Applying Regular Perturbation Analysis to HCV Viral Load Equations

There are many mathematical, time-dependent models of hepatitis type C virus (HCV) infection found in the literature. Although the evolution of the level of infection is complex, there are many successful models explaining a variety of in-vivo and in-vitro observations. These models are playing a pivotal role in the pharmaceutical industry by helping researchers and clinicians analyze the performance of HCV therapeutics. New treatments of HCV quickly drive the amount of virus in the body below measurable levels. This leaves few data points for researchers to fit models. Using regular perturbation methodologies we derive and compare a series of approximations for a standard model to understand tradeoffs between model complexity (number of parameters) and model accuracy. This interplay between perturbation analysis and numerical methods leads to numerical and analytical methods yielding superior insight into the sparse data generated from new treatment regimes.