Parasites commonly found in untreated sewage include which of the following?

The presence of parasites in untreated sewage is a significant concern for public health due to the potential for disease transmission. Hookworm, roundworms, and tapeworms are all helminths (worms) that can be found in environments contaminated with untreated sewage.

Hookworms, for instance, can infect humans through contact with contaminated soil or water, leading to gastrointestinal issues and, in severe cases, anemia. Roundworms, such as Ascaris, are also transmitted through contaminated food or hands and can cause malnutrition and other health problems. Tapeworms can reside in the intestines of hosts, leading to nutrient absorption issues. All these parasites are effective at surviving in sewage due to their resilient life cycles.

In contrast, although Giardia (a protozoan) is often associated with waterborne outbreaks, E. coli is primarily a bacterium and not classified as a parasite. Ascaris and Trichinella are also significant but are less common when specifically considering untreated sewage compared to the parasitic worms listed in the chosen answer. Salmonella and Listeria, while often discussed regarding foodborne illnesses, are bacteria rather than parasites, making them less relevant to the context of untreated sewage.