Hand, Foot, and Mouth Disease in China: Critical Community Size and Spatial Vaccination Strategies

Abstract

Hand Foot and Mouth Disease (HFMD) constitutes a considerable burden for health care systems across China. Yet this burden displays important geographic heterogeneity that directly affects the local persistence and the dynamics of the disease, and thus the ability to control it through vaccination campaigns. Here, we use detailed geographic surveillance data and epidemic models to estimate the critical community size (CCS) of HFMD associated enterovirus serotypes CV-A16 and EV-A71 and we explore what spatial vaccination strategies may best reduce the burden of HFMD. We found CCS ranging from 336,979 (±225,866) to 722,372 (±150,562) with the lowest estimates associated with EV-A71 in the southern region of China where multiple transmission seasons have previously been identified. Our results suggest the existence of a regional immigration-recolonization dynamic driven by urban centers. If EV-A71 vaccines doses are limited, these would be optimally deployed in highly populated urban centers and in high-prevalence areas. If HFMD vaccines are included in China’s National Immunization Program in order to achieve high coverage rates (>85%), routine vaccination of newborns largely outperforms strategies in which the equivalent number of doses is equally divided between routine vaccination of newborns and pulse vaccination of the community at large.

Epidemiological features and spatial clusters of hand, foot, and mouth disease in Qinghai Province, China, 2009–2015

“…Since Qinghai health officials introduced the EV-A71 vaccine as a category-2 vaccine (cost covered by ‘out-of-pocket’) in 2017, coverage has remained low. Our provincial and regional estimates can provide baseline estimates of HFMD in Qinghai for future vaccine impact assessments, including shifts in etiologic distribution, and evaluations on equitable access [ 51 ] to the vaccine in the province. Public health officials should continue to strengthen current HFMD prevention and control strategies, particularly prior to and during the peak months of HFMD transmission.…”

Stratified Space–Time Infectious Disease Modelling, with an Application to Hand, Foot and Mouth Disease in China

“…Under‐reporting was addressed for HFMD in China by Van Boeckel et al . (), who had additional detailed birth information. Adapting a previously developed method (Bartlett, ), they regressed the cumulative births on the cumulative observed cases, with the reciprocal of the estimated slope giving an estimate of the weekly reporting rate.…”

“…Xing et al (2014) carried out a large epidemiological study of HFMD and pointed out the under-reporting; in follow-up letters to Xing et al (2014) (Mao et al, 2014;Leung et al, 2014) the difficulty of adjustment has been highlighted, due to the regional variation in under-reporting. Under-reporting was addressed for HFMD in China by Van Boeckel et al (2016), who had additional detailed birth information. Adapting a previously developed method (Bartlett, 1960), they regressed the cumulative births on the cumulative observed cases, with the reciprocal of the estimated slope giving an estimate of the weekly reporting rate.…”

Enhancement of Polymerase Activity of the Large Fragment in DNA Polymerase I fromGeobacillus stearothermophilusby Site-Directed Mutagenesis at the Active Site

“…Currently, large-scale outbreaks of HFMD predominantly characterized by EV71 infection, a nonenveloped and positive-stranded RNA virus, have become a serious public health issue in China, therefore raised the widely public attention, and constituted financial burden of government health care system [21]. However, there is neither an effective vaccine nor any valid antiviral medicine for EV71 infection [22].…”