Role In Respiratory Infections Research Articles

The role of respiratory infections in the formation of airway hyperresponsiveness in children

Airway hyperresponsiveness (AHR) is a heterogeneous and complex disorder characterized by excessive narrowing of the airways in response to various exogenous and endogenous stimuli. This article presents information from the last five years, including 50 publications from PubMed and Google Scholar, on the most common viruses that provoke the development of airway hyperresponsiveness in children, including respiratory syncytial virus, rhinovirus, metapneumovirus, influenza and parainfluenza viruses, SARS-CoV-2 coronavirus, adenovirus, and bocavirus. It describes a number of pathophysiological mechanisms by which viruses damage the respiratory epithelium and lead to the formation of infectious and post-infectious bronchial hypersensitivity. The role of hyperexpression of cytokines and inflammatory mediators in the development of AHR, especially in early childhood, is emphasized. It is shown that the inflammatory process and a balanced immune response are crucial for mitigating the severity of the disease caused by viruses. Understanding the molecular mechanisms of inflammatory reactions and the immune response to acute respiratory viral infections can help develop more effective methods for the prevention and treatment of respiratory diseases in children.

Comparison of the adherence of nontypeable haemophilus influenzae to lung epithelial cells

ObjectiveNontypeable Haemophilus influenzae (NTHi) plays an important role in respiratory tract infections, and adherence to lung epithelial cells is the first step in lung infections. To explore the role of NTHi in childhood lung infections, a comparative study was conducted on the adherence of strains isolated from sputum culture and bronchoalveolar lavage fluid to A549 lung epithelial cells.MethodsHaemophilus influenzae strains were obtained from the sample bank of Shenzhen Children’s Hospital, and identified as NTHi via PCR detection of the capsule gene bexA. NTHi obtained from healthy children’s nasopharyngeal swabs culture were selected as the control group, and a comparative study was conducted on the adherence of strains isolated from sputum culture or bronchoalveolar lavage fluid of patients to A549 cells.ResultsThe adherence bacterial counts of NTHi isolated from the nasopharyngeal cultures of healthy children to A549 cells was 58.2 CFU. In patients with lung diseases, NTHi isolated from bronchoalveolar lavage fluid was 104.3 CFU, and from sputum cultures was 115.1 CFU, both of which were significantly higher in their adherence to A549 cells compared to the strains isolated from the healthy control group. There was no significant difference in adherence between the strains isolated from sputum cultures and bronchoalveolar lavage fluid (t = 0.5217, p = 0.6033).ConclusionNTHi played an important role in childhood pulmonary infections by enhancing its adherence to lung epithelial cells.

Vitamin D and Zinc Supplementation to Improve Treatment Outcomes among COVID-19 Patients in India: Results from a Double-Blind Randomized Placebo-Controlled Trial

BackgroundThere remains a need to identify low-cost interventions to improve coronavirus disease 2019 (COVID-19) outcomes. Vitamin D and zinc play a role in respiratory infections and could hold value as part of therapeutic regimens. ObjectivesTo determine the effect of vitamin D or zinc supplementation on recovery from COVID-19. MethodsWe conducted a double-blind, randomly assigned 2 x 2 factorial placebo-controlled trial with 1:1:1:1 allocation ratio, enrolling nonpregnant adults with COVID-19 from hospitals in Mumbai and Pune, India (NCT04641195). Participants (N = 181) were randomly assigned to vitamin D3 (180,000 IU bolus, then 2000 IU daily), zinc (40 mg daily), vitamin D3 and zinc, or placebo, for 8 wk. Participants were followed until 8 wk. The primary outcome was time to resolution of fever, cough, and shortness of breath. Secondary outcomes were duration of individual symptoms; need for assisted ventilation; duration of hospital stay; all-cause mortality; and blood biomarkers, including nutritional, inflammatory, and immunological markers. ResultsWe observed no effect of vitamin D or zinc supplementation on time to resolution of all 3 symptoms [vitamin D hazard ratio (HR): 0.92; 95% confidence interval (95% CI): 0.66, 1.30; P = 0.650; zinc HR: 0.94; 95% CI: 0.67, 1.33; P = 0.745)]. Neither vitamin D nor zinc supplementation was associated with secondary outcomes, except for increased endline serum vitamin D with vitamin D supplementation [median (interquartile range) difference between endline and baseline for vitamin D: 5.3 ng/mL (–2.3 to 13.7); for no vitamin D: –1.4 ng/mL (–5.6 to 3.9); P = 0.003]. We observed nonsignificant increases in serum zinc at endline following zinc supplementation. There was no evidence of interaction between vitamin D and zinc supplementation, no effect of either on hypercalcemia, and no adverse events. ConclusionsResults suggest that neither vitamin D nor zinc supplementation improves COVID-19 treatment outcomes in this population. However, much larger-scale evidence, particularly from populations with vitamin D or zinc deficiency and severe infection, is required to corroborate our findings. This trial was registered at ClinicalTrials.gov and the Clinical Trials Registry of India as NCT04641195 and CTRI/2021/04/032593 respectively.

Altered Respiratory Microbiomes, Plasma Metabolites, and Immune Responses in Influenza A Virus and Methicillin-Resistant Staphylococcus aureus Coinfection.

Influenza A virus (IAV)-methicillin-resistant Staphylococcus aureus (MRSA) coinfection causes severe respiratory infections. The host microbiome plays an important role in respiratory tract infections. However, the relationships among the immune responses, metabolic characteristics, and respiratory microbial characteristics of IAV-MRSA coinfection have not been fully studied. We used specific-pathogen-free (SPF) C57BL/6N mice infected with IAV and MRSA to build a nonlethal model of IAV-MRSA coinfection and characterized the upper respiratory tract (URT) and lower respiratory tract (LRT) microbiomes at 4 and 13 days postinfection by full-length 16S rRNA gene sequencing. Immune response and plasma metabolism profile analyses were performed at 4 days postinfection by flow cytometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The relationships among the LRT microbiota, the immune response, and the plasma metabolism profile were analyzed by Spearman's correlation analysis. IAV-MRSA coinfection showed significant weight loss and lung injury and significantly increased loads of IAV and MRSA in bronchoalveolar lavage fluid (BALF). Microbiome data showed that coinfection significantly increased the relative abundances of Enterococcus faecalis, Enterobacter hormaechei, Citrobacter freundii, and Klebsiella pneumoniae and decreased the relative abundances of Lactobacillus reuteri and Lactobacillus murinus. The percentages of CD4+/CD8+ T cells and B cells in the spleen; the levels of interleukin-9 (IL-9), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), IL-6, and IL-8 in the lung; and the level of mevalonolactone in plasma were increased in IAV-MRSA-coinfected mice. L. murinus was positively correlated with lung macrophages and natural killer (NK) cells, negatively correlated with spleen B cells and CD4+/CD8+ T cells, and correlated with multiple plasma metabolites. Future research is needed to clarify whether L. murinus mediates or alters the severity of IAV-MRSA coinfection. IMPORTANCE The respiratory microbiome plays an important role in respiratory tract infections. In this study, we characterized the URT and LRT microbiota, the host immune response, and plasma metabolic profiles during IAV-MRSA coinfection and evaluated their correlations. We observed that IAV-MRSA coinfection induced severe lung injury and dysregulated host immunity and plasma metabolic profiles, as evidenced by the aggravation of lung pathological damage, the reduction of innate immune cells, the strong adaptation of the immune response, and the upregulation of mevalonolactone in plasma. L. murinus was strongly correlated with immune cells and plasma metabolites. Our findings contribute to a better understanding of the role of the host microbiome in respiratory tract infections and identified a key bacterial species, L. murinus, that may provide important references for the development of probiotic therapies.

Responding to Higher-Than-Expected Infant Mortality Rates from Respiratory Syncytial Virus (RSV): Improving Treatment and Reporting Strategies.

Respiratory syncytial virus (RSV) has a major role in respiratory infections in young infants around the world. However, substantial progress has been made in recent years in the field of RSV. A wide variety of observational studies and clinical trials published in the past decade provide a thorough idea of the health and economic burden of RSV disease in the developing world. In this review, we discuss the impact of RSV burden of disease, major gaps in disease estimations, and challenges in generating new therapeutic options and an immune response against the virus, and briefly describe next generation technologies that are being evaluated.

2193. Epidemiology and clinical characteristics of Human adenovirus in Korean children over the past 12 years (2008-2019)

Abstract Background Human adenovirus (HAdV) is a common cause of respiratory tract infection (RTI) and clinical presentation varies by serotype. Serotypes 7 and 55 caused severe pneumonia in children during the early 2000s and in soldiers from 2014 to 2018, respectively, in South Korea. Recent data for the epidemiologic and clinical features of HAdV in Korean children are scarce. Methods Nasal aspirates were collected from patients aged 18 years or younger with suspected RTIs at Seoul National University Children's Hospital from 2008 to 2019. HAdV serotype was determined by partial sequencing of hexon gene. The demographics and clinical features were reviewed through medical records. Results A total of 186 HAdVs were randomly selected for serotyping among 503 isolates obtained for 12 years. The median age was 2.1 years (range 1 month -17.9 years) with a slight male dominance (60.8%). Ten different serotypes were identified, which included 1-7, 31, 34, 35, and 55. The most predominant serotype was HAdV-3 (n=73, 39.3%) followed by HAdV-2 (n=42, 22.6%). Lower RTI was common in children infected with HAdV-3 (n=40, 54.8%) and HAdV-2 (n=18, 42.9%). HAdV-3 showed an epidemic every three years. HAdV-7 which previously caused severe pneumonia, has not been detected since 2008. HAdV-55 (n=9, 4.9%) was sporadically detected by each one case in 2008, 2009, and 2014, while six cases were detected in 2017-18. Among children with HAdV-55 detected, most (66.7%) had upper RTI as clinical diagnosis and only two (22.2%) had a clinically considerable pneumonia. Conclusion Over the past 12 years, HAdV-3 and 2 were prevalent and played an important role in RTIs of Korean children. HAdV-55 infection in children was not clinically significant in comparison to the recent Korean military outbreak cases. Disclosures All Authors: No reported disclosures.

Promising Neutrophil-Associated Biomarkers in Lung Diseases of Patients with Antisynthetase Syndrome and Dermatomyositis.

Objectives Antisynthetase syndrome (ASS) and dermatomyositis (DM) are serious autoimmune diseases, with lungs being the most frequently involved organ and sometimes fatal. This study is aimed at clarifying the role of neutrophil-associated biological markers in suggesting ASS and DM-associated respiratory infections and interstitial lung diseases. Methods We carried out a retrospective review of the medical records of 46 cases of ASS and DM diagnosed at the Second Hospital of Zhejiang University College of Medicine, between January 2017 and December 2020. Serum myeloperoxidase (MPO), neutrophil elastase (NE), α1 anti-trypsin (AAT), and interleukin-6 (IL-6) were also detected. Results Gottron's sign is characteristic of dermatomyositis, while polyarthritis is more characteristic of ASS. Pulmonary function is worse in ASS than in DM patients. Patients with ASS and DM had abnormal lymphocyte and neutrophil counts compared to healthy subjects, but not in relation to lung function and rapid progression of interstitial lung disease (RP-ILD). Elevated serum NE, MPO, and IL-6 levels are suggestive of respiratory infections, whereas decreased circulating IL-6 is predictive of RP-ILD. Conclusion Our study identified the neutrophil-associated biomarkers MPO, NE, and IL-6 as promising indicators with different suggestive roles in respiratory infections and interstitial lung diseases in patients with ASS and DM.

High prevalence and clinical characteristics of respiratory infection by human rhinovirus in children from Lima-Peru during years 2009–2010

IntroductionHuman rhinovirus is a major cause of acute respiratory infections (ARIs) worldwide. Epidemiological data on human rhinovirus (RV) in Peru is still scarce, as well as its role in respiratory infections in children. Therefore, the aim of this study was to describe the prevalence of rhinovirus and to identify the circulating species in nasopharyngeal swabs from children with acute respiratory infections.Materials and methodsWe analyzed nasopharyngeal swab samples that were collected from children younger than 17 years old, who had a clinical diagnosis of ARI from the “Hospital Nacional Cayetano Heredia” between May 2009 and December 2010. The original study recruited 767 inpatients with ARI, 559 samples of which were included and analyzed in the current study. Detection of rhinovirus and determination of rhinovirus species were characterized by PCR.ResultsRhinovirus was detected in 42.22% samples (236/559), RV-A was detected in 10.17% (24/236) of the cases, RV-B in 16.53% (39/236), and RV-C in 73.31% (173/236). The age group with the highest number of cases was the 0–5 months group with 45.97%, followed by the 1–5 years group with 25.22%. Most of the positive RV cases, i.e., 86.44% (204/236), were hospitalized. The most common signs and symptoms found in patients who tested positive for RV were cough (72.88%), fever (68.64%), rhinorrhea (68.22%), and respiratory distress (61.44%). Infection with RV-A was associated with wheezing (p = 0.02). Furthermore, RV-C was related to cough (p = 0.01), wheezing (p = 0.002), and conjunctival injection (p = 0.03). A peak in RV-C cases was found in March (32 cases in 2010); June (18 cases in 2009 and 12 cases in 2010), which corresponds to the fall season in Peru; and also November (17 cases in 2009 and 4 cases in 2010), which corresponds to spring. RV-A and RV-B cases were constant throughout the year.ConclusionIn conclusion, we found a high prevalence of rhinovirus C infection among pediatric patients with acute respiratory infections in Lima, Peru. This viral infection was more common in children between 0 to 5 months old, and was associated with cough, wheezing, and conjunctival injection. Epidemiological surveillance of this virus should be strengthened/encouraged in Peru to determine its real impact on respiratory infections.

The microbiota in respiratory tract infections: from association to intervention.

The respiratory microbiota has a role in respiratory tract infection (RTI) pathogenesis. On the mucosa, the respiratory microbiota interacts with potential pathogenic viruses, bacteria and the host immune system, including secretory IgA (sIgA). This review discusses the role of the respiratory microbiota and its interaction with the (mucosal) immune system in RTI susceptibility, as well as the potential to exploit the microbiota to promote health and prevent RTIs. Recent studies confirm that specific microbiota profiles are associated with RTI susceptibility and during susceptibility and found accompanying RTIs, although clear associations have not yet been found for SARS-CoV-2 infection. sIgA plays a central role in RTI pathogenesis: it stands under control of the local microbiota, while at the same time influencing bacterial gene expression, metabolism and defense mechanisms. Respiratory microbiota interventions are still newly emerging but promising candidates for probiotics to prevent RTIs, such as Corynebacterium and Dolosigranulum species, have been identified. Improved understanding of the respiratory microbiota in RTIs and its interplay with the immune system is of importance for early identification and follow-up of individuals at risk of infection. It also opens doors for future microbiota interventions by altering the microbiota towards a healthier state to prevent and/or adjunctively treat RTIs.

Atmospheric environment and severe acute respiratory infections in Nanjing, China, 2018–2019

ABSTRACT The annual burden of severe acute respiratory infection (SARI) is enormous, and environmental factors may have a vital role in respiratory infections. This study aimed to investigate the potential effects of the atmospheric environment on SARI. A time-series analysis was performed on the relationship between atmospheric environment and 136,989 SARI cases by distributed lag non-linear model. Wind speed, PM10, PM2.5, O3, and CO exhibited differential effects at a range of lag times or exposure ranges. Air pressure, temperature, and diurnal temperature range showed risk effects in the full range. The lag effect of high pollution was stronger, appeared earlier, and lasted longer than that of low pollution. Most environmental factors had a certain non-linear lag relationship with SARI. Low wind speed and high air pollution may be increasing risk factors for SARI.

The association between micronutrient and hemogram values and prognostic factors in COVID-19 patients: A single-center experience from Turkey.

AimThe contribution of micronutrients to the immune system has been known for a long time. This study aimed to investigate the association between the micronutrient levels and hemogram values and prognostic factors of the disease in COVID‐19 patients in Ankara City Hospital.Materials and methodsOur study is a descriptive observational study based on a retrospective review of patient files. COVID‐19 patients over 18 years of age who were admitted to our hospital between 14 March and 1 June 2020, and with a complete micronutrient profile were included in the study. Age, gender, chronic diseases, micronutrient concentrations in the last 6 months, hemogram data on the day of hospitalization, total length of stay in hospital, and hospitalization to Intensive Care Unit (ICU)‐intubation‐death status of the patients were obtained from the patient files.ResultsA total of 310 patients whose parameters were thoroughly examined were included in our study; 51.9% of them were men and the mean age of all patients was 57.02 ± 18.28 years, and the most common comorbid disease was hypertension. The percentage of patients who were followed in the ICU, were intubated, and died was 34.5%, 13.9%, and 9.4%, respectively. The mean length of hospital stay was 15.87 ± 12.79 days. Low folate, iron, vitamin D, and hemoglobin levels of the patients and high vitamin B12 concentration were more related to poor prognostic factors. The number of white blood cells was significantly higher in patients with a worse prognosis, and the number of lymphocytes was lower in patients with ICU admission but higher in intubated and dead patients.ConclusionMicronutrient and hemogram values, advanced age, being male, and having comorbid diseases were correlated with the poor prognosis of COVID‐19 infection. Deficiency of Iron, Folate, and vitamin D should be well‐considered in COVID‐19. Excessive vitamin B12 and multivitamin supplementation should be avoided by choosing supplement wisely. In addition, attention should be paid to leukocytosis, lymphocyte counts, and anemia during COVID‐19 patient follow‐up. What’s known Some micronutrients have an immunomodulatory and anti‐inflammatory effect with antioxidant effects and thus play a protective role in respiratory tract infections as COVID‐19.Vitamin D deficiency is found to be associated with poor prognostic factors in COVID‐19.Lymphopenia is found to be associated with poor prognostic factors in COVID‐19. What’s new According to the results obtained from our study, low iron and folate levels should be controlled first in patients diagnosed with COVID‐19, low vitamin D levels should also be well‐considered, and supplementation should be provided in the case of deficiencies. On the other hand excessive use of vitamin B12 should be avoided.The fact that all micronutrients should be evaluated and managed by choosing wisely rather than a complete multivitamin supplement approach was demonstrated by the differences in the poor prognosis levels of vitamin B12 versus the other micronutrients.In addition, it was found in our study that leukocytosis, lymphocyte counts, and anemia should be taken into consideration together when evaluating hemogram parameters in the follow‐up of COVID‐19 patients.

Association of asthma severity and educational attainment at age 6–7 years in a birth cohort: population-based record-linkage study

BackgroundThere is conflicting research about the association between asthma and poor educational attainment that may be due to asthma definitions. Our study creates seven categories of current chronic and acute...

Could Vitamins Help in the Fight Against COVID-19?

There are limited proven therapeutic options for the prevention and treatment of COVID-19. The role of vitamin and mineral supplementation or “immunonutrition” has previously been explored in a number of clinical trials in intensive care settings, and there are several hypotheses to support their routine use. The aim of this narrative review was to investigate whether vitamin supplementation is beneficial in COVID-19. A systematic search strategy with a narrative literature summary was designed, using the Medline, EMBASE, Cochrane Trials Register, WHO International Clinical Trial Registry, and Nexis media databases. The immune-mediating, antioxidant and antimicrobial roles of vitamins A to E were explored and their potential role in the fight against COVID-19 was evaluated. The major topics extracted for narrative synthesis were physiological and immunological roles of each vitamin, their role in respiratory infections, acute respiratory distress syndrome (ARDS), and COVID-19. Vitamins A to E highlighted potentially beneficial roles in the fight against COVID-19 via antioxidant effects, immunomodulation, enhancing natural barriers, and local paracrine signaling. Level 1 and 2 evidence supports the use of thiamine, vitamin C, and vitamin D in COVID-like respiratory diseases, ARDS, and sepsis. Although there are currently no published clinical trials due to the novelty of SARS-CoV-2 infection, there is pathophysiologic rationale for exploring the use of vitamins in this global pandemic, supported by early anecdotal reports from international groups. The final outcomes of ongoing trials of vitamin supplementation are awaited with interest.

The correlation between vitamin a status and refractory Mycoplasma Pneumoniae pneumonia (RMPP) incidence in children

BackgroundVitamin A plays a pivotal role in respiratory infection, accurate estimation of vitamin A status was recommended in planning and implementing interventions. As infections affect serum vitamin A productions, the real status need to be adjusted by acute phase protein (APP). Mycoplasma pneumoniae is an important cause of respiratory infection in children, the association between vitamin A concentrations and refractory Mycoplasma pneumoniae pneumonia (RMPP) remains unclear.Methods181 MPP patients were enrolled in this retrospective study, adjusted vitamin A concentrations and other parameters were compared between RMPP and general-MPP (GMPP) patients. Multivariate logistic regression test was performed to evaluate the association between vitamin A levels and RMPP incidence, linear correlation tests were applied to evaluate correlation between vitamin A concentrations and fever duration, length of stay (LOS).ResultsVitamin A concentrations in RMPP group were significantly lower than those in GMPP patients (P < 0.05), vitamin A (OR = 0.795, 95% C. I 0.669–0.946) and CRP (OR = 1.050, 95% C. I 1.014–1.087) were independently associated with RMPP incidence. Linear correlation tests found vitamin A concentrations were negatively correlated with fever duration and LOS (P < 0.001).ConclusionsSerum vitamin A concentrations were independently associated with RMPP incidence, which may correlate with reduced incidence of RMPP.

A systematic review of respiratory infection due to air pollution during natural disasters

BACKGROUND Wildfire and volcano eruption occurred in Indonesia due to its geographical location, climate change, global warming, and human behavior. Various substances produced an increased risk of experiencing health problems, including respiratory infection. Evidence about the effect of pulmonary infection during natural disasters is still limited. This study was aimed to review and elaborate on previous studies to determine the effect of air pollution exposure during natural disasters and respiratory infection.&#x0D; METHODS Literature searches were conducted on PubMed, EBSCOhost, and Google Scholar, and was limited to the 10 last years, human studies, and the English language. Inclusion criteria were articles with representation for clinical questions, review articles, population studies, and the full-text article was available. Exclusion criteria were articles that only discussed the exposure to and not the association with the effect of the respiratory infection. The Oxford Center for Evidence-Based Medicine tools appraised six relevant articles.&#x0D; RESULTS Air pollution during a natural disaster enhances particulate matter to 10–70 μg/m3 and more than 5 times the aerosol optical depth measurement compared with the tolerated air concentration. The air level was consistently related to acute respiratory infection, pneumonia, bronchitis, and bronchiolitis admissions in wildfire smoke and volcanic eruption in this review. Nevertheless, there was a diverse result for upper respiratory infection cases.&#x0D; CONCLUSIONS Natural disasters increased the level of ambient air pollution that exceeded the levels recommended by the World Health Organization air quality guideline. Air pollution may play an important role in respiratory tract infection, especially among population with high exposure.

Nontuberculous mycobacteria isolated from specimens of pulmonary tuberculosis suspects, Northern Tunisia: 2002\u20132016

BackgroundReports on the worldwide ascending trend of pulmonary nontuberculous mycobacteria (NTM) isolation rates and their effective role in respiratory tract infections are compelling. However, as yet, there are no such data relating to Tunisia.MethodsHere we carried out a retrospective review of mycobacterial cultures originating from Northern Tunisia, which have been processed in the laboratory of mycobacteria of the Institut Pasteur de Tunis, during the time period 2002–2016. All pulmonary NTM (PNTM) isolates available for culture were characterized phenotypically and their taxonomic status was further established based on polymorphisms in rpoB, 16S rRNA, hsp65, and sodA DNA gene sequences.ResultsOf the 10,466 specimens collected from HIV-negative Tunisian patients with presumptive clinical pulmonary TB, 60 (0.6%) yielded PNTM isolates. An overall annual PNTM isolation prevalence of 0.2/100,000 was estimated. As far as could be ascertained, this isolation rate accounts amongst the lowest reported hitherto throughout the world. Among the 30 NTM isolates that were available for culture, 27 (90.0%) have been identified to the species level. The most commonly encountered species was Mycobacterium kansasii (23.3%) subtype 1. Strikingly, all M. kansasii cases were male patients originating from Bizerte, an industrialized region particularly known for iron industry. The remaining NTM species were M. fortuitum (16.6%), M. novocastrense (16.6%), M. chelonae (10.0%), M. gordonae (6.6%), M. gadium (6.6%), M. peregrinum (3.3%), M. porcinum (3.3%), and M. flavescens (3.3%). There were no bacteria of the M. avium complex, the most frequently isolated NTM globally, and the main driver of the rise of NTM-lung diseases.ConclusionsThis study uncovered an exceptional low prevalence of PNTM isolation among HIV-negative TB suspects in Northern Tunisia, suggesting a very low burden of NTM pulmonary disease. However, the frequent isolation of M. kansasii subtype 1, the most pathogenic subtype, particularly from the industrialized region of Bizerte, strongly suggests its effective involvement in a typical pulmonary disease.

Evaluation of Fraction of Exhaled Nitric Oxide (FeNO) in CF Children and its Association with Sputum Culture

Background: Exhaled nitric oxide (FeNO) in cystic fibrosis (CF) patients is reduced when compared with healthy people, and it has now been found that FeNO has a relative association with airway clearance index. Studies have shown the role of some infections in changing the FeNO level; however, the role of respiratory infections in FeNO has not yet been thoroughly studied. Objectives: The objective of this study was to investigate the possibility of FeNO usage to monitor the infections in CF patients. Methods: This cross-sectional case-control study was conducted on CF patients between the age of five to 18 with positive sputum culture, through simple non-random census method. FeNO levels were measured in 30 healthy children and 30 CF children with positive sputum culture. CF patients were treated by antibiotic therapy for two weeks; in the case offending negative sputum culture, the FeNO level was re-measured. FeNO levels were re-evaluated in 13 patients after four weeks. Results: There was no statistical difference between both groups in terms of age and weight. The level of FeNO in CF patients was significantly lower than in healthy children (22.1 ± 10.1 versus 30.0 ± 11.0 in the control group and P = 0.003). In 27 children, two weeks after administration of antibiotic therapy, sputum culture was negative. The mean of FeNO in these patients was 16.4 ± 5.5 at the time of the negative sputum culture, which was significantly lower than FeNO before starting the treatment. (P: 0.003). The mean FeNO was 13.0 ± 7.41 in 13 patients who were re-measured four weeks after starting the treatment. There was no significant difference between FeNO level two weeks after treatment and four weeks after starting treatment (P: 0.292). Patients with pseudomona sputum culture were not significantly different from those with non-pseudomona sputum culture in terms of primary FeNO and FeNO changes after the treatment (P value: 0.084 and 0.094, respectively). Conclusions: However, in our study, FeNO was decreased after administration of antibiotic treatment in CF patients, but according to the sample size and conflicting or similar results in other studies, currently, FeNO levels cannot be used as a way of monitoring the treatment of infection in CF patients.

Retrospective analysis of viral pathogen of acute respiratory tract infection in children in Suzhou area

Objective To study the epidemiological and clinical features of viral pathogen of acute respiratory tract infection(ARTI) in children in Suzhou.To provide the evidence-based medicine for early warning, diagnosis and treatment of respiratory tract infection in children. Methods The study population comprised of all the children ranging from 28 days to 15 years old with ARTI admitted to Department of Respiration, the Children′s Hospital Affiliated to Soochow University, between January 2006 and December 2015.The study cases were divided into 4 age groups based on ages(28 days to <1 year old, 1-<3 years old, 3-<5 years old and ≥5 years old). The nasopharyngeal aspirates and medical history were obtained by qualified medical personnel.Seven kinds of common respiratory virus were detected by using the direct immunofluorescence.Mycoplasma pneumonia(MP), chlamydia pneumonia(CP) and human bocavirus(hBoV) were detected by adopting fluorescence quantitative PCR.Human rhinovirus(HRV) and human metapneumovirus(hMPV) were detected by means of reverse transcriptionpolymerase chain reaction(RT-PCR). Sputum was cultured for bacteria. Results In 21 624 cases, 17 618 cases were detected, and the positive detection rate of virus was 30.74%(5 416 cases). The highest detection rate of virus was 44.25%(881/1 991 cases) in 2011 in the 10 years.There were 3 317 cases of single virus pathogen infection, accounting for 18.83%.Among them, respiratory syncytial virus (RSV) was the first with 9.42%(1 660/17 618 cases), followed by HRV(5.17%, 278/5 372 cases), hBoV (3.12%, 351/11 263 cases), Pinf 3(2.17%, 383/17 618 cases), and the lowest rate was Pinf 2 with 0.05%(8/17 618 cases). There were 2 099 cases of overlap infection, accounting for 11.91%.The virus combined with bacterial infection accounted for 7.86%(1 384/17 618 cases), which had the most positive cases.With the increase of age, the single virus pathogen infection rate gradually dropped.The highest detection rate was 22.82%(1 976/8 656 cases) in the group between 28 days and <1 year old, and the lowest detection rate was 7.81%(159/2 035 cases) of children over 5 years of age.The virus positive rate of the four seasons was 18.28%(833/4 556 cases), 13.86%(625/4 508 cases), 5.91%(684/4 298 cases), 27.68%(1 178/4 256 cases), respectively, and detection rate in winter was the highest, and the least in summer.In the single virus infection, bronchiolitis had the highest percentage(36.32%, 25/69 cases), and the least rate was 5.83%(63/1 080 cases) of lobar pneumonia. Conclusions Monitored for 10 years of the virus respiratory infection in Suzhou area, RSV, HRV and hBoV turned out to play an important role in respiratory tract infection in children.The children less than 3 years old are the most susceptible to virus infection.The epidemic season of each virus is different and characteristic. Key words: Child; Acute respiratory tract infection; Viral pathogen; Retrospective analysis

Target-independent high-throughput sequencing methods provide evidence that already known human viral pathogens play a main role in respiratory infections with unexplained etiology

ABSTRACT Despite the advanced PCR-based assays available, a fraction of the pediatric respiratory infections remain unexplained every epidemic season, and there is a perception that novel viruses might be present in these specimens. We systematically collected samples from a prospective cohort of pediatric patients with respiratory infections, that returned negative results by validated molecular RT–PCR assays, and studied them with a target-independent, high-throughput sequencing-based approach. We also included a matched cohort of children with no symptoms of respiratory infection, as a contrast study population. More than fifty percent of the specimens from the group of patients with unexplained respiratory infections were resolved. However, the higher rate of detection was not due to the presence of novel viruses, but to the identification of well-known viral respiratory pathogens. Our results show that already known viral pathogens are responsible for the majority of cases that remain unexplained after the epidemic season. High-throughput sequencing approaches that use pathogen-specific probes are easier to standardize because they ensure reproducible library enrichment and sequencing. In consequence, these techniques might be desirable from a regulatory standpoint for diagnostic laboratories seeking to benefit from the many advantages of these sequencing technologies.

First isolation of Ascotricha chartarum from bronchoalveolar lavage of two patients with pulmonary infections

Ascotricha chartarum is a rare human pathogen. We describe the isolation and characterization of A. chartarum from bronchoalveolar lavage samples of two patients with underlying pulmonary infections. The identity of both isolates was established by typical phenotypic characteristics and by sequencing of the internal transcribed spacer region and D1/D2 domains of recombinant DNA and β-tubulin gene fragment. The demonstration of branched, septate hyphae in direct microscopic examination of both the specimens and isolation of the fungus in pure cultures suggest its aetiologic role in the disease process. Because of phenotypic similarities of A. chartarum with Chaetomium spp. and other Chaetomium-like fungi, the application of molecular methods is needed for its accurate identification. Although in the absence of histopathologic evidence the aetiologic role of A. chartarum could not be established unequivocally, nonetheless, in view of the rarity of its isolation from clinical specimens and demonstration of hyphal elements in bronchoalveolar lavage sample, this report assumes considerable significance. It serves to create awareness about environmental fungi that previously have missed attention but may play a role in respiratory infections.