COVID-19 test-to-stay strategies found safe, effective for students

A study today in Pediatrics suggests a test-to-stay (TTS) strategy, as opposed to quarantine, was a safe and effective tool for Massachusetts public schools for the 2021-22 school year, as it was associated with both limited COVID-19 transmission and increased in-person learning days for students.

The TTS program required all students exposed to a COVID-19 case in the classroom to use a rapid antigen test for 7 days following the last exposure date. If the test was negative, students could remain in school. The program was opt-in, and for students who chose not to participate, an exposure resulted in at-home quarantine for at least 7 days following any in-school close contact if the student was not fully vaccinated.

A total of 2,298 schools signed up for TTS, and during the first 13 weeks of the program (September to December 2021) 1,959 schools used TTS for 102,373 individual, exposed students. Out of 328,271 tests performed, 2,943 positive cases were identified, for a per-person positivity rate of 2.9%, similar to during mandatory quarantine the year before.

The authors said the TTS program resulted in a minimum of 325,328 and a maximum of 497,150 days of in-person school for participants that could have been lost to quarantine.

While the study results were encouraging, a commentary in the same journal argued that TTS may not work for under-resourced schools and students. The authors are John Neatherlin, MPH, and Lisa Barrios, DrPH, ScM, of the Centers for Disease Control and Prevention, and Ebony Thomas, MPH, of Emory University.

"If TTS participants must seek testing in the community, barriers including out-of-pocket costs, transportation logistics, and access to health care provider-based testing need to be addressed," the commentators wrote.

"Unvaccinated students in school districts without the capacity to implement TTS, and students in TTS districts who have barriers to opt in to these programs, may not have equal access to in-person learning. Increasing access to and uptake of COVID-19 vaccines will allow more students to stay in the classroom."
Apr 8 Pediatrics study and commentary

Omicron COVID-19 infections appear milder, shorter than Delta cases

An observational study yesterday in The Lancet suggests that COVID-19 infections with the Omicron subvariant have less involvement of the lower respiratory tract, lower odds of hospitalization, and shorter duration of illness and infectiousness than Delta cases.

Led by King's College London researchers, the prospective study recruited 63,002 UK residents aged 16 years and older reporting their COVID-19 test results and symptoms in a smartphone app from Jun 1, 2021, to Jan 17, 2022. Participants had tested positive for COVID-19, were symptomatic, and had received at least two doses of any COVID-19 vaccine.

The primary study outcome was the likelihood of having any of 32 symptoms monitored in the app or being hospitalized within 7 days before or after testing positive during the period of Delta (Jun 1 to Nov 27, 2021) versus Omicron (Dec 20, 2021, to Jan 17, 2022) dominance.

In the first period, Delta was responsible for more than 70% of all cases in the United Kingdom and for COVID-19 infections among 4,990 participants matched for age, sex, and vaccine dose with 4,990 infected during the period in which Omicron was responsible for more than 70% of infections.

Participants reported less loss of smell during the Omicron period than during Delta (16.7% vs 52.7%; odds ratio [OR], 0.17), but sore throat was more common during Omicron than Delta (70.5% vs 60.8%; OR, 1.55). Hospitalization was less common during Omicron than Delta (1.9% vs 2.6%; OR, 0.75).

"The prevalence of symptoms that characterise an omicron infection differs from those of the delta SARS-CoV-2 variant," the study authors wrote. "Our data indicate a shorter period of illness and potentially of infectiousness, which should impact work–health policies and public health advice."

In a related commentary, Linda Houhamdi, PharmD, PhD, and Pierre-Edouard Fournier, MD, PhD, both of Aix-Marseille Universite in France, noted that people younger than 16 years and those who were obese were excluded from the study. "Indeed, omicron cases have been reported in patients younger than 16 years, and obesity is an indisputable comorbidity factor in the severity of COVID-19."
Apr 7 Lancet study and commentary

Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans

Study finds antibiotic use in Iowa hospitals wasn't affected by COVID-19

A study of hospitals in Iowa that employ three different antibiotic stewardship program (ASP) models found that core stewardship activities were maintained during the COVID-19 pandemic, researchers reported today in Antimicrobial Stewardship & Healthcare Epidemiology.

The study, conducted at 12 hospitals that are part of an integrated health system, examined trends in antibiotic days of therapy (DOT) per 1,000 days present in medical-surgical and intensive care units from Jan 1, 2019, to Feb 28, 2021.

During the first year of the pandemic, Iowa saw two significant increases in community spread of SARS-CoV-2 and a commensurate increase in COVID-19 hospitalizations, and there have been concerns that ASP team members in hospitals across the country have been diverted for COVID management. The study focused on the use of meropenem, piperacillin-tazobactam, cefepime, ceftriaxone, vancomycin, azithromycin, doxycycline, and levoflacin.

Across hospitals using the three models—which involved different levels of staffing and access to infectious disease expertise, and different daily activities—the researchers identified multiple fluctuations in the rates of antibiotic use throughout the study period. But in most cases, the average monthly percent changes in the use of key antibiotics reflected trends that preceded the pandemic.

 ^"Our assessment of longitudinal trends in prescribing revealed fluctuations that, in most instances, did not reach a statistically significant deviation from the existing trend," the study authors wrote. "There is a need for development of ASPs in settings with both limited access to the expertise of infectious diseases specialists, particularly during the COVID-19 pandemic, as well as a lack of reports of stewardship practices.
Apr 8 Antimicrob Steward Healthc Epidemiol abstract 

Framework outlines One Health collaboration on antimicrobial resistance

Originally published by CIDRAP News Apr 7

The World Health Organization (WHO), the Food and Agriculture Organization of the United Nations (FAO), the World Organization for Animal Health (OIE), and the United Nations Environment Programme (UNEP) yesterday published a strategic framework for One Health collaborations on antimicrobial resistance (AMR).

The collaboration between the four groups expands the efforts of the tripartite organizations (WHO, OIE, and FAO), which have been working together for several years to support the development and implementation of national AMR action plans that address the spread of AMR in humans and animals. With increased awareness of the role that the environment plays in developing and spreading resistant pathogens, the addition of UNEP aims to strengthen the integration of environmental aspects of AMR into the joint work.

"The overall role of the Tripartite and UNEP is intended to catalyse and support a One Health response, recognizing that many of the actions needed to address AMR are sector-specific and the responsibility of governments, civil society and the private sector," the framework states.

The two primary objectives laid out in the framework are to 1) optimize the production and use of antimicrobials along the whole life cycle, from research and development to disposal and 2) decrease the incidence of infections in humans, animals, and plants to reduce the development and spread of AMR. The groups aim to help countries achieve those objectives by helping countries recognize AMR as a priority, supporting the creation of policies and laws that support a One Health response, advocating for access to good-quality antimicrobials, and ensuring that national AMR action plans are implemented and resourced.

"We look forward to further strengthening collaboration among our four organizations and with our partners as we work to implement the framework in the coming years," the leaders of the four organizations wrote in a foreword. "Most importantly, we hope that by leveraging our organizations' respective resources and strengths that the multilateral system will make a strong contribution to results and impact across all sectors as the world strives to prevent and mitigate the impact of antimicrobial resistance."
Apr 6 One Health strategic framework

Study: Dogs, cats share resistant bacteria, resistance genes with owners

Originally published by CIDRAP News Apr 6

Observational research set to be presented later this month at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) suggests close contact with pets could result in sharing of multidrug-resistant bacteria and resistance genes.

For the study, researchers from the University of Lisbon in Portugal and the Royal Veterinary College collected fecal samples from healthy companion animals (CAs, specifically dogs and cats) and their owners from 41 households in Portugal and 42 households in the United Kingdom at monthly intervals for 4 months.

They screened fecal samples for carbapenem-resistant Enterobacterales or Acinetobacter spp. and for extended-spectrum beta-lactamase (ESBL) or plasmid-mediated AMPc (pAMPc) genes.

No carbapenem-resistant Enterobacterales or Acinetobacter were found, but 15 of 103 CAs (14.6%) and 15 of 112 humans (13.2%) harbored ESBL/pAMPc-producing Enterobacterales (ESBL-E). Of these, 7 CAs (6 in Portugal and one in the United Kingdom) and 5 household members (4 in Portugal and 1 in the United Kingdom) carried at least one multidrug-resistant strain.

In four Portuguese households, the ESBL/pAMPc resistance genes found in pets matched those in their owner's stool samples. In three of these households, matched resistance genes were only recovered at one time point, but in one household, sharing of strains was noted at two consecutive timepoints, suggesting a persistent colonization of shared bacteria within the household. 

In addition, in two of the households, the microbes in pets matched Escherichia coli strains in their owner's stool sample, but in the other two, there was no evidence of bacteria sharing.

"Although the level of sharing from the households we have studied is low, healthy carriers can shed bacteria into their environment for months, and they can be a source of infection for other more vulnerable people and animals such as the elderly and pregnant women," study coauthor Juliana Menezes, PhD, of the University of Lisbon, said in an ECCMID press release.

"Our findings reinforce the need for people to practice good hygiene around their pets and to reduce the use of unnecessary antibiotics in companion animals and people."
Apr 5 ECCMID abstract
Apr 5 ECCMID press release

Study highlights economic impact of inappropriate antibiotic use

Originally published by CIDRAP News Apr 5

An analysis of antibiotic use for upper respiratory infections (URIs) in Ghana reveals the considerable economic impact of inappropriate prescribing can have on low-resource settings, researchers reported last week in Antimicrobial Resistance & Infection Control.

Using data from the ABACUS (AntiBiotic ACcess and USe) project, conducted from 2016 to 2019 to explore community antibiotic access and consumption in Africa and Asia, researchers from Ghana and the Netherlands conducted an economic impact analysis focusing on inappropriate antibiotic use for URIs in Ghana, where self-medication with antibiotics is widespread.

Their analysis focused on two inappropriate-use situations: (1) URIs treated with antibiotics, not according to guidelines, and (2) URIs that were not treated with antibiotics but should have been.

Healthcare costs related to inappropriate antibiotic use for URIs were estimated to be around $20 million US dollars annually, including $18 million for situation 1 and $2 million for situation 2. Combined travel costs and lost income due to travel were estimated to be around $44 million for situation 1 and $18 million for situation 2. Possible healthcare cost savings range from $2 million to $12 million for situation 1 and from $0.2 million to $1 million for situation 2.

"Understanding the economic consequences of community antibiotic consumption practices is crucial to mobilise key stakeholders and design sustainable strategies to improve antibiotic use," the study authors wrote. "This economic impact analysis supports this endeavour by providing baseline data to be used by future studies investigating the cost-effectiveness of such strategies."

They added, "In a broader sense, the study can serve as a starting point for other countries, especially LMICs [low- and middle-income countries], to conduct an economic analysis related to inappropriate antibiotic use."
Apr 1 Antimicrob Resist Infect Control study