A better understanding of viral factors that contribute to influenza A virus (IAV) airborne transmission is crucial for pandemic preparedness. A limited capacity for airborne transmission was recently observed in a human A(H9N2) virus isolate (A/Anhui-Lujiang/39/2018, AL/39) that possesses a leucine (L) residue at position HA1-226 (H3 numbering), indicative of human-like receptor binding potential. To evaluate the roles of the residue at this position in virus fitness and airborne transmission, a wild-type AL/39 (AL/39-wt) and a mutant virus (AL/39-HA1-L226Q) with a single substitution at position HA1-226 from leucine to glutamine (Q), a consensus residue in avian influenza viruses, were rescued and assessed in the ferret model. The AL/39-HA1-L226Q virus lost the ability to transmit by air, although the virus had a comparable capacity for replication, induced similar levels of host innate immune responses, and was detected at comparable levels in the air surrounding the inoculated ferrets relative to AL/39-wt virus. However, ferrets showed a lower susceptibility to AL/39-HA1-L226Q virus infection compared to the AL/39-wt virus. Furthermore, the AL/39-wt and AL/39-HA1-L226Q viruses each gained dominance in different anatomic sites in the respiratory tract in a co-infection competition model in ferrets. Taken together, our findings demonstrate that the increasing dominance of HA1-L226 residue in an avian A(H9N2) virus plays multifaceted roles in virus infection and transmission in the ferret model, including improved virus fitness and infectivity. IMPORTANCE: Although the capacity for human-like receptor binding is a key prerequisite for non-human origin influenza A virus (IAV) to become airborne transmissible in mammalian hosts, the underlying molecular basis is not well understood. In this study, we investigated a naturally occurring substitution (leucine to glutamine) at residue 226 in the HA of an avian-origin A(H9N2) virus and assessed the impact on virus replication and airborne transmission in the ferret model. We demonstrate that the enhanced airborne transmission associated with the HA1-L226 virus was mainly due to the increased infectivity of the virus. Interestingly, we found that, unlike most sites in the ferret respiratory tract, ferret ethmoid turbinate lined with olfactory epithelium favors replication of the AL/39-HA1-L226Q virus, suggesting that this site may serve as a unique niche for IAV with avian-like receptor binding specificity to potentially allow the virus to spread to extrapulmonary tissues and to facilitate adaptation of the virus to human hosts.

Since 2020, there has been unprecedented global spread of highly pathogenic avian influenza A(H5N1) in wild bird populations with spillover into a variety of mammalian species and sporadically humans(1). In March 2024, clade 2.3.4.4b A(H5N1) virus was first detected in dairy cattle in the U.S., with subsequent detection in numerous states(2), leading to over a dozen confirmed human cases(3,4). In this study, we employed the ferret model, a well-characterized species that permits concurrent investigation of viral pathogenicity and transmissibility(5) in the evaluation of A/Texas/37/2024 (TX/37) A(H5N1) virus isolated from a dairy farm worker in Texas(6). Here, we show that the virus has a remarkable ability for robust systemic infection in ferrets, leading to high levels of virus shedding and spread to naïve contacts. Ferrets inoculated with TX/37 rapidly exhibited a severe and fatal infection, characterized by viremia and extrapulmonary spread. The virus efficiently transmitted in a direct contact setting and was capable of indirect transmission via fomites. Airborne transmission was corroborated by the detection of infectious virus shed into the air by infected animals, albeit at lower levels compared to the highly transmissible human seasonal and swine-origin H1 subtype strains. Our results show that despite maintaining an avian-like receptor binding specificity, TX/37 displays heightened virulence, transmissibility, and airborne shedding relative to other clade 2.3.4.4b virus isolated prior to the 2024 cattle outbreaks(7), underscoring the need for continued public health vigilance.

The sporadic occurrence of human infections with swine-origin influenza A(H3N2) viruses and the continual emergence of novel A(H3N2) viruses in swine herds underscore the necessity for ongoing assessment of the pandemic risk posed by these viruses. Here, we selected 3 recent novel swine-origin A(H3N2) viruses isolated between 2017 to 2020, bearing hemagglutinins from the 1990.1, 2010.1, or 2010.2 clades, and evaluated their ability to cause disease and transmit in a ferret model. We conclude that despite considerable genetic variances, all 3 contemporary swine-origin A(H3N2) viruses displayed a capacity for robust replication in the ferret respiratory tract and were also capable of limited airborne transmission. These findings highlight the continued public health risk of swine-origin A(H3N2) strains, especially in human populations with low cross-reactive immunity.

BACKGROUND: The second phase of the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) transitioned from scaling up HIV prevention and treatment to promoting sustainability and capacity building for programs monitoring performance and evaluating key program indicators. We assessed the success of a monitoring and evaluation (M&E) curriculum designed to build capacity in three PEPFAR-supported countries. METHODS: We customized M&E trainings based on country-specific epidemic control priorities in Ethiopia, Guatemala, and Cameroon. The M&E curriculum included five modules and three evaluation activities to assess impact: (i) in-person pre-post confidence assessment surveys (CAS), (ii) in-person pre-post knowledge tests (PPKT), and (iii) electronic 6-12 months post-training translating knowledge into practice (TKP) surveys. Pre- and post-training results were compared within and across countries and triangulation with the qualitative data evaluated overall success. RESULTS: Among 188 participants attending M&E trainings, 154 (82 %) responded to CAS and 165 (88 %) participants from Ethiopia and Cameroon completed PPKT. Overall CAS scores between pre- and post-test improved [Score mean difference:1.5-1.9]. PPKT indicated statistically significant knowledge gained. One out of five TKP respondents provided direct application examples from the M&E training. CONCLUSION: While feedback was predominantly positive overall, revisions were recommended for three of the five modules. Developing a customizable and adaptable M&E curriculum may sustain countries' ability to monitor their progress towards epidemic control.

Invasive candidiasis (IC) is an increasingly prevalent, costly, and potentially fatal infection brought on by the opportunistic yeast, Candida. Previously, IC has predominantly been caused by C. albicans which is often drug susceptible. There has been a global trend towards decreasing rates of infection secondary to C. albicans and a rise in non-albicans species with a corresponding increase in drug resistance creating treatment challenges. With advances in management of malignancies, there has also been an increase in the population at risk from IC along with a corresponding increase in incidence of breakthrough IC infections. Additionally, the emergence of C. auris creates many challenges in management and prevention due to drug resistance and the organism's ability to transmit rapidly in the healthcare setting. While the development of novel antifungals is encouraging for future management, understanding the changing epidemiology of IC is a vital step in future management and prevention.

BACKGROUND: Recently, increasing focus on patient input into research and healthcare improvements has fostered expanded patient-centered advocacy efforts. This first pan-fungal disease summit, part of the MYCology Advocacy, Research, & Education effort, brought together patients, caregivers, and mycology experts to better document patient experiences with invasive fungal disease (IFD) and establish priorities for mycology education, advocacy, and research. METHODS: Patients who had suffered from IFD, their caregivers, clinicians, industry representatives, government officials, and patient advocacy professionals were invited. Patients and caregivers shared their stories and struggles with IFD. Breakout sessions separated mycology experts from patients and caregivers for further discussions to identify commonalities and perceived gaps and to formulate recommendations. The 2 groups then reconvened to develop consensus recommendations. RESULTS: IFD patients and their caregivers shared experiences reflecting the typically lengthy prediagnosis, acute treatment, long-term treatment, and posttreatment recovery stages of IFD. They reported substantial physical, psychological, and financial burdens associated with the IFD experience, particularly related to delayed diagnoses. They reaffirmed a need for coordinated patient-centered education, peer support, and advocacy to document the burden of serious fungal infections. Mycology experts discussed strategies to address gaps in the mycology field, such as insufficient training, inadequate workforce support, and a need to partner more with patient groups. CONCLUSIONS: A summit involving patients with IFD, family caregivers, and mycology experts identified a substantial nonclinical burden of disease associated with IFD. Patients and mycology experts prioritized several goals for education, advocacy, and research to raise awareness of IFD and improve outcomes.

Clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses have caused large outbreaks within avian populations on five continents, with concurrent spillover into a variety of mammalian species. Mutations associated with mammalian adaptation have been sporadically identified in avian isolates, and more frequently among mammalian isolates following infection. Reports of human infection with A(H5N1) viruses following contact with infected wildlife have been reported on multiple continents, highlighting the need for pandemic risk assessment of these viruses. In this study, the pathogenicity and transmissibility of A/Chile/25945/2023 HPAI A(H5N1) virus, a novel reassortment with four gene segments (PB1, PB2, NP, MP) from North America lineage, isolated from a severe human case in Chile, was evaluated in vitro and using the ferret model. This virus possessed a high capacity to cause fatal disease, characterized by high morbidity and extrapulmonary spread in virus-inoculated ferrets. The virus was capable of transmission to naïve contacts in a direct contact setting, with contact animals similarly exhibiting severe disease, but did not exhibit productive transmission in respiratory droplet or fomite transmission models. Our results indicate that the virus would need to acquire an airborne transmissible phenotype in mammals to potentially cause a pandemic. Nonetheless, this work warrants continuous monitoring of mammalian adaptations in avian viruses, especially in strains isolated from humans, to aid pandemic preparedness efforts.

The designs and liquid formulations of Electronic Nicotine Delivery System (ENDS) devices continue to rapidly evolve. Thus, it is important to monitor and characterize ENDS aerosols for changes in toxic constituents. Many ENDS liquid formulations now include the addition of organic acids in a 1 to 1 molar ratio with nicotine. Metal concentrations in aerosols produced by ENDS devices with different nicotine salt formulations were analyzed. Aerosols from devices containing lactic acid had higher nickel, zinc, copper, and chromium concentrations than aerosols produced by devices containing benzoic acid or levulinic acid. Our scanning electron microscope with energy dispersive X-ray analytical findings showed that the metals determined in the inductively coupled plasma-mass spectrometry analytical results were consistent with the metal compositions of the ENDS device components that were exposed to the liquids and that nickel is a major constituent in many ENDS internal components. As a result of the exposure of the nickel-containing components to the ENDS liquids, resulting aerosol nickel concentrations per puff were higher from devices that contained lactic acid in comparison to devices with benzoic or levulinic acid. The aerosol nickel concentrations in 10 puffs from ENDS-containing lactic acid were, in some cases, hundreds of times higher than cigarette mainstream smoke nickel deliveries. Thus, the design of an ENDS device in terms of both physical construction components and the liquid chemical formulations could directly impact potential exposures to toxic constituents such as metals.

Despite the accumulation of evidence showing that airborne transmissible influenza A virus (IAV) typically has a lower pH threshold for hemagglutinin (HA) fusion activation, the underlying mechanism for such a link remains unclear. In our study, by using a pair of isogenic recombinant A(H9N2) viruses with a phenotypical difference in virus airborne transmission in a ferret model due to an acid-destabilizing mutation (HA1-Y17H) in the HA, we demonstrate that an acid-stable A(H9N2) virus possesses a multitude of advantages over its less stable counterpart, including better fitness in the ferret respiratory tract, more effective aerosol emission from infected animals, and improved host susceptibility. Our study provides supporting evidence for the requirement of acid stability in efficient airborne transmission of IAV and sheds light on fundamental mechanisms for virus airborne transmission.

Onychomycosis (tinea unguium) and tinea pedis are common, frequently concomitant infections of the nails and feet, respectively, and are often caused by dermatophyte fungi (Trichophyton, Microsporum, and Epidermophyton spp.). 1 Antifungal‐resistant tinea is an emerging global public health problem. 2 A recent, large analysis of toenail samples from US patients with suspected onychomycosis found that nearly 4% of Trichophyton spp samples had squalene epoxidase gene mutations, which are associated with terbinafine resistance. 3 Clinicians may be increasingly likely to encounter resistant tinea infections. Therefore, we aimed to assess diagnostic approaches, antifungal resistance testing practices, and treatment practices for treatment‐resistant onychomycosis and tinea pedis.

The rapid pace of name changes of medically important fungi is creating challenges for clinical laboratories and clinicians involved in patient care. We describe two sources of name change which have different drivers, at the species versus the genus level. Some suggestions are made here to reduce the number of name changes. We urge taxonomists to provide diagnostic markers of taxonomic novelties. Given the instability of phylogenetic trees due to variable taxon sampling, we advocate to maintain genera at the largest possible size. Reporting of identified species in complexes or series should where possible comprise both the name of the overarching species and that of the molecular sibling, often cryptic species. Because the use of different names for the same species will be unavoidable for many years to come, an open access online database of the names of all medically important fungi, with proper nomenclatural designation and synonymy, is essential. We further recommend that while taxonomic discovery continues, the adaptation of new name changes by clinical laboratories and clinicians be reviewed routinely by a standing committee for validation and stability over time, with reference to an open access database, wherein reasons for changes are listed in a transparent way.

Coccidioidomycosis, histoplasmosis, and blastomycosis are underrecognized and frequently misdiagnosed fungal infections that can clinically resemble bacterial and viral community-acquired pneumonia (CAP). This guidance is intended to help clinicians in outpatient settings test for these fungal diseases in patients with CAP to reduce misdiagnoses, unnecessary antibacterial use, and poor outcomes.

BACKGROUND: Public health officials are responding to an outbreak of fungal meningitis among patients who received procedures under epidural anesthesia at two clinics (River Side Surgical Center and Clinica K-3) in Matamoros, Mexico, during January 1-May 13, 2023. This report describes outbreak epidemiology and outlines interim diagnostic and treatment recommendations. METHODS: Interim recommendations for diagnosis and management were developed by the Mycoses Study Group Research Education and Consortium (MSGERC) based on the clinical experience of clinicians caring for patients during the current outbreak or during previous outbreaks of healthcare-associated fungal meningitis in Durango, Mexico, and the United States. RESULTS: As of July 7, 2023, the situation has evolved into a multistate and multinational fungal meningitis outbreak. A total of 185 residents in 22 U.S. states and jurisdictions have been identified who might be at risk of fungal meningitis because they received epidural anesthesia at the clinics of interest in 2023. Among these patients, 11 suspected, 10 probable, and 10 confirmed U.S. cases have been diagnosed, with severe vascular complications and eight deaths occurring. Fusarium solani species complex has been identified as the causative agent, with antifungal susceptibility testing of a single isolate demonstrating poor in vitro activity for most available antifungals. Currently, triple therapy with intravenous voriconazole, liposomal amphotericin B, and fosmanogepix is recommended. CONCLUSIONS: Efforts to understand the source of this outbreak and optimal treatment approaches are ongoing, but infectious diseases physicians should be aware of available treatment recommendations. New information will be available on CDC's website.

Part 1 of this tutorial addressed how environmental contamination may be minimized by using proper personal analytical practices, sample preparation environmental suggestions, avoidance of glass and low purity quartz contact with samples and standards during sample collection and preparation, and appropriate choices of high purity solvents during sample collection and preparation. Part 2 continues the discussion in terms of minimizing sample contamination issues by using high purity polymer materials for sample collection and preparation, as well as discuss the differences between instrument and method limits of detection (LODs). Accepted and appropriate procedures for calculating method LODs are related to variability in instrument response and unavoidable environmental contamination during even the cleanest sample preparation. Adherence to such practices will help analysts avoid false positives and report results with a high level of confidence. © 2023 Advanstar Communications Inc.. All rights reserved.

Importance: Evidence of the impact of COVID-19 Case Investigation and Contact Tracing (CICT) programs is lacking. Policymakers need this evidence to assess its value. Objective(s): Estimate COVID-19 cases and hospitalizations averted nationwide by US states' CICT programs. Design(s): We combined data from US CICT programs (e.g., proportion of cases interviewed, contacts notified or monitored, and days to case and contact notification) with incidence data to model CICT impacts over 60 days period (November 25, 2020 to January 23, 2021) during the height of the pandemic. We estimated a range of impacts by varying assumed compliance with isolation and quarantine recommendations. Setting(s): US States and Territories Participants: Fifty-nine state and territorial health departments that received federal funding supporting COVID-19 pandemic response activities were eligible for inclusion. Of these, 22 states and 1 territory reported all measures necessary for the analysis. These 23 jurisdictions covered 42.5% of the US population (140 million persons), spanned all 4 census regions, and reported data that reflected all 59 federally funded CICT programs. Intervention(s): Public health case investigation and contact tracing Main Outcomes and Measures: Cases and hospitalizations averted; percent of cases averted among cases not prevented by vaccination and other non-pharmaceutical interventions (other NPIs). Result(s): We estimated 1.11 million cases and 27,231 hospitalizations were averted by CICT programs under a scenario where 80% of interviewed cases and monitored contacts, and 30% of notified contacts fully complied with isolation and quarantine guidance, eliminating their contributions to future transmission. As many as 1.36 million cases and 33,527 hospitalizations could have been prevented if all interviewed cases and monitored contacts had entered into and fully complied with isolation and quarantine guidelines upon being interviewed or notified. Across all scenarios and jurisdictions, CICT averted a median of 21.2% (range: 1.3% - 65.8%) of the cases not prevented by vaccination and other NPIs. Conclusions and Relevance: CICT programs likely had a substantial role in curtailing the pandemic in most jurisdictions during the winter 2020-2021 peak. Differences in impact across jurisdictions indicate an opportunity to further improve CICT effectiveness. These estimates demonstrate the potential benefits from sustaining and improving these programs. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-ND 4.0 International license.

While primarily considered a respiratory pathogen, influenza A virus (IAV) is nonetheless capable of spreading to, and replicating in, numerous extrapulmonary tissues in humans. However, within-host assessments of genetic diversity during multicycle replication have been largely limited to respiratory tract tissues and specimens. As selective pressures can vary greatly between anatomical sites, there is a need to examine how measures of viral diversity may vary between influenza viruses exhibiting different tropisms in humans, as well as following influenza virus infection of cells derived from different organ systems. Here, we employed human primary tissue constructs emulative of the human airway or corneal surface, and we infected both with a panel of human- and avian-origin IAV, inclusive of H1 and H3 subtype human viruses and highly pathogenic H5 and H7 subtype viruses, which are associated with both respiratory disease and conjunctivitis following human infection. While both cell types supported productive replication of all viruses, airway-derived tissue constructs elicited greater induction of genes associated with antiviral responses than did corneal-derived constructs. We used next-generation sequencing to examine viral mutations and population diversity, utilizing several metrics. With few exceptions, generally comparable measures of viral diversity and mutational frequency were detected following homologous virus infection of both respiratory-origin and ocular-origin tissue constructs. Expansion of within-host assessments of genetic diversity to include IAV with atypical clinical presentations in humans or in extrapulmonary cell types can provide greater insight into understanding those features most prone to modulation in the context of viral tropism. IMPORTANCE Influenza A virus (IAV) can infect tissues both within and beyond the respiratory tract, leading to extrapulmonary complications, such as conjunctivitis or gastrointestinal disease. Selective pressures governing virus replication and induction of host responses can vary based on the anatomical site of infection, yet studies examining within-host assessments of genetic diversity are typically only conducted in cells derived from the respiratory tract. We examined the contribution of influenza virus tropism on these properties two different ways: by using IAV associated with different tropisms in humans, and by infecting human cell types from two different organ systems susceptible to IAV infection. Despite the diversity of cell types and viruses employed, we observed generally similar measures of viral diversity postinfection across all conditions tested; these findings nonetheless contribute to a greater understanding of the role tissue type contributes to the dynamics of virus evolution within a human host.

Research gaps exist in toxic metals characterization in e-cigarette, or vaping, products (EVPs) as these analytes typically have low concentrations and most standard aerosol trapping techniques have high metals background. An additional complication arises from differences in the EVP liquid formulations with nicotine products having polar properties and non-nicotine products often being non-polar. Differences in polar and non-polar matrices and the subsequent aerosol chemistries from various EVPs required modifications of our previously reported nicotine-based EVP aerosol method. Validation and application of the expanded method, suitable for both hydrophobic and hydrophilic aerosols, are reported here. The metals analyzed for this study were Al, Cr, Fe, Co, Ni, Cu, Cd, Sn, Ba, and Pb. The method limits of detection for the modified method ranged from 0.120 ng/10 puffs for Cd to 29.3 ng/10 puffs for Al and were higher than reported for the previous method. Results of the analyses for metals in aerosols obtained from 50 EVP products are reported. Cannabinoid based EVP aerosols were below reportable levels, except for one sample with 16.08 ng/10 puffs for Cu. Nicotine-based EVP results ranged from 6.72 ng/10 puffs for Pb to 203 ng/10 puffs for Sn. Results of the analyses for these metals showed that aerosols from only 5 of the 50 devices tested had detectable metal concentrations. Concentrations of toxic elements in the aerosols for nicotine-based EVP aerosol metal concentration ranges were consistent with previously published results of aerosol analyses from this class of devices.

Pressing challenges in the treatment of invasive fungal infections (IFI) include emerging and rare pathogens, resistant/refractory infections, and antifungal armamentarium limited by toxicity, drug-drug interactions, and lack of oral formulations. Development of new antifungal drugs is hampered by the limitations of the available diagnostics; clinical trial endpoints; prolonged trial duration; difficulties in patient recruitment, including subpopulations (e.g., pediatrics); and heterogeneity of the IFIs. On August 4, 2020, the U.S. Food and Drug Administration convened a workshop that included IFI experts from academia, industry, and other government agencies to discuss the IFI landscape, unmet need, and potential strategies to facilitate the development of antifungal drugs for treatment and prophylaxis. This paper summarizes the key topics presented and discussed during the workshop, such as incentives and research support for drug developers, nonclinical development, clinical trial design challenges, lessons learned from industry, and potential collaborations to facilitate antifungal drug development.

Competition assays were conducted in vitro and in vivo to examine how the Delta (B.1.617.2) variant displaced the prototype Washington/1/2020 (WA/1) strain. While WA/1 virus exhibited a moderately increased proportion compared to that in the inoculum following co-infection in human respiratory cells, Delta variant possessed a substantial in vivo fitness advantage as this virus becoming predominant in both inoculated and contact animals. This work identifies critical traits of the Delta variant that likely played a role in it becoming a dominant variant and highlights the necessities of employing multiple model systems to assess the fitness of newly emerged SARS-CoV-2 variants.

BACKGROUND: No rabies post-exposure prophylaxis (PEP) failure has been documented in humans in the United States using modern cell-culture vaccines. In January 2021, an 84-year-old male died from rabies six months after being bitten by a rabid bat despite receiving timely rabies post-exposure prophylaxis (PEP). We investigated the cause of breakthrough infection. METHODS: We reviewed medical records, laboratory results, and autopsy findings, and performed whole genome sequencing (WGS) to compare patient and bat virus sequences. Storage, administration, and integrity of PEP biologics administered to the patient were assessed; samples from leftover rabies immunoglobulin were evaluated for potency. We conducted risk assessments for persons potentially exposed to the bat and for close contacts of the patient. RESULTS: Rabies virus antibodies present in serum and cerebrospinal fluid were non-neutralizing. Antemortem blood testing revealed the patient had unrecognized monoclonal gammopathy of unknown significance. Autopsy findings showed rabies meningoencephalitis and metastatic prostatic adenocarcinoma. Rabies virus sequences from the patient and the offending bat were identical by WGS. No deviations were identified in potency, quality control, administration, or storage of administered PEP. Of 332 persons assessed for potential rabies exposure to the case patient, three (0.9%) warranted PEP. CONCLUSION: This is the first reported failure of rabies PEP in the Western Hemisphere using a cell culture vaccine. Host-mediated primary vaccine failure attributed to previously unrecognized impaired immunity is the most likely explanation for this breakthrough infection. Clinicians should consider measuring rabies neutralizing antibody titers after completion of PEP if there is any suspicion for immunocompromise.

Confronted with a novel coronavirus, countries worldwide were forced to rapidly adjust their public health systems, platforms, and tools to respond to COVID-19. The US Centers for Disease Control and Prevention (CDC) and its global partners adapted health systems and programs originally developed for other purposes, such as controlling the HIV/AIDS pandemic through the US President’s Emergency Plan for AIDS Relief (PEPFAR), Global Health Security Agenda implementation, influenza surveillance, and vaccine-preventable disease elimination and eradication. This special supplement of Emerging Infectious Diseases highlights responses to the early phases of the COVID-19 pandemic from >80 countries, spanning 6 continents and representing >130 organizations. This article summarizes global adaptations of core public health functions during COVID-19: surveillance, information, and laboratory systems; workforce, institutional, and public health capacity; and clinical and health services delivery.

We report an immunocompromised patient in Alabama, USA, 75 years of age, with relapsing fevers and pancytopenia who had spirochetemia after a tick bite. We identified Borrelia lonestari by using PCR, sequencing, and phylogenetic analysis. Increasing clinical availability of molecular diagnostics might identify B. lonestari as an emerging tickborne pathogen.

The ferret transmission model is routinely used to evaluate the pandemic potential of newly emerging influenza A viruses. However, concurrent measurement of viral load in the air is typically not a component of such studies. To address this knowledge gap, we measured the levels of virus in ferret nasal washes as well as viral RNA emitted into the air for 14 diverse influenza viruses, encompassing human-, swine-, and avian-origin strains. Here we show that transmissible viruses display robust replication and fast release into the air. In contrast, poorly- and non-transmissible viruses show significantly reduced or delayed replication along with lower detection of airborne viral RNA at early time points post inoculation. These findings indicate that efficient ferret-to-ferret transmission via the air is directly associated with fast emission of virus-laden particles; as such, quantification of viral RNA in the air represents a useful addition to established assessments of new influenza virus strains.

Despite reports of confirmed human infection following ocular exposure with both influenza A virus (IAV) and SARS-CoV-2, the dynamics of virus spread throughout oculonasal tissues and the relative capacity of virus transmission following ocular inoculation remain poorly understood. Furthermore, the impact of exposure route on subsequent release of airborne viral particles into the air has not been examined previously. To assess this, ferrets were inoculated by the ocular route with A(H1N1)pdm09 and A(H7N9) IAVs and two SARS-CoV-2 (early pandemic Washington/1 and Delta variant) viruses. Virus replication was assessed in both respiratory and ocular specimens, and transmission was evaluated in direct contact or respiratory droplet settings. Viral RNA in aerosols shed by inoculated ferrets was quantified with a two-stage cyclone aerosol sampler (National Institute for Occupational Safety and Health [NIOSH]). All IAV and SARS-CoV-2 viruses mounted a productive and transmissible infection in ferrets following ocular inoculation, with peak viral titers and release of virus-laden aerosols from ferrets indistinguishable from those from ferrets inoculated by previously characterized intranasal inoculation methods. Viral RNA was detected in ferret conjunctival washes from all viruses examined, though infectious virus in this specimen was recovered only following IAV inoculation. Low-dose ocular-only aerosol exposure or inhalation aerosol exposure of ferrets to IAV similarly led to productive infection of ferrets and shedding of aerosolized virus. Viral evolution during infection was comparable between all inoculation routes examined. These data support that both IAV and SARS-CoV-2 can establish a high-titer mammalian infection following ocular exposure that is associated with rapid detection of virus-laden aerosols shed by inoculated animals. IMPORTANCE Documented human infection with influenza viruses and SARS-CoV-2 has been reported among individuals wearing respiratory protection in the absence of eye protection, highlighting the capacity of these respiratory tract-tropic viruses to exploit nonrespiratory routes of exposure to initiate productive infection. However, comprehensive evaluations of how ocular exposure may modulate virus pathogenicity and transmissibility in mammals relative to respiratory exposure are limited and have not investigated multiple virus families side by side. Using the ferret model, we show that ocular exposure with multiple strains of either coronaviruses or influenza A viruses leads to an infection that results in shedding of detectable aerosolized virus from inoculated animals, contributing toward onward transmission of both viruses to susceptible contacts. Collectively, these studies support that the ocular surface represents a susceptible mucosal surface that, if exposed to a sufficient quantity of either virus, permits establishment of an infection which is similarly transmissible as that following respiratory exposure.

The continued spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans necessitates evaluation of variants for enhanced virulence and transmission. We used the ferret model to perform a comparative analysis of four SARS-CoV-2 strains, including an early pandemic isolate from the United States (WA1), and representatives of the Alpha, Beta, and Delta lineages. While Beta virus was not capable of pronounced replication in ferrets, WA1, Alpha, and Delta viruses productively replicated in the ferret upper respiratory tract, despite causing only mild disease with no overt histopathological changes. Strain-specific transmissibility was observed; WA1 and Delta viruses transmitted in a direct contact setting, whereas Delta virus was also capable of limited airborne transmission. Viral RNA was shed in exhaled air particles from all inoculated animals but was highest for Delta virus. Prior infection with SARS-CoV-2 offered varied protection against reinfection with either homologous or heterologous variants. Notable genomic variants in the spike protein were most frequently detected following WA1 and Delta virus infection. IMPORTANCE Continued surveillance and risk assessment of emerging SARS-CoV-2 variants are critical for pandemic response and preparedness. As such, in vivo evaluations are indispensable for early detection of variants with enhanced virulence and transmission. Here, we used the ferret model to compare the pathogenicity and transmissibility of an original SARS-CoV-2 isolate (USA-WA1/2020 [WA1]) to those of a panel of Alpha, Beta, and Delta variants, as well as to evaluate protection from homologous and heterologous reinfection. We observed strain-specific differences in replication kinetics in the ferret respiratory tract and virus load emitted into the air, revealing enhanced transmissibility of the Delta virus relative to previously detected strains. Prior infection with SARS-CoV-2 provided varied levels of protection from reinfection, with the Beta strain eliciting the lowest level of protection. Overall, we found that ferrets represent a useful model for comparative assessments of SARS-CoV-2 infection, transmission, and reinfection.

BACKGROUND: In March 2020, the World Health Organization declared COVID-19, caused by the SARS-CoV-2 virus, a pandemic. Patients with severe cases resulting in hospitalization and mechanical ventilation are at risk for COVID-19-associated pulmonary aspergillosis, an invasive fungal infection, and should be screened for aspergillosis if they have persistent hemodynamic instability and fever. Early detection and treatment of this fungal infection can significantly reduce morbidity and mortality in this population. OBJECTIVE: To develop an evidence-based care step pathway tool to help intensive care unit clinicians assess, diagnose, and treat COVID-19-associated pulmonary aspergillosis. METHODS: A panel of 18 infectious disease experts, advanced practice registered nurses, pharmacists, and clinical researchers convened in a series of meetings to develop the Care Step Pathway tool, which was modeled on a tool developed by advanced practice nurses to evaluate and manage side effects of therapies for melanoma. The Care Step Pathway tool addresses various aspects of disease management, including assessment, screening, diagnosis, antifungal treatment, pharmacological considerations, and exclusion of other invasive fungal coinfections. RESULTS: The Care Step Pathway tool was applied in the care of a patient with COVID-19-associated aspergillosis. The patient was successfully treated. CONCLUSION: The Care Step Pathway is an effective educational tool to help intensive care unit clinicians consider fungal infection when caring for COVID-19 patients receiving mechanical ventilation in the intensive care unit, especially when the clinical course is deteriorating and antibiotics are ineffective.

Influenza A viruses (IAVs) in the swine reservoir constantly evolve, resulting in expanding genetic and antigenic diversity of strains that occasionally cause infections in humans and pose threat of emerging as a strain capable of human-to-human transmission. For these reasons, there is an ongoing need for surveillance and characterization of newly emerging strains to aid pandemic preparedness efforts, particularly for the selection of candidate vaccine viruses and conducting risk assessments. Here, we performed a parallel comparison of the pathogenesis and transmission of genetically and antigenically diverse swine-origin A(H1N1) variant (v) and A(H1N2)v, and human seasonal A(H1N1)pdm09 IAVs using the ferret model. Both groups of viruses were capable of replication in the ferret upper respiratory tract; however, variant viruses were more frequently isolated from the lower respiratory tract as compared to the human-adapted viruses. Regardless of virus origin, observed clinical signs of infection differed greatly between strains, with some viruses causing nasal discharge, sneezing and, in some instances, diarrhea in ferrets. The most striking difference between the viruses was the ability to transmit through the air. Human-adapted viruses were capable of airborne transmission between all ferret pairs. In contrast, only one out of the four tested variant viruses was able to transmit via the air as efficiently as the human-adapted viruses. Overall, this work highlights the need for sustained monitoring of emerging swine IAVs to identify strains of concern such as those that are antigenically different from vaccine strains and that possess adaptations required for efficient respiratory droplet transmission in mammals.

IMPORTANCE: Evidence of the impact of COVID-19 case investigation and contact tracing (CICT) programs is lacking, but policy makers need this evidence to assess the value of such programs. OBJECTIVE: To estimate COVID-19 cases and hospitalizations averted nationwide by US states' CICT programs. DESIGN, SETTING, AND PARTICIPANTS: This decision analytical model study used combined data from US CICT programs (eg, proportion of cases interviewed, contacts notified or monitored, and days to case and contact notification) with incidence data to model outcomes of CICT over a 60-day period (November 25, 2020, to January 23, 2021). The study estimated a range of outcomes by varying assumed compliance with isolation and quarantine recommendations. Fifty-nine state and territorial health departments that received federal funding supporting COVID-19 pandemic response activities were eligible for inclusion. Data analysis was performed from July to September 2021. EXPOSURE: Public health case investigation and contact tracing. MAIN OUTCOMES AND MEASURES: The primary outcomes were numbers of cases and hospitalizations averted and the percentage of cases averted among cases not prevented by vaccination and other nonpharmaceutical interventions. RESULTS: In total, 22 states and 1 territory reported all measures necessary for the analysis. These 23 jurisdictions covered 42.5% of the US population (approximately 140 million persons), spanned all 4 US Census regions, and reported data that reflected all 59 federally funded CICT programs. This study estimated that 1.11 million cases and 27 231 hospitalizations were averted by CICT programs under a scenario where 80% of interviewed cases and monitored contacts and 30% of notified contacts fully complied with isolation and quarantine guidance, eliminating their contributions to future transmission. As many as 1.36 million cases and 33 527 hospitalizations could have been prevented if all interviewed cases and monitored contacts had entered into and fully complied with isolation and quarantine guidelines upon being interviewed or notified. Across both scenarios and all jurisdictions, CICT averted an estimated median of 21.2% (range, 1.3%-65.8%) of the cases not prevented by vaccination and other nonpharmaceutical interventions. CONCLUSIONS AND RELEVANCE: These findings suggest that CICT programs likely had a substantial role in curtailing the pandemic in most jurisdictions during the 2020 to 2021 winter peak. Differences in outcomes across jurisdictions indicate an opportunity to further improve CICT effectiveness. These estimates demonstrate the potential benefits from sustaining and improving these programs.