Epidemiological characteristics and pathogens attributable to hand, foot, and mouth disease in Shanghai, 2008–2013

Abstract

Introduction: Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by enteroviruses. A passive surveillance system has been implemented in Shanghai Pudong since 2008 and etiology surveillance since 2009.We characterized the epidemiology and the etiology of HFMD in Pudong from 2008-2013. Methodology: Health care providers were required to report any clinically diagnosed HFMD to Pudong District Center for Disease Control and Prevention. For all severe cases and randomly selected mild HFMD cases, throat or rectal swabs or feces were collected for enterovirus detection by real time reverse transcription polymerase chain reaction. Results: A total of 50,149 cases were reported, with average 8,508 per year (range: 3,577-13,202) and average incidence of 167.5/100,000 persons (range: 81.4-254.1/100,000 persons). HFMD was more likely to occur in children under five years of age (85.6%), while severe cases were more likely to happen in children under three years of age (63.9%). Every year in May or June, HFMD peaked in the region; two peaks were observed from 2011 to 2013.The most common etiologic agents are EV71 and CA16.Different types of enterovirus circulate in different years. EV71 was the predominant pathogen in severe cases. The proportions of EV71 in severe cases was higher than in mild cases at the children's medical center (p<0.001). Conclusions: HFMD remains an important public health issue in Shanghai. HFMD pathogen surveillance is required for more types of enteroviruses besides EV71 and CA16, which would give a better picture of the etiology of HFMD.

Epidemiological and serological surveillance of hand-foot-and-mouth disease in Shanghai, China, 2012–2016

“…Statistical analysis of the age and gender distribution in the present study showed that children under age five were the most susceptible to HFMD, which is consistent with previous reports 19 , 28 , 43 , 44 . Male predominance of HFMD was observed both in severe and mild cases in our study, possibly because of higher activity and poorer hygiene 45 , 46 .…”

“…Since the latter half of 2012, however, the positive rates of non-EV71 and non-CV-A16 EV-associated HFMD have grown rapidly, and these viruses became major factors in the Shanghai HFMD epidemic. Similar trends were also reported in Shanghai 28 – 30 and other cities in China 12 – 18 , 31 , 32 . Recently, CV-A6 displaced EV71 and CV-A16 to become the predominant enteroviral serotype in Shanghai.…”

“…Seasonal circulation patterns among EV-predominant serotypes revealed that Shanghai, as with other southern cities in China, had semi-annual outbreaks of HFMD in May and September-October over the last few years 1 , 28 , 35 . Our data showed that EV71 and CV-A16, mainly circulating in May to July, were responsible for the summer HFMD epidemic.…”

Understanding the epidemiological characteristics of EV71 and CVA16 infection to aid the diagnosis and treatment of hand, foot, and mouth disease

“…Although immunogenicity in the maternal serum has been examined in some reports, the pattern of immune responses against HFMD has not been well examined. In this study, we observed that the expression of IgM was high over 0 ‐96 hours followed by a gradual decline, whereas the expression of IgG was the opposite, with a gradual increase over time.…”

“…Neutralization titers were determined as the highest serum dilution that could prevent the appearance of a CPE in 50% of the cell cultures (performed in quadruplicate). The lowest dilution at which a CPE was observed in >50% of wells was considered the antibody titer of the serum sample, and a titer ≥1:8 was considered the cutoff for a positive antibody response …”