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Background Early and accurate identification of infection viruses among children can benefit the personalized medical treatment and management, and reduce the future occurrence of serious symptoms. Thus, it is critical to develop a high-throughput multiplex real-time RT-PCR method to improve the accuracy and efficiency in routine clinical lab tests. Methods We developed a real time RT-PCR combined with melting curve analysis (RRCMC) method for simultaneous detection of rotavirus A, B, C, norovirus GI and GII, adenovirus, astrovirus and sapovirus. Results Stool samples were collected from 160 children with acute diarrhea and tested by RRCMC assay. A total of 71 patients were tested positive with norovirus, adenovirus or rotavirus. The RRCMC assay has high specificity. There is no internal cross-reaction among the 8 diarrhea viruses and no cross-reaction of other commonly intestinal pathogens and human genome. The limit detection was ranged from 1 × 102 to 1 × 105 nucleic acid copies/ml for each diarrhea virus. Conclusion The RRCMC method is a suitable rapid clinical test for infectious viruses, with the advantages of high-throughput, low cost, high sensitivity and specificity.

Human metapneumovirus (HMPV), which is distributed worldwide, is a significant viral respiratory pathogen responsible for causing acute respiratory tract infections (ARTIs) in children. The aim of the present study was to investigate the epidemiological and genetic characteristics of HMPV in pediatric patients in Hangzhou China following the peak of onset of coronavirus disease 2019 (COVID‐19). A total of 1442 throat swabs were collected from the pediatric patients with a diagnosis of ARTI from November 2020 to March 2021. The following viruses were detected by real‐time polymerase chain reaction analysis: HMPV, RSV, adenovirus, hPIV1‐3, influenza A, and influenza B. A two‐step method was used to amplify the F genes of the HMPV‐positive samples. Following sequencing, phylogenetic analyses were conducted using the MEGA version 7 software package. Among the 1442 samples, 103 (7.14%) were positive for HMPV. No significant differences were observed in the gender distribution. The highest incidence of HMPV occurred in children older than 6 years and the lowest was noted in children younger than 6 months. Lower respiratory tract infections were diagnosed at a higher rate than upper respiratory tract infections in HMPV‐infected children. Only 10 HMPV‐infected children (5.41%) were inpatients compared with 93 outpatients (7.39%). Co‐infection was observed in 31 HMPV‐positive samples including 24 samples of double infection and seven samples of triple infection. A total of 61F gene fragments of HMPV, which were approximately 727 bp in length were successfully sequenced. All the HMPVs belonged to the genotype B and were clustered into subgenotypes B1 (1.6%, 1/61) and B2 (98.4%, 60/61). A total of four specific amino acid substitutions were noted as follows: aa280, aa296, aa392, and aa396. These substitutions were present between sequences derived from the subgenotypes B1 and B2 in the fusion open reading frame from position 244 to 429. In conclusion, the present study provided significant information regarding the epidemiological and genetic characteristics of HMPV in children living in Hangzhou. Following the first peak of the COVID‐19 pandemic, HMPV was considered an important viral respiratory pathogen present in children with ARTI.

Objective Our aim was to investigate the association between gene polymorphisms in catalase (CAT), a well-known oxidative stress regulator, and susceptibility to idiopathic nephrotic syndrome (INS) or responses to steroid therapy in a Chinese pediatric population. Methods We analyzed 3 CAT single-nucleotide polymorphisms (SNVs; rs7943316, rs769217, and rs12270780) using multi-polymerase chain reaction combined with next-generation sequencing in 183 INS patients and 100 healthy controls. Results For the allele and genotype frequencies of the CAT SNVs, no significant differences were observed between INS patients and controls. Patients with C allele of CAT rs769217 had a higher risk of developing steroid-dependent nephrotic syndrome than the steroid-sensitive nephrotic syndrome patients (P = 0.018; odds ratio = 1.76). Conclusion Our data suggests that genetic variations in CAT were unlikely to confer susceptibility to INS in Chinese children, whereas the C allele of the CAT rs769217 polymorphism showed a strong association with steroid-dependent responses in Chinese INS children.

Objective Acute respiratory tract infection (ARTI) is one of the main diseases in childhood. This study aimed to monitor the distribution of respiratory tract viruses in children with ARTI in the impact of coronavirus disease 2019 (COVID-19). Methods We conducted surveillance of 2019 novel coronavirus, human metapneumovirus, respiratory syncytial virus, human adenovirus, human parainfluenza virus 1–3, and influenza A and B virus by using quantitative real-time polymerase chain reaction. Results During the winter of 2020 to 2021, among the 1,442 throat swabs we collected, 937 (64.98%, 937/1,442) were positive for respiratory viruses. Respiratory syncytial virus was the most frequently detected respiratory virus (34.12%, 492/1,442) and 2019 novel coronavirus and influenza A and B virus were not detected in the study period. Coinfection was observed in 156 positive samples including 149 samples of double infection and 7 of triple infection. The positive rate of viral respiratory tract infection in infants less than 6 months was the highest (72.95%) in the study period. Conclusion There are some differences in the distribution of respiratory viruses in children after the outbreak of COVID-19 in Hangzhou, China.