悪疫[akueki] epidemic
疫学[ekigaku] epidemiology
疫病神[yakubyougami] jinx (lit: god of pestilence)
疫痢[ekiri] children's dysentery
疫癘[ekirei] epidemic

検疫[keneki] quarantine
鼠疫[soeki] plague
能動免疫[noudoumeneki] active immunity
防疫[boueki] communicable disease control (e.g. by quarantine, disinfection, etc.)
免疫[meneki] immunity