BACKGROUND:Antimicrobial resistance (AMR) is widely considered to be driven by antimicrobial consumption through within-host selection. However, whether this mechanism adequately explains population-level patterns of resistance in invasive infections remains uncertain. If antimicrobial use is the dominant determinant, resistance should be highest in demographic groups with the greatest exposure. METHODS:We conducted a retrospective analysis of 44,792 community-onset Escherichia coli bloodstream infection episodes identified through national Australian surveillance data (2013-2024). Resistance prevalence across individual antimicrobials and composite multidrug resistance panels was analysed by age and sex. These data were compared with community antimicrobial dispensing derived from the Pharmaceutical Benefits Scheme. Mean resistance was modelled as a function of age and sex. RESULTS:Antimicrobial use was substantially higher in females than males (~23% overall) and increased markedly with age, with individuals aged ≥80 years receiving approximately three times more antimicrobials than those aged 25-30 years. In contrast, resistance was consistently lower in females across most antimicrobials and composite measures. Resistance demonstrated an inverted U-shaped age distribution, peaking at 30-40 years before declining in older age groups. From early adulthood to older age, antimicrobial dispensing increased threefold, whereas mean resistance declined by approximately 20%. These patterns were consistent across antimicrobial classes, years, and jurisdictions. CONCLUSIONS:These findings show that demographic patterns of antimicrobial resistance in community-onset E. coli bloodstream infections are not well explained by a simple population-level consumption model. These findings should be interpreted as important hypothesis-generating insights. Although antimicrobial exposure remains important for individual-level selection, the observed discordance between prescribing and resistance suggests that other factors, including differences in transmission pathways, healthcare contact, disease prevalence, community sanitation and socioeconomic circumstances may also significantly shape resistance patterns.

Background: Globally, females and older people often use more antimicrobials than males and younger people. However, little is known about whether these differences in antimicrobial use are associated with higher rates of antimicrobial resistance. Methods: The Australian Group on Antimicrobial Resistance monitors antimicrobial resistance in bloodstream infections in adults and children using commercial automated susceptibility methods. Community-onset E. coli episodes, with matching demographic data, were used for analysis; 44,792 episodes from 2013 to 2024. The national Pharmaceutical Benefits Scheme was used to measure antimicrobial use. Results: Females were dispensed 23% more antimicrobials than males, and antimicrobial use increased markedly with age. Despite this, antimicrobial resistance rates decreased at older ages. Additionally, antimicrobial resistance rates were generally lower in females compared with males for most antimicrobials, including fluoroquinolones, cephalosporins and aminoglycosides, and lower mean resistance across multi-drug panels was observed. In females, although ampicillin resistance rates remained similar to young males, trimethoprim/sulfamethoxazole resistance was higher.The mean drug resistance trend was fitted by regression model to an equation with age and age-squared for each sex. Coefficients were statistically significant (p< 0.001). Conclusions: Higher community antimicrobial use in females and older age were not associated with an increase in antimicrobial resistance in community-onset E. coli bloodstream infections.

Background: The carriage of resistant bacteria and prior antimicrobial treatment are related, but in an individual, this diminishes over time. To better manage antimicrobial resistance risks, it is crucial that we better untangle any lasting impact of antibiotic use compared to other factors. This understanding is essential for informing antimicrobial stewardship programs and to better manage other important factors that likely contribute to persistently higher rates of antimicrobial resistance in different populations. The true association between antibiotic use and resistance is likely to be significantly overestimated due to the confounding influence of varying infection risk patterns within populations. Though missing explanatory covariates are a well-known cause of falsely interpreted statistical findings, how the problem manifests in this context has a particular and interpretable structure. This issue does not appear to have been previously addressed with clarity. To be more easily understood, a simple model is used to demonstrate this. Results: In our theoretical model case study, when we exclude an effect of past antibiotic usage, clinical history alone can predict future resistance patterns. Heterogeneity in infection risk and antibiotic resistance carriage rates, along with consequently observed antimicrobial treatment, often suffice to predict a pattern of resistance that mimics what is assumed to be caused by genuine biologically driven resistance by the associated use of antibiotics. The biological impact and/or lasting effects of antibiotics are not necessary for this prediction. Conclusions: Antimicrobial stewardship policies and future research must directly address how much of the apparent persistence of resistant bacteria results from biological consequences of antibiotic use compared to pure statistical confounding arising due to heterogeneous risks in community infection patterns.

Healthcare-associated infections (HAI) are the most frequent hospital-acquired complication, resulting in significant mortality, disability, and system-level costs in Australian hospitals. Many HAIs can be prevented with appropriate infection prevention and control (IPC) measures, including IPC programs led by infection control professionals (ICPs). Despite recent improvements in hospital IPC practices in Australia, such as the introduction of National Safety and Quality Health Service (NSQHS) Standards for hospital accreditation, there are currently no evidence-based minimum standards for the content, composition, and governance of IPC programs, nor the identification of their core elements. Furthermore, there is a similar lack of evidence-based minimum standards guiding the practice requirements, skills, and competencies of hospital ICPs. This protocol outlines a sequential three-phase research design to establish the core requirements for the elements and governance of IPC programs, as well as minimum practice standards for ICPs in Australian hospitals. Phase 1 will involve two integrative reviews to synthesise the elements and governance systems of international IPC programs, and the competencies, education and practice standards for hospital ICPs globally. Phase 2 will use survey and interview methodologies to examine the current content and structure of IPC programs and governance systems in Australian hospitals, as well as the academic and professional content of IPC education and training courses for ICPs in Australia. In Phase 3, a modified electronic Delphi study will be conducted to generate expert consensus on the core requirements of Australian hospital IPC programs and systems of governance, and the professional practice, qualifications and competencies for Australian ICPs. The outcomes of Phase 3 will form the basis for the development of new standards that aim to equip the Australian acute care sector to deliver evidence-based IPC practices, education, resources, and governance.

OBJECTIVES:Antimicrobial-resistant bacteria are a major global health threat. Mobile genetic elements (MGEs) have been crucial for spreading resistance to new bacterial species, including human pathogens. Understanding how MGEs promote resistance could be essential for prevention. Here we present an investigation of MGEs and their association with resistance genes in pathogenic bacteria collected from 59 diagnostic units during 2020, representing a snapshot of clinical infections from 35 counties worldwide. METHODS:We analysed 3,095 whole-genome sequenced clinical bacterial isolates from over 100 species to study the relationship between resistance genes and MGEs. The mobiliome of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Klebsiella pneumoniae were further examined for geographic differences, as these species were prevalent in all countries. Genes potentially mobilized by MGEs were identified by finding DNA segments containing MGEs and ARGs preserved in multiple species. Network analysis was used to investigate potential MGE interactions, host range, and transmission pathways. RESULTS:The prevalence and diversity of MGEs and resistance genes varied among species, with E. coli and S. aureus carrying more diverse elements. MGE composition differed between bacterial lineages, indicating strong vertical inheritance. 102 MGEs associated with resistance were found in multiple species, and four of these elements seemed to be highly transmissible as they were found in different phyla. We identified 21 genomic regions containing resistance genes potentially mobilized by MGEs, highlighting their importance in transmitting genes to clinically significant bacteria. CONCLUSION:Resistance genes are spread through various MGEs, including plasmids and transposons. Our findings suggest that multiple factors influence MGE prevalence and their transposability, thereby shaping the MGE population and transmission pathways. Some MGEs have a wider host range, which could make them more important for mobilizing genes. We also identified 103 resistance genes potentially mobilised by MGEs, which could increase their transmissibility to unrelated bacteria.

Antimicrobial resistance is one of the leading causes of mortality globally. However, little is known about the distribution of antibiotic resistance genes (ARGs) in human gut metagenomes, collectively referred to as the resistome, across socio-demographic gradients. In particular, limited evidence exists on gender-based differences. We investigated how the resistomes differ between women and men in a global dataset of 14,641 publicly available human gut metagenomes encompassing countries with widely variable economic statuses. We observed a 9% higher total ARG load in women than in men in high-income countries. However, in low- and middle-income countries, the difference between genders was reversed in univariate models, but not significant after adjusting for covariates. Interestingly, the differences in ARG load between genders emerged in adulthood, suggesting resistomes differentiate between genders after childhood. Collectively, our data-driven analyses shed light on global, gendered antibiotic resistance patterns, which may help guide further research and targeted interventions.

Background: Tourists returning home and visitors from abroad often carry antimicrobial-resistant (AMR) bacteria. Many of these resistant bacteria are acquired from, or were spread via, the environment (especially water). Understanding the impact from acquiring resistant bacteria via tourism upon global antimicrobial resistance is limited. Methods: Traveller transmission of AMR bacteria can be estimated from combining the numbers of travellers with AMR bacteria rates in different regions and the prevalence of communicable diseases. We used resistance data (WHO and contemporary publications) to measure the prevalence of E.coli resistance to third-generation cephalosporins. The study uses data from 2019, the year with the most complete dataset that also predates disruptions to travel caused by the COVID-19 pandemic. We then used the global burden of disease study and travel data from the World Travel and Tourism to create regional and country level indices measuring the impact of AMR bacteria for 241 countries. Estimates of global travel patterns were obtained using a gravity-style trip distribution model. Findings: Regions with the highest impact of AMR bacteria from returning travellers were Northern Europe and Western Europe. The region with the highest impact of AMR bacteria from visiting travellers was the Caribbean where small island countries receive large numbers of visitors. For countries/administrative regions with populations greater than 5 million, the AMR bacterial travel impacts measured in decreasing risk order from the highest were Hong Kong, Denmark, New Zealand, Hungary, Norway and Sweden. Interpretation: For some countries the incidence of AMR infection among both visitors and returning travellers is much higher than in the domestic population. This impact and how these bacteria are acquired from the environment, must be factored into public health policies for containing global spread of AMR bacteria and as part of a One Health approach.

Consensus statements can be very influential in medicine and public health. Some of these statements use systematic evidence synthesis but others fail on this front. Many consensus statements use panels of experts to deduce perceived consensus through Delphi processes. We argue that stacking of panel members toward one particular position or narrative is a major threat, especially in absence of systematic evidence review. Stacking may involve financial conflicts of interest, but nonfinancial conflicts of strong advocacy can also cause major bias. Given their emerging importance, we describe here how such consensus statements may be misleading, by analyzing in depth a recent high-impact Delphi consensus statement on COVID-19 recommendations as a case example. We demonstrate that many of the selected panel members and at least 35% of the core panel members had advocated toward COVID-19 elimination (Zero-COVID) during the pandemic and were leading members of aggressive advocacy groups. These advocacy conflicts were not declared in the Delphi consensus publication, with rare exceptions. Therefore, we propose that consensus statements should always require rigorous evidence synthesis and maximal transparency on potential biases toward advocacy or lobbyist groups to be valid. While advocacy can have many important functions, its biased impact on consensus panels should be carefully avoided.

Background:Antibiotic resistance is rising globally and is a major One Health problem. How much person-to-person transmission or 'contagion' contributes to the spread of resistant strains compared with antibiotic usage remains unclear. As part of its COVID-19 response, Australia introduced strict people movement restrictions in early 2020. Along with internal lockdown measures, movement of people into Australia from overseas was severely restricted. These circumstances provided a unique opportunity to examine the association of people movements with changes in resistance rates. Methods:Monthly resistance data on over 646 000 Escherichia coli urine isolates from 2016 till 2023 were modelled for statistical changes in resistance trends during pre-lockdown, lockdown and post-lockdown periods. Data were available for three clinical contexts (community, hospital and aged-care facilities). Data were also available for antibiotic usage volumes and movements of people into Australia. Results:In 2020, arrivals into Australia decreased by >95%. Antibiotic community use fell by >20%. There were sharp falls in trend rates of resistance for all antibiotics examined after restrictions were instituted. This fall in trend rates of resistance persisted during restrictions. Notably, trend rates of resistance fell in all three clinical contexts. After removal of restrictions, an upsurge in trend rates of resistance was seen for nearly all antibiotics but with no matching upsurge in antibiotic use. Conclusions:Restricting the movement of people appeared to have a dramatic effect on resistance rates in E. coli. The resulting reduced person-to-person interactions seems more closely associated with changes in antibiotic resistance than antibiotic usage patterns.

Background: Australia has a high rate of antibiotic use. Government policy interventions are one strategy to optimise the use of antibiotics. On 1 April 2020, the Australian Government Department of Health introduced a policy intervention to increase the quality use of four antibiotics.Objectives: To assess if the government policy intervention improved the appropriate supply of the four antibiotics amoxicillin, amoxicillin-clavulanic acid, cefalexin and roxithromycin.Method: This study employed a retrospective cohort study design comparing a 10% sample (n = 345,018) of four antibiotics prescribed and dispensed in Australia during a three-month period (May, June, July) in 2019, and again in 2020 (after the policy intervention). The 10% sample of PBS data was obtained from the Australian Government Department of Health. Descriptive statistics, bivariate and multivariable logistic regression analysis were carried out.Results: The results suggest the policy change improved the appropriate supply of original prescriptions in 2020 compared to 2019 OR = 1.75 (95% CI = 1.68-1.82, p < 0.001), and appropriate supply of repeat prescriptions OR = 1.56 (95% CI = 1.25-1.96, p < 0.001). In 2020, the proportion of appropriate supply of original pre-scriptions increased by an absolute difference of 1.8% (95% CI = 1.6-1.9%; P < 0.001), and appropriate supply of repeat prescriptions increased by 3.9% (95% CI = 2.2-5.5%; P < 0.001). The total number of antibiotic prescriptions prescribed and dispensed in 2019 (N = 219,960) reduced in 2020 (N = 125,058) after the policy intervention.Conclusion: The study provides evidence for the impact of a government policy intervention to improve the appropriate supply of antibiotics, although some of the reduction in antibiotic use was likely due to the concomitant COVID-19 pandemic. Further research is required to assess the impact of the intervention outside a pandemic.

The Two Weeks in the World research project has resulted in a dataset of 3087 clinically relevant bacterial genomes with pertaining metadata, collected from 59 diagnostic units in 35 countries around the world during 2020. A relational database is available with metadata and summary data from selected bioinformatic analysis, such as species prediction and identification of acquired resistance genes.

Australia avoided the worst effects of the COVID-19 pandemic, but still experienced many negative impacts.Reflecting on lessons from Australia's public health response, an Australian expert panel composed of relevant discipline experts identified the following key lessons: 1) movement restrictions were effective, but their implementation requires careful consideration of adverse impacts, 2) disease modelling was valuable, but its limitations should be acknowledged, 3) the absence of timely national data requires re-assessment of national surveillance structures, 4) the utility of advanced pathogen genomics and novel vaccine technology was clearly demonstrated, 5) decisionmaking that is evidence informed and consultative is essential to maintain trust, 6) major system weaknesses in the residential aged-care sector require fixing, 7) adequate infection prevention and control frameworks are critically important, 8) the interests and needs of young people should not be compromised, 9) epidemics should be recognised as a 'standing threat', 10) regional and global solidarity is important.It should be acknowledged that we were unable to capture all relevant nuances and context specific differences.However, the intent of this review of Australia's public health response is to critically reflect on key lessons learnt and to encourage constructive national discussion in countries across the Western Pacific Region.

Outdoors, the risks of transmission of COVID-19 and many other respiratory infections are low. Several environmental factors are known to reduce the viability of viruses and other infectious pathogens in the air. They include variations in temperature, relative humidity, solar ultraviolet radiation, and dilution effects. But one agent that reduces the viability of both viruses and bacteria outdoors, the germicidal open-air factor (OAF), has not been properly recognized for decades. This is despite robust evidence that the OAF can influence both the survival of airborne pathogens and the course of infections. The germicidal effects of outdoor air were widely exploited during the late 19th and early 20th centuries. Firstly, in the treatment of tuberculosis patients who underwent 'open-air therapy' in sanatoria; and secondly by military surgeons during the First World War. They used the same open-air regimen in specially designed hospital wards to disinfect and heal severe wounds among injured soldiers. It was also used on influenza patients during the 1918-19 pandemic. Later, in the 1950s, open-air disinfection and treatment of burns were proposed in the event of nuclear warfare. During the 1960s, the OAF briefly returned to prominence when biodefence scientists conducted experiments proving that open air has a potent germicidal effect. When this work ended in the 1970s, interest in the OAF again fell away, and it remains largely ignored. The COVID-19 pandemic has revived interest in understanding the transmission dynamics and survival of viruses in the air. The pandemic has also stimulated research in the science and practice of improved ventilation to control respiratory infections. Such work is incomplete without an appreciation of the inactivation of viruses and other pathogens by the OAF, but this needs further investigation as a matter of urgency. Research to better understand the conditions under which the OAF can be preserved indoors is urgently needed. We need to review building design with better regard to infection control and patient recovery. But we need to act without delay, as there is already sufficient evidence to show that public health generally would improve if more emphasis was placed on increased exposure to outdoor air.

BACKGROUND:The effect of eye protection to prevent SARS-CoV-2 infection in the real-world remains uncertain. We aimed to synthesize all available research on the potential impact of eye protection on transmission of SARS-CoV-2.METHODS:We searched PROSPERO, PubMed, Embase, The Cochrane Library for clinical trials and comparative observational studies in CENTRAL, and Europe PMC for pre-prints. We included studies that reported sufficient data to estimate the effect of any form of eye protection including face shields and variants, goggles, and glasses, on subsequent confirmed infection with SARS-CoV-2.RESULTS:We screened 898 articles and included 6 reports of 5 observational studies from 4 countries (USA, India, Columbia, and United Kingdom) that tested face shields, goggles, and wraparound eyewear on 7567 healthcare workers. The three before-and-after and one retrospective cohort studies showed statistically significant and substantial reductions in SARS-CoV-2 infections favouring eye protection with odds ratios ranging from 0.04 to 0.6, corresponding to relative risk reductions of 96% to 40%. These reductions were not explained by changes in the community rates. However, the one case-control study reported odds ratio favouring no eye protection (OR 1.7, 95% CI 0.99, 3.0). The high heterogeneity between studies precluded any meaningful meta-analysis. None of the studies adjusted for potential confounders such as other protective behaviours, thus increasing the risk of bias, and decreasing the certainty of evidence to very low.CONCLUSIONS:Current studies suggest that eye protection may play a role in prevention of SARS-CoV-2 infection in healthcare workers. However, robust comparative trials are needed to clearly determine effectiveness of eye protections and wearability issues in both healthcare and general populations.

Fosfomycin is a broad-spectrum antibiotic that targets UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), an important enzyme in the early stages of peptidoglycan biosynthesis. In Escherichia coli, fosfomycin resistance can occur through the presence of fos genes (typically fosA3) which encode fosfomycin-inactivating enzymes (FosA, FosC2), or by mutations in proteins important for the uptake of fosfomycin (CyaA, GlpT, PtsI, UhpA, UhpT) or for its action (MurA) [1].

Remarkably, a year after the COVID-19 outbreak, we remain ineffectual against widespread community infection. Perhaps, something major is missing in our approach? The importance of aerosols versus droplets1Jones NR Qureshi ZU Temple RJ Larwood JPJ Greenhalgh T Bourouiba L Two metres or one: what is the evidence for physical distancing in covid-19?.BMJ. 2020; 370m3223Crossref PubMed Scopus (240) Google Scholar is debated—most viral transmission appears to be via virus-laden droplets, with the greatest risk in crowded, inadequately ventilated environments. Proximity to those infected poses the greatest risk. Currently, the presumed major viral invasion modalities involve inhalation or hand contamination of mucosal surfaces, despite studies to the contrary from a century ago2Maxcy KF The transmission of infection through the eye.JAMA. 1919; 72: 636-639Crossref Scopus (12) Google Scholar showing the importance of eyes as an influenza infection route. Ocular surface droplet deposition is greatly underappreciated as a probable, frequent route for SARS-CoV-2 transmission.3Coroneo MT The eye as the discrete but defensible portal of coronavirus infection.Ocul Surf. 2021; 19: 176-182Crossref PubMed Scopus (38) Google Scholar An observational study, referred to in a commentary,4Maragakis LL Eye protection and the risk of coronavirus disease 2019: does wearing eye protection mitigate risk in public, non-health care settings?.JAMA Ophthalmol. 2020; 1381199Crossref PubMed Scopus (13) Google Scholar reported an apparent protective effect against SARS-CoV-2 transmission from routinely wearing spectacles for more than 8 h per day. Spectacles acting as a barrier to eye touching was hypothesised to help prevent SARS-CoV-2 transmission. We believe that a physical barrier to the deposition of virus-containing droplets is another explanation for the study findings. The commentary4Maragakis LL Eye protection and the risk of coronavirus disease 2019: does wearing eye protection mitigate risk in public, non-health care settings?.JAMA Ophthalmol. 2020; 1381199Crossref PubMed Scopus (13) Google Scholar provides an epidemiologist's caution of avoiding the inference of a causal relationship from a single observational study, yet the criteria of temporality (ie, spectacles worn before viral exposure) plus biological plausibility (ie, ocular viral transmission with spectacles as a direct barrier or indirectly against digital contamination) were met. Eye-protective face shields have been proposed to prevent community transmission.5Perencevich EN Diekema DJ Edmond MB Moving personal protective equipment into the community: face shields and containment of COVID-19.JAMA. 2020; 323: 2252-2253Crossref PubMed Scopus (96) Google Scholar A large study6Bhaskar ME Arun S SARS-CoV-2 infection among community health workers in India before and after use of face shields.JAMA. 2020; 324: 1348-1349Crossref PubMed Scopus (43) Google Scholar showed that 19% of health-care workers became infected, despite wearing three-layered surgical masks, gloves, and shoe covers and using alcohol rub. After the introduction of face shields, no worker was infected. In his landmark 1919 study,2Maxcy KF The transmission of infection through the eye.JAMA. 1919; 72: 636-639Crossref Scopus (12) Google Scholar Maxcy used an atomised solution of Serratia marcescens as a marker to show that in adequately masked patients who had their eyes exposed, bacteria could be readily cultured from the nasopharynx. The ocular surface and its connection via the nasolacrimal duct, permits access of respiratory viruses, to the respiratory system, gut, and circulation. These viruses are more appropriately termed oculotropic.7Belser JA Zeng H Katz JM Tumpey TM Ocular tropism of influenza A viruses: identification of H7 subtype-specific host responses in human respiratory and ocular cells.J Virol. 2011; 85: 10117-10125Crossref PubMed Scopus (29) Google Scholar The eyes are located at a vantage point, simultaneously sensing high bandwidth information but are also exposed to the airborne risk.3Coroneo MT The eye as the discrete but defensible portal of coronavirus infection.Ocul Surf. 2021; 19: 176-182Crossref PubMed Scopus (38) Google Scholar Ocular surface area, including periocular structures, is large compared with the surface of the mouth and nares and is readily available for droplet deposition.2Maxcy KF The transmission of infection through the eye.JAMA. 1919; 72: 636-639Crossref Scopus (12) Google Scholar This area has been calculated to be around 10 000 mm2, two orders of magnitude greater than for the nares and mouth.3Coroneo MT The eye as the discrete but defensible portal of coronavirus infection.Ocul Surf. 2021; 19: 176-182Crossref PubMed Scopus (38) Google Scholar The tear film protects the ocular surface but also provides an unrecognised vehicle for viral carriage into the nose. The most superficial lipid tear film layer is likely to attract SARS-CoV-2 by both electrostatic and lipophilic properties.3Coroneo MT The eye as the discrete but defensible portal of coronavirus infection.Ocul Surf. 2021; 19: 176-182Crossref PubMed Scopus (38) Google Scholar A seemingly paradoxical low rate of conjunctivitis and keratitis of around 12% in people with COVID-19, despite the presence of viral invasion-enabling receptors (although receptor expression is substantially lower than in the respiratory tract) as well as low tear viral detection rates,8Liu YC Ang M Ong HS Wong TY Mehta JS SARS-CoV-2 infection in conjunctival tissue.Lancet Respir Med. 2020; 8: e57Summary Full Text Full Text PDF PubMed Scopus (6) Google Scholar could be explained by the physical tear barrier, high tear turnover rates (5–21% per min) and tear film antiviral activity. The predominant physical barrier approach, by masking mouths and noses, provides variable protection and ease of use and comfort but could be inadequate when worn for extended periods of time. Masks serve a dual purpose of preventing droplet transmission and wearer protection. However, a 2020 meta-analysis concluded that the wearing of surgical masks in non-health-care settings was not associated with a significant reduction in acute respiratory illness incidence;9Wang MX Gwee SXW Chua PEY Pang J Effectiveness of surgical face masks in reducing acute respiratory infections in non-healthcare settings: a systematic review and meta-analysis.Front Med (Lausanne). 2020; 7564280Crossref PubMed Scopus (14) Google Scholar furthermore, there are several supportive studies.10Bundgaard H Bundgaard JS Raaschou-Pedersen DET et al.Effectiveness of adding a mask recommendation to other public health measures to prevent Sars-CoV-2 infection in Danish mask wearers: a randomized controlled trial.Ann Intern Med. 2020; (published online Nov 18.)https://doi.org/10.7326/M20-6817Crossref PubMed Scopus (223) Google Scholar In 1919 and during the great world plague epidemics, “masking of the whole face, eyes included, [had] been wonderfully effective”2Maxcy KF The transmission of infection through the eye.JAMA. 1919; 72: 636-639Crossref Scopus (12) Google Scholar, yet the relative importance of protecting eyes remains unexplored. Eye protection is underappreciated but still has problems. Various eye protectors might not exclude circumventing air currents, such as the human convective boundary layer. Protectors can obstruct vision, fog up, get in the way (particularly with optical instruments), are uncomfortable (hence diminished or improper use), and when worn as part of a helmet device, reduce communication. Hermetically sealed eye protectors, are generally designed for short-term or medium-term use rather than for 4–8 h intensive care unit shifts. Fogging remains a major problem,11Douglas D Douglas R Addressing the corona virus pandemic: will a novel filtered eye mask help?.Int J Infect Dis. 2020; 95: 340-344Summary Full Text Full Text PDF PubMed Scopus (9) Google Scholar due to tear and sweat evaporation, limiting usability and compliance. COVID-19 has brought into focus many important factors that limit personal protective equipment efficacy, including frequent failure to use eye protection. Inadequate eye protection might explain why front-line workers who, despite wearing apparently adequate gloves, gowns, and masks, still can remain at increased risk of infection. The ocular surface can also serve as a site for prophylactic and early treatment. In the eye, angiotensin-converting enzyme 2 and associated receptors are located on the apical (rather than basolateral) cell surfaces, so are best accessed via topical (rather than systemic) treatment.3Coroneo MT The eye as the discrete but defensible portal of coronavirus infection.Ocul Surf. 2021; 19: 176-182Crossref PubMed Scopus (38) Google Scholar Any drugs applied to the ocular surface will rapidly reach the nose via the nasolacrimal ducts. Many drugs can be safely used topically in the eye, repurposed from use for other ocular conditions,3Coroneo MT The eye as the discrete but defensible portal of coronavirus infection.Ocul Surf. 2021; 19: 176-182Crossref PubMed Scopus (38) Google Scholar and, when used in this way, will reduce the risk of systemic side-effects and cost. Thus, there is strong circumstantial evidence that person-to-person transmission can be mediated via viral-laden particles that access the eyes and tear film and are relatively quickly transmitted via lacrimal drainage to a nasopharyngeal reservoir. This pathway had been “disregarded in planning measures for the prevention of the spread of contagious diseases”2Maxcy KF The transmission of infection through the eye.JAMA. 1919; 72: 636-639Crossref Scopus (12) Google Scholar in 1919, and little has changed. We need to better protect the eyes, at least from droplets, by increasing the use of eye protection devices, such as face shields. The importance of a strong evidence base to any intervention is understood, yet an apparent rigorous approach, within narrow silos of knowledge, evident in this pandemic, might not have served us well. The failure to acknowledge historical precedent might also have delayed an effective response to this crisis. There is an urgent need to develop better eye protective strategies, based on the understanding of ocular interactions with the environment, and also to reconsider the potential of early topical interventions as prophylaxis. MTC has filed patent applications in relation to treatment methods, as well as personal and slit-lamp protective devices, relevant to viral infection. Over the past 3 years, MTC has received royalties from Alcon, Dutch Ophthalmic Research Center International, and Katena Products in relation to intellectual property. MTC has received consulting fees from Allgenesis and Novartis Pharma. PJC declares no competing interests.

Keywords: antimicrobial resistance, bacterial infections, COVID-19, epidemiology, preventionMots-clés : antibiorésistance, COVID-19, épidémiologie, infections bactériennes, prévention

The coronavirus, named SARS-CoV-2, is the cause of COVID-19. This virus spreads readily from person to person and predominantly to and from the respiratory route and through droplets. There are many different interventions that can be and are used to decrease successfully the risk and spread of COVID-19. Most of the principles underpinning these interventions relate to isolation and social distancing. These will need to be continued, at least in part, until safe and very effective vaccines become widely available and are delivered extensively and successfully globally. This new norm is isolation, plus social and physical distancing, and this new norm will likely be with us for some time to come. It will also be with us in any future pandemics, whether caused by bacteria or viruses, but especially when the causative pathogen spreads predominantly through the respiratory route. However, lockdowns and restrictions also cause many adverse but unintended economic, social and health consequences. Therefore, what is put into place needs to be proportionate to levels of risk of disease as well as spread, and which will vary in different localities and with time.