It appears capable of surviving two to three days in sewage at room temperature, but may survive for more than two weeks in raw sewage at lower temperatures. Although the HIV virus may be found in raw sewage, the risk of becoming infected seems highly unlikely. Transmission would require puncture of the skin or contact with cuts or other damaged skin tissue. In addition, given the low concentration of virus likely to be present, it seems improbable than any significant risk of infection exists. An infection caused by the amoeba, Entamoeba histolytica, is acquired by the fecal-oral route.
Symptoms can vary from minor abdominal cramps to severe diarrhea alternating with constipation.
An infection of the upper small intestines by Giardia lamblia , a flagellate protozoan, is acquired by the fecal-oral route. Symptoms, while usually asymptomatic, include chronic diarrhea, abdominal cramps, bloating, fatigue and weight loss. Several parasitic intestinal worms are found in wastewater. These parasites are a potential hazard to the public health in general and to treatment plant workers in particular. Taeniasis results from beef tapeworms, Taenia saginata , being ingested through the mouth.