1.Epidemiology of rubella and its viral genetic characterization in China, 2021-2022
Cheng QIAN ; Ying LIU ; Jianlin CAI ; Aili CUI ; Liqun LI ; Lixia FAN ; Li LIU ; Shujie ZHOU ; Ying CHEN ; Xiaoxian CUI ; Naiying MAO ; Yan ZHANG ; Zhen ZHU
Chinese Journal of Experimental and Clinical Virology 2024;38(1):49-57
Objective:To understand the epidemiology of rubella and the genetic characteristics of the virus circulating during the period 2021-2022, providing basic scientific data for rubella prevention and control in China.Methods:National rubella incidence data for the period 2021-2022 were obtained from the Infectious Disease Surveillance System module and the Surveillance Report Management module of the China′s Disease Prevention and Control Information System. Positive rubella virus(RuV)isolates were obtained from the National Measles/Rubella Laboratory Network. Two nucleotide (nt) fragments [F1-480 (8 633-9 112 nt) and F2-633 (8 945-9 577 nt)] located in the E1 gene were amplified and determined by reverse transcription polymerase chain reaction (RT-PCR), and the target gene (E1-739) was obtained after collating and splicing. The sequences obtained in this study were used to construct a phylogenetic tree with the reported reference strains for genotype and lineage identification. Additionally, the phylogenetic analysis was performed to assess their genetic relatedness of RuV strains prevalent in China during 2018-2020 from GenBank database.Results:In 2021-2022, the rubella incidence in China was 0.06/100, 000 (2021: 840 cases; 2022: 784 cases), with cases primarily concentrated in the western and southern provinces. Age distribution analysis showed that rubella cases in 2021-2022 was mainly in children under 5 years of age (2021: 34.17%, 287/840; 2022: 42.09%, 330/784), with the highest proportion in children aged 0-2 years. Further analysis of the immunization history of cases revealed that in the 8-23 months age group, a significant proportion of cases had received only one dose of rubella containing vaccine (RCV); cases in the 2-14 years age group were mainly among children who had received two or more doses of RCV; however, cases over 15 years of age were primarily found in individuals who had not received RCV or had unknown immunization history. National virological surveillance data showed that totally 22 RuV virus isolates were obtained, from 6 provinces in China during 2021-2022, which belonged to lineage 1E-L2 (11 strains) and 2B-L2c (11 strains). And these viruses displayed high genetic homology with RuV prevalent from 2018 to 2020.Conclusions:The incidence of rubella in China was maintained at a low level during 2021-2022, and the prevalent RuV strains were lineage 1E-L2 and 2B-L2c.
2.Isolation and identification of a severe acute respiratory syndrome coronavirus 2 strain in feces from COVID-19 patients in Shanghai
Yanqiu ZHOU ; Xiaoxian CUI ; Jiabin MOU ; Fanghao FANG ; Zheng TENG ; Huanyu WU ; Min CHEN ; Xi ZHANG
Shanghai Journal of Preventive Medicine 2022;34(12):1173-1179
ObjectiveTo isolate and study the biological characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from feces of coronavirus disease 2019 (COVID-19) patients. MethodsVero E6 cells were used for virus isolation and the isolated strains were tested by nucleic acid test, immunofluorescence test, virulence test and whole genome sequencing. 50% tissue culture infective dose (TCID50) was calculated after the cell cultures of each generation were collected ResultsEight fecal specimens were inoculated with Vero E6 cells after treatment and cultured for 48 h. One specimen showed obvious cytopathic effect on Vero E6 cells. One SARS-CoV-2 out of 8 fecal samples from COVID-19 patients were isolated, and separation rate was 12.5%. The TCID50 of P1, P2 and P3 were 104.0/0.2 mL, 104.5/0.2 mL and 104.75/0.2 mL, respectively. Only one of the 8 stool samples had SARS-CoV-2 virus replication and amplification, and the Ct value of the nucleic acid detection was about 10. The sequence of the isolation was more than 99.99% homologous with that of Wuhan-Hu-1(GenBank MN908947). ConclusionThe SARS-CoV-2 strain is isolated from the fecal samples of COVID-19 cases and is confirmed by genomic sequencing and immunofluorescence test, which indicates the presence of live virus in feces of COVID-19 cases.
3.Analysis of the suspected cases of measles and rubella in Pudong New Area of Shanghai, 2013‒2022
Xiao WANG ; Aihua ZHANG ; Huiqin FU ; Yuying YANG ; Xiaoxian CUI ; Lipeng HAO ; Yanqiu ZHOU ; Lifeng PAN
Shanghai Journal of Preventive Medicine 2024;36(6):534-539
ObjectiveTo analyze the epidemic characteristics of measles and rubella in Pudong New Area of Shanghai from 2013 to 2022, and to provide data support for the elimination of measles and rubella. MethodsEnzyme linked immunosorbent assay was used to detect IgM antibodies in serum samples. The sequence of 630 nucleotides at the C-terminal of N gene of measles virus was amplified by reverse transcription-polymerase chain reaction and the phylogenic tree was constructed. ResultsA total of 1 529 suspected cases of measles were detected from 2013 to 2022, among which the positive rate of measles IgM antibody was 33.55% (513/1 529). The highest positive rate (20.73%) was from March to May , and the positive rate of rubella IgM antibody was 6.80% (104/1 529). The positive rate of both IgM was higher in males than that in females (P<0.05). The IgM against measles was mainly detected in 0‒ years old (63.16%, 96/152) and 20‒ years old (45.61%, 161/353). The IgM against rubella was mainly detected in 10‒20 years old (27.27%, 18/66). The IgM antibody could be detected more easily from 4 to 28 days after eruption, and the IgM antibody positive rate of measles/rubella from 2020 to 2022 was significantly lower than previous years (2013‒2019). There were 2 D8 genotype strains, and the rest were H1a gene subtypes. ConclusionThe positive rate of IgM antibodies against measles/rubella in Pudong New Area of Shanghai decreased significantly. People aged 0‒ years and 20‒ years old are more susceptible to measles, and rubella is concentrated in 10‒ years old. It is necessary to strengthen the vaccination of school-age children, in order to achieve the goal of eliminating measles. The age group with high risk of exposure should be checked for vaccination status to ensure the enhanced immunization, and the surveillance of imported measles cases should be strengthened.