Diseases Of Upper Respiratory Tract Research Articles

Screening and Immune Efficacy Evaluation of Antigens with Protection Against Feline Calicivirus.

Feline calicivirus (FCV), a pathogen that causes upper respiratory tract diseases in felids, primarily leads to oral ulcers and various respiratory symptoms, which can be fatal in severe cases. Currently, FCV prevention and control rely primarily on vaccination; however, the existing vaccine types in China are mainly inactivated vaccines, leading to a single prevention and control method with suboptimal outcomes. This study commences with a genetic evolution analysis of Chinese FCV isolates, confirming the presence of two major genotypes, GI and GII with GI emerging as the dominant form. We subsequently selected the broadly neutralizing vaccine candidate strain DL39 as the template for the truncation and expression of multiple recombinant proteins. Through serological assays, we successfully confirmed the optimal protective antigen region, which is designated CE39 (CDE). Further investigation revealed the location of the optimal protective antigen region within the CE region for both the GI and GII genotype strains. Capitalizing on this discovery, a bivalent recombinant protein, designated CE39-CEFB, was generated. Cat antisera generated against CE39 and CE39-CEFB proteins were used in cross-neutralization against various strains of different genotypes, yielding high neutralization titers ranging from 1:45 to 1:15 and from 1:48 to 1:29, respectively, which surpassed those induced by antisera from cats vaccinated with Mi-aosanduo (commercial vaccine, strain 255). Ultimately, in vivo challenge experiments were per-formed after immunizing cats with the CE39 and CE39-CEFB proteins, utilizing Miaosanduo as a control for comparison. The results demonstrated that immunization with both proteins effectively made cats less susceptible to FCV GI, GII, and VSD strains infection, resulting in superior immune efficacy compared with that in the Miaosanduo group. These results indicate that this study successfully identified the antigen CE39, which has broad-spectrum antigenicity, through in vivo and in vitro experiments. These findings pre-liminarily demonstrate that the optimal protective antigen region of FCV strains is the CE region, laying a theoretical foundation for the development of novel broad-spectrum vaccines against FCV disease.

A "plus one" strategy impacts replication of felid alphaherpesvirus 1, Mycoplasma and Chlamydia, and the metabolism of coinfected feline cells.

Coinfections are known to play an important role in disease progression and severity. Coinfections are common in cats, but no coinfection studies have investigated the in vitro dynamics between feline viral and bacterial pathogens. In this study, we performed co-culture and invasion assays to investigate the ability of common feline bacterial respiratory pathogens, Chlamydia felis and Mycoplasma felis, to replicate in and invade into Crandell-Rees feline kidney cells. We subsequently investigated how coinfection of these feline cells with each bacterium (C. felis or M. felis) and the common feline viral pathogen, felid alphaherpesvirus 1 (FHV-1), affects replication of each agent in this cell culture system. We also investigated the metabolic impact of each co-pathogen using metabolomic analysis of infected and coinfected cells. C. felis was able to invade and replicate in CRFKs, while M. felis had little capacity to invade. During coinfection, FHV-1 replication was minimally affected by the presence of either bacterial pathogen, but bacterial replication kinetics were more affected, particularly in M. felis. Both C. felis and M. felis replicated to higher levels in the presence of a secondary pathogen. Coinfections resulted in reprogramming of the glycolysis pathway, the pentose phosphate pathway, and the tricarboxylic acid cycle. The distinct metabolic profiles of coinfected cells compared to those of cells infected with just one of these three pathogens, as well as the impact of coinfections on viral or bacterial load, suggest strong interactions between these three pathogens and possible synergistic mechanisms enhancing virulence that need further investigation.IMPORTANCEIn the natural world, respiratory pathogens coexist within their hosts, but their dynamics and interactions remain largely unexplored. Herpesviruses, mycoplasmas, and chlamydias are common and significant causes of acute and chronic respiratory and system disease in animals and people, and these diseases are increasingly found to be polymicrobial. This study investigates how coinfection of feline cells between three respiratory pathogens of cats impact each other as well as the host innate metabolic response to infection. Each of these pathogens have been implicated in the induction of feline upper respiratory tract disease in cats, which is the leading cause of euthanasia in shelters. Understanding how coinfection impacts co-pathogenesis and host responses is critical for improving disease management.

Serpentoviruses in Free-Ranging Shingleback Skinks (Tiliqua rugosa) in Western Australia and South Australia, Australia.

Serpentoviruses are strongly associated with upper respiratory tract disease in captive and free-ranging bluetongued skinks (Tiliqua spp.). In Australia, bluetongue serpentoviruses were first reported in shingleback skinks (Tiliqua rugosa) with upper respiratory tract disease that presented to wildlife rehabilitation facilities in Perth, Western Australia. Since then, serpentoviruses have been detected commonly in captive bluetongued skinks from most areas of Australia, yet knowledge about the prevalence and distribution of these viruses in free-ranging bluetongued skinks, and other skink species, remains limited. Oral swabs were collected from 162 shingleback skinks from four areas in Western Australia and neighboring South Australia to screen for bluetongue serpentoviruses by PCR. The proportions of PCR positives were 0% (0/4) for Rottnest Island (a small island west of Perth, Western Australia), 3% (1/32) for the Shire of Kent (∼5,600 km2 in the southwest of Western Australia), 1% (1/91) from an approximately 250,000 km2 area across South Australia and Western Australia, and 0% (0/35) from Mount Mary (∼150 km2 in the mid north of South Australia). Neither of the two PCR-positive shingleback skinks had overt signs of upper respiratory tract disease. These results are consistent with serpentoviruses occurring at a relatively low crude prevalence of 1.4% (95% confidence interval, 0.2-4.9%) across these areas, although the potential bias from sampling active and apparently healthy individuals may mean that this estimate is lower than the true prevalence. This contrasts with the high proportion of PCR positives reported in captive individuals. In the absence of experimental or observational data on viral clearance and recovery, Tiliqua spp. skinks that are intended for release into the wild should be housed with strict biosecurity to prevent interactions with captive individuals and screened to ensure that they are not PCR positive before release.

Evaluation of patients who re-admitted to the emergency department within 24 hours

Aim: It was conducted to investigate the demographic and clinical characteristics of patients who re-admitted to the emergency department within 24 hours and to contribute to studies on reducing the re-admission rate. Methods: The data of patients who re-admitted to the emergency department within 24 hours between November 2021 and September 2023 in a secondary level public hospital were retrospectively examined. Data regarding the patients' demographic information, admission dates and times, clinical characteristics, examinations, diagnoses, consultations, hospitalization and referral status were obtained from the hospital automation system. Results: 496270 patients admitted to the emergency department during the study period. 6991 (1.4%) of the patients were admitted to the emergency department again within 24 hours. 40.3% of these patients were between the ages of 19-35 and 52.4% were women. The most common reason for re-admission to the emergency department was upper respiratory tract diseases. It was determined that 66.7% of the patients applied to the emergency department again 13-24 hours after their first admission. In their second admission, 43 patients were hospitalized or transferred for various reasons; It was determined that 1 of these patients died 5 months after being admitted to the intensive care unit. Conclusion: Effective triage practices, directing green area patients to family physicians, making the referral chain effective, increasing health literacy, making an accurate diagnosis, allocating appropriate time to patients and explaining the treatment and expectations from treatment, ensuring that patients referred to polyclinics are evaluated as soon as possible and returned to the emergency department will significantly reduce applications.

Изменения климата и лесные пожары как факторы риска здоровью (аналитический обзор)

Climate change in Russia contributes to an increase in the number of forest fires, especially in Siberia and the Far East, leading to the rise in the forest fire danger index. Increased air pollution, which is typical for a number of cities in these regions, is the reason for changes in population health due to the influx of significant volumes of smoke gases from forest fires into populated areas. Smoke from forest fires, consists of aerosols and gases and contains more than 40 pollutants. During fires, frequency of calls for emergency medical care for children tends to increase due to exacerbation of upper respiratory tract diseases, including laryngitis, pharyngitis and acute respiratory infections, as well as attacks of bronchial asthma, and longer exacerbation periods of this disease. Such respiratory dysfunctions appear a few days after fires, which should be taken into account when organizing health monitoring in such situations. Among adult population, an increase in the number of deaths from cardiovascular and respiratory diseases has been proven during forest fires, and there tends to be an increase in the number of requests for medical care for COPD, bronchial asthma, myocardial infarction, coronary heart disease and other diseases. Fires in forest highlands in the Khabarovsk Krai result in deteriorating health of patients with neurological diseases. The generalization of the results obtained by domestic and foreign studies on this issue confirms the need to improve the air pollution monitoring system during forest fires with the determination of PM for timely preventive measures by health systems, Rospotrebnadzor, FMBA and other agencies. It also seems necessary to develop modeling of pollutant spread in ambient air in settlements exposed to them, with assessments of population health risks and development of preventive measures. Given the relevance of these studies, it is advisable to hold seminars with BRICS countries within the framework of international cooperation.

Climate change and forest fires as health risk factors (Analytical review)

Climate change in Russia contributes to an increase in the number of forest fires, especially in Siberia and the Far East, leading to the rise in the forest fire danger index. Increased air pollution, which is typical for a number of cities in these regions, is the reason for changes in population health due to the influx of significant volumes of smoke gases from forest fires into populated areas. Smoke from forest fires, consists of aerosols and gases and contains more than 40 pollutants. During fires, frequency of calls for emergency medical care for children tends to increase due to exacerbation of upper respiratory tract diseases, including laryngitis, pharyngitis and acute respiratory infections, as well as attacks of bronchial asthma, and longer exacerbation periods of this disease. Such respiratory dysfunctions appear a few days after fires, which should be taken into account when organizing health monitoring in such situations. Among adult population, an increase in the number of deaths from cardiovascular and respiratory diseases has been proven during forest fires, and there tends to be an increase in the number of requests for medical care for COPD, bronchial asthma, myocardial infarction, coronary heart disease and other diseases. Fires in forest highlands in the Khabarovsk Krai result in deteriorating health of patients with neurological diseases. The generalization of the results obtained by domestic and foreign studies on this issue confirms the need to improve the air pollution monitoring system during forest fires with the determination of PM for timely preventive measures by health systems, Rospotrebnadzor, FMBA and other agencies. It also seems necessary to develop modeling of pollutant spread in ambient air in settlements exposed to them, with assessments of population health risks and development of preventive measures. Given the relevance of these studies, it is advisable to hold seminars with BRICS countries within the framework of international cooperation.

Comparison of PCR, Nested PCR, and RT-LAMP for Rapid Detection of Feline Calicivirus Infection in Clinical Samples.

Feline calicivirus (FCV) is a highly contagious virus that causes upper respiratory tract disease, commonly known as cat flu. It is widely distributed worldwide and poses a major threat to feline health. Therefore, it is essential to find an efficient and rapid method for detecting FCV. In this study, the colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay, using neutral red as an indicator, was developed and validated to target the ORF2 gene of FCV for the first time. Additionally, the study compared the diagnostic abilities of polymerase chain reaction (PCR), nested PCR, and RT-LAMP assays for detecting FCV in clinical samples. The optimized RT-LAMP amplification was carried out at 56.3 °C. The technique visually detected FCV within 70 min, with a limit of detection of 14.3 × 101 copies/µL, and showed no cross-reactivity with other feline pathogens. Out of 54 oropharyngeal swab samples, 17 tested positive for FCV using both nested PCR and RT-LAMP, while only one tested positive using conventional PCR. The positivity rate was higher with nested PCR and RT-LAMP (31.48%) compared to conventional PCR (1.85%). Consequently, these results demonstrated the effectiveness of the colorimetric RT-LAMP assay developed in this study as an alternative for diagnosing FCV in cats.

Estimating the Acute Health Effects of Smoke Exposure from an Urban Factory Fire Accident: A Case Study of a Tire Factory Fire in Korea.

A major industrial fire accident occurred in a tire manufacturing factory in Daejeon, Korea, on 12 March 2023 and lasted for 3 d, generating air pollutant emissions. Although evidence regarding the health effects of urban fires is limited, residents near tire factory may have experienced health hazards due to smoke exposure from fire plumes. Capitalizing on the timing of this fire incident as a natural experiment, we estimated the attributable excess air pollution exposure and associated disease development among residents living near the tire factory. We used the generalized synthetic control method to estimate air pollution exposure and health burden attributable to the accident among residents living in smoke-exposed districts. Based on satellite images and air pollution monitoring results, three administrative districts (within from the factory) were defined as smoke-exposed, and the other 79 districts of Daejeon were defined as controls. Among the 11 monitoring stations in Daejeon, the station located from the factory was used to estimate excess air pollution exposure (, , , , , and CO) for residents in the exposed districts. The number of daily district-level disease-specific incidence cases were acquired from the National Health Insurance Database and used to estimate excess health burden resulting from the fire. During the first week following the factory fire, residents of exposed districts had an estimated excess exposure to 125.2 [95% confidence interval (CI): 44.9, 156.7] of , 50.4 (95% CI: 12.7, 99.8) ppb of , and 32.0 (95% CI: 21.0, 35.9) ppb of . We also found an average increase in the incidence cases of other diseases of upper respiratory tract [20.6 persons (95% CI: 6.2, 37.4)], lung disease due to external agents [2.5 persons (95% CI: 2.1, 3.3)], urticaria and erythema [5.9 persons (95% CI: , 11.2)], and episodic and paroxysmal disorders [8.5 persons (95% CI: 3.7, 13.4)] in exposed districts. Excessive air pollution exposure and disease incidence were identified among residents living close to the tire factory. Preventive measures, such as a warning system, to avoid health impacts to people breathing fire-related pollution may be beneficial for communities impacted by such events. https://doi.org/10.1289/EHP14115.

Predicting hospital admissions for upper respiratory tract complaints: An artificial neural network approach integrating air pollution and meteorological factors.

This study uses artificial neural networks (ANNs) to examine the intricate relationship between air pollutants, meteorological factors, and respiratory disorders. The study investigates the correlation between hospital admissions for respiratory diseases and the levels of PM10 and SO2 pollutants, as well as local meteorological conditions, using data from 2017 to 2019. The objective of this study is to clarify the impact of air pollution on the well-being of the general population, specifically focusing on respiratory ailments. An ANN called a multilayer perceptron (MLP) was used. The network was trained using the Levenberg-Marquardt (LM) backpropagation algorithm. The data revealed a substantial increase in hospital admissions for upper respiratory tract diseases, amounting to a total of 11,746 cases. There were clear seasonal fluctuations, with fall having the highest number of cases of bronchitis (N = 181), sinusitis (N = 83), and upper respiratory infections (N = 194). The study also found demographic differences, with females and people aged 18 to 65years having greater admission rates. The performance of the ANN model, measured using R2 values, demonstrated a high level of predictive accuracy. Specifically, the R2 value was 0.91675 during training, 0.99182 during testing, and 0.95287 for validating the prediction of asthma. The comparative analysis revealed that the ANN-MLP model provided the most optimal result. The results emphasize the effectiveness of ANNs in representing the complex relationships between air quality, climatic conditions, and respiratory health. The results offer crucial insights for formulating focused healthcare policies and treatments to alleviate the detrimental impact of air pollution and meteorological factors.

Screening for promising multi-target bioactive components from Cortex Mori Radicis for the treatment of chronic cor pulmonale based on immobilized beta1-adrenergic receptor and beta2-adrenergic receptor chromatography

Cortex Morin Radicis (CMR) is the dried root bark of Morus alba. L. It has a variety of effects such as antibacterial, anti-tumour, treatment of cardiovascular diseases or upper respiratory tract disease and so on. The pursuit for drugs selected from Cortex Mori Radicis having improved therapeutic efficacy necessitates increasing research on new assays for screening bioactive compounds with multi-targets. In this work, we applied immobilized β1-AR and β2-AR as the stationary phase in chromatographic column to screen bioactive compounds from Cortex Morin Radicis. Specific ligands of the two receptors (e.g. esmolol, metoprolol, atenolol, salbutamol, methoxyphenamine, tulobuterol and clorprenaline) were utilized to characterize the specificity and bioactivity of the columns. We used high performance affinity chromatography coupled with ESI−MS to screen targeted compounds of Cortex Morin Radicis. By zonal elution, we identified morin as a bioactive compound simultaneously binding to β1-AR and β2-AR. The compound exhibited the association constants of 3.10 × 104 and 2.60 × 104 M−1 on the β1-AR and β2-AR column. On these sites, the dissociation rate constants were calculated to be 0.131 and 0.097 s−1. Molecular docking indicated that the binding of morin to the two receptors occurred on Asp200, Asp121, and Val122 of β1-AR, Asn312, Thr110, Asp113, Tyr316, Gly90, Phe193, Ile309, and Trp109 of β2-AR. Likewise, mulberroside C was identified as the bioactive compound binding to β2-AR. The association constants and dissociation rate constants were calculated to be 1.08 × 104 M−1 and 0.900 s−1. Molecular docking also indicated that mulberroside C could bind to β2-AR receptor on its agonist site. Taking together, we demonstrated that the chromatographic strategy to identify bioactive natural products based on the β1-AR and β2-AR immobilization, has potential for screening bioactive compounds with multi-targets from complex matrices including traditional Chinese medicines.

Isolation and characterization of Chlamydia felis and its pathogenesis in cats

Feline upper respiratory tract disease (URTD) is a common but complicated disease that occurs in domestic cats, worldwide. 396 cats in Guangxi Province, China were screened for URTD-associated pathogens from March 2022 to August 2023. Mycoplasma felis was found to be the most prevalent infectious agent with a positivity rate of 24.75 %, followed by feline calicivirus (FCV), Chlamydia felis, feline herpesvirus 1 (FHV-1) and feline influenza A virus (FeIAV) with rates of 15.91, 11.62, 5.56 and 1.52 %, respectively. In particular, C. felis and M. felis were found in 13 of 55 co-infected cats. Of the 46 C. felis-positive samples, one strain, named as GXNN36, was successfully isolated using chicken embryos and it was characterized both in vivo and in vitro. For the cat studies, both high- and low-dose challenged groups showed severe conjunctivitis, accompanied by transient fever and respiratory symptoms. C. felis replicated well in turbinate, trachea and lung tissues with high copy numbers and the infection subsequently spread to the livers, spleens, pancreas, kidneys, hearts and intestines. These findings will help our understanding of the role of C. felis in feline URTD and provide a valuable model to evaluate the efficacy of vaccines and therapeutic remedies in the future.

Changes in the epidemiology and clinical characteristics of viral gastroenteritis among hospitalized children in the Mainland of China: a retrospective study from 2016 to 2020

BackgroundAcute gastroenteritis (AGE) causes significant morbidity in children worldwide; however, the disease burden of children hospitalized with viral gastroenteritis in China has been rarely described. Through this study, we analyzed the data of hospitalized children with viral gastroenteritis to explore the changes in the epidemiology and clinical characteristics of viral gastroenteritis in the mainland of China.MethodsData were extracted from Futang Children's Medical Development Research Center (FRCPD), between 2016 and 2020, across 27 hospitals in 7 regions. The demographics, geographic distribution, pathogenic examination results, complications, hospital admission date, length of hospital stays, hospitalization charges and outcomes were collected and analyzed.ResultsViral etiological agents included rotavirus (RV), adenovirus (ADV), norovirus (NV) and coxsackievirus (CV) that were detected in 25,274 (89.6%), 1,047 (3.7%), 441 (1.5%) and 83 (0.3%) cases. There was a higher prevalence of RV and NV infection among children younger than 3 years of age. RV and NV had the highest detection rates in winter, while ADV in summer. Children with viral gastroenteritis were often accompanied by other diseases, such as myocardial diseases (10.98–31.04%), upper respiratory tract diseases (1.20–20.15%), and seizures (2.41–14.51%). Among those cases, the co-infection rate with other pathogens was 6.28%, with Mycoplasma pneumoniae (M. pneumoniae), Epstein-Barr virus (EBV), and influenza virus (FLU) being the most common pathogens. The median length of stay was 5 days, and the median cost of hospitalization corresponded to587 US dollars.ConclusionsThis finding suggests that viral gastroenteritis, especially those caused by RV, is a prevalent illness among younger children. Co-infections and the presence of other diseases are common. The seasonality and regional variation of viral etiological agents highlight the need for targeted prevention and control measures. Although viral gastroenteritis rarely leads to death, it also results in a significant economic burden on healthcare systems.

Update on feline calicivirus: viral evolution, pathogenesis, epidemiology, prevention and control.

Feline calicivirus (FCV) is a prevalent and impactful viral pathogen affecting domestic cats. As an RNA virus, FCV exhibits high mutability and genetic plasticity, enabling its persistence within cat populations. Viral genetic diversity is associated with a broad spectrum of clinical manifestations, ranging from asymptomatic infections and mild oral and upper respiratory tract diseases to the potential development of virulent systemic, and even fatal conditions. This diversity poses distinctive challenges in diagnosis, treatment, and prevention of diseases caused by FCV. Over the past four decades, research has significantly deepened understanding of this pathogen, with an emphasis on molecular biology, evolutionary dynamics, vaccine development, and disease management strategies. This review discusses various facets of FCV, including its genomic structure, evolution, innate immunity, pathogenesis, epidemiology, and approaches to disease management. FCV remains a complex and evolving concern in feline health, requiring continuous research to enhance understanding of its genetic diversity, to improve vaccine efficacy, and to explore novel treatment options.

Epidemiological characteristics of chronic non-communicable diseases in Dongfang, China, 2021: a cross-sectional survey

ObjectivesThe study aimed to understand the composition, epidemiological characteristics and disease burden of chronic non-communicable diseases and to evaluate the association between sociodemographic factors and chronic non-communicable diseases.DesignA cross-sectional study.Setting...

Meta-analysis of the human upper respiratory tract microbiome reveals robust taxonomic associations with health and disease

BackgroundThe human upper respiratory tract (URT) microbiome, like the gut microbiome, varies across individuals and between health and disease states. However, study-to-study heterogeneity in reported case–control results has made the identification of consistent and generalizable URT-disease associations difficult.ResultsIn order to address this issue, we assembled 26 independent 16S rRNA gene amplicon sequencing data sets from case–control URT studies, with approximately 2–3 studies per respiratory condition and ten distinct conditions covering common chronic and acute respiratory diseases. We leveraged the healthy control data across studies to investigate URT associations with age, sex, and geographic location, in order to isolate these associations from health and disease states.ConclusionsWe found several robust genus-level associations, across multiple independent studies, with either health or disease status. We identified disease associations specific to a particular respiratory condition and associations general to all conditions. Ultimately, we reveal robust associations between the URT microbiome, health, and disease, which hold across multiple studies and can help guide follow-up work on potential URT microbiome diagnostics and therapeutics.

A meta-analysis for prevalence of infectious laryngotracheitis in chickens in mainland China in 1981–2022

BackgroundInfectious laryngotracheitis (ILT) is a highly infectious upper respiratory tract disease of chickens caused by infectious laryngotracheitis virus or Gallid herpesvirus 1 (GaHV-1). ILT is an important respiratory disease of chickens and annually causes significant economic losses in the chicken industry. Although numerous relevant studies have been published, the overall prevalence of ILT infection among chicken in mainland China is still unknown, and associated risk factors need to be evaluated to establish preventive measures.ResultsThe present study reviewed the literature on the prevalence of ILT in chickens in China as of December 20, 2022, retrieved from six databases—CNKI, Wanfang, VIP, PubMed, Web of Science, and ScienceDirect—were used to retrieve relevant studies published between January 1, 1981 and December 20, 2022. The literature quality of studies was assessed, and 20 studies with a total of 108,587 samples were included in the meta-analysis. Results of the meta-analysis showed that the overall prevalence of ILT was 10% (95% confidence interval: 8 –12%) through the random-effects model, which showed high heterogeneity, I2 = 99.4%. Further subgroup analyses showed that the prevalence of ILT decreased over time; furthermore, the prevalence in Northwest China was slightly lower than that in North China and South China, and the prevalence estimated using the diagnostic technique AGP was higher than that reported using other diagnostic techniques.ConclusionsILT is prevalent to some extent in mainland China. Given that the ILT attenuated live vaccine has a certain level of virulence and the prevalence differences between regions, we recommend controlling breeding density, improving immunization programs and continuously monitoring viruses and to prevent ILT prevailing in mainland China.

Complete genome sequences of Mycoplasma cynos and Mycoplasma felis isolated from dogs and cats with infectious respiratory disease.

Mycoplasma cynos is a primary agent of pneumonia in dogs, and Mycoplasma felis is associated with upper respiratory tract disease in cats. We present complete genome sequences of 26 isolates from clinically affected dogs and cats. These genome sequences will facilitate new molecular and epidemiological analyses.

Ultrasensitive and visual detection of Feline herpesvirus type-1 and Feline calicivirus using one-tube dRPA-Cas12a/Cas13a assay

BackgroundFeline herpesvirus type 1 (FHV) and Feline calicivirus (FCV) are the primary co-infecting pathogens that cause upper respiratory tract disease in cats. However, there are currently no visual detection assays available for on-site testing. Here, we develop an ultrasensitive and visual detection method based on dual recombinase polymerase amplification (dRPA) reaction and the hybrid Cas12a/Cas13a trans-cleavage activities in a one-tube reaction system, referred to as one-tube dRPA-Cas12a/Cas13a assay.ResultsThe recombinant plasmid DNAs, crRNAs, and RPA oligonucleotides targeting the FCV ORF1 gene and FHV-1 TK gene were meticulously prepared. Subsequently, dual RPA reactions were performed followed by screening of essential reaction components for hybrid CRISPR-Cas12a (targeting the FHV-1 TK gene) and CRISPR-Cas13a (targeting the FCV ORF1 gene) trans-cleavage reaction. As a result, we successfully established an ultra-sensitive and visually detectable method for simultaneous detection of FCV and FHV-1 nucleic acids using dRPA and CRISPR/Cas-powered technology in one-tube reaction system. Visual readouts were displayed using either a fluorescence detector (Fluor-based assay) or lateral flow dipsticks (LDF-based assay). As expected, this optimized assay exhibited high specificity towards only FHV-1 and FCV without cross-reactivity with other feline pathogens while achieving accurate detection for both targets with limit of detection at 2.4 × 10− 1 copies/μL for the FHV-1 TK gene and 5.5 copies/μL for the FCV ORF1 gene, respectively. Furthermore, field detection was conducted using the dRPA-Cas12a/Cas13a assay and the reference real-time PCR methods for 56 clinical samples collected from cats with URTD. Comparatively, the results of Fluor-based assay were in exceptional concordance with the reference real-time PCR methods, resulting in high sensitivity (100% for both FHV-1 and FCV), specificity (100% for both FHV-1 and FCV), as well as consistency (Kappa values were 1.00 for FHV-1 and FCV). However, several discordant results for FHV-1 detection were observed by LDF-based assay, which suggests its prudent use and interpretaion for clinical detection. In spite of this, incorporating dRPA-Cas12a/Cas13a assay and visual readouts will facilitate rapid and accurate detection of FHV-1 and FCV in resource-limited settings.ConclusionsThe one-tube dRPA-Cas12a/Cas13a assay enables simultaneously ultrasensitive and visual detection of FHV-1 and FCV with user-friendly modality, providing unparalleled convenience for FHV-1 and FCV co-infection surveillance and decision-making of URTD management.

Influenza and acute viral infection prevention in children with recurrent respiratory pathology

Introduction. Despite numerous scientific works devoted to the problem of acute respiratory diseases, its relevance does not decrease throughout the world, since serious complications with an unfavorable prognosis are possible.Aim. To evaluate the effectiveness of preventive antiviral therapy in children with recurrent respiratory pathology.Materials and methods. Under observation were 43 children (average age 7.43 ± 3.05 years) with recurrent respiratory pathology, who underwent health treatment in the summer period once for 14 days. The main group consisted of 22 children who were prescribed the antiviral therapy as a monotherapy for prophylactic use. The comparison group included 21 patients who underwent preventive treatment using nasopharyngeal irrigation with local antiseptic chemicals. The observation period was 3 months after prophylactic treatment.Results and discussion. After preventive treatment, the total number of episodes of ARI during the observation period in the main group in relation to the comparison group was according to nosologies: acute pharyngitis (p = 0.0317), exacerbation of chronic tonsillitis (p = 0.0137), acute rhinitis (p = 0.0692), rhinosinusitis (p = 0.0429). In the main group, during the observation period, when episodes of upper respiratory tract diseases occurred, antibacterial drugs were prescribed statistically significantly less frequently (p = 0.0296). After the preventive course, compared with the initial data, there was a decline in the number of cases of upper respiratory tract diseases per child on average per quarter. Thus, in the main group, a more pronounced significant difference was revealed in all nosological forms (acute rhinitis, rhinosinusitis p = 0.0081, acute pharyngitis p = 0.0129, tonsillopharyngitis p = 0.0384). In the comparison group – respectively: p = 0.0426; 0.0387; 0.0439.Conclusions. Carrying out preventive treatment as monotherapy in children with recurrent respiratory pathology demonstrated high effectiveness (86.37%) of the antiviral therapy.

The Relationship between Fine Particle Matter (PM2.5) Exposure and Upper Respiratory Tract Diseases.

PM2.5 is one of the most harmful components of airborne pollution and includes particles with diameters of less than 2.5 μm. Almost 90% of the world's population lives in areas with poor air quality exceeding the norms established by the WHO. PM2.5 exposure affects various organs and systems of the human body including the upper respiratory tract which is one of the most prone to its adverse effects. PM2.5 can disrupt nasal epithelial cell metabolism, decrease the integrity of the epithelial barrier, affect mucociliary clearance, and alter the inflammatory process in the nasal mucosa. Those effects may increase the chance of developing upper respiratory tract diseases in areas with high PM2.5 pollution. PM2.5's contribution to allergic rhinitis (AR) and rhinosinusitis was recently thoroughly investigated. Numerous studies demonstrated various mechanisms that occur when subjects with AR or rhinosinusitis are exposed to PM2.5. Various immunological changes and alterations in the nasal and sinonasal epithelia were reported. These changes may contribute to the observations that exposure to higher PM2.5 concentrations may increase AR and rhinosinusitis symptoms in patients and the number of clinical visits. Thus, studying novel strategies against PM2.5 has recently become the focus of researchers' attention. In this review, we summarize the current knowledge on the effects of PM2.5 on healthy upper respiratory tract mucosa and PM2.5's contribution to AR and rhinosinusitis. Finally, we summarize the current advances in developing strategies against PM2.5 particles' effects on the upper respiratory tract.