Aetiology is a web log discussing a wide variety of issues pertaining to the science of biology. While much of the focus is on the epidemiology of infectious disease or general microbiology, these are fields that lend themselves to discussion of a much wider range of topics: general epidemiology, vaccines, medicine, public health, pseudoscience, and politics, just to name a handful. A discussion of the microbial world reaches into many facets of our everyday lives.