Pathogens In Children Research Articles

Актуальные вопросы лечения внутриклеточных инфекций у детей

The article considers the issues of pharmacodynamics, clinical efficacy and safety of macrolide antibiotics. It also discusses the development of microorganisms resistance to macrolides. A number of studies in vivo and in vitro on various cellular and animal models have shown that macrolides have anti-inflammatory and immunomodulatory effects. The presence of these effects in macrolides may be especially relevant during the period of increasing incidence of influenza and the new COVID-19 coronavirus infection. It is known that the severity of viral infections is associated with the release of proinflammatory cytokines. Macrolides change the entire inflammatory response cascade by weakening the excess production of cytokines. Besides, macrolides can affect the activity of phagocytes, changing their function, including chemotaxis, phagocytosis, destroying bacteria and viruses. Earlier it was reported that macrolides (in particular, clarithromycin) can interfere with the replication cycle of the influenza virus, thus leading to its production inhibition by intracellular proteolysis of hemagglutinin. One of the commonly prescribed drugs in this group is clarithromycin. The article summarizes the literature data and presents the materials of our own clinical observations on the clarithromycin treatment of children with intracellular bacterial pathogens, the causative agents of which are Mycoplasma pneumoniae and Chlamydia pneumoniae. KEYWORDS: macrolides, clarithromycin, intracellular bacterial pathogens, children, antibacterial therapy. FOR CITATION: Savenkova M.S., Savenkov M.P. Topical issues concerning treatment of intracellular bacterial pathogens in children. Russian Journal of Woman and Child Health. 2020;3(4):326–335. DOI: 10.32364/2618-8430-2020-3-4-326-335.

High concentrations of middle ear antimicrobial peptides and proteins and proinflammatory cytokines are associated with detection of middle ear pathogens in children with recurrent acute otitis media.

Recurrent and chronic otitis media (OM) are often refractory to antibiotics due to bacterial persistence in biofilm within the middle ear. In vitro and in vivo studies have demonstrated that antimicrobial proteins and peptides (AMPs) are bactericidal against otopathogens, indicating potential therapeutic value for recalcitrant OM. We measured concentrations of 6 AMPs and 14 cytokines in middle ear effusion (MEE) from 67 children undergoing ventilation tube insertion for recurrent acute OM. Sixty one percent of children had bacterial otopathogens detected in their MEE, 39% by PCR and 22% by PCR and culture. Groups were defined as: PCR-negative/culture-negative (absence of bacterial otopathogen), n = 26; PCR-positive/culture-negative (presence of nonculturable bacterial otopathogen), n = 26; PCR-positive/culture-positive (presence of culturable bacterial otopathogen), n = 15. Age, antibiotic usage, day-care attendance, presence of respiratory viruses in MEE and number of AOM episodes were similar between groups. AMP and cytokine concentrations were higher in children with bacterial otopathogens in their MEE compared to those with no bacterial otopathogens. Median concentrations of AMPs (except HBD2) were 3 to 56-fold higher in MEE from children with bacterial otopathogens detected in their MEE (P ≤ 0.01). Similarly, median cytokine concentrations (except TGFβ) were >16-fold higher in MEE with bacterial otopathogens detected (P ≤ 0.001). This is the first study to measure AMPs in MEE and together with the cytokine data, results suggest that elevated AMPs and cytokines in MEE are a marker of inflammation and bacterial persistence. AMPs may play an important role in OM pathogenesis.

Molecular and clinical characterization of human adenovirus associated with acute respiratory tract infection in hospitalized children

BackgroundHuman adenovirus (HAdV) is a common pathogen in children that can cause acute respiratory tract infection (ARTI), but the molecular epidemiological and clinical information relating to HAdV among hospitalized children with ARTI are few reported in China. ObjectivesTo evaluate the epidemiological, clinical, and molecular characteristics of HAdV infections among hospitalized children with ARTI in Hebei, Northern China from June 2017 to May 2018. Study designA 12-month longitudinal, retrospective study on HAdV, typed by nested polymerase chain reaction targeting the hexon gene’s hypervariable region (typing was merely performed by sequencing of the hexon neutralization epitope and thus genotypes could not be identified unequivocally), associated with ARTI was performed. The epidemiological and clinical data of different types of HAdV were analyzed using statistical product and service solutions (SPSS) 21.0 software. ResultsHAdV was detected in 330 (3.71%) of the 8906 specimens, with most (88.48%, 292/330) HAdV-positives cases detected among children < 3 years old. HAdV were detected throughout the year with a higher prevalence in spring. 11 types were identified, with HAdV-2 (33.33%, 110/330) as the predominant type, followed by HAdV-3 (21.21%, 70/330) and HAdV-7 (13.94%, 46/330). Of the 330 HAdV-positive specimens, 247 (74.85%) were co-detected with other respiratory pathogens, most commonly rhinovirus (HRV) (58.7%, 145/247). Additionally, patients with HAdV-7 positive had longer duration of fever than HAdV-2 or -3 positive patients. ConclusionsDuring the study period, HAdV-2, HAdV-3 and HAdV-7 were the predominant types identified from children with ARTI in Hebei Province. Pediatric patients with HAdV-7 positive may not present more severe clinical outcome except a longer duration of fever.

Clinical and Molecular Epidemiology of Invasive Haemophilus influenzae Serotype a Infections in Utah Children.

Following widespread use of the Haemophilus influenzae serotype b (Hib) vaccine, H. influenzae serotype a (Hia) has emerged as an important pathogen in children in some regions. We describe the clinical features and molecular epidemiology of invasive Hia disease in children in Utah over an 11-year period. We identified cases of invasive Hia disease, defined as detection of Hia from a normally sterile site, in children aged <18 years from Utah between 2007 and 2017. Medical records were reviewed to determine demographic characteristics and clinical outcomes. Available Hia isolates were genotyped using multilocus sequence typing, and phylogenetic division was determined using sodC polymerase chain reaction. Presence of the putative virulence-associated IS1016-bexA duplication-deletion was evaluated. We identified 51 children with invasive Hia. The average annual incidence was 1.7 cases per 100 000 children aged <5 years; 4.8 cases per 100 000 children aged <1 year. The median age was 11.3 months. The most common clinical presentation was meningitis (53%), followed by pneumonia (14%) and septic arthritis (14%). Twenty-two children (43%) required admission to an intensive care unit; 1 died. Sequence type (ST) 62, phylogenetic division II isolates caused 75% (21/28) of disease. No isolates contained the virulence-associated IS1016-bexA duplication-deletion. Hia is a significant cause of severe invasive bacterial infection in Utah. The majority of infections were caused by ST62 isolates, a phylogenetic division II Hia type that lacks the IS1016-bexA duplication-deletion. Hia ST62 has not been commonly reported elsewhere, suggesting a unique molecular epidemiology in our population.

Short-term antibiotic exposure affected the type and resistance of uropathogens similar to long-term antibiotic prophylaxis in children hospitalised for urinary tract infections.

We investigated the impact of any antibiotic exposure on unusual and resistant pathogens in children with a urinary tract infection (UTI). This was a retrospective cohort study of 695 children (54% female) hospitalised with 711 UTI episodes at Heraklion University Hospital, Greece, from January 2007 to December 2017. Three groups were studied: no previous antibiotic exposure, ongoing prophylaxis and short-term exposure to antibiotics in the last six months. The median age at hospitalisation was 0.8years (range 25days to 15.9years). Previous short-term exposure and prophylaxis were important determinants of non-Escherichia coli (E. coli) (OR 2.05, 95% CI 1.25-3.36, P=.0017 and OR 3.84, 95% CI 2.32-6.34, P<.0001, respectively) and extended-spectrum beta-lactamase-positive uropathogens (OR 2.43, 95% CI 1.36-4.32, P=.0025 and OR 2.63, 95% CI 1.31-5.33, P=.0070, respectively). Short-term antibiotics in the last 30days or intravenous antibiotics were mostly associated with non-E. coli pathogens (OR 6.71 and OR 2.55, respectively). The most important determinants of E. coli resistance were short-term antibiotics for ampicillin (OR 2.58) and prophylaxis for cotrimoxazole (OR 2.64). Recent short-term exposure to antibiotics and ongoing prophylaxis both had a significant impact on the type and resistance of uropathogens.

Respiratory syncytial virus-associated mortality in a healthy 3-year-old child: a case report

BackgroundRespiratory syncytial virus (RSV) is the most frequently identified pathogen in children with acute lower respiratory tract infection. Fatal cases have mainly been reported during the first 6 months of life or in the presence of comorbidity.Case presentationA 47-month-old girl was admitted to the pediatric intensive care unit following sudden cardiopulmonary arrest occurring at home. The electrocardiogram showed cardiac asystole, which was refractory to prolonged resuscitation efforts. Postmortem analyses detected RSV by polymerase chain reaction in an abundant, exudative pericardial effusion. Histopathological examination was consistent with viral myoepicarditis, including an inflammatory process affecting cardiac nerves and ganglia. Molecular analysis of sudden unexplained death genes identified a heterozygous mutation in myosin light chain 2, which was also found in two other healthy members of the family. Additional expert interpretation of the cardiac histology confirmed the absence of arrhythmogenic right ventricular dysplasia or hypertrophic cardiomyopathy.ConclusionsRSV-related sudden death in a normally developing child of this age is exceptional. This case highlights the risk of extrapulmonary manifestations associated with this infection, particularly arrhythmia induced by inflammatory phenomena affecting the cardiac autonomic nervous system. The role of the mutation in this context is uncertain, and it is therefore necessary to continue to assess how this pathogenic variant contributes to unexpected sudden death in childhood.

Long-term, single-center surveillance of non-invasive group A streptococcal (GAS) infections, emm types and emm clusters.

Group A streptococci (GAS) are among the most frequent pathogens in children. Many epidemiological studies focus on specific GAS infections (such as tonsillopharyngitis or invasive disease), on GAS carriers or on post-streptococcal sequelae. By comparison, reports on regional GAS characteristics, particularly circulating non-invasive GAS in Europe, are rare. In a monocentric study, all GAS isolated from pediatric patients at a tertiary care hospital over a 6-year period (2006-2012) were characterized. GAS emm types and clusters were determined. Associated patient data were analyzed. Five hundred sixty-six GAS strains were collected. GAS tonsillopharyngitis was most common (71.6%), followed by pyoderma (6.0%), otitis media (3.7%), perineal dermatitis (3.4%), and invasive infections (1.4%). Colonizing strains represented 13.6% of GAS. GAS emm12 was most prevalent among invasive and non-invasive isolates. Emm1, emm4, emm28, and emm89 were the most frequent non-invasive GAS strains. The emm E4 cluster was most common, followed by the A-C4, A-C3, and E1. Among the GAS infections, different emm types and clusters were identified, e.g., emm4 was more common among patients with scarlet fever. Three new emm subtypes were characterized: emm29.13, emm36.7, and emm75.5. This comprehensive review of a large, local GAS cohort points to the differences between and similarities among GAS genotypes and disease manifestations, while minimizing regional variations. Considerable deviation from previous epidemiological findings is described, especially regarding the frequent detection of emm1 and emm89 in non-invasive GAS infections. Periodic updates on molecular and epidemiological GAS characteristics are needed to track the multifaceted pathogenic potential of GAS.

Isolation and Characterization of Clinical RSV Isolates in Belgium during the Winters of 2016-2018.

Respiratory Syncytial Virus (RSV) is a very important viral pathogen in children, immunocompromised and cardiopulmonary diseased patients and the elderly. Most of the published research with RSV was performed on RSV Long and RSV A2, isolated in 1956 and 1961, yet recent RSV isolates differ from these prototype strains. Additionally, these viruses have been serially passaged in cell culture, which may result in adaptations that affect virus–host interactions. We have isolated RSV from mucosal secretions of 12 patients in the winters 2016–2017 and 2017–2018, of which eight RSV-A subtypes and four RSV-B subtypes. Passage 3 of the isolates was assessed for viral replication kinetics and infectious virus production in HEp-2, A549 and BEAS-2B cells, thermal stability at 37 °C, 32 °C and 4 °C, syncytia formation, neutralization by palivizumab and mucin mRNA expression in infected A549 cells. We observed that viruses isolated in one RSV season show differences on the tested assays. Furthermore, comparison with RSV A2 and RSV B1 reveals for some RSV isolates differences in viral replication kinetics, thermal stability and fusion capacity. Major differences are, however, not observed and differences between the recent isolates and reference strains is, overall, similar to the observed variation in between the recent isolates. One clinical isolate (BE/ANT-A11/17) replicated very efficiently in all cell lines, and remarkably, even better than RSV A2 in the HEp-2 cell line.

Characteristic and drug resistance of pathogens in children with intractable mycoplasma pneumonia and changes of serum IL-18 and IL-33 levels

Objective To investigate the characteristics and drug resistance of pathogenic bacteria of refractory mycoplasma pneumonia in children and the changes of serum interleukin-18 (IL-18) and interleukin-33 (IL-33) levels. Methods From January 2016 to December 2017, 103 children with refractory mycoplasma infection admitted to the Maternal and Child Health Hospital of Zhoushan were selected in the study.Another 60 healthy subjects in our Hospital from January 2016 to December 2017 were selected as control group.The oropharyngeal secretions were collected in all children with refractory mycoplasma pneumonia, isolated and cultured pathogenic bacteria.Disk diffusion (K-B method) was used to detect the drug resistance of the main pathogens.Enzyme-linked immunosorbent assay was used to determine serum IL-18 and IL-33 levels. Results The 117 strains of pathogenic bacteria were isolated from 103 children with refractory mycoplasma infection, of which 68 strains (58.12%) were Gram-negative bacilli, 39 strains (33.33%) were Gram-positive cocci, and 10 strains (8.55%) were fungi.Klebsiella pneumoniae was more resistant to cefuroxime than Acinetobacter baumannii to cefuroxime and ceftriaxone.Staphylococcus aureus and Staphylococcus epidermidis were more resistant to erythromycin and penicillin G than other Gram-positive cocci.The levels of serum IL-18 and IL-33 in the study group were higher than those in the control group (all P<0.05). Conclusion Gram-negative bacilli are the main pathogens of refractory mycoplasma pneumonia in children.The resistant rate of main Gram-negative bacilli to cephalosporins is higher.The resistant rate of main Gram-positive cocci to penicillin G and erythromycin is higher.The levels of serum IL-18 and IL-33 are significantly higher in patients with refractory mycoplasma pneumonia. Key words: Pneumonia, mycoplasma; Pathogenic bacteria; Drug resistance; Interleukin-18; Interleukin-33

Flavobacteriaceae Bacteremia in Children: A Multicenter Study.

The Flavobacteriaceae family includes rare pathogens in children; Chryseobacterium indologenes and Elizabethkingia meningosepticum are the most common pathogenic species, with a wide range of clinical presentations and high mortality rate. Although rare, diagnosis is important due to inherent resistance to multiple antibiotics, especially those typically prescribed for empiric treatment of aerobic Gram-negative bacterial infections. A multicenter retrospective study conducted in 5 Israeli hospitals, describing Flavobacteriaceae bacteremia confirmed by positive blood culture from 1998 to 2018. Thirteen cases were included; 9 isolates were C. indologenes. Bacteremia was nosocomial or healthcare-associated in all cases. Bacteremia was associated with young age (median, 1 year, range 24 days-17 years), with only 2 (15.4%) cases in neonates, Central line-associated bloodstream infection as a source (5/13, 38%) and malignancy (7/13, 54.8%). Thirty-day all-cause mortality was 23% (3/13). Ninety-one percent of isolates were susceptible to trimethoprim-sulfamethoxazole, 82% to piperacillin-tazobactam and 92% to ciprofloxacin. C. indologenes and E. meningosepticum are rare, nosocomial- or healthcare-associated pediatric bacteremia pathogens. Bacteremia was associated with young age, but in contrast to the literature, the majority of our cases were older than the neonatal age period. In addition, they were associated with central line-associated bloodstream infection and malignancy. The most adequate antibiotics according to resistance patterns were ciprofloxacin, trimethoprim-sulfamethoxazole and piperacillin-tazobactam.

1522. Clinical and Molecular Epidemiology of Invasive Haemophilus influenzae Serotype a Infections in Utah Children

BackgroundFollowing widespread use of the Haemophilus influenzaeserotype b (Hib) vaccine,H. influenzae serotype a (Hia) has emerged as an important pathogen in children. Rates of Hia disease are particularly high in Utah. We describe the clinical features and molecular epidemiology of invasive Hia disease in children in Utah over 11 years.MethodsCases of invasive Hia disease in children less than 18 years were identified through electronic clinical and microbiology records. Demographic data and clinical outcomes were abstracted from the medical record for all cases. Available Hia isolates were collected for molecular analysis. Isolates were genotyped by multi-locus sequence typing (MLST) and clonal division was determined using sodC PCR. Presence or absence of the putative virulence-associated IS1016-bexA duplication-deletion was evaluated.ResultsWe identified 51 children with invasive Hia between 2007 and 2017. Median age was 11.3 months. The average annual incidence was 1.7 cases per 100,000 children aged <5 years (95% CI 1.2–2.2). Incidence was highest among children less than one year of age (4.8/100,000; 95% CI 3.1–6.9). Incidence rates were similar by race and ethnicity, although the confidence intervals were wide. The annual number of cases was similar over the 11-year study period (figure). The most common clinical manifestation was meningitis (54%; half had intracranial complications, 25% suffered hearing loss), followed by pneumonia (14%), and arthritis (14%). Twenty-two children (44%) required ICU care and one child died. Twenty-eight isolates (56%) were available for molecular analysis. ST62, clonal division II isolates caused 75% (21/28) of disease. No isolates contained the virulence-associated IS1016-bexA duplication-deletion.ConclusionHia is an important cause of severe invasive bacterial infection in Utah. Molecular analyses revealed that a majority of infections were caused by ST62 isolates, a clonal division II Hia type lacking the IS1016-bexA duplication-deletion. Hia ST62 has not been commonly reported in other settings, suggesting a unique molecular epidemiology in our population. Disclosures All authors: No reported disclosures.

A Seven-Year Evaluation of Viral Central Nervous System Infections

Identification of viral agents causing central nervous system (CNS) infections increased by the application of nucleic acid tests. In this study, the results of polymerase chain reaction (PCR) for viral agents were evaluated in cerebrospinal fluid (CSF) samples taken from patients with CNS infection. CSF samples taken from 1185 patients between 2010 and 2017 were tested for the presence of Herpes simplex virus (HSV) type 1 and 2, Varicella Zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), adenovirus ve enterovirus by PCR in Dokuz Eylul University Hospital. Tests were performed according to the clinicians' orders and results were evaluated retrospectively. The number of tests performed were 1038 for HSV, 882 for adenovirus, 865 for enterovirus, 496 for VZV, 100 for EBV and 92 for CMV. Commercial tests were used for EBV, CMV (Artus QS-RGQ Kits, Qiagen, Germany) and enterovirus (GeneXpert, Cepheid, USA) while the other viruses (HSV, VZV, adenovirus) were tested by in-house real-time PCR assays. Ninety-one CSF (7.7%) samples were positive. The mean age was 13 (<1 to 76 years) while median was seven. The most frequently detected pathogens were enterovirus (63/91, 69%) and HSV-1 (14/91,15%). The number of patients positive for adenovirus, VZV, EBV and CMV were five, four, three and two, respectively. In one patient, both enterovirus (Ct: 29.5) and EBV (Ct: 38.53) were positive. The number of positive samples were increased in summer months. Enterovirus RNA positive patients (n= 60/63, 95.2%) were ≤ 18 years old while 29% were younger than one year of age. Enterovirus positive samples peaked in 2012 and 2014 and detected mainly in summer (60.3%) and autumn (20.6%) months. VZV was mostly detected in patients greater than 65 years of age. Mean Ct of the positive reactions was 31.87 ± 3.5 (22.88-40.32). The lowest and the highest Ct values were detected in HSV-1 assay. The mean Ct value of enterovirus assay (30.4; 25.7-35.9) was lower than the other pathogens' values. In the seven-year period, 7.7% of the1185 patients' CSF samples were positive for viral nucleic acids. As expected, enteroviruses were the most common pathogens in children and detected mainly in summer-autumn period. Syndromic approach in CNS infections could increase the viral pathogen detection.

Relationship between urinalysis findings and responsible pathogens in children with urinary tract infections

Pyuria, presence of bacteria, leukocyte esterase, and nitrite positivity in urinalysis should be considered together, and simultaneous urine culture test should be performed in the diagnostic evaluation of urinary tract infection (UTI). The absence of pyuria in urinalysis cannot exclude UTI in patients with suggestive clinical findings. It was aimed to assess relationship between urinalysis tests and uropathogen and to evaluate antibiotic resistance in children. The study included patients (aged 0-18 years) with significant uropathogen growth in urine culture tests. The patients' data regarding age, gender, results of urine microscopy, urine culture, and antibiogram were recorded retrospectively. Overall, 705 patients (562 girls, 143 boys) with significant growth in urine culture test were included. Median age was 72 months among girls and 12 months among boys. Most common uropathogens were Escherichia coli (79.6%) and Klebsiella pneumoniae (8.2%). E. coli was more commonly among girls (87%) and Klebsiella spp. among boys (53.3%). Pyuria was positive in urinalysis in 75% of patients. Pyuria presence was more common in patients with E.coli or Proteus spp. (80.6% and 71.4%, respectively) than those with Enterococcus spp. and Klebsiella spp. (52.0% and 53.3%, respectively). In culture antibiogram tests, ampicillin resistance was 100% in Klebsiella oxytoca and Enterobacter spp. and 72% in E. coli strains. No ceftriaxone resistance was observed in K. oxytoca, Citrobacter spp., Pseudomonas aeruginosa, and Enterobacter spp. Most UTIs were seen in older girls. Pyuria might be lacking in UTIs associated to Klebsiella spp. and Enterococcus spp., and absence of pyuria may not exclude UTI in patients with compatible clinical findings. Ceftriaxone is still an option in empirical treatment; unnecessary use of third-generation cephalosporins should be avoided, particularly in infections other than UTI. It was found that E. coli more commonly caused leukocyturia, leukocyte esterase positivity, and pyuria; that pyuria might be lacking in UTIs associated to Klebsiella spp. and Enterococcus spp. and that pyuria was more prevalent among girls. It is though that urine culture tests should be performed in children with suspected UTI even in the absence of pyuria because lack of pyuria may lead delay in diagnosis and treatment as well as renal scar formation.

Infectious Causes of Acute Gastroenteritis in US Children Undergoing Allogeneic Hematopoietic Cell Transplant: A Longitudinal, Multicenter Study.

Acute gastroenteritis (AGE) in hematopoietic cell transplant (HCT) patients causes significant morbidity and mortality. Data regarding the longitudinal assessment of infectious pathogens during symptomatic AGE and asymptomatic periods, particularly in children, are limited. We investigated the prevalence of AGE-associated infectious pathogens in children undergoing allogeneic HCT. From March 2015 through May 2016, 31 pediatric patients at 4 US children's hospitals were enrolled and had stool collected weekly from pre-HCT through 100 days post-HCT for infectious AGE pathogens by molecular testing. Demographics, clinical symptoms, antimicrobials, vaccination history, and outcomes were manually abstracted from the medical record into a standardized case report form. We identified a pathogen in 18% (38/206) of samples, with many detections occurring during asymptomatic periods. Clostridioides difficile was the most commonly detected pathogen in 39% (15/38) of positive specimens, although only 20% (3/15) of C. difficile-positive specimens were obtained from children with diarrhea. Detection of sapovirus, in 21% (8/38) of pathogen-positive specimens, was commonly associated with AGE, with 87.5% of specimens obtained during symptomatic periods. Norovirus was not detected, and rotavirus was detected infrequently. Prolonged shedding of infectious pathogens was rare. This multicenter, prospective, longitudinal study suggests that the epidemiology of AGE pathogens identified from allogeneic HCT patients may be changing. Previously reported viruses, such as rotavirus and norovirus, may be less common due to widespread vaccination and institution of infection control precautions, and emerging viruses such as sapoviruses may be increasingly recognized due to the use of molecular diagnostics.

Identification of Enteropathogens by Multiplex PCR among Rural and Urban Guatemalan Children with Acute Diarrhea.

Multiplex polymerase chain reaction (PCR) platforms have enhanced understanding of intestinal pathogens in low- and middle-income countries (LMICs). However, few such studies have been performed in Latin America, where poverty, poor sanitation, and undernutrition persist. Multiplex PCR (BioFire, Salt Lake City, UT) was used to identify viral, bacterial, and parasitic pathogens in stool collected on day 1 and 31 from children aged 6 to 35 months with acute, non-bloody diarrhea in two locations (rural and urban) in Guatemala. We analyzed correlation between pathogens and clinical, demographic, and socioeconomic variables; described patterns of pathogen acquisition, persistence, and clearance over the 30-day period; and calculated population attributable fractions (PAFs) for diarrheal causation for individual pathogens. We analyzed 316 subjects (144 urban; 172 rural) enrolled between March 2015 and January 2016. Rural subjects had significantly more malnutrition, animal exposure, and unimproved water/sanitation infrastructure. The majority of subjects had multiple pathogens/sample (4.8 rural and 2.7 urban). Few meaningful correlates were identified between individual pathogens and clinical, demographic, or environmental variables. Escherichia coli pathotypes, Shigella, Campylobacter, and Giardia had high rates of persistence between initial and 30-day follow-up. Statistically significant adjusted PAFs were identified for Campylobacter (14.9%, 95% CI: 3.2-23.1), norovirus (10.2%, 95% CI: 0.4-17.1), sapovirus (7.6%, 95% CI: 2.3-10.9), and adenovirus 40/41 (5.6%, 95% CI: 0.3-8.7). These observations further characterize the diversity and complexity of enteric pathogens in children in LMICs. Patterns of chronic symptomatic and asymptomatic infection among Latin American children are similar to those observed in other LMIC regions. Findings have direct implications for practitioners treating individuals with acute infectious diarrhea and should inform regional public health strategies.

Concerning the discovery of mechanism for enterovirus B infection published in Cell.

Concerning the discovery of mechanism for enterovirus B infection published in Cell.

A retrospective analysis of the pathogens in the airways of patients with primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is a rare genetically heterogeneous disorder of motile cilia, which leads to recurrent and chronic airway infections. Detailed information about infection causing pathogens is scarce. With this study, we aimed to determine the prevalence and susceptibility of the most common respiratory pathogens in PCD patients retrospectively in a cross-sectional and the dynamics of the microbiological diversity in a longitudinal study. Microbiological and clinical data of 106 patients between 2010 and 2016 were analysed cross-sectionally and of 28 patients longitudinally. Dynamics in microbiological diversity were assessed by calculating the mean rate of alteration (MRA). Haemophilus influenzae was the most common pathogen (n = 41; 38.7%) followed by Staphylococcus aureus (n = 36; 34%), Moraxella catarrhalis (n = 18; 17%) and Pseudomonas aeruginosa (n = 16; 15.1%). Nontuberculous mycobacteria were cultured from two patients (1.9%). H. influenzae was the most prevalent pathogen in children (n = 31; 45.6%), S. aureus in adults (n = 15; 39%). Two patients were infected by methicillin-resistant S. aureus. P. aeruginosa was mostly susceptible to standard antibiotics with highest rates of resistance against fosfomycin (63.6%; 7/11). The culture of P. aeruginosa correlated negatively with age adjusted FEV1% predicted (p = 0.04), while the MRA was positively associated with age (rho 0.411, p = 0.032). In PCD patients, the prevalence of pathogens differed in children and adults with H. influenzae and S. aureus being the most common pathogens in children, S. aureus and P. aeruginosa in adults, respectively. Unexpectedly, the MRA increased by age.

Multi‐season analyses of causative pathogens in children hospitalized with asthma exacerbation

BackgroundRespiratory viral and mycoplasma infections are associated with childhood asthma exacerbations. Here, we explored epidemiologic profile of causative pathogens and possible factors for exacerbation in a single center over a three‐year period.MethodsHospitalized asthmatic children with attack aged 6 months‐17 years were recruited between 2012 and 2015 (n = 216). Nasopharyngeal mucosa cell samples were collected from the participants and examined by reverse transcription‐polymerase chain reaction to detect rhinovirus (RV), respiratory syncytial virus (RSV), enterovirus (EV), parainfluenza virus (PIV), Mycoplasma pneumoniae, and others. Clinical features, laboratory data, asthma exacerbation intensity, and asthma severity were compared among participants. Epidemiologic profile of causative pathogens and possible factors for exacerbation were explored.ResultsViruses and/or Mycoplasma pneumoniae were detected in 75% of the participants. Rhinovirus (48%) was the most commonly detected virus in the participants with single infection, followed by RSV (6%). The median age at admission in the RV group was significantly higher than that in the RSV group. Insufficient asthma control and allergen sensitization were significantly related to RV‐associated asthma exacerbation. There was no seasonality of pathogen types associated with asthma exacerbation although a sporadic prevalence of EV‐D68 was observehinovirud. Rhinovirus were repeatedly detected in multiple admission cases.ConclusionOur three‐year analysis revealed that patients with RV infection were significantly prone to repeated RV infection in the subsequent exacerbation and good asthma control could prevent RV‐associated asthma development and exacerbation. Multiple‐year monitoring allowed us to comprehend the profile of virus‐ and/or mycoplasma‐induced asthma exacerbation.

Diarrhea pathogens in rotavirus-negative infants in Hangzhou

Objective To investigate the distribution of diarrhea pathogens in infants without rotavirus-detection in Hangzhou. Methods 605 stool samples of children with rotavirus-negative diarrhea were collected from Hangzhou First People's Hospital of Zhejiang University, Children's Hospital of Zhejiang University and Hangzhou Children's Hospital from March 2017 to June 2018. The routine test results were analyzed retrospectively and Bristol score was used for the characteristics of stool samples. DNA and/or RNA were extracted from fecal samples with DNA and RNA extraction kit. The extracted DNA and RNA-reversed cDNA were used as templates. 7 common pathogens DNA and/or RNA were amplified by polymerase chain reaction (PCR). The amplified products were detected by agarose gel electrophoresis. The positive rates of pathogens were analyzed by chi-square test. Results Among 605 children, 375 were male(28±11) months and 230 were female (29±10) months. Bristol score of stool samples was mainly in type 6 (496, 82%), followed by type 7 (85, 14%) and type 5 (24, 4%). Among 605 results 97 cases were occult blood positive (positive rate 16%) and 170 cases were white blood cell positive (positive rate 28%).452 of 605 stool samples were positive for pathogen target genes. The positive rate was 74.7%. 319 cases detected single pathogen gene fragments. 127 cases detected two pathogen genes and 6 cases detected three pathogen gene fragments. The positive rate of Clostridium difficile toxin B (48.9%, 296/605)was the highest than the others, followed by Salmonella (20.0%, 121/605) and Norovirus (10.9%, 66/605). The positive rate of Clostridium difficile toxin A was 1.0% (6/605). The positive rates of pathogens in male and female children were 86.7% (325/375) and 86.5% (199/230) respectively, with (χ2=0.002, P=0.959). Conclusions Salmonella and Norovirus were the main pathogens in children with diarrhea who were negative for rotavirus detection in Hangzhou. The high positive rate of Clostridium difficile toxin B may be related to the colonization of Clostridium difficile in the gastrointestinal tract of infants rather than the pathogen of diarrhea because of the low positive rate of Clostridium difficile toxin A. There was no gender difference in the detection rate of diarrhea pathogens. Key words: Diarrhea; Salmonella; Norovirus; Bacterial toxins; Polymerase chain reaction; Epidemiologic studies

Evaluation of FilmArray respiratory panel for the rapid and multi-pathogen detection in children with severe pneumonia

Objective To evaluate the value of nested polymerase chain reaction (PCR) for the rapid detection of pathogens in children with severe pneumonia. Methods We prospectively enrolled the patients with severe community-acquired pneumonia admitted to pediatric intensive care unit (PICU) in Shanghai Children′s Hospital from January 2017 to June 2018.The sputum for PCR were collected within 24 h after PICU admission.Both nested PCR and routine microbiological methods were performed.Respiratory Panel (R-Panel) based on nested PCR could detect 17 kinds of respiratory pathogen at the same time. Results A total of 65 patients were enrolled in this study and the samples were detected using both R-Panel and routine microbiological method.(1) A total of 15 patients (23.08 %) showed positive routine microbiological detection including 13 cases with virus-positive and 2 cases with mycoplasma-positive; (2) A total of 38 patients (58.46%) showed positive results using R-Panel within 2 h including 46 cases with virus-positive and 5 cases with mycoplasma-positive.The mainly primary infection was human rhinovirus and enterovirus in 15 cases (23.08%), followed by adenovirus in 10 cases (15.38%); and the positive rate of 2 or more pathogens was 18.46% (12/65); (3) The rate of adenovirus-positive using R-Panel was significantly higher than that using routine microbiological methods (15.38 % vs.4.62%, χ2=4.188, P=0.041); the sensitivity of R-Panel for detection of adenovirus, respiratory syncytial virus, and parainfluenza virus was significantly higher than those of routine microbiological methods (100% vs.30%, χ2=107.692; 50.00% vs.16.67%, χ2=24.442; 100% vs.80%, χ2=22.222; 100% vs.40%, χ2=85.714; all P<0.001). Conclusion R-Panel using nested PCR is a rapid, sensitive, and specific method for the detection of pathogens in children with severe community acquired pneumonia, which is valuable for targeted therapy in time. Key words: Severe pneumonia; Respiratory panel (R-Panel); Multiplex polymerase chain reaction; Critically ill; Children