shigella

diarrhea vs. dysentery: what is diarrhea?

fluids secreted into the intestines; watery stool

often in response to toxins in the gut

diarrhea vs. dysentery: what is dysentery?

damage to the intestinal lining

diarrhea is often a symptom of dysentery

often accompanied by blood and/or white blood cells in the stool

high fever associated as well

is shigellosis a diarrheal or dysenteric disease?

bacillary dysentery → damage to intestinal epithelium

what are the symptoms of shigellosis?

bloody stool

high fever

intestinal pain

diarrhea

pus, immune cells in the feces

is Shigella invasive or non-invasive?

invasive

kills infected, nearby cells

invasive growth triggers inflammation and fever

does Shigella produce a toxin?

produces an exotoxin (Shiga toxin)

Shiga toxin causes cell death and can damage the kidney (hemolytic uremic syndrome)

how does Shigella evade the immune system?

invade the epithelium of the intestine and move laterally through epithelial cells

delays the immune response, prolongs infection

what other food-born pathogen uses a similar technique?

salmonella (both non-typhoid salmonellosis and typhoid fever)

how are Shigella infections are acquired?

all shigellosis is due to person to person infection

• outbreaks aften at schools

some individuals are carriers without symptoms

how is shigellosis best treated?

antibiotics (very important)

hydration

how is shigellosis prevented?

good hygiene/sanitation will prevent spread

• keeping our food and water supplies clear of fecal matter