ABSTRACT
Objective:To analyze the etiological and epidemiological characteristics of hand, foot and mouth disease (HFMD) in Xi′an from 2019 to 2021, so as to provide evidence for the prevention and control of HFMD.Methods:Stool specimens and anal swabs were collected from patients with HFMD. Enteroviruses (EVs) including enterovirus 71 (EV71), coxsackievirus A16 (CVA16), CVA6 and CVA10 were detected by RT-PCR. Excel 2007 and SPSS18.0 software were used for data collection and statistical analysis, respectively. The epidemiological data of HFMD cases were analyzed by descriptive epidemiology method. The VP1 gene sequence of the representative strain of each CVA6 genotype was downloaded. Phylogenetic trees were constructed using MEGA X software and the genetic characteristics were analyzed.Results:A total of 1 531 HFMD cases were involved and 1 365 were positive for EVs with a positive rate of 89.16%. The detection rates of EV71, CVA16, CVA6, CVA10 and other EVs were 1.31% (20/1 531), 32.46% (497/1 531), 38.47% (589/1 531), 5.09% (78/1 531) and 11.23% (172/1 531), respectively. There were significant differences in the pathogen composition in HFMD cases of different clinical types (χ 2=46.14, P<0.01) and occupations (χ 2=34.65, P<0.01) as well as in different years (χ 2=462.86, P<0.01). The average age was greater in patients with CVA16 infection than in those with CVA6 or CVA10 infection ( F=6.00, P<0.01). In 2019, the HFMD cases were mainly caused by CVA16, while in 2020 and 2021, the main pathogen was CVA6. Enterovirus-positive cases showed a bimodal distribution with the main peak from May to July and the secondary peak from September to November. CVA16 was the predominant pathogen in spring and summer, and CVA6 was the predominant pathogen in autumn. CVA6 was the dominant pathogen in eight districts and counties of Xi′an; CVA16 was the dominant pathogen in six districts and counties; CVA6 and CVA16 co-circulated in one district. The CVA6 isolates belonged to two evolutionary branches of D3a subtype. Conclusions:CVA6 and CVA16 were the prevalent pathogens of HFMD and CVA6 subtype D3a circulated in Xi′an from 2019 to 2021. The pathogen composition of HFMD cases showed obvious differences in population, time and regional distribution.
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Objective:To investigate the positive rates of 2019-nCoV nucleic acid in different specimens from confirmed COVID-19 cases during hospitalization and after discharge.Methods:Patients with confirmed COVID-19 were enrolled from designated hospitals. Nasal swabs, throat swabs, and specimens of stool, urine and blood were collected during hospitalization. After the patients were discharged, nasal swabs, throat swabs and stool specimens were collected during follow-up. Real-time RT-PCR was used to detect 2019-nCoV nucleic acid.Results:This study involved 25 confirmed COVID-19 cases. During hospitalization, all patients tested positive in both nasal and throat swab 2019-nCoV nucleic acid tests, and nine of them (36.00%) were positive in stool specimen test. Urine and blood specimen test results were all negative. Nasal swabs, throat swabs and stool specimens were collected from each patient 7 d and 14 d after discharge. Two patients (8.00%) tested positive for 2019-nCoV nucleic acid again in nasal and throat swab tests on 7 d, while all stool specimen tests were negative. No 2019-nCoV nucleic acid was detected in nasal swabs, throat swabs or stool samples on 14 d.Conclusions:2019-nCoV nucleic acid was detected in stool samples of confirmed COVID-19 cases during hospitalization. Nasal and throat swab nucleic acid tests turned positive again in some patients after discharge.
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Objective To understand the distribution of novel coronaviruses in the external environment of confirmed COVID-19 cases. Methods Environmental surface swab specimens such as bed rails, doorknob, closestool, hand washing sink, table, locker,ward pager, mobile phone, cup, clothes, were collected from the sentinel hospital of COVID-19, and samples were collected for the nucleic acid detection by RT-PCR. Results A total of 150 environmental samples were collected from 30 confirmed COVID-19 cases, 6 samples were determined to be novel coronaviruses postive (positive rate 4.00%). The total 14 mobile phone showed 3 novel coronaviruses positive.Among the 30 confirmed COVID-19 cases, 6 cases (positive rate 20.00%)were found novel coronaviruses in the external environment. Conclusions Novel coronaviruses exists in external environment of confirmed COVID-19 cases, which indicates the potential risk of COVID-19 infection.