Fecal-oral route

The fecal-oral route, or alternatively, the oral-fecal route or orofecal route is a route of transmission of diseases, in which they are passed when pathogens in fecal particles from one host are introduced into the oral cavity of another potential host.

There are usually intermediate steps, sometimes many of them. Among the more common causes are:

water that has come in contact with feces and is then inadequately treated before drinking;
food that has been handled with feces present;
poor sewage treatment along with disease vectors like houseflies;
poor or absent cleaning after handling feces or anything that has been in contact with it;
sexual practices that may involve feces, such as analingus.
sexual fetishes that involve feces, known collectively as coprophilia (its eating is known as coprophagia)

Some of the diseases that can be passed via the fecal-oral route include:

Poliomyelitis
Giardiasis^[1]
Hepatitis A^[2]
Hepatitis E^[3]
Rotavirus
Shigellosis (bacillary dysentery)^[4]
Typhoid fever^[5]
Vibrio parahaemolyticus infections^[6]
Enteroviruses, including poliomyelitis
Cholera
Clostridium difficile
Cryptosporidiosis
Ascariasis

Transmission of Helicobacter pylori by oral-fecal route has been demonstrated in murine models.^[7]

References

^ Meyer EA (1996). Other Intestinal Protozoa and Trichomonas Vaginalis in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
^ Zuckerman AJ (1996). Hepatitis Viruses in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
^ Wang L, Zhuang H (2004). "Hepatitis E: an overview and recent advances in vaccine research". World J Gastroenterol 10 (15): 2157–62. PMID 15259057.
^ Hale TL, Keusch GT (1996). Shigella in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
^ Giannella RA (1996). Salmonella:Epidemiology in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
^ Finkelstein RA (1996). Cholera, Vibrio cholerae O1 and O139, and Other Pathogenic Vibrios in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
^ Cellini et al. (1998). "Evidence for an oral-faecal transmission of Helicobacter pylori infection in an experimental murine model". APMIS 107(1-6): 477-484.[1]