The COVID-19 pandemic underlined the importance of controlling infectious disease outbreaks. My doctoral research has so far focused on developing mathematical theory and statistical framework for understanding the mechanisms driving the spread of infectious diseases and devising appropriate control strategies. In this talk, I will introduce basic ideas and tools for modeling epidemics. I will further discuss real-life applications of these tools, such as designing COVID-19 testing strategies on a university campus, and developing a new surveillance platform for endemic childhood diseases.