Molecular epidemiology of enterovirus from children with herpangina or hand, foot, and mouth disease in Hangzhou, 2016.

Enteroviruses (EVs) are the major cause of hand, foot, and mouth disease (HFMD) and herpangina in children. In this study, we conducted a molecular investigation of EVs in throat swab samples from children in Hangzhou, China with a diagnosis of HFMD or herpangina. EVs were detected using one-step real-time RT-PCR, and their serotypes were determined based on partial VP1 gene sequences. The molecular typing results revealed the presence of six different EV serotypes in HFMD cases, including coxsackievirus (CV) A16 (20/30, 66.7%), CVA4 (3/30, 10.0%), CVA6 (3/30, 10.0%), EVA71 (2/30, 6.7%), CVB4 (1/30, 3.3%), and CVB5 (1/30, 3.3%). Eleven different EV serotypes were detected in herpangina cases, among which CVA4 was the most frequently detected serotype (105/170, 61.8%), followed by CVA16 (30/170, 17.6%), CVB4 (9/170, 5.3%), CVA6 (6/170, 3.5%), CVB3 (5/170, 2.9%), CVA10 (3/170, 1.8%), EVA71 (4/170, 2.4%), Echo9 (3/170, 1.8%), CVA9 (2/170, 1.2%), CVB1 (3/170, 1.8%) and CVA5 (1/170, 0.6%). The nucleotide sequence identity of EV strains from the same subtype ranged from 80.7% to 100%, and most of the EVs were closely related to virus strains found in Australia and mainland China. In conclusion, CVA 16 and CVA 4 were the main serotypes causing HFMD and herpangina, respectively, in children in Hangzhou in 2016. Most of these EVs were closely related to virus strains from Australia and mainland China.

Epidemiology of childhood enterovirus infections in Hangzhou, China.

BACKGROUND: There are over 100 serotypes of enterovirus species A-D, which are the common cause of various symptoms in infants, such as meningitis, encephalitis and hand foot mouth disease (HFMD). This study aims to investigate the epidemiological characteristics of enteroviruses in Hangzhou, Zhejiang province, China, and to provide relevant information to guide public health responses and interventions. METHODS: Systematic surveillance was conducted on enterovirus infections. Samples were collected from children admitted to the inpatient wards and outpatient departments between January 2010 and December 2012 in the Children's Hospital, Zhejiang University School of Medicine. Enteroviruses from all specimens were detected by RT-PCR using a commercialized detection kit. RESULTS: From 13026 samples collected and examined, 2673 (21.21%) were found positive for enteroviruses. The annual enterovirus-positive rate decreased from 32.78% in 2010 to 14.23% in 2012. Positivity rate for enteroviruses was highest among children aged less than 5 years. The monthly positivity rate for enterovirus infection ranged from 2.6% to 34.83%, with a peak in June and July. Serotypes causing severe symptoms such as HFMD including EV71 and CA16 were decreasing, while the proportion of unidentified EV serotypes causing herpangina and viral encephalitis were on the rise. CONCLUSIONS: EV infection is highly prevalent among young children in Hangzhou, as it is in the most other parts of the world. Further surveillance using methods that can subtype all EVs is warranted to better monitor these infections and their etiology.

[Analysis of the epidemic characteristics of the etiological agents in children with hand, foot and mouth disease and its clinical significance].

OBJECTIVE: To investigate the epidemic characteristics of etiological agents in children with hand, foot and mouth disease (HFMD) and analyze the differences between the severe and mild cases with HFMD seen from 2008 to 2009 in the Children's Hospital. METHODS: A total of 154 patients with HFMD were enrolled from May 2008 to September 2008 and from May 2009 to September 2009, including 28 severe HFMD patients. Data from 80 cases with suspected herpangina were collected as control. Enterovirus universal type, enterovirus type 71 (EV71) and coxsackie virus group A 16 (CA16) were detected by real-time RT-PCR respectively. RESULTS: The positive rate of enterovirus universal type in the 154 patients with HFMD was 81.82%(126/154). EV71 positive rate in these 126 patients with enterovirus universal type infection was 57.14%(72/126). The positive rate of enterovirus universal type in the 80 cases with suspected herpangina was 68.75%(55/80). There was no EV71 infection in these 80 cases with suspected herpangina. EV71 infection was mainly popular in 2008. Both EV71 and CA16 were prevalent in 2009. The epidemic characteristics of enterovirus infection with HFMD between 2008 and 2009 had significant differences (χ(2) = 23.50, P = 0.000) (P < 0.01). The epidemic characteristics of enterovirus infection between severe and mild HFMD patients also had significant differences (χ(2) = 29.85, P < 0.01). There were 28 cases with severe HFMD, in whom the EV71 positive rate was 92.86% (26/28). EV71 positive rate in the mild HFMD was 36.51% (46/126) (χ(2) = 29.22, P < 0.01). There was no significant difference in the gender (χ(2) = 0.135, P = 0.714) and virus load (t = 0.141, P = 0.889) between the mild and severe HFMD cases. But the age of mild and severe HFMD showed a significant difference (t = 2.926, P = 0.009). Patients who were less than 2 years of age had a proportion of 88.89% (8/9) with severe HFMD. The mean age of mild HFMD patients was 3.19 years. CONCLUSION: HFMD showed different epidemic characteristics at different times of enterovirus infection. There was no significant difference in the gender and virus load between the mild and severe cases with HFMD. Children under 3 years of age with EV71 infection were at high risk for severe HFMD.