Mathematical models for the transmission dynamics of HIV and its progression to AIDS in Ireland

Despite advances m understanding the basic biology of HIV the aetiological agent of AIDS, medica1, public health and health education planning is plagued by uncertainties Mathematical models of the dynamics of HIV transmission and its progression to AIDS can clarify what data must be collected in order to predict future prevalence, make predictions about the likely effect of future intervention pobcies and provide predictions for several decades ahead. The motivation of this research is to provide reliable estimates of the incidence of HIV infection and AIDS in the Irish population. In Chapters 1 and 2 we discuss the background to the disease in Ireland and the role of mathematical modelling in the spread AIDS. From this we show where key epidemiological data is lacking and how models to date have concentrated on the spread of the disease within the homosexual population. In Chapter 3 we describe the adjustment of the number of AIDS cases to allow for reporting delays Subsequently we consider the solution of the integral equation models generated by the back-projection method for the adjusted AIDS cases. In Chapter 4 we improve upon the estimates of the incidence of HIV infection found in Chapter 3 by evaluating the integral arising in back-projection, in terms of a gamma function plus a remainder in the form of a series in t. We also provide error bounds for the remainder. This new solution allows us to predict new and more reliable estimates of the level of HIV infection m Ireland. In Chapter 5 we provide estimates of the minimum number of deaths from AIDS, based on the number of AIDS cases known to the Department of Health and the distribution of the length of survival times after the onset of AIDS. The results of a HIV transmission survey are presented in Chapter 6 These provide detailed information on the habits and behaviour of those at risk of HIV infection and allow us to derive preliminary model parameters. Finally in Chapter 7 we develop and implement a nonlinear deterministic differential equation model for the spread of HIV and its progression to AIDS m the Irish IVDU and homosexual populations. We examine the effects of likely intervention policies on the extent and spread of the disease and we make recommendations based on our thesis findings

The Inbetweeners: Identifying And Quantifying The Unmet Mental Health Needs Of Children And Adolescents In Tallaght

Youth mental health is significant issue nationally as well as within South County Dublin. There is aperception amongst both service providers and parents that many children and young people are beingexposed to increasingly complex stressors and that the range of influences on their wellbeing are agrowing challenge. Whether this is the case or not, we do know that services are under pressure to respondeffectively, quickly and appropriately.This Report is the result of strong inter-agency working, bringing together statutory services with the community and voluntary sector, engaging with hospitals and community based providers, andoffering an opportunity for a number of disciplines and services to share their collective wisdom andinsights to better understand local dynamics.

ROSIE Findings 6: a summary of 3-year outcomes.

The Research Outcome Study in Ireland (ROSIE) is the first national, prospective, longitudinal, multi-site drug treatment outcome study in the country. The National Advisory Committee on Drugs (NACD) commissioned this research in 2002 as required by the National Drugs Strategy Action 99. The aim of the study was to recruit and follow opiate users entering treatment over a period of time, documenting the changes observed. The study recruited 404 opiate users entering treatment. Outcomes at 3-years for drug use, involvement in crime, injecting-related behaviour, physical and mental health, among others, are presented in this paper. Statistically significant differences are given emphasis in this document

ROSIE Findings 2: summary of 1-year outcomes: detoxification modality.

The Research Outcome Study in Ireland (ROSIE) is the first national, prospective, longitudinal, multi-site drug treatment outcome study in the country. The National Advisory Committee on Drugs (NACD) commissioned this research in 2002 as required by the National Drugs Strategy Action 99. The aim of the Study is to recruit and follow opiate users entering treatment over a period of time documenting the changes observed. Detoxification cohort: follow-up rates: Of the 81 people recruited within the detoxification modality, 93% (n=75) were located, and 77% (n=62) successfully completed a 1-year interview. One individual died within the follow-up period, four people withdrew from the study, eight people were located but not successfully interviewed, and an additional six participants were not located. These 19 people ‘lost’ to follow-up were excluded from the comparative analysis to allow for valid assessment across the two time periods.This is the second paper in the ROSIE Findings series and it provides a snapshot of the outcomes for people in the detoxification modality one year after treatment intake

Prevalence Rates and Comparisons of Obesity Levels in Ireland

This article compares the prevalence of the overweight and obesity levels in Irish school children aged 4–13 years from data collected by one of the authors in 2007, with data collected from a previous Irish study in 2002 by Whelton et al (2007). Both data sets were analyzed using the International Obesity Taskforse (IOTF) international cut-off points for body mass index (BMI). From the data collected in 2007 the overall prevalence of the overweight was 17.8% and the rate of obesity was 6.8%. The prevalence of the overweight and obese was 24.6%. No correlation was found between gender and BMI, however a positive and significant correlation was observed between age and BMI, indicating that as age increased so too did BMI (R = 0.35, p < 0.001). Comparing results with data from 2002 (Whelton et al, 2007), no statistically significant changes in the proportions of overweight and obese children were observed within this age group in the 5-year period from 2002 to 2007. While the results of our data suggest that rates of being overweight or obese among Irish children in this age group may be stabilizing, larger and preferably longitudinal Irish studies are required if this assertion is to be fully validated in the Irish context

A mathematical model for measles epidemics in Ireland

The aim of this work is to establish a matnematical model for measles epidemics and to predict levels of vaccination coverage require! in Ireland in order to eradicate tne disease The emphasis througnout has oeen to derive the parameters of the model using data collected in Ireland. To achieve this a nonlinear differential equation model first oroposed by Anderson R M. and May R.M. has been adopted and adjusted to meet our application. In Chapter 1 we introduce the concept of mathematically modelling the dynamics of an infectious disease and we also propose a simple constant parameter model We then move on in Chapter 2 to discuss what is known as ”the force of the infection". This is then calculated for Ireland by testing over 100 blood samples for measles antibodies. In Chapter 3 we estimated the Irish interepidemic period using Hopf's bifurcation theorem. In Chapter 4 we move on to the more detailed model with age dependence. We also estimate the age dependent survival rate jj(a) for the Irish population. Finally, in Chapters 5 and 6, we look at immunisation and the results predicted by the model. In Chapter 5 we derive c(a), the Irish age dependent vaccination rate This is accomplished by computerising over 4,000 immunisations. We also predict how the reproductive rate, R , of the disease will change with vaccination. In Chapter 6 we numerically analyse the model with the Irish age dependent parameters and we predict the levels of vaccination required in order to eradicate measles in Ireland

A response from Comiskey et al

The abstract is included in the text