Bluetongue virus(BTV)is classified as a category Ⅱ animal epidemic disease in China,infecting multiple species and posing significant threats to the ruminant breeding industry.There are 29 serotypes of BTV,with BTV16 being one of the major serotypes currently prevalent in Chi-na.Bluetongue virus infection mainly manifests as a latent infection,making the establishment of ELISA assays crucial for epidemiological detection.In this study;the expression of the BTV16 VP2 protein was achieved using a prokaryotic expression system,and polyclonal antibodies were pre-pared using BALB/c mice.An indirect ELISA assay using VP2 protein as the encapsulated antigen was established and optimized.Clinical samples from the Guangxi Zhuang Autonomous Region were tested and analyzed for compliance with commercial kits.The results showed that the BTV16 VP2 protein was successfully expressed and purified,and the prepared polyclonal antibody exhibi-ted good immunogenicity.The ELISA assay had good specificity,with no cross-reactivity against ruminant diseases such as AKAV,FMDV and GETV.The critical values for negativity and positivity were determined to be 0.314,and the coefficients of variation(Cv)between batches and within batches were both less than 5％,indicating good reproducibility.The ELISA assay revealed a positive rate of 92.4％for 79 samples from the Guangxi Zhuang Autonomous Region,with a compliance rate of 98.7％when compared to the commercialized kit.In conclusion,this study suc-cessfully established an indirect ELISA method for BTV16,facilitating the detection of bovine clin-ical samples.

Bluetongue virus(BTV)is classified as a category Ⅱ animal epidemic disease in China,infecting multiple species and posing significant threats to the ruminant breeding industry.There are 29 serotypes of BTV,with BTV16 being one of the major serotypes currently prevalent in Chi-na.Bluetongue virus infection mainly manifests as a latent infection,making the establishment of ELISA assays crucial for epidemiological detection.In this study;the expression of the BTV16 VP2 protein was achieved using a prokaryotic expression system,and polyclonal antibodies were pre-pared using BALB/c mice.An indirect ELISA assay using VP2 protein as the encapsulated antigen was established and optimized.Clinical samples from the Guangxi Zhuang Autonomous Region were tested and analyzed for compliance with commercial kits.The results showed that the BTV16 VP2 protein was successfully expressed and purified,and the prepared polyclonal antibody exhibi-ted good immunogenicity.The ELISA assay had good specificity,with no cross-reactivity against ruminant diseases such as AKAV,FMDV and GETV.The critical values for negativity and positivity were determined to be 0.314,and the coefficients of variation(Cv)between batches and within batches were both less than 5％,indicating good reproducibility.The ELISA assay revealed a positive rate of 92.4％for 79 samples from the Guangxi Zhuang Autonomous Region,with a compliance rate of 98.7％when compared to the commercialized kit.In conclusion,this study suc-cessfully established an indirect ELISA method for BTV16,facilitating the detection of bovine clin-ical samples.

Objective:To investigate the complicated virus infection of infants with pertussis and its effect on the disease.Methods:From January 2019 to March 2020, a total of 100 hospitalized infants with pertussis were admitted to the Second Affiliated Hospital of Medical College of Shantou University, nasopharyngeal swabs were collected for detection of ten pathogens including pertussis, namely respiratory syncytial virus(RSV), parainfluenza virus(PIV), bordetella pertussis (BP), human rhinovirus(HRV), human bocavirus(HBoV), human metapneumovirus(hMPV), influenza B virus (INF-B), adenovirus, influenza A virus and cytomegalovirus(CMV). According to the results of pathogen detection, all infants were divided into single detection group of BP(single detection group) and co-detection group of BP combined with viruses(co-detection group). The clinical data of the two groups were retrospectively analyzed and compared to explore the differences of clinical characteristics and its impact on the course of disease.Results:Among 100 cases, there were 54(54.0%) boys and 46(46.0%)girls.The age ranged from 28 days to 2 years and 5 months, with a median age of 3.5 months.Fifty-six cases were classified as single detection group, while 44 cases were included into co-detection group.Among infants in co-detection group, fourteen cases were co-infected with CMV(31.8%, 14/44), seven cases with HRV(15.9%, 7/44), seven cases with PIV(15.9%, 7/44), four cases with RSV(9.1%, 4/44), one case with hMPV(2.2%, 1/44), eight cases with CMV+ HRV(18.2%, 8/44), one case with HRV+ HBoV (2.2%, 1/44), one case with CMV+ PIV(2.2%, 1/44)and one case with CMV+ PIV+ INF-B(2.2%, 1/44). The number of infants in the single detection group who had cyanosis before treatment, requiring repiratory support, PICU admission, severe pneumonia or abnormal myocardial enzymes were higher than those in the co-detection group( P<0.05), while the months of age were lower than that in the co-detection group( P<0.05). When comparing the clinical characteristics of infants over three months of age, only the number of cases of combined cyanosis before treatment and the number of days in hospital were higher in the single detection group than those in the co-detection group ( P<0.05), no statistically significant differences were found in the other clinical characteristics between the two groups( P>0.05). Conclusion:The cases of infants requiring repiratory support, complicated with severe pneumonia or abnormal myocardial enzymes in the single detection group are higher than those in the co-detection group, which may be attributed to the small age of months.

Objective:To analyze the detection rate of respiratory syncytial virus(RSV)and human rhinovirus(HRV), in different months and age groups, and the clinical characteristics in children in eastern Guangdong from 2019 to 2020.Methods:Pharyngeal swabs were collected from 6 658 children with respiratory tract infections hospitalized in the Second Affiliated Hospital of Shantou University Medical College from January 2019 to December 2020, and respiratory pathogen nucleic acid was detected.The detection rate, month distribution, age group distribution, and clinical characteristics of single RSV as well as single HRV positive cases were analyzed and compared.Results:There were 416 single RSV positive cases(6.25%)and 341 single HRV positive cases(5.12%).The detection rates of RSV was higher than those of HRV, and the difference was statistically significant( χ2=7.880, P<0.05).The detection rates of HRV in March, April, November and December were higher than those of RSV, and the detection rates of RSV in July, August and September were higher than those of HRV, with statistically significant difference( P<0.05).The highest detection rate of RSV was in the age group of ≤6 months with a detection rate of 13.47%(192/1 425), which gradually decreased with age, and the difference was statistically significant( P<0.01).The detection rates of HRV fluctuated between 4.21% and 6.13% in each age group, and the differences among the detection rates of each age group were not statistically significant( P>0.05).All RSV-positive cases showed cough, while 77.13%(263/341)of HRV-positive cases showed cough, with a statistically significant difference( P<0.001).The incidence of wheezing in RSV-positive cases was 37.26%(155/416)compared with 28.45%(97/341)in HRV-positive cases, with a higher incidence of wheezing in RSV than that in HRV, and the difference was statistically significant( P<0.05).In terms of indicators to assess severe pneumonia, RSV-positive cases showed a higher proportion of increased respiratory rate, decreased oxygen saturation or dyspnea than HRV-positive cases, and all differences were statistically significant( P<0.05). Conclusion:The detection rate of single RSV is higher than that of single HRV in children with respiratory infections in eastern Guangdong from 2019 to 2020.The epidemic season of RSV is mainly in autumn, and the epidemic season of HRV is mainly in winter and spring.RSV is more susceptible up to 6 months of age, and the detection rate decreases gradually with age, and there is no significant difference in the detection rate of HRV by age.RSV-positive cases are more likely to have cough and wheeze.RSV-positive cases are more likely to have increased respiratory rate, decreased oxygen saturation, or respiratory distress.

Objective:To investigate the clinical features of adenoviral encephalitis (AE), and to provide reference for clinical diagnosis and treatment of adenoviral encephalitis.Methods:From January 2012 to December 2020, 1 185 cerebrospinal fluid (CSF) samples of hospitalized children with suspected central nervous system infection in the Second Affiliated Hospital of Shantou University Medical College were collected for the detection of 22 common respiratory pathogens and common pathogens for encephalitis by polymerase chain reaction. Records of patients with adenovirus positive in CSF were reviewed and relevant clinical manifestations, laboratory tests and imaging examination results were collected for analysis.Results:Among 1 185 CSF samples, 242 samples were positive for viral nucleic acid, with detection rate of 20.4%, including 1.9%(23/1 185) of adenovirus. As for 23 children diagnosed with AE, 18 were male, five were female, with the age of (44.8±35.9) months, ranging from two months and 19 days to 10 years. Of 23 children, 21(91.3%) presented with fever, followed by convulsions (16 cases, 69.6%), headache (four cases, 17.4%), vomiting (11 cases, 47.8%), consciousness change (11 cases, 47.8%) and emotion disturbance (three cases, 13.0%). Among 23 children, eight cases had white blood cell counts (WBC) of (6 to <10)×10 9/L, 10 cases had WBC of (10 to 20)×10 9/L and the white blood cell classification was mainly neutrophils (21 cases, 91.3%), and C reactive protein of 20 cases (87.0%) was in the normal range. Cerebrospinal fluid examination showed that WBC were less than 15×10 6/L in 20 cases (87.0%), and WBC ≥15×10 6/L in three cases, which were up to 500×10 6/L; the protein of 19 cases was in the normal range, the glucose of 15 cases was in the normal range, and the chloride of 19 cases was in the normal range. Among 16 cases with brain magnetic resonance imaging examination, eight cases did not show abnormality, six cases with local meningeal linear enhancement, one case with small intracranial malacia, and one case with extensive intracranial lesions. For 13 cases who received electroencephalogram (EEG) test, seven cases showed normal EEG or marginal state, four cases showed extensive medium and high amplitude slow wave, one case showed spike wave or spike slow wave and one case had both of the above two changes. Among 23 children, 22 cases recovered including one case had secondary epilepsy, and the remaining one case had severe brain dysfunction and was unable to suck when discharged, with an indwelling gastric tube and accompanied by secondary epilepsy. Conclusions:The clinical manifestations and auxiliary examinations of children with AE have no obvious specificity. Most children with AE have a good prognosis, but a small number of them may have serious sequelae.