OBJECTIVETo analyze the polio immunity level of persistent population in Beijing, 2012.

METHODSA total of 1 676 subjects residing more than 6 months in Beijing were selected by stratified random cluster sampling design in 2012. Demographic characteristics, history of oral poliovirus vaccine (OPV) immunization were investigated by questionnaire. All 5 ml blood sample were collected for testing of polio neutralizing antibody using the method of microcell neutralization. The positive rate and the geometric mean titer (GMT) of polio neutralizing antibody type I, II and III were analyzed in different groups.

RESULTSThe positive rate of type I, II and III were 98.2% (1 645/1 676), 98.1% (1 644/1 676), 97.6% (1 635/1 676); The GMT were 1:130.2, 1: 113.4 and 1: 79.7. Three types of positive rates in<15 years group (99.7% (664/666), 99.8% (665/666), 99.5% (663/666)) were higher than those of ≥ 15 years group (97.1% (981/1 010), 96.9% (979/1 010), 96.2% (972/1 010)), the differences were significant (all the values of P < 0.01); The GMT in<15 years group (1:325.9, 1:250.5, 1:190.7) were higher than that of ≥ 15 years group (1: 71.1, 1: 67.2, 1: 44.8), the difference was significant (all the values of P < 0.01). The positive rate (99.0%-100%) and GMT (1: 128.8-1: 300.7) in vaccination information confirmed population were higher. The highest positive rate (all were 100%) and GMT(1: 409.7-1: 636.7) were observed in children who vaccinated three times.

CONCLUSIONThe polio antibody of healthy population was at a high level in Beijing in 2012; Especially the age groups of < 15 years which were covered by vaccines.Immunization barrier had been formed firmly to interrupt the transmission of wild poliovirus and vaccine-derived poliovirus.

Adaptive Immunity ; Adolescent ; Antibodies, Neutralizing ; Antibodies, Viral ; Child ; Humans ; Poliomyelitis ; Poliovirus ; Poliovirus Vaccine, Oral ; Vaccination ; statistics & numerical data

Objective To analyze the polio immunity level of persistent population in Beijing , 2012.Methods A total of 1 676 subjects residing more than 6 months in Beijing were selected by stratified random cluster sampling design in 2012.Demographic characteristics , history of oral poliovirus vaccine ( OPV) immunization were investigated by questionnaire.All 5 ml blood sample were collected for testing of polio neutralizing antibody using the method of microcell neutralization.The positive rate and the geometric mean titer ( GMT ) of polio neutralizing antibody type Ⅰ,Ⅱ and Ⅲ were analyzed in different groups.Results The positive rate of type Ⅰ,Ⅱ and Ⅲ were 98.2%( 1 645/1 676 ) , 98.1%( 1 644/1 676),97.6%(1 635/1 676);The GMT were 1∶130.2,1∶113.4 and 1∶79.7.Three types of positive rates in<15 years group(99.7%(664/666),99.8%(665/666),99.5%(663/666)) were higher than those of≥15 years group (97.1%(981/1 010),96.9%(979/1 010),96.2%(972/1 010)),the differences were significant(all the values of P<0.01); The GMT in<15 years group(1∶325.9,1∶250.5,1∶190.7)were higher than that of ≥15 years group (1∶71.1,1∶67.2,1∶44.8),the difference was significant (all the values of P<0.01).The positive rate(99.0%-100%) and GMT(1∶128.8-1∶300.7) in vaccination information confirmed population were higher.The highest positive rate (all were 100%) and GMT(1∶409.7-1∶636.7) were observed in children who vaccinated three times.Conclusion The polio antibody of healthy population was at a high level in Beijing in 2012; Especially the age groups of <15 years which were covered by vaccines.Immunization barrier had been formed firmly to interrupt the transmission of wild poliovirus and vaccine-derived poliovirus.

Objective To analyze the polio immunity level of persistent population in Beijing , 2012.Methods A total of 1 676 subjects residing more than 6 months in Beijing were selected by stratified random cluster sampling design in 2012.Demographic characteristics , history of oral poliovirus vaccine ( OPV) immunization were investigated by questionnaire.All 5 ml blood sample were collected for testing of polio neutralizing antibody using the method of microcell neutralization.The positive rate and the geometric mean titer ( GMT ) of polio neutralizing antibody type Ⅰ,Ⅱ and Ⅲ were analyzed in different groups.Results The positive rate of type Ⅰ,Ⅱ and Ⅲ were 98.2%( 1 645/1 676 ) , 98.1%( 1 644/1 676),97.6%(1 635/1 676);The GMT were 1∶130.2,1∶113.4 and 1∶79.7.Three types of positive rates in<15 years group(99.7%(664/666),99.8%(665/666),99.5%(663/666)) were higher than those of≥15 years group (97.1%(981/1 010),96.9%(979/1 010),96.2%(972/1 010)),the differences were significant(all the values of P<0.01); The GMT in<15 years group(1∶325.9,1∶250.5,1∶190.7)were higher than that of ≥15 years group (1∶71.1,1∶67.2,1∶44.8),the difference was significant (all the values of P<0.01).The positive rate(99.0%-100%) and GMT(1∶128.8-1∶300.7) in vaccination information confirmed population were higher.The highest positive rate (all were 100%) and GMT(1∶409.7-1∶636.7) were observed in children who vaccinated three times.Conclusion The polio antibody of healthy population was at a high level in Beijing in 2012; Especially the age groups of <15 years which were covered by vaccines.Immunization barrier had been formed firmly to interrupt the transmission of wild poliovirus and vaccine-derived poliovirus.

Objective:To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy.Methods:According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method .Results:The [ M（ P25， P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 ( P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID 50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID 50 per 100 μl in 2016 and 2018 ( P<0.001). Conclusion:Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.

Objective:To analyze the changing trend of polio vaccine immunization effectiveness and vaccine titer in Beijing in 2012, 2014, 2016 and 2018 before and after the adjustment of polio vaccine immunization program strategy.Methods:According to the convenient sampling method,the vaccination clinics of Chaoyang and Yanqing Districts in 2012, Fengtai and Daxing Districts in 2014, Tongzhou and Pinggu Districts in 2016, Dongcheng and Shunyi Districts in 2018 were selected as monitoring points. A total of 292 children were selected 4-8 weeks after the completion of 3 doses polio vaccine basic immunization which were 3 doses of trivalent oral poliovirus vaccine（tOPV）schedule before the strategy adjustment in 2012-2014 and 1 dose of inactivated poliovirus vaccine (IPV) following 2 doses of bivalent oral poliovirus vaccine (bOPV) sequential schedule after the adjustment in 2016-2018. About 1.0 ml blood samples were collected to detect type Ⅰ and Ⅲ neutralizing poliovirus antibody. A total of 9 oral poliovirus vaccines (8 vaccines in 2012) were selected from different sources of vaccine storage every year to test the vaccine titer using random number method .Results:The [ M（ P25， P75）] age of 292 children was 5 (5, 6) months, and the ratio of male to female was 1.04 (149/143). In 2012, 2014, 2016 and 2018, 66,72,68 and 86 children were investigated respectively. After basic immunization, antibody positive rates for type Ⅰ and Ⅲ poliovirus were 100%, except 98.61% (71) for type Ⅰ poliovirus in 2014. The neutralizing antibody titer of type Ⅰ and Ⅲ poliovirus was higher in 2016 and 2018 than that in 2012 and 2014 ( P<0.001). The average titer of tOPV were (6.05±0.15) and (6.16±0.12) lgCCID 50 per dose in 2012 and 2014. The average titer of bOPV were (6.88±0.21) and (6.26±0.14) lgCCID 50 per 100 μl in 2016 and 2018 ( P<0.001). Conclusion:Before and after the adjustment of polio vaccine immunization strategy in Beijing, the basic immunization success rate of the IPV-bOPV sequential immunization schedule was good as well as full tOPV schedule. The level of polio antibody produced by the IPV-bOPV sequential immunization schedule was higher. After adjustment, bOPV titer in 2016 was significantly higher than those before adjustment, while bOPV titer decreased significantly in 2018.

Objective:To analyze the epidemiological characteristics of Chlamydia pneumoniae infection among patients with acute respiratory infection in Beijing from 2015 to 2019. Methods:The epidemiological data of acute respiratory infection patients from 35 sentinel hospitals in Beijing were collected by the respiratory pathogen surveillance system in Beijing. The clinical samples were collected to detect Chlamydia pneumoniae, and the sequence of the VD4 region of the ompA gene in positive samples was analyzed. Results:From January 2015 to December 2019, the overall positive rate of Chlamydia pneumoniae among patients with acute respiratory infection in Beijing was 0.34% (129/37 460). The positive rate of Chlamydia pneumoniae generally increased in March, reaching the peak in May, and started to drop in July, with a duration of about 5-8 months. The epidemic season in different years fluctuated by 1-2 months. The positive monthly rate of Chlamydia pneumoniae was no less than 0.30% in every epidemic season. The positive rate of Chlamydia pneumoniae was the highest in the 5-44 years old group and the highest in 10-14 year-olds. The risk of Chlamydia pneumoniae infection increased with age in patients younger than 25 years old and decreased in those older one aged than 25 years of age. The positive rates in male and female patients were 0.33% (68/20 830) and 0.37% (61/16 528), respectively, and there was no significant difference between the two groups ( χ 2=0.486, P=0.486). The positive rate of Chlamydia pneumoniae in patients with common pneumonia was higher than that in patients with upper pneumonia and severe pneumonia ( χ 2=36.797, P<0.01). Other respiratory pathogens were also detected in the Chlamydia pneumoniae samples, and the top four pathogens appeared as Haemophilus influenzae (15 cases), Streptococcus pneumoniae (13 cases), Rhinovirus (8 cases), and Stenotrophomonas maltophilia (7 cases). 101 strains of 129 Chlamydia pneumoniae positive samples were identified as type A by sequencing. Conclusions:The annual epidemic pattern of Chlamydia pneumoniae in Beijing, is unimodal, and the epidemic season generally appears from March to July. The seasonal characteristics of Chlamydia pneumoniae in Beijing can be used for the differential diagnosis of Chlamydia pneumoniae from other respiratory pathogens. Chlamydia pneumoniae is most common in people aged 5-44 years, and the primary genotype is type A. People aged 10-44 years old suffer the highest incidence. If the nucleic acid positive rate of Chlamydia pneumoniae exceeds 0.30% for two consecutive months, the high prevalence period of Chlamydia pneumoniae can be preliminarily expected. Chlamydia pneumoniae infection has a higher probability of progressing to severe pneumonia from general pneumonia.

Objective:To aralyze the clinical characteristics of Chlamydia pneumoniae infection in Beijing.Methods:Based on Beijing Respiratory Pathogen Surveillance System, acute respiratory infection patients were recruited from 35 different types of sentinel hospitals in Beijing. Their epidemiological and clinical data were systematically collected and clinical specimens were also obtained. Nuclear acid testing was performed for 30 types of respiratory pathogens (including Chlamydia pneumoniae). The identified patients of Chlamydia pneumoniae infection were divided into two groups, the acute upper respiratory tract infection (AURI) group and pneumoniae group. The differences in clinical characteristics, laboratory examination and prognosis were compared by using independent sample t test, Mann-Whitney U test, χ 2 test or Fisher′s exact probability test. Results:A total of 119 patients of Chlamydia pneumoniae infection were included, including 12 patients in the AURI group and 107 patients in pneumoniae group. Chlamydia pneumoniae infection mainly occurred in people aged from 5 to 44 years, accounting for 81.5% (97/119). The three most common clinical symptoms were cough (92.4%, 110/119), fever (88.8%, 95/107), and sputum production (76.5%, 91/119). White blood cell counts increased in 39.3% (46/117) of patients. Neutrophile granulocyte proportion increased in 39.7% (46/116) of patients. Platelet count increased in 36.9% (41/111) of patients. An increase of the creatine kinase MB isoenzyme (CKMB) was observed in 12 pneumonia patients (24.5%, 12/49). Radiological examination showed that 90.6% (87/105) of patients in the pneumoniae group had pulmonary parenchymal changes; the lesion occurred most commonly in the lower right lung lobe (34.3%, 36/105) and the lower left lung lobe (27.6%, 29/105). Although 73.8% (79/107) of patients in the pneumoniae group were hospitalized, no case received intensive care unit or mechanical ventilation. As to outcomes, one patient developed respiratory failure and 6 patients suffered myocardial injury. No death was observed in this study. The median days of hospitalization and course of illness for pneumonia patients M( P25, P75) were 10.0 (7.0, 13.0) days and 18.0 (13.5, 22.0) days, respectively. Conclusion:Generally, Chlamydia pneumoniae infections in Beijing from 2015 to 2019 were mild, and the main clinical manifestations were cough, fever and sputum. However, most patients in the pneumoniae group caused by Chlamydia pneumoniae still required hospitalization but with a better outcome.

Objective:To aralyze the clinical characteristics of Chlamydia pneumoniae infection in Beijing.Methods:Based on Beijing Respiratory Pathogen Surveillance System, acute respiratory infection patients were recruited from 35 different types of sentinel hospitals in Beijing. Their epidemiological and clinical data were systematically collected and clinical specimens were also obtained. Nuclear acid testing was performed for 30 types of respiratory pathogens (including Chlamydia pneumoniae). The identified patients of Chlamydia pneumoniae infection were divided into two groups, the acute upper respiratory tract infection (AURI) group and pneumoniae group. The differences in clinical characteristics, laboratory examination and prognosis were compared by using independent sample t test, Mann-Whitney U test, χ 2 test or Fisher′s exact probability test. Results:A total of 119 patients of Chlamydia pneumoniae infection were included, including 12 patients in the AURI group and 107 patients in pneumoniae group. Chlamydia pneumoniae infection mainly occurred in people aged from 5 to 44 years, accounting for 81.5% (97/119). The three most common clinical symptoms were cough (92.4%, 110/119), fever (88.8%, 95/107), and sputum production (76.5%, 91/119). White blood cell counts increased in 39.3% (46/117) of patients. Neutrophile granulocyte proportion increased in 39.7% (46/116) of patients. Platelet count increased in 36.9% (41/111) of patients. An increase of the creatine kinase MB isoenzyme (CKMB) was observed in 12 pneumonia patients (24.5%, 12/49). Radiological examination showed that 90.6% (87/105) of patients in the pneumoniae group had pulmonary parenchymal changes; the lesion occurred most commonly in the lower right lung lobe (34.3%, 36/105) and the lower left lung lobe (27.6%, 29/105). Although 73.8% (79/107) of patients in the pneumoniae group were hospitalized, no case received intensive care unit or mechanical ventilation. As to outcomes, one patient developed respiratory failure and 6 patients suffered myocardial injury. No death was observed in this study. The median days of hospitalization and course of illness for pneumonia patients M( P25, P75) were 10.0 (7.0, 13.0) days and 18.0 (13.5, 22.0) days, respectively. Conclusion:Generally, Chlamydia pneumoniae infections in Beijing from 2015 to 2019 were mild, and the main clinical manifestations were cough, fever and sputum. However, most patients in the pneumoniae group caused by Chlamydia pneumoniae still required hospitalization but with a better outcome.