Modelling the effects of behavioral change on the transmission dynamics of Herpes Simplex Virus Type 2 (HSV-2).

Abstract

Herpes simplex virus type 2 (HSV-2) is the most prevalent sexually transmitted disease worldwide, despite the availability of highly effective anti-viral treatment. It is of great concern that as other sexually transmitted infections (STIs) are on the decrease, HSV-2 is on the rise in other parts of the world. HSV-2 is very expensive to control and it is one of themajor contributors to the prevalence of HIV. Numerous statistical and mathematical models for investigating the transmission dynamics of HSV-2 have been proposed. This study aims to extend all the experience acquired from these studies in order to assess the effects of behavioural change on the transmission dynamics of HSV-2. Behavioural changes can be implemented to complement the already existing intervention strategies. Deterministic models in the form of non linear differential equations are developed and analysed to study the effects of various behavioural changes on the transmission dynamics of HSV-2. Prior studies have shown that adolescents are the most vulnerable group to HSV-2 due to their risky sexual behaviours. The models developed capture the effects of some risky sexual behaviours among the adolescents and the general population. Two deterministic models for investigating the dynamics of HSV-2 among adolescents have been proposed. The models focus on (i) the spread of HSV-2 within a community with substance abusing adolescents (ii) assess the impact of sexting and peer influence on the spread of HSV-2. Further, two other deterministic models for investigating the dynamics of HSV-2 among the general population have been proposed. The models focus on, (iii) investigating the impact of poor treatment adherence on the prevalence of HSV-2 and (iv) explore the association between gender and poor treatment adherence. In all the constructed models, the effects of prevention and intervention strategies on controlling the spread of HSV-2 have been comprehensively investigated. Analysis of the models suggest that various behavioural changes have an effect on reducing the prevalence and transmission of HSV-2. Results from the study suggest that educational campaigns and condom use are effective on reducing HSV-2 among substance abusing adolescents. The v study also realised that, awareness campaigns and filtering are effective in reducing the prevalence of HSV-2 among the sexting adolescents. Among the general population, monitoring and counselling all the HSV-2 patients under treatment would be vital in reducing HSV-2 prevalence. We further noted that, for us to keep the levels of HSV-2 cases as low as possible it is vital to keep the level of female adherence as high as possible compared to the one for males. Directions for further research studies are also suggested in this thesis.