocardial infarction and cardiac arrest (3.2% vs 0.9%), more days requiring mechanical ventilation (3.33 vs 1.49 days), and a longer overall hospital stay (11.41 days vs 7.24 days).

Patients in the ICU with COVID also stayed, on average, a day and a half longer than their negative counterparts (4.92 days vs 3.41 days) and had higher hospital costs ($176,505 vs $107,591).

"This is the one of the first studies to look at the impact of COVID in trauma patients with no clinical or radiological signs of infection, and we demonstrated higher incidence of cardiac events, longer length of stay and increased costs in positive trauma patients compared with a matched population of similar negative patients," said lead author and research fellow Marco Sozzi, MD, in a press release.

"Simply put, you don’t have to have symptoms for the virus to potentially affect your body," he said. "Further studies will need to look at further indicators that may put patients at risk."
Oct 16 American College of Surgeons press release

Avian flu strikes more turkey farms, backyard flocks

Six states reported more avian flu outbreaks in poultry, mostly involving backyard flocks and commercial turkey farms, according to the latest updates from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).

In the West, California reported an outbreak at a turkey producer in Stanislaus County that houses 54,900 birds, and Utah reported two more outbreaks at commercial turkey operations in Sanpete County, which had 158,700 birds combined. Also, Wyoming reported an outbreak in backyard birds in Fremont County.

Elsewhere, New Jersey reported the virus in backyard birds in Warren County, the state's second outbreak in poultry and its first since the middle of June. Also, Michigan reported an outbreak in a backyard flock in Genesee County, and South Dakota reported two more outbreaks, one at a commercial turkey farm in Beadle County involving 71,400 birds and the other involving a backyard flock in Hamlin County.

Since the Eurasian H5N1 strain was first detected in US poultry in early February, outbreaks spanning 42 states have led to the loss of more than 47.4 million poultry.
USDA APHIS poultry outbreak updates

In international developments, chief veterinary officers from England, Scotland, and Wales today declared an avian flu protection zone across all of Great Britain, which legally requires all bird keepers in the region to follow strict biosecurity measures, the UK's Department for Environment, Food, and Rural Affairs (DEFRA) announced today.

The United Kingdom is experiencing its largest outbreak ever, with 190 confirmed since late October 2021, with more than 30 confirmed since the beginning of this month. East England has been the main hot spot for events involving poultry and captive birds, but outbreaks have been reported in the southwest and in wild birds at multiple locations across Great Britain.
Oct 17 DEFRA statement

Stewardship / Resistance Scan for Oct 17, 2022

News brief

Study: Antimicrobial resistance rates rose in US hospitals during COVID-19

A new analysis of data on US hospital patients during the COVID-19 pandemic finds that patients tested for SARS-CoV-2 had a higher rate of antimicrobial resistance (AMR), researchers reported today in Open Forum Infectious Diseases.

To evaluate changes in AMR rates among hospital patients before and during the pandemic, researchers with Merck and Becton, Dickinson and Company analyzed record on adults hospitalized for at least 1 day at 271 US hospitals from July 2019 through October 2021.

All admissions with an AMR event, defined as a non-contaminated first positive culture for gram-negative or gram-positive pathogens of interest with reported non-susceptibility, were included in the analysis. The researchers evaluated overall AMR rates, comparing the pre-pandemic period (July 2019 through February 2020) with the pandemic period (March 2020 through October 2021).

Of the more than 5.5 million admissions evaluated, AMR events were detected in 35.4 per 1,000 admissions during the pre-pandemic period and 34.7/1,000 admissions during the pandemic period. Patients tested for SARS-CoV-2 had a significantly higher AMR rate than that observed in the pre-pandemic period (49.2/1,000 admissions for patients who tested positive, 41.1/1,000 admissions for negative patients, and 25.7/1,000 admissions for untested patients).

AMR rates among community-onset (CO) infections during the pandemic were lower compared with pre-pandemic levels (26.1/1,000 admissions vs 27.6/1,000), while AMR rates for hospital-onset (HO) infections were higher (8.6/1,000 admissions vs 7.7/1,000), driven largely by SARS-CoV-2–positive admissions (21.8/1,000 admissions). Multivariable analysis found that rates of AMR were associated with overall antibiotic use, rates of positive cultures, longer hospital stays, and higher use of inadequate empiric antibiotic therapy.

"While our data suggest no significant change in overall AMR rates during the pandemic compared to pre-pandemic periods, higher rates of AMR in SARS-CoV-2–positive HO infections have been observed," the study authors wrote. "To mitigate the potential-long-term impact of COVID-19 on AMR, it is critical to continue to monitor AMR rates in later stages of the pandemic, effective antimicrobial use, as well as strategies to control modifiable factors contributing to AMR, particularly in SARS-CoV-2–positive patients with HO infections."
Oct 17 Open Forum Infect Dis abstract

New One Health plan aims to address AMR, other epidemics

Four international organizations today released a new One Health Joint Plan of Action that includes a framework for collaboration on AMR.

The framework outlined by the Quadripartite Organizations—the World Health Organization (WHO), the World Organization for Animal Health, the United Nations Environment Programme, and the Food and Agriculture Organization of the United Nations—calls for the organizations to do more to support AMR control at the country level.

Among the deliverables listed in the plan are helping low- and middle-income countries (LMICs) implement One Health-based AMR National Action Plans and providing technical support and guidance to help LMICs build integrated AMR and antibiotic use surveillance systems and develop AMR awareness campaigns.

The framework also calls on the organizations to coordinate the global One Health response to AMR, provide political advocacy, strengthen regional collaboration and global AMR governance structures, develop a prioritized research agenda, and conduct monitoring and evaluation of country-level efforts.

The One Health concept views the health of humans, animals, and the environment as intrinsically linked. Addressing AMR is one of six "action tracks" listed in the plan, which aims to improve the world's ability to prevent, predict, detect, and respond to health threats against humans, animals, plants, food, and the environment.

"Because AMR has multiple drivers and needs to be tackled on many fronts, a One Health approach is essential to ensure that all sectors and stakeholders communicate and work effectively together," the plan states.

Other action tracks include strengthening health systems, reducing risks from zoonotic epidemics and pandemics, controlling and eliminating vector-borne diseases, and strengthening assessment, management, and communication of food safety risks.

"It's clear that a One Health approach must be central to our shared work to strengthen the world's defences against epidemics and pandemics such as COVID-19. That's why One Health is one of the guiding principles of the new international agreement for pandemic prevention, preparedness and response, which our Member States are now negotiating," WHO Director-General Tedros Adhanom Ghebreyesus, PhD, said in a press release.
Oct 17 One Health Joint Plan of Action
Oct 17 WHO press release