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@#Objective To understand the epidemiological characteristics of rubella in Liaoning Province in 2019,and analyze the epidemiological characteristics of rubella virus genotypes and gene subtypes at molecular level.Methods By collecting the incidence data of rubella in Liaoning Province in 2019 from the national notifiable infectious diseases reporting system,the epidemiological characteristics of rubella were analyzed.At the same time,the measles/rubella laboratory network of Liaoning Province was used to collect throat swab samples from suspected rubella outbreaks and sporadic cases.After three generations of blind transmission of positive samples,rubella virus isolates were obtained.Viral nucleic acid was extracted,amplified and the 739 bp nucleotide fragment sequence of E1 gene of positive rubella virus isolates was determined.The phylogenetic tree was constructed with the genotype reference strain sequences recommended by WHO and the published gene subtype reference strain sequences.The genotypes and subtypes were compared and the amino acid variation sites were analyzed.Results The reported incidence of rubella in Liaoning Province in 2019 was 0.927/100 000,which showed an obvious trend of recovery after a significant decrease in the incidence of rubella from 2017 to 2018,and the age of rubella patients was mainly 15 to 19 years old.A total of 55 rubella virus strains were isolated from 7 cities in Liaoning Province in 2019.Sequence phylogenetic analysis showed that all rubella isolates belonged to 1E-L2 gene subtype,which was also the dominant gene subtype of rubella epidemic in China.The nucleotide and amino acid homology among the strains were 99.051%～99.864% and 98.780%～100% respectively.Compared with the BRD-Ⅱ vaccine strain,the rubella isolates mainly showed A333T mutation and showed highly conserved amino acid sequence.Conclusion The 2019 rubella isolates in Liaoning Province were all 1E-L2 gene subtypes,which led to the resurgence of rubella epidemic.Therefore,molecular epidemiological surveillance of rubella virus should be further strengthened to provide a basis for the formulation and elimination of rubella prevention and control measures in Liaoning Province.
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@#Abstract: Objective By collecting and sorting the information of varicella cases reported in Liaoning Province from 2006 to 2021, the epidemiological characteristics were analyzed, and the monthly incidence data were predicted, so as to explore the prevention and control strategy of varicella disease in Liaoning Province. Methods By collecting the characteristic information of varicella cases in Liaoning Province, epidemiological analysis was carried out on the regional, population, and temporal characteristics of varicella incidence. The monthly incidence data of varicella were fitted with Eviews software, seasonal ARIMA model was used for modeling, and models were selected according to SC and AIC. After modeling, the model was used to predict the incidence data in 2022. Results The incidence rate of varicella in Liaoning Province has increased in recent years. The onset time was "bimodal distribution", with the main peak occurring from November to January of the next year and the secondary peak occurring from May to June. Since 2019, the onset age has shifted backward. From the original 0-<10 age group with the highest incidence rate, it shifted to the 10-<20 age group with the highest incidence rate. From 2006 to 2021, the incidence of varicella mainly concentrated in people aged 0 to <40 years old, and the incidence rate of the population over 40 years old showed a cliff-like decline. The incidence of chickenpox was higher in the central region of Liaoning Province, such as Shenyang, Dalian, Anshan and Panjin, and relatively low in Huludao, Jinzhou, Fuxin and Liaoyang. The distribution of the population was mainly students, followed by kindergartens and scattered children. ARIMA model of monthly incidence data was established by software as ARIMA (1, 0, 1) (1, 1, 1)12. Conclusions The incidence rate of varicella in Liaoning Province has been rising in recent years. The incidence is obviously seasonal, and the age group of the affected population has moved backward. It is predicted that the incidence will continue to increase in 2022. The prevention and control of varicella should still be the current key work. In order to reduce the population incidence rate, two-dose vaccination strategies should be vigorously promoted the implementation of the, and the inclusion of varicella vaccine in the immunization program should be achieved as soon as possible.
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@#Abstract：Objective To carry out serological analysis of varicella⁃zoster virus（VZV）IgG antibody level in healthy people aged 1 ~ 30 years in Liaoning Province. Methods In October 2020，3～5 mL venous blood samples were collected from 617 healthy people aged 1～30 years selected from six counties and districts in Shenyang，Fuxin and Dandong of Liaoning Province by stratified random sampling method，of which serum samples were collected and determined for VZV IgG antibody level by ELISA. The positive rate of serum antibody and geometric mean concentration（GMC）of antibody were calculated and compared. Results Among 617 serum samples，302 samples were positive for VZV IgG antibody，the positive rate was 48. 947%，and the GMC was 112. 772 mIU／mL. The positive rate of VZV IgG antibody was 29. 670%～75. 789% and the GMC was 45. 508～366. 559 mIU／mL in healthy people of various ages. Both of the antibody positive rate（χ2 = 67. 104， P < 0. 001）and GMC（F = 20. 685，P < 0. 001）showed significant differences. The positive rates of VZV IgG antibody in male and female were 44. 817% and 53. 633% respectively，which showed significant difference（χ2 = 4. 779，P = 0. 029）， while the GMCs were 96. 983 and 133. 829 mIU／mL respectively（t = -1. 958，P = 0. 051）with no significant difference. The positive rates of VZV IgG antibody of healthy people in Shenyang，Fuxin and Dandong of Liaoning Province were 55. 224%，40. 201% and 51. 152% respectively with significant differences（χ2 = 9. 683，P = 0. 008），of which the positive rate of FuxinwassignificantlylowerthanthoseofShenyangandDandong（χ2 =9. 046and5. 013，P =0. 003and0. 025，respectively）； While the GMCs were 133. 523，85. 953 and 123. 713 mIU／mL respectively with no significant difference（F = 0. 514， P = 0. 598）. Among 617 serum samples，54 sampleswere suspicious，which remained within the criticalrange afterre⁃examina⁃ tion，while the gap between positive rate and the total percentage of positive and suspicious results gradually decreased with the increase of age，indicating that the immunity to varicella gradually increased with the increase of age. Conclusion The VZV⁃IgG antibody level of healthy people aged 1～30 years in Liaoning Province increased gradually with age，while the overall level was low. To control the spread of varicella virus，it is recommended to increase varicella vaccine coverage in vulnerable areas and susceptible population to build VZV immune barrier.