First detection of multiple cases related to CV-A16 strain of B1c clade in Beijing in 2022.

Coxsackievirus A16 (CV-A16) is a significant etiologic agent of hand, foot, and mouth disease (HFMD) and herpangina (HA), with the capacity to progress to severe complications, including encephalitis, aseptic meningitis, acute flaccid paralysis, myocarditis, and other critical conditions. Beijing's epidemiological surveillance system, established in 2008, encompasses 29 hospitals and 16 district disease control centers. From 2019 to 2021, the circulation of CV-A16 was characterized by the co-circulation of B1a and B1b clades. Multiple cases of HFMD linked to clade B1c has not been reported in Beijing until 2022. This study enrolled 400 HFMD and 493 HA cases. Employing real-time RT-PCR, 368 enterovirus-positive cases were identified, with 180 selected for sequencing. CV-A16 was detected in 18.89% (34/180) of the cases, second only to CV-A6, identified in 63.33% (114/180). Full-length VP1 gene sequences were successfully amplified and sequenced in 22 cases, revealing the presence of clades B1a, B1b, and B1c in 14, 3, and 5 cases, respectively. A cluster of five B1c clade cases occurred between June 29 and July 17, 2022, within a 7-km diameter region in Shunyi District. Phylogenetic analysis of five complete VP1 gene sequences and two full-genome sequences revealed close clustering with the 2018 Indian strain (GenBank accession: MH780757.1) within the B1c India branch, with NCBI BLAST results showing over 98% similarity. Comparative sequence analysis identified three unique amino acid variations (P3S, V25A, and I235V). The 2022 Shunyi District HFMD cases represent the first instances of spatiotemporally correlated CV-A16 B1c clade infections in Beijing, underscoring the necessity for heightened surveillance of B1c clade CV-A16 in HFMD and HA in this region.

Phylogenetics and phylogeographic characteristics of coxsackievirus A16 in hand foot and mouth disease and herpangina cases collected in Beijing, China from 2019 to 2021.

Coxsackievirus A16 (CV-A16) is a significant pathogen responsible for causing hand foot and mouth disease (HFMD) and herpangina (HA). This study aimed to investigate the recent evolution and spread of CV-A16 by monitoring HFMD and HA cases in 29 hospitals across 16 districts in Beijing from 2019 to 2021. The first five cases of HFMD and the first five cases of HA each month in each hospital were included in the study. Real-time reverse transcription polymerase chain reaction was used to identify CV-A16, CV-A6, and EV-A71. From each district, two to four CV-A16 positive samples with a relatively long sampling time interval every month were selected for sequencing. A total of 3344 HFMD cases and 2704 HA cases were enrolled in this study, with 76.0% (2541/3344) of HFMD and 45.4% (1227/2704) of HA cases confirmed to be infected by enterovirus. Among the EV-positive samples, CV-A16 virus was detected in 33.61% (854/2541) of HFMD cases and 13.4% (165/1227) of HA cases, with the predominant cluster being B1a. Both B1a and B1b had a co-circulation of local and imported strains, with different origin time (1993 vs. 1995), different global distribution (14 countries vs. 10 countries), and different transmission centers but mainly distributed in the southern and eastern regions of Beijing. Strengthening surveillance of HFMD in southern and eastern regions will improve the prevention and control efficiency of enterovirus infections.

Detecting spatial-temporal cluster of hand foot and mouth disease in Beijing, China, 2009-2014.

BACKGROUND: The incidence of hand, foot, and mouth disease (HFMD) is extremely high, and has constituted a huge disease burden throughout Beijing in recent years. This study aimed to determine the spatiotemporal distribution and epidemic characteristics of HFMD. METHODS: Descriptive statistics was used to analyze the data and estimate the epidemic peaks in 2009-2014. Space-time scanning detected spatiotemporal clusters and identified high-risk locations. Global and local Moran's I statistics were used to measure the spatial autocorrelation. Geocoding was performed in ArcGIS, based on the present address codes of the patients and the centroids of the towns. Maps were created in ArcGIS to show the geographic spread of HFMD. RESULTS: In total, 220,451probable cases of HFMD were reported in Beijing between January 2009 and December 2014: 12,749 (5.78 %) were laboratory confirmed, and 35 (0.02 %) were fatal. The median age of reported cases was 3.12 years (interquartile range 1.96-4.39). Coxsackievirus A16 (CV-A16), enterovirus 71 (EV-A71), and other enteroviruses accounted for 39.31, 35.36, and 25.33 % of the 12,749 confirmed cases, respectively. Many more severe cases were caused by EV-A71 (χ (2) = 186.41, df = 1, P < 0.001) and other enteroviruses (χ (2) = 156.44, df = 1, P < 0.001) than by CV-A16. A large single distinct peak occurred between May and July each year. Spatiotemporal clusters of HFMD were identified in Beijing during 2009-2014. The most likely clusters were detected and tended to move from the southwest (Fengtai and Daxing) southeastwards to Daxing and Tongzhou in 2009-2014. The incidence of HFMD was not randomly distributed, but showed global and local spatial autocorrelations. CONCLUSIONS: There were obvious spatiotemporal clusters of HFMD in Beijing in 2009-2014. High-incidence areas mainly occurred at the junctions of urban and rural zones. More attention should be paid to the epidemiological and spatiotemporal characteristics of HFMD to establish new strategies for its control. Health issues should be especially promoted in kindergartens and at urban-rural junctions.

Excretion of enterovirus 71 in persons infected with hand, foot and mouth disease.

BACKGROUND: Hand, foot and mouth disease (HFMD) is a common illness in young children. It also can be seen in adults occasionally. Enterovirus 71 (EV71), a pathogen that causes not only HFMD but also neurological complications and even death, has caused many HFMD outbreaks in China. However, till now the data about the duration of EV71 shedding is very limited. RESULTS: A total of 136 throat swabs and fecal samples were collected from 27 children and 3 adults, which includs 7 close contacts, 9 mild cases and 14 severe cases,. The participants were divided into three groups namely, severe case group, mild case group and close contact group. All the samples were assayed with real-time polymerase chain reaction (PCR). Kruskal-Wallis Test was employed to compare the difference in duration of viral RNA shedding among three groups. The results showed that significant difference in duration of EV71 shedding was found among three groups (P < 0.01). The longest duration of EV71 shedding in fecal samples is 54 days and 30 days in throat swabs. CONCLUSIONS: HFMD is characterized by extended excretion of EV71. Our results suggest that the duration of EV71 shedding is correlated with the severity of the disease. EV71 shedding through feces can persist more than 54 days. Prolonged virus shedding is a potential risk factor of proliferating HFMD epidemic.

Solvothermal synthesis of antimony sulfide dendrites for electrochemical detection of dopamine.

Sb2S3 dendrites composed of 1-dimensional rods were prepared by a facile solvothermal reaction. The dosage of the poly(acrylic acid) (PAA) morphology-controlling reagent and the reaction temperature are key factors determining the final morphology of the product. Temporal experiments revealed that the formation of Sb2S3 dendrites experienced successive stages including precipitate reaction, crystallization and tip splitting. The as-prepared Sb2S3 dendrites were further employed as sensing material for electrochemical detection of dopamine (DA). A cyclic voltammogram (CV) showed that an Sb2S3 dendrite modified electrode enables the selective electro-oxidation of DA in the presence of ascorbic acid (AA). The constructed biosensor demonstrated a linear response range of 0.125-160 µM and a detection limit of 0.1 µM, which suggests that the Sb2S3 dendrites are promising sensing materials in the electrochemical analysis of DA.

[Etiology of hand-foot-and-mouth disease and genetic characteristics of Coxsackievirus A16 in Beijing, 2009].

This study aimed to reveal the pathogen spectrum of hand-foot-and-mouth disease (HFMD) and genetic characteristics of Coxsackievirus A16 (CoxA16) isolates in Beijing in 2009. From 1044 clinical specimens collected from 975 HFMD cases at Beijing Pediatrics Hospital, Beijing You'an Hospital and Beijing Ditan Hospital in 2009, viral nucleic acids of enterovirus were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Enterovirus isolations were conducted with rhabdomyosarcoma (RD) cell line on 200 throat swabs having positive RT-PCR results. Sequencing and analyses of VP1 encoding gene were performed on 9 CoxA16 isolates in this study. The results showed that CoxA16 (49.4%) and EV71 (36.4%) were the major pathogens for the epidemics of HFMD in 2009 in Beijing, and CoxA16 was the predominant serotype, while there were also other enterovirus co-circulating, such as CoxA4, CoxA10, and CoxA9; the CoxA16 strains prevalent in Beijing in 2009 belonged to subgenotype B1a and B1b.