Shigellosis: characteristics and causes

Also known as bacillary dysentery, shigellosis, an invasive disease of the human colon is present worldwide. Shigellosis is a significant cause of foodborne illness in developed as well as underdeveloped countries. It is a bacterial infection cause by organsism in the Shigella genus, with four species that include S. dysenteriae, S. flexneri, S. boydii and S. sonnei.

Food microbiologists should be aware that shigella species can cause a rather severe form of foodborne illness and relatively low numbers of the organisms can cause disease.

Shigellosis is characterised by fever abdominal cramps, tenesmus, and dysenteric stools containing mucus blood and pus. These symptoms reflect invasion of the colonic mucosa by Shigella, the critical stage in the pathogenc process.

Product suspected of causing food poisoning should be analysed for shigella. Shigella sp. cause a diarrhea. The diarrhea may be bloody or nonbloody. Humans and other large primates are the only natural reservoirs of Shigella spp.

Transmission of from person to person by ingestion of fecally contaminated food or water. Disease onset typically occurs between 12 hours to 2 days after exposure. The infectious dose is quite small, as few as 10-200 organisms.
Shigellosis: characteristics and causes