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Streptococcus pneumoniae (pneumococcus) is the most common respiratory pathogen worldwide. Nasopharyngeal carriage with S. pneumoniae is the major source of lower respiratory tract infection and horizontal spread among children. Investigating nasopharyngeal S. pneumoniae is crucial for clinicians to control pneumococcus disease. Here, we retrospectively analyzed clinical information of 5,960 hospitalized children, focusing on pneumonia children less than five years with positive nasopharyngeal pneumococcal cultures. Nasopharyngeal aspirates (NPAs) were collected between June 2009 and December 2016, which were outside the pneumococcal conjugate vaccine(PCV) period. NPAs were subjected to common bacterial culture and antibiotic susceptibility tests, and serotypes were identified by both multiplex PCR and DNA sequencing. Results clearly revealed that clinical manifestations of the children whose NPAs were S. pneumoniae culture positive were serious, especially in those less than twelve months old. Fifteen different serotypes of nasopharyngeal S. pneumoniae were detected, the most common ones being 19F (35.2%), 6A/B (23.8%), 19A (11.4%), 15B/C (9.3%) and 23F (7.8%). Eight serotypes, accounting for 85.5% of the isolates, corresponded to the PCV13 serotypes. Approximately one-third of all S. pneumoniae strains were susceptible to penicillin. Overall, we consider nasopharyngeal S. pneumoniae culture is beneficial in assessing the situations of pneumonia children. Moreover, PCV13 could be useful in preventing pneumococcal disease in Chongqing, China.

Secondary thrombocytosis (ST) is frequently observed in children with a variety of clinical conditions. The leading cause of ST is respiratory tract infection (RTI) in children. Nasopharyngeal aspirate samples were collected and assessed for common respiratory viruses. The relationships between virus infections and secondary thrombocytosis were analyzed retrospectively. The blood platelet count and the presence of respiratory viruses were determined for 3156 RTI patients, and 817 (25.9%) cases with platelet ≥500 × 10(9)/L were considered as the thrombocytosis group. Compared with the normal group, the detection rates of respiratory syncytial virus (RSV) and human rhinovirus (HRV) were significantly higher in the thrombocytosis group (P = 0.017 and 0.042, respectively). HRV single infection was a risk factor associated with thrombocytosis [odds ratio (OR) = 1.560, 95% confidence interval (CI) = 1.108-2.197]. Furthermore, ST was more likely to occur in younger patients who had clinical manifestations of wheezing and dyspnea and who had been diagnosed with bronchiolitis. Furthermore, the course of disease lasted longer in these patients. ST is associated with viral respiratory tract infections, especially RSV and HRV infections. HRV single infection is a risk factor associated with thrombocytosis.

The epidemiology and clinical features of the Saffold cardiovirus (SAFV) remain ambiguous. The present study was designed to systematically and intensively investigate the epidemiological features of SAFV in pediatric patients in China. Three cohorts of pediatric patients were recruited from 2009 to 2012. Cohort 1 comprised patients with acute respiratory tract infections. Cohort 2 comprised patients with diarrhea. Cohort 3 comprised hand, foot, and mouth disease (HFMD) patients. A total of 115 patients (1.6%) among 6052 (17/1647, 12/2013, and 86/2392 in cohorts 1, 2, and 3, respectively) were SAFV-positive. The samples from 82 SAFV-positive patients were successfully sequenced, and four genotypes were identified: 8 SAFV-1, 41 SAFV-2, 29 SAFV-3, and 4 SAFV-6. A significantly higher detection rate was found in the HFMD patients than in other two cohorts (both P <0.001). A higher frequency of severe clinical outcome and nervous system manifestation were also observed in the SAFV-positive HFMD patients. Additionally, 6 (3.5%) cerebrospinal fluid and 7 (2.2%) serum samples from the HFMD-associated encephalitis patients were SAFV-positive. Based on the VP1 sequences, all four genotypes displayed distinct geographical clustering. SAFV infection might be associated with a wide clinical spectrum and contribute to HFMD.