This study proposes Natural Semantic Metalanguage semantic explications for the English words ‘virus’ (in two senses), ‘bacteria’, ‘germs’, and for the related words ‘sick’, ‘ill’, and ‘disease’. We concentrate on their “naïve” or “folk” meanings (Apresjan 1992) in everyday English, as opposed to scientific or semi-scientific meanings. In this way, the paper makes a start on uncovering the folk epidemiology embedded in the English lexicon. The semantics of words like ‘virus’, ‘bacteria’ and ‘germs’ is not, however, a purely academic matter. It is also a matter of effective health education and health communication. To reach people at a time of an epidemic, explanations need to connect with “ordinary people’s” ways of thinking and speaking. This paper argues that the simple and cross-translatable words of NSM, and minimal languages based on it, can be effective tools not only for linguistic semantics but also for education and communication everywhere - at the local school and in the world at large.