From The Health Hazards of Excreta: Theory and Control:
Many species of parasitic worms, or helminths, have human hosts. Helminths do not multiply within the human host and this is of great importance in understanding their transmission. Helminthic disease is not an all-or-nothing phenomenon. In infections due to viruses, bacteria and protozoa, where massive asexual reproduction occurs within the host, once infection occurs its severity cannot be related easily to the infecting dose of organisms. One either has measles or a common cold or not and it is not meaningful to say someone has “a lot of measles.” By contrast, with helminthic infections it is essential to think quantitatively. The question is not just whether or not someone has a hookworm infection but how many worms has he. Sometimes worm burdens can be determined by purging the patient immediately after an antihelminthic. … within any sex and age group of an infected community there will be a few people who are carrying a heavy worm burden and a much larger number with light intensities of infection.
Worm burden! Worm burden! I love writing this book. Or not-quite-writing it. I wonder what my worm burden is. I wonder what your worm burden is.