SARS-CoV-2 Variant Surveillance Using Tandem Targeted RT-PCR-based Genotyping Assays and Whole Genome Sequencing

Genomic surveillance is critical for tracking SARS-CoV-2 Variants of Concern (VOC) and for rapid detection of emerging variants. Whole genome sequencing (WGS) is the predominant method for genomic surveillance; but it is a laborious process for large-scale testing. The aim of this study was to assess the performance of a PCR-based mutation panel for the discrimination of 5 known VOC; Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2) and Omicron (B.1.1.529). Genotyping analysis was performed on 128 SARS-CoV-2 positive samples collected at the Life Science Testing Center at Northeastern University from April-December 2021. RNA extraction was performed using MagMax Viral/Pathogen II Nucleic Acid Isolation Kit. SARS-CoV-2 detection was confirmed using the TaqPath COVID-19 Combo Kit. Variant determination was conducted using a panel of TaqMan SARS-CoV-2 single nucleotide polymorphism (SNP) assays. On November 25, 2021, the emerging VOC (Omicron) was reported by South Africa and the panel was quickly modified to detect Omicron by substituting P681H and K417N assays. Based on the SNP panel analysis, variant identification in 128 samples were as follows: Alpha (N=34), Beta (N=1), Gamma (N=7), Delta (N=41) and Omicron (N=21). The genotyping panel accurately assigned lineages to 104 samples, confirmed by Ion Torrent GeneStudio S5 WGS. VOC discrimination using RT-PCR genotyping is a rapid, versatile method for detecting known and emerging SARS-CoV-2 variants. The versatility of SNP panels allows monitoring of emerging strains by simple layout adaptations. RT-PCR genotyping assays can expedite variant identification, enable high-throughput variant surveillance, and support WGS prioritization for detection of new variants.

[The related factors influencing development of language understanding and expression of early-children].

OBJECTIVE: To assess the level of language understanding and expression of healthy children aged from 8 to 16 months in urban Beijing and to investigate the children's physical and psychological development conditions and social and economic status of children's family as to identifying the related factors to children's language development and providing a basis for instructing parents child-rearing and promoting early children language development. METHODS: A quantitative Cross-sectional Study was made. The parents or care givers of 636 healthy young children, randomly stratified and selected in two districts in Beijing were interviewed. T-test was used to compare the scores of language understanding and expression between boys and girls in the same age. Single and multiple factors analysis were used so as to find out the related factors. RESULTS: For boys, the average scores of language were respectively 115.0 for 8 months, 243.0 for 12 months and 410.6 for 16 months; for girls the average scores were respectively 109.9 for 8 months, 286.4 for 12 months and 456.2 for 16 months. The average score of language understanding of boys was higher than that of girls only in the 11 month group. The average scores of language expression of girls were higher than those of boys in 11, 12, 14, 15 month groups. Multiple factors analysis showed that parent-child book reading, parent-child tape listening, higher education level of grandmothers, children' extroversion personality, child being able to speak one word and children's age were positively related to the children' language score. CONCLUSION: Providing rich language environment should be helpful to early children's language development.

Individual and family factors influencing vocabulary development in toddlers / 中华儿科杂志

<p><b>OBJECTIVE</b>Many researchers have conducted studies on child language development and relevant risk factors, but most of these studies were about English-speaking children and few of them were on Chinese-speaking children, and less reports of studies on language development of infants or toddlers are available as compared to those on children above 3 years of age. The objective of this study was to assess the level of vocabulary development of healthy toddlers in urban Beijing and to investigate toddlers' physical and psychological development and socioeconomic status of toddlers' family so as to identify factors related to toddlers' language development and provide basis for instructing parents child-rearing.</p><p><b>METHOD</b>This is a quantitative cross-sectional study. Using Chinese Communicative Development Inventory mandarin version, (CCDI) and related background questionnaire, a survey was conducted among the parents or care givers of 1056 healthy toddlers (16 approximately 30 months), randomly stratified and selected from two areas of four urban districts in Beijing. The children who were born prematurely, who had low birth weight, or who were deaf, dumb or with disability, were excluded from this study. The mothers who were deaf, dumb or having disability were not included in this study, either. Rank sum test was used to compare the vocabulary scores between boys and girls at the same age. Single and multiple factors analysis were used to find related factors.</p><p><b>RESULTS</b>By 16 months of age, boys could speak about 22 words and girls 84 words on the CCDI. By 29 - 30 months of age, boys could speak about 725 words and girls 752 words on the CCDI. The level of vocabulary development of healthy toddlers in urban Beijing was higher than that reported in previous studies of English-speaking children. Girls had higher vocabulary scores than boys in a few different age groups. Single factor analysis showed that the ages of father and mother, income of father, the language used by care-givers and GDP of the families were factors related to families of toddlers and the age, gender, height, weight and the age at which the toddlers began to speak were factors related to individuals. Multiple factors analysis showed that higher education level of mothers, younger father, earlier beginning of children to speak, toddlers' amiable disposition and emotion, girls, toddlers' age and height positively correlated with toddlers' vocabulary score.</p><p><b>CONCLUSION</b>The level of vocabulary development of healthy toddlers in urban Beijing is on the high side. Certain individual and familial factors may influence toddlers' language development. It is suggested that health workers should pay attention to the toddlers' language development. The toddlers' parents and caregivers should be taught how to interact with and talk to their children and how to promote children to develop healthy disposition and emotion.</p>