ABSTRACT
Objective:To investigate the molecular features of hand, foot and mouth disease (HFMD) caused by coxsackievirus A10 (CVA10) in Qingdao and analyze the clinical features of mild and severe cases.Methods:A total of 6 677 cases of HFMD routinely monitored by Qingdao Women and Children Hospital from 2014 to 2021 were enrolled. Throat swab samples were collected. Clinical data of these cases were retrospectively analyzed. Virus nucleic acid was extracted from the samples and the serotypes of enteroviruses were identified. The VP1 genes of CVA10 strains were amplified and sequenced. A phylogenetic tree based on the VP1 gene sequences was constructed using MEGA7. 0 software. SPSS23.0 software was used for statistical analysis.Results:There were 285 cases positive for CVA10, including 183 males and 102 females, and children under five years old accounted for 89.8%. Most of CVA10 infection occurred between the months of April to September. The count of white blood cells, the percentage of neutrophils, the concentration of hemoglobin, and the levels of aspartate aminotransferase and alanine transaminase were significantly higher in severe patients than in mild patients. Besides, chest radiography and brain CT revealed more abnormalities in severe patients, and the duration of ECG monitoring was longer in them. Compared with mild cases, severe cases developed rash early than fever with rash mostly on buttocks ( P<0.05). Phylogenetic analysis showed that most of the CVA10 strains circulating in Qingdao between 2014 and 2021 belonged to clade Ⅰ, and there were two variations A23V and I283V in the amino acid sequence of clade Ⅰ. Conclusions:This study showed that children of all ages were susceptible to CVA10, especially those under five years old. CVA10 showed complex and diverse epidemic trends in different regions and years.
ABSTRACT
Objective@#To illuminate the gene characteristics and clinical characterization of Coxsackievirus B5 (CV-B5) strains isolated from patients with sevre hand, foot and mouth disease (HFMD) in Qingdao city.@*Methods@#A total of 1 844 patients of HFMD were consecutively admitted to Qingdao Women and Children's Hospital from 2013 to 2014. Information of the study population described above was collected retrospectively. The samples were collected from at least 1 site (throat swab, cerebrospinal fluid), which viral nucleic acid extracted and the entire VP1 gene sequences of CV-B5 isolates were amplified and sequenced, then the homology and phylogeny analysis were conducted by MEGA7.0. The prototype Faulkner strain and other VP1 amino acid sequences were derived from the GenBank database.@*Results@#A total of 8 CV-B5 positive cases were obtained, including 4 males and 4 females; 6 severe hospitalized cases and 2 outpatients. The age of 6 hospitalized patients ranged from 3 to 48 months, with a median of 26 months. For the six inpatients, fever, convulsions vomiting, diarrhea and rash were the main clinical manifestation, and all combined with viral encephalitis. Compared with the prototype strain Faulkner, in the VP1 region,the nucleotide and the amino acid homologies was 77.3%-78.8% and 95.5%-97.0% respectively. Five out of the six severe cases with substitution of serine (S) to asparagine (N) at amino acid site 95 in the VP1 region. The sequences of 8 CV-B5 strains were classified into genogroup D.@*Conclusion@#Hand, foot and mouth disease associated with CV-B5 virus infection can result in nervous system involvement and the main complication was viral encephalitis. The CV-B5 strains associated with severe hand, foot and mouth disease had high nucleotide homology and present a certain regional aggregation.