Cause Of Respiratory Infections Research Articles

Ethanolic Extract from Echinacea purpurea (L.) Moench Inhibits Influenza A/B and Respiratory Syncytial Virus Infection in vitro: Preventive Agent for Viral Respiratory Infections.

Among the most frequent causes of respiratory infections in humans are influenza A virus H1N1 (H1N1), influenza B virus (IVB), and respiratory syncytial virus (RSV). Echinacea is a perennial wildflower belonging to the Asteraceae family. Echinacea purpurea (L.) Moench is a species belonging to the Echinacea genus. Its characteristic compound, chicoric acid (CA), is known for its physiological activities, including antiviral effects and immune enhancement. Activities of E. purpurea 60% ethanol extract (EPE) and CA in inhibiting infections caused by H1N1, IVB, and RSV subtype A (RSV-A) were evaluated through plaque inhibition tests, quantification of viral gene expression, and analysis of transmission electron microscopy (TEM) images. Additionally, inhibitory activities of EPE and CA for hemagglutination and neuraminidase (NA) of H1N1 and IVB were determined. In the plaque reduction assays, both EPE and CA reduced infectivity against H1N1, IVB, and RSV-A. Furthermore, quantitative real-time polymerase chain reaction analysis revealed that EPE and CA reduced gene expression levels for H1N1, IVB, and RSV-A, whereas TEM image analysis confirmed their inhibitory effects on host cell infection by these viruses. Hemagglutination assays exhibited the ability of EPE and CA to hinder H1N1 and IVB attachment to host cell receptors. Furthermore, EPE and CA displayed inhibition activity against the NA of H1N1 and IVB. These findings suggest that EPE and CA can suppress the infection and propagation of H1N1, IVB, and RSV-A, demonstrating their potential as preventive and therapeutic agents for viral respiratory infections or as ingredients for health functional foods.

Misuse of Antibiotics in Pediatric Patients – A Comprehensive Review .

To identify and assess the likely causes of antibiotic overuse in the Pediatric outpatient department (OPD) of a busy teaching hospital. Overuse of antibiotics has emerged as a significant global pediatric concern. Specifically, the sale of drugs without a prescription from a doctor and other circumstances may have an impact on the abuse of antibiotics. Antibiotic resistance is encouraged by the misuse of antibiotics, particularly when antibiotics are used, even when they are not the recommended course of therapy. The Centers for Disease Control and Prevention estimate that between one-third and half of all antibiotic usage in humans is unwarranted or improper. Viral pathogens are the primary cause of respiratory tract infections (RTI) in children compared to adults. Interestingly, compared to adults with RTI, very little is known regarding the usage of antibiotics in children.

Detection of Mycoplasma sp using next-generation DNA sequencing is common on nasal swabs from both healthy and unhealthy pet rabbits (Oryctolagus cuniculus).

Upper respiratory infections are a frequent problem in pet rabbits and rodents, and Mycoplasma pulmonis is 1 of the most common causes of respiratory infections in pet rats. M pulmonis was detected in 1967 in laboratory rabbits via culture of the nares and oropharynx, but overall, Mycoplasma is not commonly identified in the upper airway of rabbits. The objective of this study was to compare the prevalence of Mycoplasma sp detection via next-generation DNA sequencing on nasal swabs obtained from healthy and unhealthy rabbits. The results of nasal swabs from both healthy and unhealthy rabbits submitted for next-generation DNA sequencing from January 2022 to February 2023 were reviewed. Data gathered included signalment, whether or not Mycoplasma sp was detected, and the cell count and relative predominance of Mycoplasma sp compared to other organisms. 91 rabbits met the inclusion criteria, of which 49 were healthy and 42 were unhealthy. Overall, 52 of 91 (57.1%) rabbits were positive and 39 of 91 (42.8%) were negative for Mycoplasma sp. Mycoplasma positivity was significantly (P < .001) more common in healthy rabbits (37/49 [75.5%]) compared to unhealthy rabbits (15/42 [35.7%]). The fact that Mycoplasma positivity was common in both groups of rabbits, and particularly common in rabbits without upper respiratory signs, suggests that Mycoplasma may be normal nasal flora in rabbits. Further research is needed to determine whether Mycoplasma could function as an opportunistic pathogen in rabbits.

Establishment and evaluation of MIRA-qPCR assay for the rapid and sensitively detection of Mycoplasma pneumoniae.

Aim: Mycoplasma pneumoniae (MP) is a common cause of respiratory infections, and its incidence has increased post-COVID-19 due to "immune debt." Real-time quantitative polymerase chain reaction (qPCR) is the standard for detecting MP, but it has a lengthy detection time. This study aimed to establish a highly sensitive rapid detection method for MP.Materials & methods: We developed an integrated assay combining multienzyme isothermal rapid amplification (MIRA) with qPCR, referred to as MIRA-qPCR, for the rapid detection of MP, delivering results within approximately 40min.Results: The analytic sensitivity of the MIRA-qPCR assay was 10copies per reaction, and it exhibited no cross-reactivity with other respiratory pathogens, ensuring high specificity. Clinical sample analysis demonstrated higher sensitivity for MIRA-qPCR compared to qPCR reported in the literature, and 100% concordance with commercial qPCR kit.Conclusion: The MIRA-qPCR method established in this study is a promising tool for the clinical detection of MP, offering significant advantages for the rapid diagnosis of MP infections.

Antigenic analysis of the influenza B virus hemagglutinin protein

Influenza B viruses (IBVs) primarily infect humans and are a common cause of respiratory infections in humans. Here, to systematically analyze the antigenicity of the IBVs Hemagglutinin (HA) protein, 31 B/Victoria and 19 B/Yamagata representative circulating strains were selected from Global Initiative of Sharing All Influenza Data (GISAID), and pseudotyped viruses were constructed with the vesicular stomatitis virus system. Guinea pigs were immunized with three doses of vaccines (one dose of DNA vaccines following two doses of pseudotyped virus vaccines) of the seven IBV vaccine strains, and neutralizing antibodies against the pseudotyped viruses were tested. By comparing differences between various vaccine strains, we constructed several pseudotyped viruses that contained various mutations based on vaccine strain BV-21. The vaccine strains showed good neutralization levels against the epidemic virus strains of the same year, with neutralization titers ranging from 370 to 840, while the level of neutralization against viruses prevalent in previous years decreased 1–10-fold. Each of the high-frequency epidemic strains of B/Victoria and B/Yamagata not only induced high neutralizing titers, but also had broadly neutralizing effects against virus strains of different years, with neutralizing titers ranging from 1000 to 7200. R141G, D197N, and R203K were identified as affecting the antigenicity of IBV. In this study, pseudotyped virus system was used to monitor the cross-neutralizing efficacy of high-frequency epidemic strains and vaccine strains recommended by the World Health Organization. Additionally, we identified three mutation sites that can seriously affect the antigenicity of B/Victoria vaccine strains. These mutation sites provide valuable references for the selection and design of a universal IBV vaccine strain in the future.

Patterns and Influencing Factors of Organisms and Sensitivity in Sputum at Sylhet

Background: Respiratory tract infections, especially pneumonia and tuberculosis, remain significant public health problems in Bangladesh. This information alone is critical to manage local pathogen distributions, antibiotic susceptibility, and response plans. Objectives: To evaluate the frequency of bacterial pathogens in sputum samples, test their antibacterial sensitivity, and relate them to various demographic factors among patients in Sylhet, Bangladesh. Methods: This cross-sectional study was carried out in the Chest Disease Clinic, Sylhet from January to June 2024.Sputum samples were taken from 120 patients diagnosed with lower respiratory tract infections. Colony and bacterial identification was done microbiologically, and antibiotic susceptibility was determined by using the Kirby-Bauer disk diffusion method. Results: The cocci were the most prevalent, with gram-positive bacteria constituting 75% of all isolates: Staphylococcus aureus 29. Co-amoxiclav had the highest sensitivity of 23 percent, while the highest resistance was recorded for linezolid at 50 percent. Tobacco use was described in 79. Overall, there was a significant association between TB-positive status and the isolation of Klebsiella pneumoniae (p = 0.032). Most participants were of lower SES, and this was observed in 59.32% of the study’s participants. Conclusions: This research found that gram-positive organisms are the most frequent cause of respiratory infections in Sylhet, with S. aureus being the most dominant isolate. The high tobacco use and the link to S. aureus colonization indicate that interventions could and should be targeted. Concerning antibiotic susceptibility patterns, the need to exercise reasonable use of antibiotics and constant monitoring of antimicrobial resistance cannot be overemphasized. These findings may help the local clinicians, help set up empirical antibacterial therapy, and facilitate the design of some targeted health interventions. Scholars Middle East Publishers Browse Journals Payments Publication Ethics SUBMIT ARTICLE

Identification of distinct genotypes in circulating RSV A strains based on variants in the virus replication-associated genes.

Respiratory syncytial virus (RSV) is a common cause of respiratory infection that often leads to hospitalization of infected younger children and older adults. RSV is classified into two strains, A and B, each with several subgroups or genotypes. One issue with the definition of these subgroups is the lack of a unified method of identification or genotyping. We propose that genotyping strategies based on the genes coding for replication-associated proteins could provide critical information on the replication capacity of the distinct subgroups, while clearly distinguishing genotypes. Here, we analyzed the virus replication-associated genes N, P, M2, and L from de novo assembled RSV A sequences obtained from 31 newly sequenced samples from hospitalized patients in Philadelphia and 78 additional publicly available sequences from different geographic locations within the United States. In-depth analysis and annotation of variants in the replication-associated proteins identified the polymerase protein L as a robust target for genotyping RSV subgroups. Importantly, our analysis revealed non-synonymous variations in L that were consistently accompanied by conserved changes in its co-factor P or the M2-2 protein, suggesting associations and interactions between specific domains of these proteins. Similar associations were seen among sequences of the related human metapneumovirus. These results highlight L as an alternative to other RSV genotyping targets and demonstrate the value of in-depth analyses and annotations of RSV sequences as it can serve as a foundation for subsequent in vitro and clinical studies on the efficiency of the polymerase and fitness of different virus isolates.IMPORTANCEGiven the historical heterogeneity of respiratory syncytial virus (RSV) and the disease it causes, there is a need to understand the properties of the circulating RSV strains each season. This information would benefit from an informative and consensus method of genotyping the virus. Here, we carried out a variant analysis that shows a pattern of specific variations among the replication-associated genes of RSV A across different seasons. Interestingly, these variation patterns, which were also seen in human metapneumovirus sequences, point to previously defined interactions of domains within these genes, suggesting co-variation in the replication-associated genes. Our results also suggest a genotyping strategy that can prove to be particularly important in understanding the genotype-phenotype correlation in the era of RSV vaccination, where selective pressure on the virus to evolve is anticipated. More importantly, the categorization of pneumoviruses based on these patterns may be of prognostic value.

Emerging Methods in the Identification of Bacterial Respiratory Tract Pathogens.

Here, we will review different bacterial causes of respiratory tract infections and discuss the available diagnostic methods. Moreover, we will provide some recently published patents and newer techniques, such as respiratory panels and omics approaches, and express the challenges in this path. Respiratory tract infections (RTIs) include those infections that can lead to the involvement of different respiratory parts, including the sinuses, throat, airways, and lungs. Acute respiratory tract infection is the leading cause of death from infectious illnesses worldwide. According to the World Health Organization, 1.6 to 2.2 million deaths have occurred due to acute respiratory infections in children under five years of age. About 4 million people die annually from respiratory infections, 98% of which are caused by lower respiratory infections. Depending on the type of pathogen, the severity of the infection can vary from mild to severe and even cause death. The most important pathogens involved in respiratory tract infections include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The symptoms are often similar, but the treatment can vary greatly. Therefore, correct diagnosis is so important. There are several methods for diagnosing respiratory infections. Traditional tests include the culture of respiratory samples, considered the primary tool for diagnosing respiratory infections in laboratories, and less common standard tests include rapid and antigenic tests. It is essential to think that the culture method is reliable. In the original method of diagnosing respiratory infections, some bacteria were challenging to grow successfully, and many clinical laboratories needed to be equipped for viral cultures. Another issue is the time to get the results, which may take up to 7 days. Rapid and antigenic tests are faster but need to be more accurate. The clinical laboratories are trying to be equipped with molecular methods for detecting respiratory pathogens and identifying the genetic material of the infectious agent in these new methods as the primary method in their agenda.

Immune Response to Respiratory Syncytial Virus

Abstract Respiratory syncytial virus (RSV) is an important cause of respiratory infection among children and infants globally. The first line of the immune response against this virus is neutrophils, macrophages, and innate lymphoid cells. Antigen-presenting cells such as dendritic cells which present the viral antigen to T lymphocytes that mediate viral clearance by T cytotoxic cells and initiate systemic lymphopenia. Humoral immunity will also be stimulated through B-cell-stimulating factors derived from epithelial cells of the respiratory tract that play an important factor in antibody production and induction memory to reinfection through IgG and IgA protective antibodies that are useful in vaccine production.

Cost-Effectiveness Analysis of Maternal Respiratory Syncytial Virus Vaccine in Protecting Infants from RSV Infection in Japan.

Respiratory syncytial virus (RSV) is one of the major causes of respiratory tract infections among children. Until recently, the monoclonal antibody palivizumab was the only RSV prophylaxis available in Japan. In 2024, the bivalent RSV prefusion F protein-based (RSVpreF) vaccine was approved for the prevention of RSV infection in infants by active immunization of pregnant women. In this study, we assessed the cost-effectiveness of a combined strategy of RSVpreF vaccine and palivizumab in Japanese setting. Using a Markov model, we evaluated prevented cases and deaths of medically attended RSV infections from birth to age 11months for each of the three healthcare settings: inpatient (hospitalization), emergency department visits, and outpatient visits. Incremental cost-effectiveness ratios (ICERs) were calculated from economic outcomes (intervention costs, medication costs, and productivity losses) and quality-adjusted life years (QALYs). Further, we calculated the maximum price of RSVpreF vaccine within which the program would be cost-effective. In comparison with the current prophylaxis (palivizumab alone), a combined prophylaxis of year-round RSVpreF vaccination of pregnant women and palivizumab prescription for premature infants born in < 32weeks gestational age (wGA) and all infants with high risk prevented 14,382 medically attended cases of RSV (hospitalization, 7490 cases; emergency department, 2239 cases; outpatient, 4653 cases) and 7 deaths, respectively. From a healthcare payer perspective, when the price of RSVpreF vaccine was equal to or less than ¥23,948 (US$182), a combination prophylaxis was cost-effective under the ICER threshold of ¥5million per QALY. The other combination prophylaxis of year-round RSVpreF vaccination and palivizumab prescription of premature born in < 32wGA regardless of risk in infants was a dominant strategy (more effective and less costly). A combined prophylaxis of year-round RSVpreF vaccine and palivizumab could be a cost-effective strategy to protect neonates throughout the infant stage (< 1years old) in Japan.

Epidemiology of respiratory syncytial virus in hospitalized children over a 9-year period and preventive strategy impact.

Background: Respiratory Syncytial Virus (RSV) is the primary cause of respiratory infections and hospitalizations in young children globally, leading to substantial disease burden and mortality. The aim of the present study was to review and provide updates on how the SARS-CoV-2 pandemic have significantly influenced RSV epidemiology on hospitalized children due to RSV infection. A potential impact of the available preventive strategies on the same population were provided. Methods: All children aged 0-6years hospitalized at Meyer Children's Hospital IRCCS for RSV infection from September 2014 to March 2023 were retrospectively recorded. Seasonal trends before and after SARS-CoV-2 pandemic, age distribution, ICU admission and co-infections, comorbidities and prematurity were retrieved. Predictions on the number of hospitalizations avoided by the deployment of different preventive strategies were provided. Results: A total of 1,262 children with RSV infection were included in the study. The 70% of them had less than 1 year-of-age at the moment of hospitalization and almost 50% less than 3months. In the post-pandemic seasons, a 317% increase in the number of hospitalizations was recorded with a significant increase in older children compared to the pre-pandemic seasons. ICU support was required for 22% of children, the majority of whom were under 3months of age. Almost 16% of hospitalized children were born preterm and only 27% of hospitalized children had prior comorbidities. The rate of comorbidities among RSV hospitalized children increased with age. Nirsevimab prophylaxis could have prevented more than 46% of hospitalizations in this cohort. A preventive strategy addressing also children aged 7months to 6years of age with co-existing comorbidities would increase that rate above 57%. Discussion: The identification of RSV hospitalization-related features is informing the decision-maker for the deployment of the wisest preventive approach on a population scale.

Curcumin and quercetin co-encapsulated in nanoemulsions for nasal administration: A promising therapeutic and prophylactic treatment for viral respiratory infections

One of the most frequent causes of respiratory infections are viruses. Viruses reaching the airways can be absorbed by the human body through the respiratory mucosa and mainly infect lung cells. Several viral infections are not yet curable, such as coronavirus-2 (SARS-CoV-2). Furthermore, the side effect of synthetic antiviral drugs and reduced efficacy against resistant variants have reinforced the search for alternative and effective treatment options, such as plant-derived antiviral molecules. Curcumin (CUR) and quercetin (QUE) are two natural compounds that have been widely studied for their health benefits, such as antiviral and anti-inflammatory activity. However, poor oral bioavailability limits the clinical applications of these natural compounds. In this work, nanoemulsions (NE) co-encapsulating CUR and QUE designed for nasal administration were developed as promising prophylactic and therapeutic treatments for viral respiratory infections. The NEs were prepared by high-pressure homogenization combined with the phase inversion temperature technique and evaluated for their physical and chemical characteristics. In vitro assays were performed to evaluate the nanoemulsion retention into the porcine nasal mucosa. In addition, the CUR and QUE-loaded NE antiviral activity was tested against a murine β-COV, namely MHV-3. The results evidenced that CUR and QUE loaded NE had a particle size of 400 nm and retention in the porcine nasal mucosa. The antiviral activity of the NEs showed a percentage of inhibition of around 99 %, indicating that the developed NEs has interesting properties as a therapeutic and prophylactic treatment against viral respiratory infections.

Inhalation of 2, 4-di-tert-butylphenol-Loaded micelles suppresses respiratory syncytial virus infection in mice

Human respiratory syncytial virus (RSV) is a common cause of respiratory infections in infants, young children, and elderly people. However, there are no effective treatments or vaccines available in most countries. In this study, we explored the anti-RSV potential of 2, 4-Di-tert-butylphenol (2, 4-DTBP), a compound derived from Houttuynia cordata Thunb. To overcome the poor solubility of 2, 4-DTBP, we encapsulated it in polymeric micelles and delivered it by inhalation. We found that 2, 4-DTBP-loaded micelles inhibited RSV infection in vitro and improved survival, lung pathology, and viral clearance in RSV-infected mice. Our results suggested that 2, 4-DTBP-loaded micelle is a promising novel therapeutic agent for RSV infection.

الكشف عن بعض عوامل الضراوة بين المبيضات المعزولة من المرضى وانتشار جين candidalysin ECE1

المبيضات البيضاء هي مسبب شائع لعدوى الجهاز التنفسي وداء المبيضات الفموي لدى الناس ، ومسببات أمراض الخميرة الانتهازية والأسباب الرئيسية للمرض والوفيات لدى الأشخاص الذين يعانون من نقص المناعة وتسبب التهابات سطحية على الأسطح المخاطية التي تصيب ملايين الأشخاص في جميع أنحاء العالم. كان الهدف الرئيسي من هذه الدراسة هو التحقق من انتشار بعض عوامل الضراوة التي لها القدرة على تكوين الأغشية الحيوية (Biofilm)، والبروتينيز (Proteinase)، وإنتاج الهيمولايسين( Hymolysine) بين عزلات C. albicans التي تشمل انتشار جين Candidalysin (ECE1). تم جمع العينات خلال الفترة من ايار 2022 الى اب 2022 من 280 عينة (مسحة) لمرضى عراقيين من مختلف الاعمار والاجناس غير مكررين كانوا يعانون من داء المبيضات الفموي وامراض الجهاز التنفسي في مستشفيات بغداد (مستشفى مدينه الطب و مستشفى اليرموك التعليمي ومستشفى مدينه الامامين الطبية التعليمية). تم زراعة العينات التي تم جمعها على وسط اكار السابرويد دكستروز (SDA) مضاف اليه كلورامفينيكول كمضاد للبكتيريا بتركيز 10 ميكجم / مل ، وتم حضن الاطباق الملقحة على وسط SDA عند 37 درجة مئوية لمدة تتراوح بين 24-48 ساعة.أظهرت نتائج الاستنبات أن 102 عينة كانت موجبه، منها58 (56.86%) من تجويف الفم و 44 (43.14%) من الجهاز التنفسي، بينما 178 منها كانت سالبة , تم الكشف عن عزلات المبيضات باستخدام الطرق التقليدية والتي تشمل (النمو على وسط HiCrome Candida ، إنتاج الأنبوب الجرثومي Germ tube ، تكوين الابواغ الكلاميديه Clamydospore وتم تأكيد نتئج التعريف باستخدام نضام VITEK-2 بينت النتائج ان من بين 102 عزلة C. albicans هي الاكثر شيوعا بين الانواع بنسبة 68.63 % ثم تلتها C. tropicalis بنسبة %10.78 ثم C. kruzei %5.88 وC. kefyr %5.88 C. parapsilosis % 4.9 بينما كانت C. glabrata % 3.9 وتمثل النسبة الاقل بين الانواع . تم فحص حساسية عزلات المبيضات للأدوية المضادة للفطريات بطريقة انتشار القرص ، والتي أجريت على النحو الموصى به بواسطة(CLSI) M44-A -وثيقة . أظهرت العزلات درجة عالية من الحساسية للأمفوتريسين-ب 93.14% وكلوتريمازول 90.20% ونسياتين 85.92% ،تم التحقق من انتشار جينCandidalysin (ECE1) بين 70 عزلة من C. albicans باستخدام تقنية تفاعل البلمرة المتسلسل PCR ، وأظهرت النتائج أن 41 58.57% تحتوي على جين Ece1 في تجويف الفم والجهاز التنفسي. و 34 عزلة 48.57% من C. albicans كانت منتجة قوية للغشاء الحيوي, بينما 30 عزلة 42.86% عزلة انتجت بروتيناز و 20 عزلة 28.57% عزلة لديها القدرة على تحلل الدم.

RSV Disease Burden in Primary Care in Italy: A Multi-Region Pediatric Study, Winter Season 2022-2023.

Human respiratory syncytial virus (RSV) is one of the most frequent causes of respiratory infections in children under 5 years of age, but its socioeconomic impact and burden in primary care settings is still little studied. During the 2022/2023 winter season, 55 pediatricians from five Italian regions participated in our community-based study. They collected a nasal swab for RSV molecular test from 650 patients under the age of 5 with acute respiratory infections (ARIs) and performed a baseline questionnaire. The clinical and socioeconomic burden of RSV disease in primary care was evaluated by two follow-up questionnaires completed by the parents of positive children on Days 14 and 30. RSV laboratory-confirmed cases were 37.8% of the total recruited ARI cases, with RSV subtype B accounting for the majority (65.4%) of RSV-positive swabs. RSV-positive children were younger than RSV-negative ones (median 12.5 vs. 16.5 months). The mean duration of symptoms for all children infected by RSV was 11.47 ± 6.27 days. We did not observe substantial differences in clinical severity between the two RSV subtypes, but RSV-A positive patients required more additional pediatric examinations than RSV-B cases. The socioeconomic impact of RSV infection was considerable, causing 53% of children to be absent from school, 46% of parents to lose working days, and 25% of families to incur extra costs. Our findings describe a baseline of the RSV disease burden in primary care in Italy before the introduction of upcoming immunization strategies.

Respiratory Syncytial Virus Infections in Recipients of Bone Marrow Transplants: A Systematic Review and Meta-Analysis.

Human Respiratory Syncytial Virus (RSV) is a common cause of respiratory tract infections. Usually associated with infants and children, an increasing amount of evidence suggests that RSV can cause substantial morbidity and mortality in immunocompromised individuals, including recipients of bone marrow transplantation (BMT). The present systematic review was therefore designed in accordance with the PRISMA guidelines to collect available evidence about RSV infections in BMT recipients. Three medical databases (PubMed, Embase, and MedRxiv) were therefore searched for eligible observational studies published up to 30 September 2023 and collected cases were pooled in a random-effects model. Heterogeneity was assessed using I2 statistics. Reporting bias was assessed by means of funnel plots and regression analysis. Overall, 30 studies were retrieved, including 20,067 BMT cases and 821 RSV infection episodes. Of them, 351 were lower respiratory tract infections, and a total of 78 RSV-related deaths were collected. A pooled attack rate of 5.40% (95% confidence interval [95%CI] 3.81 to 7.60) was identified, with a corresponding incidence rate of 14.77 cases per 1000 person-years (95%CI 9.43 to 20.11), and a case fatality ratio (CFR) of 7.28% (95%CI 4.94 to 10.60). Attack rates were higher in adults (8.49%, 95%CI 5.16 to 13.67) than in children (4.79%, 95%CI 3.05 to 7.45), with similar CFR (5.99%, 95%CI 2.31 to 14.63 vs. 5.85%, 95%CI 3.35 to 10.02). By assuming RSV attack rates as a reference group, influenza (RR 0.518; 95%CI 0.446 to 0.601), adenovirus (RR 0.679, 95%CI 0.553 to 0.830), and human metapneumovirus (RR 0.536, 95%CI 0.438 to 0.655) were associated with a substantially reduced risk for developing corresponding respiratory infection. Despite the heterogeneous settings and the uneven proportion of adult and pediatric cases, our study has identified high attack rates and a substantial CFR of RSV in recipients of BMT, stressing the importance of specifically tailored preventive strategies and the need for effective treatment options.

Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil.

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

Antiviral effect of alkaloids-free Ephedra Herb extract on respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in children. Despite decades of efforts, no effective therapies are available. We recently reported that extracts of Ephedra Herb and Cinnamon Bark interacted with the G attachment protein of RSV to inhibit infectivity. The present in vitro study aimed to investigate the antiviral effect of ephedrine alkaloids-free Ephedra Herb extract (EFE), which is characterized by free of harmful effects of ephedrine alkaloids in Ephedra Herb, on experimental RSV infection. Infection of RSV into A549 cells simultaneously with EFE resulted the significant reduction of RSV RNA, viral protein, and viral titers after the incubation of the cells. We found that RSV attachment to the cell surface was inhibited both in the presence of EFE and when RSV particles were pre-treated with EFE. We also found that EFE specifically interacted with the central conserved domain of RSV G protein by surface plasmon resonance, demonstrating that specific binding of G protein to the cellular receptor was inhibited by EFE. Another mechanism was found in which a higher concentration of EFE inhibited the viral load immediately after the viral entry into host cells, suggesting the inhibition of viral RNA replication. These results demonstrate that EFE worked against RSV infection through multiple antiviral mechanisms, a unique feature of this crude drug extract.

Clinical differences between Mycoplasma pneumoniae pneumonia and Streptococcus pneumoniae pneumonia: a case control study.

Mycoplasma pneumoniae pneumonia (MPP) and Streptococcus pneumoniae pneumonia (SPP) are frequent causes of respiratory tract infection, the aims of the study were to explore the differences in clinical features between children with MPP and those with SPP. This retrospective study included admitted children who were diagnosed with MPP or SPP over 5 years from January 2015 to January 2020. Children with MPP were compared to children with SPP in terms of clinical features. 506 patients with MPP were compared to 311 patients with SPP in terms of clinical differences. The MPP group with a median age of 60 [29-89] months and the SPP group with a median age of 24 [10-40] months. Patients with MPP were older and had a higher occurrence of receiving antibiotics before admission, fever, dry cough, polypnea and diarrhea than patients with SPP (all p < 0.01). Patients with SPP were more likely to have wheezing, cyanosis and irritability (all p < 0.01). Laboratory findings in our study showed that there were significant differences between MPP and SPP patients in mean leucocyte count, neutrophil % (N%), lymphocyte % (L%), ALT levels, AST levels, LDH levels and incidence of accelerated procalcitonin (PCT) (all p < 0.01). Lower age, no dry cough, no polypnea, lower LDH levels, and higher PCT might lead to the diagnosis of SPP. Our study showed that age had a higher accuracy in predicting MPP than LDH levels, with an age >48.5 months shown to be an independent predictive factor for the early evaluation and identification of MPP. In conclusion, patients with MPP and SPP usually present with fever, cough and some nonspecific symptoms. Our study showed that age, dry cough, polypnea, LDH levels, and PCT levels were independent predictive factors associated with MPP and SPP.

The association of fibrinogen-albumin ratio and neutrophil-lymphocyte ratio with the severity of respiratory syncytial virus infection in children.

Respiratory syncytial virus (RSV) is a common cause of respiratory infections. It is responsible for more than half of lower respiratory tract infections in infants requiring hospitalization. This study aimed to investigate the correlation between the fibrinogen-albumin ratio (FAR) and the severity of RSV infection and to compare its effectiveness with the neutrophil-lymphocyte ratio (NLR). This was a retrospective cohort study with patients aged from 29 days to two years who had been admitted to the pediatric clinic of our hospital. Patients were divided into four groups: group 1 (mild disease), group 2 (moderate disease), group 3 (severe disease), and group 4 (control). FAR and NLR were measured in all groups. FAR was significantly higher in group 3 than in the other groups, in group 2 than in groups 1 and 4, and in group 1 than in group 4 (p<0.001 for all). NLR was significantly higher in group 4 than in the other groups and in group 3 than in groups 1 and 2 (p<0.001 for all). FAR totaled 0.078 ± 0.013 in patients with bronchiolitis; 0.099 ± 0.028, in patients with bronchopneumonia; and 0.126 ± 0.036, in patients with lobar pneumonia, all with statistically significant differences (p<0.001). NLR showed no significant statistical differences. This study found a statistically significant increase in FAR in the group receiving invasive support when compared to that receiving non-invasive support (0.189 ± 0.046 vs. 0.112 ± 0.030; p=0.003). Mechanical ventilation groups showed no differences for NLR. FAR was used to identify severe RSV-positive patients, with a sensitivity of 84.4%, a specificity of 82.2%, and a cutoff value of >0.068. This study determined a cutoff value of ≤1.49 for NLR, with a sensitivity of 62.2% and a specificity of 62.2% to find severe RSV-positive patients. Also, statistically significant associations were found between FAR and hospitalization and treatment length and time up to clinical improvement (p<0.001 for all). NLR and hospitalization and treatment length showed a weak association (p<0.001). In children with RSV infection, FAR could serve to determine disease severity and prognosis and average lengths of hospitalization, treatment, and clinical improvement. Additionally, FAR predicted disease severity more efficiently than NLR.