Modelling the Spread of the Human Papillomavirus on the Cervix

Abstract

Cervical cancer is the fourth most common cancer in women. It is caused by the hu- man papillomavirus (HPV). There are many different types of HPV, some of which are high-risk, highly associated with cancer, and low-risk. While HPV is very common— most sexually active individuals will contract some sexually transmitted HPV infec- tion in their lifetime—most infections are cleared without any complication. However, persistent infections may establish and develop into cancerous lesions. Two vaccines have been developed against the two most high-risk types, and have shown high lev- els of efficacy thus far. However, infections are still occurring and it is not clear why some individuals develop persistent infections while others do not. In this thesis, we develop a model to describe how the infection spreads within the host. We express the basic reproduction number R0, a threshold for the establishment of an infection. We solve for the diseased equilibrium, providing insight about whether an infection will persist or not. We develop a spatial model to examine how spatiality of the infec- tion process affects the establishment or clearance. Lastly, we develop a multi-type HPV model to examine whether competitive HPV types are able to coexist in the host for different levels of competition. Ultimately, this work provides groundwork for within-host modelling of HPV and can provide direction for future research.