scholarly journals Hand, Foot, and Mouth Disease in Thailand: A Comprehensive Modelling of Epidemic Dynamics

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Suraj Verma ◽  
M. A. Razzaque ◽  
U. Sangtongdee ◽  
C. Arpnikanondt ◽  
B. Tassaneetrithep ◽  
...  
Keyword(s):  
Basic Reproduction Number ◽  
Clustering Algorithm ◽  
Reproduction Number ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Seasonal Effect ◽  
Epidemic Dynamics ◽  
District Hospitals ◽  
Foot And Mouth ◽  
The Basic Reproduction Number

Hand, foot, and mouth disease (HFMD) is a highly contagious disease with several outbreaks in Asian-Pacific countries, including Thailand. With such epidemic characteristics and potential economic impact, HFMD is a significant public health issue in Thailand. Generally, contagious/infectious diseases’ transmission dynamics vary across geolocations due to different socioeconomic situations, demography, and lifestyles. Hence, a nationwide comprehensive model of the disease’s epidemic dynamics can provide information to understand better and predict a potential outbreak of this disease and efficiently and effectively manage its impact. However, there is no nationwide and comprehensive (i.e., the inclusion of reinfections in the model) model of HFDM dynamics for Thailand. This paper has endeavoured to promote nationwide comprehensive modelling of HFMD’s epidemic dynamics and comprehend the reinfection cases. We have formulated the SEIRS epidemiological model with dynamic vitals, including reinfections, to explore this disease’s prevalence. We also introduced periodic seasonality to reproduce the seasonal effect. The pattern of spread of this disease is uneven across the provinces in Thailand, so we used K -means clustering algorithm to cluster those provinces into three groups (i.e., highly, moderately, and least affected levels). We also analysed health records collected from district hospitals, which suggest significant reinfection cases. For example, we found that 11% (approximately) of infectious patients return for repeat treatment within the study period. We also performed sensitivity analysis which indicates that the basic reproduction number ( R 0 ) is sensitive to the rate of transmission ( β ) and the rate at which infected people recover ( γ ). By fitting the model with HFMD confirmed data for the provinces in each cluster, the basic reproduction number ( R 0 ) was estimated to be 2.643, 1.91, and 3.246 which are greater than 1. Based on this high R 0 , this study recommends that this disease will persist in the coming years under identical cultural and environmental conditions.

scholarly journals The Modelling of Hand, Foot, and Mouth Disease in Contaminated Environments in Bangkok, Thailand

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Sudarat Chadsuthi ◽  
Surapa Wichapeng
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Direct Transmission ◽  
Free Living ◽  
Indirect Transmission ◽  
Foot And Mouth ◽  
Asymptomatic Individuals ◽  
The Basic Reproduction Number

Hand, foot, and mouth disease (HFMD) has spread widely in a continuing endemic in Thailand. There are no specific vaccines or antiviral treatments available that specifically target HFMD. Indirect transmission via free-living viruses from the environment may influence HFMD infections because the virus can survive for long periods in the environment. In this study, a new mathematical model is proposed to investigate the effect of indirect transmission from contaminated environments and the impact of asymptomatic individuals. By fitting our model to reported data on hospitalized individuals of HFMD endemic in Bangkok, Thailand, 2016, the basic reproduction number was estimated as 1.441, which suggests that the disease will remain under current conditions. Numerical simulations show that the direct transmission from asymptomatic individuals and indirect transmission via free-living viruses are important factors which contribute to new HFMD infections. Sensitivity analysis indicates that the basic reproduction number is sensitive to the transmission rate of asymptomatic and symptomatic subgroups and indirect transmission. Our findings suggest that cleaning the environment frequently and healthcare precautions which include the reduction of direct transmission rates should be promoted as effective control strategies for preventing the HFMD spread.

scholarly journals Basic Reproduction Number of Enterovirus 71 Coxsackievirus A16 and A6: Evidence from Outbreaks of Hand, Foot and Mouth Disease in China between 2011 and 2018

2020 ◽  
Author(s):  
Zhong Zhang ◽  
Yang Liu ◽  
Fengfeng Liu ◽  
Minrui Ren ◽  
Taoran Nie ◽  
...  
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Mainland China ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Initial Growth ◽  
Coxsackievirus A16 ◽  
Foot And Mouth ◽  
Common Serotypes

Abstract Background Enterovirus 71 (EV-A71), Coxsackievirus A16 (CV-A16) and Coxsackievirus A6 (CV-A6) are common serotypes causing hand, foot, and mouth disease (HFMD). Analyses on the basic reproduction number (R0) of common pathogens causing HFMD are limited and there are no related studies using field data from outbreaks in mainland China. Methods We estimated the pathogen-specific basic reproduction number based on laboratory-confirmed HFMD outbreaks (clusters of ≥10 HFMD cases) reported to the national surveillance system between 2011 and 2018. The reproduction numbers were calculated using a mathematical model and the cumulative cases during the initial growth periods. Results This study included 539 outbreaks, of which 198 were caused by EV-A71, 316 by CV-A16, and 25 by CV-A6. All 10417 cases involved were children. Assuming the outbreaks occurred in closed systems and the incubation period is 5 days, the median R0s of EV-A71, CV-A16, and CV-A6 were 5.06 [2.81, 10.20], 4.84 [3.00, 9.00] and 5.94 [3.27, 10.00] (Median [IQR]). After adjusting for seroprevalences, the R0s for EV-A71, CV-A16 (optimistic and conservative scenarios), and CV-A6 were 12.60 [IQR: 7.35, 25.40], 9.29 [IQR: 6.01, 19.20], 15.50 [IQR: 9.77, 30.40], and 25.80 [IQR: 14.20, 43.50], respectively. We did not observe changes in the R0s of EV-A71 after vaccine licensure (p-value = 0.67). Conclusions HFMD is highly transmissible when caused by the three most common serotypes. In mainland China, it primarily affects young children. Although a vaccine became available in 2016, we have not yet observed any related changes in the disease dynamics.

Basic reproduction number of coxsackievirus type A6 and A16 and enterovirus 71: estimates from outbreaks of hand, foot and mouth disease in Singapore, a tropical city-state

2015 ◽  
Vol 144 (5) ◽  
pp. 1028-1034 ◽  
Author(s):  
C. T. K. LIM ◽  
L. JIANG ◽  
S. MA ◽  
L. JAMES ◽  
L. W. ANG
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Measures ◽  
Initial Growth ◽  
Cumulative Number ◽  
Coxsackievirus A6 ◽  
Foot And Mouth

SUMMARYCoxsackievirus A6 (CV-A6), coxsackievirus A16 (CV-A16) and enterovirus 71 (EV-A71) were the major enteroviruses causing nationwide hand, foot and mouth disease (HFMD) epidemics in Singapore in the last decade. We estimated the basic reproduction number (R0) of these enteroviruses to obtain a better understanding of their transmission dynamics. We merged records of cases from HFMD outbreaks reported between 2007 and 2012 with laboratory results from virological surveillance. R0 was estimated based on the cumulative number of reported cases in the initial growth phase of each outbreak associated with the particular enterovirus type. A total of 33 HFMD outbreaks were selected based on the inclusion criteria specified for our study, of which five were associated with CV-A6, 13 with CV-A16, and 15 with EV-A71. The median R0 was estimated to be 5·04 [interquartile range (IQR) 3·57–5·16] for CV-A6, 2·42 (IQR 1·85–3·36) for CV-A16, and 3·50 (IQR 2·36–4·53) for EV-A71. R0 was not significantly associated with number of infected children (P = 0·86), number of exposed children (P = 0·94), and duration of the outbreak (P = 0·05). These enterovirus-specific R0 estimates will be helpful in providing insights into the potential growth of future HFMD epidemics and outbreaks for timely implementation of disease control measures, together with disease dynamics such as severity of the cases.

scholarly journals Hand, Foot, and Mouth Disease in Thailand: A Comprehensive Modelling of Epidemic Dynamics

2020 ◽  
Author(s):  
Suraj Verma ◽  
Mohammad Abdur Razzaque ◽  
U Sangtongdee ◽  
C Arpnikanondt ◽  
Boonrat Tassaneetrithep ◽  
...  
Keyword(s):  
Learning Algorithm ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Public Health Issue ◽  
Seasonal Effect ◽  
Epidemic Dynamics ◽  
Foot And Mouth ◽  
Asian Pacific

Abstract Background Hand Foot and Mouth Disease (HFMD) is a highly contagious disease and has become an epidemic in many Asian-Pacific countries, including Thailand. With such epidemic characteristics and potential economic impact, HFMD is a significant public health issue. Comprehensive modelling of HFMD’s epidemic dynamics can be useful in understanding and predicting any potential outbreak of it, and manage its impact efficiently and effectively. Generally, the transmission dynamics of infectious diseases vary across geolocations due to different socio-economic situations, demography, and people’s lifestyles. However, there is no nation-wide and comprehensive (i.e., the inclusion of reinfections in the model) modelling of HFDM dynamics in Thailand. We aim to develop a nation-wide comprehensive modelling of HFMD’s epidemic dynamics and understand the reinfection cases in Thailand.Methods We have formulated Susceptible - Exposed - Infectious - Recovered - Susceptible (SEIRS) epidemiological model with dynamic vitals, including reinfections, to investigate the transmission of this disease in Thailand. We also introduced periodic seasonality to model the seasonal effect. According to the model, the spread of this disease is uneven throughout the provinces in Thailand. So, we have grouped the provinces into three clusters (i.e., highly, moderately and least affected provinces) using K-means unsupervised machine learning algorithm for better estimation of the parameters and fitting the model. We collected data from three local hospitals in Thailand to analyze the reinfection cases.Results The result from the analysis of HFMD recorded cases from three hospital (years 2012 to 2016) shows that 11% (approximately) are reinfections. By fitting the model with HFMD confirmed cases (years 2011 to 2019) and considering the reinfections, the basic reproductive number (R0) was estimated to be 2.643, 1.91 and 3.246 for three clustered provinces.Conclusion In a conclusion, it is found that HFMD is re-infectious disease in Thailand. It is also found that the spread of HFMD is not uniform across the provinces in Thailand. The basic reproductive number R 0 was estimated to be greater than 1 for all the three clusters. This indicates that under the same social and environmental condition, this disease will persist in coming years.

Evolution of SARS-CoV-2 in the state of Alagoas-Brazil via an adaptive SIR model

2020 ◽  
pp. 2150040
Author(s):  
I. F. F. Dos Santos ◽  
G. M. A. Almeida ◽  
F. A. B. F. De Moura
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Sir Model ◽  
The State ◽  
Epidemic Dynamics ◽  
Historical Series ◽  
Input Parameters ◽  
Number Formula ◽  
Near Future ◽  
The Basic Reproduction Number

We investigate the spreading of SARS-CoV-2 in the state of Alagoas, northeast of Brazil, via an adaptive susceptible-infected-removed (SIR) model featuring dynamic recuperation and propagation rates. Input parameters are defined based on data made available by Alagoas Secretary of Health from April 19, 2020 on. We provide with the evolution of the basic reproduction number [Formula: see text] and reproduce the historical series of the number of confirmed cases with less than [Formula: see text] error. We offer predictions, from November 16 forward, over the epidemic situation in the near future and show that it will keep decelerating. Furthermore, the same model can be used to study the epidemic dynamics in other countries with great easiness and accuracy.

scholarly journals Interaction analysis on transmissibility of main pathogens of hand, foot, and mouth disease in Xi’an: a modelling study

2019 ◽  
Author(s):  
Yao Bai ◽  
Kun Liu ◽  
Zhongjun Shao ◽  
Zhijun Chen ◽  
Tianmu Chen
Keyword(s):  
Disease Burden ◽  
Reproduction Number ◽  
Interaction Analysis ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Enterovirus A71 ◽  
Foot And Mouth ◽  
Xi’An City ◽  
High Disease Burden

Abstract Objectives: Hand, foot, and mouth disease (HFMD) has spread widely and led to high disease burden in many countries, but the interaction among the pathogens of the disease remains unclear. In this study, we aimed to analyze the interaction of the main pathogens of HFMD using a mathematical model. Method: A dataset on reported HFMD cases was collected in Xi’an City. A long-term etiological surveillance was conducted focusing on the pathogens of the disease including Enterovirus A71 (EV71), Coxsachievirus A16 (CoxA16), and other enteroviruses. A susceptible–infectious–recovered model was adopted to calculate the reproduction number during the ascending period of reported cases (defined as Rasc) and the descending period (defined as Rdes). Results: In Xi’an, Rasc and Rdes of HFMD was 1.39 (95% CI: 1.31 – 1.48) and 0.70 (95% CI: 0.65 – 0.74), respectively. CoxA16 and other enteroviruses interacted with each other and decreased the value of Rasc. However, Rdes of CoxA16 was increased by other enteroviruses directionally.However, during the reported cases decreasing period, interactions only occurred between EV71 and other enteroviruses and between CoxA16 and other enteroviruses. These interactions all decreased Rasc but increased Rdes of affected pathogens. Conclusions: The interaction of the pathogens exists in Xi’an City. The reproduction number of the affected pathogen is adjusted and verges to 1 by the interaction.

scholarly journals Epidemic dynamics, interactions and predictability of enteroviruses associated with hand, foot and mouth disease in Japan

2018 ◽  
Vol 15 (146) ◽  
pp. 20180507 ◽  
Author(s):  
Saki Takahashi ◽  
C. Jessica E. Metcalf ◽  
Yuzo Arima ◽  
Tsuguto Fujimoto ◽  
Hiroyuki Shimizu ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Vaccine Development ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Asia Pacific ◽  
Series Data ◽  
Inhibitory Interaction ◽  
Epidemic Dynamics ◽  
Foot And Mouth

Outbreaks of hand, foot and mouth disease have been documented in Japan since 1963. This disease is primarily caused by the two closely related serotypes of Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16). Here, we analyse Japanese virologic and syndromic surveillance time-series data from 1982 to 2015. As in some other countries in the Asia Pacific region, EV-A71 in Japan has a 3 year cyclical component, whereas CV-A16 is predominantly annual. We observe empirical signatures of an inhibitory interaction between the serotypes; virologic lines of evidence suggest they may indeed interact immunologically. We fit the time series to mechanistic epidemiological models: as a first-order effect, we find the data consistent with single-serotype susceptible–infected–recovered dynamics. We then extend the modelling to incorporate an inhibitory interaction between serotypes. Our results suggest the existence of a transient cross-protection and possible asymmetry in its strength such that CV-A16 serves as a stronger forcing on EV-A71. Allowing for asymmetry yields accurate out-of-sample predictions and the directionality of this effect is consistent with the virologic literature. Confirmation of these hypothesized interactions would have important implications for understanding enterovirus epidemiology and informing vaccine development. Our results highlight the general implication that even subtle interactions could have qualitative impacts on epidemic dynamics and predictability.

scholarly journals Lyapunov Stability Analysis of a Delayed Foot-and-Mouth Disease Model with Animal Vaccination

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Hove-Musekwa ◽  
Steady Mushayabasa
Keyword(s):  
Disease Virus ◽  
Disease Model ◽  
Intervention Strategy ◽  
Ecological Factors ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Sub Saharan Africa ◽  
Epidemic Dynamics ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Foot-and-mouth disease virus remains one of the most important livestock diseases in sub-Saharan Africa and several Southeast Asian countries. Vaccination of livestock has been recognized as an important tool for the control of foot-and-mouth disease virus. However, this intervention strategy has some limitations. Generally, vaccine production is a complex multistep process which involves development, manufacturing, and delivery processes, and through this extensive process, some challenges such as poor vaccine storage often arise. More often, these challenges alter the validity of the vaccination. Foot-and-mouth disease virus epidemic dynamics have been extensively explored, but understanding the role of vaccination validity on virus endemicity is lacking. We present a time-delayed foot-and-mouth disease model that incorporates relevant biological and ecological factors, vaccination effects, and disease carriers. We determined the basic reproduction number and demonstrated that it is an important metric for persistence and extinction of the disease in the community. Numerical illustrations were utilised to support some of the analytical results.

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