Phylogenetic analysis of the VP1 gene of Enterovirus 71 in Guangzhou during the high occurrence period of 2008.

An outbreak of hand, foot, and mouth disease (HFMD) in Guangzhou in 2008 affected over 10,000 children and resulted in high hospital admission rates. To investigate the molecular epidemiological pattern of EV71 infections in Guangzhou, throat swab samples were collected from 102 children clinically diagnosed with HFMD from May to July of 2008 in Guangzhou. Partial VP1 (virus protein 1) fragments of Enterovirus 71 (EV71) isolates were sequenced, and used alongside EV71 sequences entered in GenBank to construct a phylogenetic tree using MEGA5.0. Blast and phylogenetic analyses showed that all 21 sequences belonged to subgenogroup C4 of EV71. In early May, diverse strains were circulating in Guangzhou, but by July, only a small number of these strains could be detected. These results could indicate that geographic and climatic features may affect the epidemic characteristics of EV71, and that some C4 strains might retain their infectivity at higher temperatures.

Identifying risk factors for neurological complications and monitoring long-term neurological sequelae: protocol for the Guangzhou prospective cohort study on hand-foot-and-mouth disease.

INTRODUCTION: Hand-foot-and-mouth disease (HFMD) is a paediatric infectious disease that is particularly prevalent in China. Severe HFMDs characterised by neurological involvement are fatal and survivors who have apparently fully recovered might still be afflicted later in life with neurocognitive impairments. Only when a well-designed, prospective cohort study is in place can we develop clinical tools for early warning of neurological involvement and can we obtain epidemiological evidence regarding the lingering effects of the sequelea. METHODS AND ANALYSIS: A prospective, hospital-based cohort study is underway in Guangzhou, China. Clinical data and biosamples from hospitalised children (<14 years of age) with an admission diagnosis of HFMD will be collected to determine risk factors for subsequent neurological involvement. Clinical tools for early detection of severe HFMDs will be developed by integrating clinical and biological information. Questionnaire surveys and neurocognitive assessments will be conducted at discharge and each year in the first 2 years of follow-up and every 2 years afterwards until study participants turn 16 years of age or show no evidence of neurocognitive deficits. The association between childhood enterovirus infection and neurocognitive impairment later in life will be examined. ETHICS AND DISSEMINATION: A written informed consent from parents/guardians is a prerequisite for study entry. The protocol of this study has been approved by the hospital's ethics committee. Data usage follows the rules of the hospital's data oversight committee. Findings of this study will be disseminated through publications in international peer-reviewed journals and will be presented in academic conferences. TRIAL REGISTRATION NUMBER: ChiCTR-EOC-17013293; Pre-results.

[Etiology of hand, foot and mouth disease in Guangzhou in 2008].

OBJECTIVE: To understand the etiology of hand, foot and mouth disease (HFMD) in Guangzhou area in 2008. METHOD: Totally 1023 clinical specimens were collected from pediatric patients suspected of HFMD in 2008. TaqMan real-time RT-PCR were used for detection of enterovirus 71 (EV71), Coxsackievirus A16 (CA16) and other enteroviruses. The specimens which were enterovirus positive by RT-PCR method with universal primer but EV71 and CA16 negative, were amplified and sequenced for 5'untranslated region. RESULT: Enterovirus was identified from 434 of 1023 samples and detection rate of enterovirus was 42.42%; of the 434 samples, 276 were positive for EV71 (63.6%), 126 for CA16 (29%), 4 samples for enterovirus 84, 3 for Echovirus 11, 2 for Echovirus 9, 3 for Coxsackievirus B3, 4 for Coxsackievirus A10, 3 for Coxsackievirus A6, 6 for Coxsackievirus A12 or A5, and for 7 samples typing was difficult. CONCLUSION: The major causative agents of HFMD in Guangzhou were EV71 and CA16 in 2008, and EV84, CA10, CA12, CA6, COSB3, ECHV11, ECHV9 were also the pathogens for smaller proportions of patients.