A Hand-Foot-and-Mouth Disease Model with Periodic Transmission Rate in Wenzhou, China

We establish an SEIQRS epidemic model with periodic transmission rate to investigate the spread of seasonal HFMD in Wenzhou. The value of this study lies in two aspects. Mathematically, we show that the global dynamics of the HFMD model can be governed by its reproduction number R0; if R01, the model has at least one positive periodic solution and is uniformly persistent, which indicates that HFMD becomes an endemic disease. Epidemiologically, based on the statistical data of HFMD in Wenzhou, we find that the HFMD becomes an endemic disease and will break out in Wenzhou. One of the most interesting findings is that, for controlling the HFMD spread, we must increase the quarantined rate or decrease the treatment cycle

Modelling the effects of contaminated environments in mainland China on seasonal HFMD infections and the potential benefit of a pulse vaccination strategy

Substantial and increasing outbreaks of EV71-related hand, foot and mouth disease (HFMD) have occurred recently in mainland China with serious consequences for child health. The HFMD pathogens can survive for long periods outside the host in suitable conditions, and hence indirect transmission via free-living pathogens in the environment cannot be ignored. We propose a novel mathematical model of both periodic direct transmission and indirect transmission followed by incorporation of an impulsive vaccination strategy. By applying Floquet theory and the comparison theorem of impulsive differential equations, we obtained a threshold parameter which governs the extinction or the uniform persistence of the disease. The rate, frequency and timing of pulse vaccination were found to affect the basic reproduction number and the number of infected individuals significantly. In particular, frequent vaccination with a high coverage rate leads to declines in the basic reproduction number. Moreover, for a given rate of vaccination or frequency, numerical studies suggested that there was an optimal time (September, just before the start of new school terms) when the basic reproduction number and hence new HFMD infections could be minimised. Frequent high intensity vaccinations at a suitable time (e.g. September) and regular cleaning of the environment are effective measures for controlling HFMD infections

Detection and characterisation of enteroviruses and the gut virome in islet autoimmunity and type 1 diabetes using novel molecular methods

Type 1 diabetes (T1D) is a chronic autoimmune condition affecting over 8.4 million individuals globally. Usually preceded by islet autoimmunity (IA), T1D results from a complex interplay between host genetics and environmental factors, with virus infections, especially enteroviruses (EV) identified as a prominent candidate factor. Advances in molecular techniques including next generation sequencing (NGS) have enabled sensitive and high-throughput virus detection, improving on cell culture and serology techniques. There are over 110 human/primate EVs identified, classified within four species (A-D). Elucidation of which subtypes precipitate IA/T1D would inform the design of primary prevention studies. The project aimed to 1) develop a novel method of EV amplification using NGS; 2) optimise capture-based sequencing of viruses in stools of children at-risk of T1D; 3) characterise viruses in stools of participants in the Viruses in the Genetically at Risk (VIGR) and Environmental Determinants of Islet Autoimmunity (ENDIA) Australian longitudinal cohorts; and 4) update our previous systematic review examining the association between EVs and IA/T1D. Near full-length EV was detected in 67% of 113 VIGR stools and 96% of 23 EV prototypes examined. Coxsackievirus (CV)B3, ECHO18/30, and infection with multiple EV subtypes were associated with IA in VIGR stools. Polymorphisms frequently mapped to VP2/VP1 capsid regions in cases and to 2C/VP2/VP3/3A in controls. Children in the VIGR study had 129 differentially abundant gut viruses, with EV-As CVA2/5/6/8/14 and EV-Bs CVB3 and ECHO6/18/30 more abundant in cases. Infants of mothers with T1D enrolled in ENDIA were more likely to have a virus infection, with bocavirus/rotavirus more abundant and CVA6/RV-C/torque teno viruses less abundant. Systematic review of 3,266 publications revealed 60 eligible studies (40 T1D, 9 IA, 11 both) comprising 12,077 individuals. Meta-analysis demonstrated significant associations between EV and IA (odds ratio 2.1; 95% confidence interval 1.3 to 3.3; P=0.002), T1D (8.0; 4.9 to 13.0; P<0.00001); within one month of T1D (16.2; 8.6 to 30.5; P <0.00001). Substantial heterogeneity was observed between studies. These results strengthen the rationale for EV-targeted vaccines for primary prevention of IA/T1D. Future studies will examine virus infection during pregnancy and early life in populations with and without genetic risk for T1D

Public health interventions to promote oral health and well-being in patients with type 2 diabetes: a systematic review

Background and objective: Poor oral health and type 2 diabetes mellitus (T2DM) are chronic conditions affecting a wide proportion of the population. Both conditions share many risk factors and are linked by a chronic inflammation state. This review aimed at identifying public health interventions that could promote oral health and diabetes control in patients with poor oral health and T2DM. Methods: The systematic review was performed according to the PRISMA Statement and registered in the International Prospective Register of Systematic Reviews (PROSPERO registration: CRD42022310974). Seven electronic databases were searched (PubMed, Scopus, Embase, Web of Science, CINAHL, PsycInfo, Cochrane Library) from inception to 21 January 2022, and additional hand searching was performed across reviews’ references. A qualitative analysis was conducted, including all primary studies on diabetic patients, about interventions whose effectiveness and/or feasibility was measured for at least one outcome related to oral health or T2DM. Results: Of the 3153 records obtained after deduplication, 89 studies were considered eligible for inclusion. The most frequently evaluated outcomes were HbA1c and fasting glucose for T2DM, and parameters such as probing depth, bleeding on probing and clinical attachment loss for periodontitis. Most studies assessed the use of non-surgical periodontal treatment (especially scaling and root planing, sometimes corroborated by antibiotics): evidence confirmed effectiveness on periodontal parameters, but was more contrasting regarding T2DM outcomes. Three studies evaluated interventions involving group education for lifestyle modification, which showed to be effective on both outcomes. Also, community-based oral hygiene interventions and glycaemic control appeared to improve T2DM and periodontal outcomes. Conclusions: A variety of interventions are described in the literature. Of those included in this review, many indicated that there is a potential opportunity to promote good oral health alongside T2DM. An integrated approach involving health education, oral hygiene and glycaemic control may offer synergic improvement of both conditions

Optimal Control Strategies of HFMD in Wenzhou, China

In this paper, we investigate the dynamics and optimal control strategies of a modified hand, foot, and mouth disease (HFMD) model incorporating the EV-A71 vaccination in Wenzhou, China, analytically and numerically. We define the basic reproduction number R0 and show that it can be used to determine whether HFMD becomes extinct or not. Based on the monthly reported HFMD cases in Wenzhou for 76 months, we estimate the parameters in the dynamic model by using the method of minimum chi-square fitting, conduct the sensitivity analysis to investigate the influence of each uncertain parameter on R0 with the methods of Latin hypercube sampling and partial rank correlation coefficient, and find that the EV-A71 vaccination does not lead to the extinction of HFMD, but slightly reduces the incidence of HFMD. In order to control the spread of HFMD in Wenzhou, we need to increase the rate of EV-A71 vaccination, decrease the contact rates, and shorten the course of disease