What is HFMD?
Hand, foot, and mouth disease (HFMD) is a common, typically self-limited viral syndrome in children and adults, especially under 3 years old. It is marked by fever, oral ulcers, and skin manifestations affecting the palms, soles, and buttocks, with symptoms usually lasting less than 1 week. A portion of HFMD can be self-healing, but a few severe complications still can occur due to the infection, which cause a serious of complications, such as encephalitis, aseptic meningitis, and acute flaccid paralysis, etc. Through long-time pathogen research, it is found that Enterovirus Type 71 (EV71) is a major virus for HFMD, especially, severe hand, foot and mouth disease (HFMD).There is no specific drug to cure now but ease the symptom. Therefore, vaccination is the best way to prevent it.
Human Enterovirus Type 71 (EV71) is a small, nonenveloped, icosahedral virus that belongs to the human Enterovirus species A in the genus Enterovirus within the family Picornaviridae. The single-stranded positive-sense RNA genome of EV71 is around 7.4-kb long, which is flanked by 5’and 3’untranslated regions (UTRs). The polyprotein consists of P1, P2, and P3 regions, which encodes structural proteins, VP4, VP2, VP3, VP1, and non-structural proteins,2A, 2B, 2C and 3A, 3B, 3C, 3D, respectively. Based on molecular typing using VP4 and VP1 gene sequences, EV71 is classified into three genotypes, A, B(subgenotypes B1-B5), and C (subgenotypes C1-C5).Although EV71 family consists of 11members,there is only one serotype which contributes to vaccine development and cross-protection.
What about the epidemic of HFMD?
Cyril C. Y. Yip1, Susanna K. P. Lau,Patrick C. Y. Woo and Kwok-Yung Yuen. Human enterovirus 71 epidemics:what’s next? Emerg Health Threats J 2013,6:19780.