scholarly journals The transmission dynamics of hepatitis B in the UK: a mathematical model for evaluating costs and effectiveness of immunization programmes

1996 ◽  
Vol 116 (1) ◽  
pp. 71-89 ◽  
Author(s):  
J. R. Williams ◽  
D. J. Nokes ◽  
G. F. Medley ◽  
R. M. Anderson
Keyword(s):  
Mathematical Model ◽  
Hepatitis B ◽  
Vaccine Coverage ◽  
Vaccine Dose ◽  
Transmission Dynamics ◽  
Costs And Benefits ◽  
Vaccination Strategies ◽  
The Uk ◽  
The Impact ◽  
Immunization Programmes

SummaryComplex hepatitis B (HBV) epidemiology makes it difficult to evaluate and compare effectiveness of different immunization policies. A method for doing so is presented using a mathematical model of HBV transmission dynamics which can represent universal infant and adolescent vaccination strategies and those targeted at genito-urinary (GU) clinic attenders and infants born to infectious mothers. Model structure, epidemiological underpinning, and parameterization, are described. Data from the UK National Survey of Sexual Attitudes and Lifestyles is used to define patterns of sexual activity and GU clinic attendance; data deficiencies are discussed, in particular that of UK seroprevalence of HBV markers stratified by age, sex, and risk factors. General model predictions of endemic HBV marker prevalence in homosexual and heterosexual populations seem consistent with published UK data. The simulations exhibit non-linearities in the impact of different vaccination strategies. Estimated number of carriers prevented per vaccine dose for each strategy provides a measure of costs and benefits, varying temporally over the course of a programme, and with level of vaccine coverage. Screening before vaccination markedly increases payback per dose in homosexuals but not in heterosexuals; mass infant vaccination gives the poorest effectiveness ratio and vaccination of infants after antenatal screening the best; in general, increasing vaccine coverage yields lower pay-back per dose. The model provides a useful framework for evaluating costs and benefits of immunization programmes, but for precise quantitative comparison more UK epidemiological data is urgently needed.

scholarly journals Hepatitis B infection among Iraqi children: the impact of sanctions

2004 ◽  
Vol 10 (1-2) ◽  
pp. 6-11
Author(s):  
H. Y. M. Ali
Keyword(s):  
Hepatitis B ◽  
Vaccine Dose ◽  
United Nations Security Council ◽  
Enzyme Linked Immunosorbent Assay ◽  
The Public ◽  
Hbsag Carriers ◽  
Vaccine Availability ◽  
Vaccine Shortages ◽  
The Impact

Effect of sanctions on hepatitis B vaccine availability and occurrence of viral hepatitis B among Iraqi children was studied. Between June 2000 and June 2001, families of patients attending the Public Health Laboratory, Mosul, for hepatitis B follow-up were screened. Enzyme-linked immunosorbent assay was used to test for HBsAg, HBeAg and anti-HBe. We diagnosed 74 children born 1994-1998 as HBsAg carriers. For 62 of 74 cases, parents had consulted vaccine centres promptly:41 were not vaccinated and 21 had only one vaccine dose. HBeAg marker was positive for 9 [14.5%] and anti-HBe for 50 [80.7%]. Parental reluctance was the reason for non-vaccination for 12. Vaccine shortages during the birth years of cases were documented, even after implementation of United Nations Security Council Resolution 986

scholarly journals Effect of Control on the Mathematical Model of Hepatitis B Virus with Infective Migrant

2020 ◽  
pp. 58-70
Author(s):  
Folahan S. Akinboro ◽  
T. O. Oluyo ◽  
O. O. Kehinde ◽  
S. Alao
Keyword(s):  
Mathematical Model ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Control Strategy ◽  
Transmission Dynamics ◽  
Optimal Control Strategy ◽  
Control Variables ◽  
B Virus ◽  
Implicit Finite Difference ◽  
The Mathematical Model

The transmission dynamics of Hepatitis B Virus in a population with infective immigrant is presented with the inclusion of an optimal control strategy to curtail the spread of the virus. To understand the spread of this infection, we develop a mathematical model with control variables of migrant screening and public sensitization. The optimality system is characterized using Pontryagin’s maximum principle and solve numerically with an implicit finite difference method.  Result of the numerical simulation is presented to illustrate the feasibility of this control strategy. The analysis reveals that combination of both control variables could be the most fruitful way to reduce the incidence of Hepatitis B virus.

scholarly journals Characterizing the Transmission Dynamics of the Cases Registered by Covid-19 in Venezuela According to Epidemic Wave and the Value of the Mantissa

2020 ◽  
Vol 2 (2) ◽  
pp. 8-12
Author(s):  
Raúl Isea
Keyword(s):  
Mathematical Model ◽  
Input Data ◽  
Transmission Dynamics ◽  
Model Based ◽  
The Government ◽  
The Impact ◽  
Epidemic Wave ◽  
Over Time

This work characterizes the transmission dynamics of the cases registered by Covid-19 in Venezuela. The needed input data were obtained from the official gazettes issued by the Government of Venezuela, from March 15 to September 9, 2020. Later, the value of the mantissa was determined, revealing the impact of the different outbreaks with special attention to the events at the baseball stadium in Nueva Esparta State, and the Las Pulgas Market located in Maracaibo. Finally, a mathematical model based on four epidemic waves revealed that the cases are increasing significantly over time after the episode that occurred in the Las Pulgas Market.

Modelling the impact of one-dose vs. two-dose vaccination regimens on the epidemiology of varicella zoster virus in Australia

2009 ◽  
Vol 138 (4) ◽  
pp. 457-468 ◽  
Author(s):  
Z. GAO ◽  
H. F. GIDDING ◽  
J. G. WOOD ◽  
C. R. MacINTYRE
Keyword(s):  
Mathematical Model ◽  
Varicella Zoster Virus ◽  
Vaccination Strategy ◽  
Vaccination Schedule ◽  
Varicella Zoster ◽  
Dose Strategy ◽  
Vaccination Strategies ◽  
Age Of Infection ◽  
The Impact

SUMMARYWe examined the impact of one-dose vs. two-dose vaccination strategies on the epidemiology of varicella zoster virus (VZV) in Australia, using a mathematical model. Strategies were assessed in terms of varicella (natural and breakthrough) and zoster incidence, morbidity, average age of infection and vaccine effectiveness (VE). Our modelling results suggest that compared to a one-dose vaccination strategy (Australia's current vaccination schedule), a two-dose strategy is expected to not only produce less natural varicella cases (5% vs. 13% of pre-vaccination state, respectively) but also considerably fewer breakthrough varicella cases (only 11·4% of one-dose strategy). Therefore a two-dose infant vaccination programme would be a better long-term strategy for Australia.

scholarly journals Assessing the Impact of Drug Resistance on the Transmission Dynamics of Typhoid Fever

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
S. Mushayabasa ◽  
C. P. Bhunu ◽  
E. T. Ngarakana-Gwasira
Keyword(s):  
Public Health ◽  
Mathematical Model ◽  
Drug Resistance ◽  
Typhoid Fever ◽  
Public Health Problem ◽  
Transmission Dynamics ◽  
Reproductive Number ◽  
Major Public Health Problem ◽  
Drug Resistant ◽  
The Impact

Typhoid fever continues to be a major public health problem in the developing world. Antibiotic therapy has been the main stay of treating typhoid fever for decades. The emergence of drug-resistant typhoid strain in the last two decades has been a major problem in tackling this scourge. A mathematical model for investigating the impact of drug resistance on the transmission dynamics of typhoid fever is developed. The reproductive number for the model has been computed. Numerical results in this study suggest that when a typhoid outbreak occurs with more drug-sensitive cases than drug-resistant cases, then it may take 10–15 months for symptomatic drug-resistant cases to outnumber all typhoid cases, and it may take an average of 15–20 months for nonsymptomatic drug-resistant cases to outnumber all drug-sensitive cases.

scholarly journals Impact of Hygiene on Malaria Transmission Dynamics: A Mathematical Model

2021 ◽  
Author(s):  
Temidayo Oluwafemi ◽  
Emmanuel Azuaba
Keyword(s):  
Mathematical Model ◽  
Malaria Transmission ◽  
Basic Reproduction Number ◽  
Human Population ◽  
Reproduction Number ◽  
Model System ◽  
Transmission Dynamics ◽  
The Impact ◽  
Disease Free ◽  
The Basic Reproduction Number

Malaria continues to pose a major public health challenge, especially in developing countries, 219 million cases of malaria were estimated in 89 countries. In this paper, a mathematical model using non-linear differential equations is formulated to describe the impact of hygiene on Malaria transmission dynamics, the model is analyzed. The model is divided into seven compartments which includes five human compartments namely; Unhygienic susceptible human population, Hygienic Susceptible Human population, Unhygienic infected human population , hygienic infected human population and the Recovered Human population  and the mosquito population is subdivided into susceptible mosquitoes  and infected mosquitoes . The positivity of the solution shows that there exists a domain where the model is biologically meaningful and mathematically well-posed. The Disease-Free Equilibrium (DFE) point of the model is obtained, we compute the Basic Reproduction Number using the next generation method and established the condition for Local stability of the disease-free equilibrium, and we thereafter obtained the global stability of the disease-free equilibrium by constructing the Lyapunov function of the model system. Also, sensitivity analysis of the model system was carried out to identify the influence of the parameters on the Basic Reproduction Number, the result shows that the natural death rate of the mosquitoes is most sensitive to the basic reproduction number.

scholarly journals Estimating the health impact of vaccination against 10 pathogens in 98 low and middle income countries from 2000 to 2030

2019 ◽  
Author(s):  
Xiang Li ◽  
Christinah Mukandavire ◽  
Zulma M Cucunubá ◽  
Kaja Abbas ◽  
Hannah E Clapham ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Birth Cohort ◽  
Vaccine Coverage ◽  
Health Impact ◽  
Childhood Vaccination ◽  
Middle Income ◽  
Middle Income Countries ◽  
Life Years ◽  
The Impact ◽  
Low And Middle Income

AbstractBackgroundThe last two decades have seen substantial expansion of childhood vaccination programmes in low and middle income countries (LMICs). Here we quantify the health impact of these programmes by estimating the deaths and disability-adjusted life years (DALYs) averted by vaccination with ten antigens in 98 LMICs between 2000 and 2030.MethodsIndependent research groups provided model-based disease burden estimates under a range of vaccination coverage scenarios for ten pathogens: hepatitis B (HepB), Haemophilus influenzae type b (Hib), human papillomavirus (HPV), Japanese encephalitis (JE), measles, Neisseria meningitidis serogroup A (MenA), Streptococcus pneumoniae, rotavirus, rubella, yellow fever. Using standardized demographic data and vaccine coverage estimates for routine and supplementary immunization activities, the impact of vaccination programmes on deaths and DALYs was determined by comparing model estimates from the no vaccination counterfactual scenario with those from a default coverage scenario. We present results in two forms: deaths/DALYs averted in a particular calendar year, and in a particular annual birth cohort.FindingsWe estimate that vaccination will have averted 69 (2.5-97.5% quantile range 52-88) million deaths between 2000 and 2030 across the 98 countries and ten pathogens considered, 35 (29-45) million of these between 2000-2018. From 2000-2018, this represents a 44% (36-57%) reduction in deaths due to the ten pathogens relative to the no vaccination counterfactual. Most (96% (93-97%)) of this impact is in under-five age mortality, notably from measles. Over the lifetime of birth cohorts born between 2000 and 2030, we predict that 122 (96-147) million deaths will be averted by vaccination, of which 58 (39-75) and 38 (26-52) million are due to measles and Hepatitis B vaccination, respectively. We estimate that recent increases in vaccine coverage and introductions of additional vaccines will result in a 72% (61-79%) reduction in lifetime mortality caused by these 10 pathogens in the 2018 birth cohort.InterpretationIncreases in vaccine coverage and the introduction of new vaccines into LMICs over the last two decades have had a major impact in reducing mortality. These public health gains are predicted to increase in coming decades if progress in increasing coverage is sustained.

scholarly journals A unified activities-based approach to the modelling of viral epidemics and COVID-19 as an illustrative example

2020 ◽  
Author(s):  
Yulii D. Shikhmurzaev ◽  
Vladislav D. Shikhmurzaev
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Social Interactions ◽  
Clinical Picture ◽  
Simple Mathematical Model ◽  
New Approach ◽  
Social Distancing ◽  
The Uk ◽  
The Impact

AbstractA new approach to formulating mathematical models of increasing complexity to describe the dynamics of viral epidemics is proposed. The approach utilizes a map of social interactions characterizing the population and its activities and, unifying the compartmental and the stochastic viewpoints, offers a framework for incorporating both the patterns of behaviour studied by sociological surveys and the clinical picture of a particular infection, both for the virus itself and the complications it causes. The approach is illustrated by taking a simple mathematical model developed in its framework and applying it to the ongoing pandemic of SARS-CoV-2 (COVID-19), with the UK as a representative country, to assess the impact of the measures of social distancing imposed to control its course.

scholarly journals Modeling the Impact of Seasonal Weather Variations on the Infectiology of Brucellosis

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Nkuba Nyerere ◽  
Livingstone S. Luboobi ◽  
Saul C. Mpeshe ◽  
Gabriel M. Shirima
Keyword(s):  
Mathematical Model ◽  
Numerical Simulations ◽  
Transmission Dynamics ◽  
Wild Animals ◽  
Indirect Transmission ◽  
Transmission Parameters ◽  
Domestic Ruminants ◽  
Weather Variations ◽  
The Impact ◽  
Seasonal Weather

A deterministic mathematical model for brucellosis that incorporates seasonality on direct and indirect transmission parameters for domestic ruminants, wild animals, humans, and the environment was formulated and analyzed in this paper. Both analytical and numerical simulations are presented. From this study, the findings show that variations in seasonal weather have the great impact on the transmission dynamics of brucellosis in humans, livestock, and wild animals. Thus, in order for the disease to be controlled or eliminated, measures should be timely implemented upon the fluctuation in the transmission of the disease.

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