The influence of Streptococcus pneumoniae nasopharyngeal colonization on the clinical outcome of the respiratory tract infections in preschool children

Background: Streptococcus pneumoniae (SPn) is an important pathogen causing a variety of clinical manifestations. The effects of SPn nasopharyngeal colonization on respiratory tract infections are poorly studied. We evaluated the association of SPn colonization with features of respiratory tract infections. Methods: Children under the age of 6 years who visited a primary care physician because of respiratory tract infections were enrolled in the study. History was taken, children were clinically assessed by the physician, and nasopharyngeal swabs were obtained and cultured for SPn. Positive samples were serotyped. Associations of SPn colonization with clinical signs and symptoms, recovery duration, absence from day care centre, frequencies of specific diagnoses, and treatment with antimicrobials were evaluated. Results: In total 900 children were enrolled. The prevalence of SPn colonization was 40.8 % (n = 367). There were minor differences between male and female subjects (199 of 492, 40.4 % vs 168 of 408, 41.2 %, p = 0.825). Children with and without siblings had similar colonization rates (145 of 334, 43.4 % vs 219 of 562, 39.0 %, p = 0.187). Clinical signs and symptoms were not associated with SPn colonization. Children colonized with SPn had longer recovery duration compared to non-colonized children (114 of 367, 31.1 % vs 98 of 533, 18.4 %, p < 0.001) and were longer absent from day care (270 of 608, 44.4 % vs 94 of 284, 33.1 %, p = 0.001). Pneumonia, sinusitis, and acute otitis media were more frequently diagnosed in children colonized with SPn. Children attending day care centres had significantly higher prevalence of SPn colonization (270 of 367, 44.4 % vs 338 of 533, 33.1 %, p = 0.001). Children with pneumonia, sinusitis and acute otitis media were more frequently treated with antimicrobials than children with other diagnoses. Conclusions: SPn nasopharyngeal colonization has a negative impact on the course of respiratory tract infection, likely because of SPn being the cause of the disease or a complicating factor. It is also associated with and may be responsible for higher frequencies of bronchitis, pneumonia, acute otitis media, sinusitis and the need of antimicrobial treatment

Antibiotic resistance of Streptococcus pneumoniae, isolated from nasopharynx of preschool children with acute respiratory tract infection in Lithuania

Background: Increasing pneumococcal resistance to commonly used antibiotics and multidrug resistance is a serious public health concern. Data on distribution of resistant Streptococcus pneumoniae (SPn) strains among children in Lithuania are limited. We evaluated the circulation of SPn serotypes and antimicrobial susceptibility among preschool children in Lithuania before the introduction of universal infant pneumococcal vaccination. Methods: A prospective study was carried out from February 2012 to March 2013 in five cities of Lithuania. A total of 900 children under six years of age who presented to primary care centre or a hospital emergency department with acute respiratory tract infection were enrolled in the study. Nasopharyngeal swabs were obtained and cultured for SPn. Positive samples (n = 367) were serotyped and tested for antimicrobial susceptibility. Associations of pneumococcal non-susceptibility with study site, season, age, sex, attendance of day care centre and treatment with antimicrobials (between one and six months prior the study) were evaluated. Results: About a half (56.7 %) of SPn strains were susceptible to all the antibiotics tested. Pneumococcal non-susceptibility to penicillin, erythromycin, clindamycin and trimethoprim–sulphamethoxazole was 15.8, 21.3, 16.9 and 27.3 %, respectively. None of the tested isolates was resistant to norfloxacin or vancomycin. We found a geographical variation of pneumococcal resistance within the cities of the country. Age, sex, the attendance of day care centre and treatment with antimicrobials prior the study was not significantly associated with a carriage of non-susceptible SPn strains. Among non-susceptible SPn serotypes 67.9 %–82.4 % were present in currently available pneumococcal conjugate vaccines. Conclusions: The rates of nasopharyngeal SPn susceptibility to penicillin and macrolides are still high among preschool children in Lithuania, however they are lower compared with previous studies. A strict policy with respect to antibiotic prescription together with widespread use of vaccination could potentially reduce the carriage rate of antibiotic-resistant pneumococci in our country

SERPINA1 gene polymorphisms in a population‐based ALSPAC cohort

Background: There is an association between persistent preschool wheezing phenotypes and school-age asthma. These wheezing/asthma phenotypes likely represent clinical entities having specific genetic risk factors. The SERPINA1 gene encodes α 1-antitrypsin (AAT), and mutations in the gene are important in the pathophysiology of pulmonary diseases. We hypothesized that there might be an association between SERPINA1 gene polymorphisms and the risk of developing wheezing/school age asthma. Objective: To examine 10 single nucleotide polymorphisms (SNPs) of SERPINA1 (rs6647, rs11832, rs17580, rs709932, rs1243160, rs2854254, rs8004738, rs17751769, rs28929470, and rs28929474) and relate them to childhood wheezing phenotypes and doctor-diagnosed asthma in the population-based Avon Longitudinal Study of Parents and Children (ALSPAC) cohort. Methods: Wheeze data, reports of physician-diagnosed asthma and data on the SERPINA1 gene SNPs, were available for 7964 children. Binary logistic regression was used to assess the associations between allele prevalence and wheezing and asthma phenotypes. P values were adjusted to account for multiple hypotheses using the Benjamini-Hochberg false discovery rate. Results: Only within a subgroup of children with asthma who had no prior diagnosis of preschool wheeze was there a trend for association between rs28929474 (Glu342Lys, Pi*Z causing AAT deficiency; P =.0058, adjusted P =.058). No SNP was associated with wheezing and asthma in those with preschool wheeze. Conclusion: Analyzed SNPs in SERPINA1 are not associated with wheezing/asthma phenotypes. Only rs28929474, the most common pathologic SNP (Pi*Z) in the SERPINA1 gene, might be associated with a risk of developing school-age asthma without exhibiting preschool wheeze