Estimation of the Basic Reproduction Number of Enterovirus 71 and Coxsackievirus A16 in Hand, Foot, and Mouth Disease Outbreaks

2011 ◽  
Vol 30 (8) ◽  
pp. 675-679 ◽  
Author(s):  
Edmond Ma ◽  
Connie Fung ◽  
Steven H. L. Yip ◽  
Christine Wong ◽  
Shuk Kwan Chuang ◽  
...  
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Enterovirus 71 ◽  
Disease Outbreaks ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Coxsackievirus A16 ◽  
Foot And Mouth ◽  
The Basic Reproduction Number

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.

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.

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 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 Enterovirus 71 related severe hand, foot and mouth disease outbreaks in South-East Asia: current situation and ongoing challenges

2014 ◽  
Vol 68 (6) ◽  
pp. 500-502 ◽  
Author(s):  
Saraswathy Sabanathan ◽  
Le Van Tan ◽  
Louise Thwaites ◽  
Bridget Wills ◽  
Phan Tu Qui ◽  
...  
Keyword(s):  
East Asia ◽  
Enterovirus 71 ◽  
Disease Outbreaks ◽  
Foot And Mouth Disease ◽  
Current Situation ◽  
Mouth Disease ◽  
South East Asia ◽  
Foot And Mouth
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