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1.
Math Biosci Eng ; 18(1): 904-932, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33525125

RESUMO

An alcohol consumption model with health education and three time delays is formulated and analyzed. The alcoholism generation number is defined. Two steady states of the model are found. At the same time, the corresponding global dynamics of the model are analyzed respectively in four cases with different time delays. Then, the effects of health education and three time delays in controlling the alcohol problem are discussed. Some numerical simulation results are also given to support our theoretical predictions.


Assuntos
Alcoolismo , Consumo de Bebidas Alcoólicas/epidemiologia , Alcoolismo/epidemiologia , Simulação por Computador , Educação em Saúde , Humanos
2.
Math Biosci Eng ; 17(4): 3618-3636, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32987547

RESUMO

A new COVID-19 epidemic model with media coverage and quarantine is constructed. The model allows for the susceptibles to the unconscious and conscious susceptible compartment. First, mathematical analyses establish that the global dynamics of the spread of the COVID-19 infectious disease are completely determined by the basic reproduction number R0. If R0 ≤ 1, then the disease free equilibrium is globally asymptotically stable. If R0 > 1, the endemic equilibrium is globally asymptotically stable. Second, the unknown parameters of model are estimated by the MCMC algorithm on the basis of the total confirmed new cases from February 1, 2020 to March 23, 2020 in the UK. We also estimate that the basic reproduction number is R0 = 4.2816(95%CI: (3.8882, 4.6750)). Without the most restrictive measures, we forecast that the COVID-19 epidemic will peak on June 2 (95%CI: (May 23, June 13)) (Figure 3a) and the number of infected individuals is more than 70% of UK population. In order to determine the key parameters of the model, sensitivity analysis are also explored. Finally, our results show reducing contact is effective against the spread of the disease. We suggest that the stringent containment strategies should be adopted in the UK.


Assuntos
Betacoronavirus , Meios de Comunicação , Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Quarentena , Algoritmos , Número Básico de Reprodução/estatística & dados numéricos , COVID-19 , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Humanos , Cadeias de Markov , Conceitos Matemáticos , Modelos Biológicos , Método de Monte Carlo , Pandemias/prevenção & controle , Pandemias/estatística & dados numéricos , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , SARS-CoV-2 , Fatores de Tempo , Reino Unido/epidemiologia
3.
Bull Math Biol ; 82(6): 73, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32533498

RESUMO

Influenza usually breaks out seasonally in temperate regions, especially in winter, infection rates and mortality rates of influenza increase significantly, which means that dry air and cold temperatures accelerate the spread of influenza viruses. However, the meteorological factors that lead to seasonal influenza outbreaks and how these meteorological factors play a decisive role in influenza transmission remain unclear. During the epidemic of infectious diseases, the neglect of unreported cases leads to an underestimation of infection rates and basic reproduction number. In this paper, we propose a new non-autonomous periodic differential equation model with meteorological factors including unreported cases. First, the basic reproduction number is obtained and the global asymptotic stability of the disease-free periodic solution is proved. Furthermore, the existence of periodic solutions and the uniformly persistence of the model are demonstrated. Second, the best-fit parameter values in our model are identified by the MCMC algorithm on the basis of the influenza data in Gansu province, China. We also estimate that the basic reproduction number is 1.2288 (95% CI:(1.2287, 1.2289)). Then, to determine the key parameters of the model, uncertainty and sensitivity analysis are explored. Finally, our results show that influenza is more likely to spread in low temperature, low humidity and low precipitation environments. Temperature is a more important factor than relative humidity and precipitation during the influenza epidemic. In addition, our results also show that there are far more unreported cases than reported cases.


Assuntos
Surtos de Doenças , Influenza Humana/epidemiologia , Modelos Biológicos , Algoritmos , Número Básico de Reprodução/estatística & dados numéricos , China/epidemiologia , Biologia Computacional , Simulação por Computador , Surtos de Doenças/estatística & dados numéricos , Humanos , Umidade , Influenza Humana/transmissão , Cadeias de Markov , Conceitos Matemáticos , Conceitos Meteorológicos , Método de Monte Carlo , Estações do Ano , Temperatura
4.
Math Biosci Eng ; 16(5): 3561-3622, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31499628

RESUMO

A new alcoholism model with treatment and effect of Twitter is introduced. The stability of all equilibria which is determined by the basic reproductive number ro is obtained. The occurrence of backward and forward bifurcation for a certain defined range of ro are established by the center manifold theory. Numerical results and sensitivity analysis on several parameters are conducted. Our results show that Twitter may be a good indicator of alcoholism model and affect the emergence and spread of drinking behavior.


Assuntos
Alcoolismo/epidemiologia , Alcoolismo/mortalidade , Alcoolismo/fisiopatologia , Meios de Comunicação de Massa , Mídias Sociais , Algoritmos , China/epidemiologia , Simulação por Computador , Comportamento de Ingestão de Líquido , Humanos , Modelos Teóricos , Sensibilidade e Especificidade
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