An atypical winter outbreak of hand, foot, and mouth disease associated with human enterovirus 71, 2010

Abstract

BackgroundTo analyze the epidemiological characteristics and pathogenic molecular characteristics of an hand, foot, and mouth disease (HFMD) outbreak caused by enterovirus 71 in Linyi City, Shandong Province, China during November 30 to December 28, 2010.MethodsOne hundred and seventy three stool specimens and 40 throat samples were collected from 173 hospitalized cases. Epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak.ResultsAmong the 173 cases reported in December 2010, the male–female ratio was 1.88: 1; 23 cases (13.3%) were severe. The majority of patients were children aged < 5 years (95.4%). Some patients developed respiratory symptoms including runny nose (38.2%), cough (20.2%), and sore throat (14.5%). One hundred and thirty eight EV71 positive cases were identified based on real time reverse-transcription PCR detection and 107 isolates were sequenced with the VP1 region. Phylogenetic analysis of full-length VP1 sequences of 107 Linyi EV71 isolates showed that they belonged to the C4a cluster of the C4 subgenotype and were divided into 3 lineages (Lineage I, II and III). The two amino acid substitutions (Gly and Gln for Glu) at position 145 within the VP1 region are more likely to appear in EV71 isolates from severe cases (52.2%) than those recovered from mild cases (8.3%).ConclusionThis outbreak of HMFD was caused by EV71 in an atypical winter. EV71 strains associated with this outbreak represented three separate chains of transmission. Substitution at amino acid position 145 of the VP1 region of EV71 might be an important virulence marker for severe cases. These findings suggest that continued surveillance for EV71 variants has the potential to greatly impact HFMD prevention and control.

A prospective, comparative study of severe neurological and uncomplicated hand, foot and mouth forms of paediatric enterovirus 71 infections

“…4 EV-A71 strains sequenced in the present study associated with uncomplicated illness. et al, 2007) or VP1 amino acid substitution (Liu et al, 2014) have also been studied. Co-infection and antibody responses have not been shown to be related to severe forms (Ooi et al, 2007;Yang et al, 2011a).…”

“…EV-A71 associated disease is usually mild with children typically recovering within 4-6 days. However, the virus has been associated with fulminant disease during large outbreaks in many parts of the World, including Bulgaria (Shindarov et al, 1979), Hungary (Nagy et al, 1982), Malaysia (Chan et al, 2000), Taiwan (Huang et al, 1999), Singapore (Chong et al, 2003), and China (Li et al, 2012;Liu et al, 2014;Huang et al, 2014). A meta-analysis has estimated case-fatality rates for hospitalized cases of HFMD associated with EV-A71 at 1.7% (Zhao et al, 2015).…”

Comparative epidemiology and virology of fatal and nonfatal cases of hand, foot and mouth disease in mainland China from 2008 to 2014

“…Since the isolation of the prototype BrCr strain of EV71 in California, USA, in 1969 [14], subsequent outbreaks associated with EV71 infection spread through Europe into countries constituting the Western Pacific Region (WPR): Australia, Taiwan, Malaysia, Singapore, China, Hong Kong, and Japan. WPR, as the major circulating area, has experienced large HFMD epidemics associated with EV71 infection [3,5,[15][16][17][18][19]. In recent years, the incidence of HFMD, particularly that caused by EV71 infection, appears to be increasing across the region, and China is the major epidemic area.…”

A case with atypical hand-mouth-foot disease accompanying with onicomadesis and a small-scale outbreak

“…Hastalığın klinik formlarının bilinmesi herpes virüs için fazladan antiviral tedavi kullanımını önlemiş olur. Hem tipik hem de atipik el-ayak-ağız hastalığı kendini sınırlayıcı olduğundan tedavi destek tedavisi şeklindedir (2,3,7,9) . Sonuç olarak, yaygın vezikülobüllöz döküntüsü olan, özellikle dorsal yüzlerde ve ağız çevresinde tutulumun belirgin olduğu, onikomadezisin eşlik ettiği özellikle 2 yaş altındaki çocuk hastalarda atipik el-ayak-ağız hastalığı ayırıcı tanıda düşünülmeli ve izlemde temas ve hava yolu izolasyon önlemleri sıkı bir şekilde uygulanmalıdır.…”