Escherichia Coli 0157 H7

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Angelique and Ethan's infectious disease presentation.


<ul><li> 1. Escherichia Coli 0157:H7 Angelique and Ethan</li></ul> <p> 2. E. Coli 0157:H7 </p> <ul><li><ul><li>large and diverse group of bacteria </li></ul></li></ul> <ul><li><ul><li>most strains are harmless but others cause disease by making a toxin called Shiga toxin </li></ul></li></ul> <ul><li><ul><li><ul><li>"Shiga toxin-producing" E. coli - STEC </li></ul></li></ul></li></ul> <ul><li><ul><li>when you hear news reports about E.coli infections they're usually about 0157:H7 </li></ul></li></ul> <p> 3. Epidemiology </p> <ul><li><ul><li>first recognized by the Centers for Disease Control as a pathogen in 1982 </li></ul></li></ul> <ul><li><ul><li>during an outbreak of Hemolytic-uremic Syndrome in Oregon and Michigan </li></ul></li></ul> <ul><li><ul><li>associated with eating hamburgers at the restaurants of one national chain </li></ul></li></ul> <ul><li><ul><li>reported to cause large outbreaks as well as isolated sporadic infections in small numbers </li></ul></li></ul> <p> 4. Shiga Toxin </p> <ul><li><ul><li>released into the intestinal tract </li></ul></li></ul> <ul><li><ul><li>inhibits protein synthesis in target cells </li></ul></li></ul> <ul><li><ul><li><ul><li> cuts off several neucleobases from RNA compromising the ribosomes </li></ul></li></ul></li></ul> <ul><li><ul><li>structure has two units </li></ul></li></ul> <ul><li><ul><li><ul><li>B subunit binds to specific glyco-lipids on the host cell </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>A subunit is internalised and divided </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>A1 binds to ribosomes </li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li>toxin requires specific receptors on the cell surface </li></ul></li></ul> <ul><li><ul><li><ul><li> cattle, swine, and deer do not have these receptors </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>harbor the bacteria and excrete it in their feces </li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li>damages red blood cells as they pass through the intestinal tract</li></ul></li></ul> <p> 5. STEC E. Coli </p> <ul><li><ul><li>STEC strains can survive for long periods of time on little sustenance </li></ul></li></ul> <ul><li><ul><li><ul><li>several weeks on a countertop </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>up to a year in materials such as compost </li></ul></li></ul></li></ul> <ul><li><ul><li>takes a very small amount of bacteria to infect a human </li></ul></li></ul> <ul><li><ul><li><ul><li>as few as 10 cells can be infected and still cause the symptoms </li></ul></li></ul></li></ul> <ul><li><ul><li>toxin classified as a potential biochemical terrorist agent by the CDC</li></ul></li></ul> <p> 6. How's It Spread ? </p> <ul><li><ul><li>ingesting tiny amounts of human or animal feces </li></ul></li></ul> <ul><li><ul><li><ul><li>consumption of contaminated food </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>unpasteurized (raw) milk </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>water that has not been disinfected </li></ul></li></ul></li></ul> <ul><li><ul><li>contact with cattle </li></ul></li></ul> <ul><li><ul><li>contact with the feces of infected people</li></ul></li></ul> <p> 7. 8. Signs and Symptoms </p> <ul><li><ul><li>bloody diarrhea </li></ul></li></ul> <ul><li><ul><li>severe abdominal pain and tenderness without fever </li></ul></li></ul> <ul><li><ul><li>colitis - swelling of the large intestines </li></ul></li></ul> <ul><li><ul><li>an acute infection </li></ul></li></ul> <ul><li><ul><li><ul><li>recovery in 5-10 days without any specific treatment </li></ul></li></ul></li></ul> <ul><li><ul><li>more serious in children under 5 yrs old and the elderly </li></ul></li></ul> <ul><li><ul><li><ul><li>Hemolytic-uremic Syndrome (HUS) </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>Thrombotic Thrombocytopenic Purpura (TTP) </li></ul></li></ul></li></ul> <p> 9. Hemolytic-uremic Syndrome </p> <ul><li><ul><li>caused in young children</li></ul></li></ul> <ul><li><ul><li>most worrisome complication - potentially fatal </li></ul></li></ul> <ul><li><ul><li>"hemolytic" refers to the breakup of red blood cells </li></ul></li></ul> <ul><li><ul><li><ul><li>leads to anemia </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>destruction of platelets </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>leads to thrombocytopenia - low blood levels of platelets </li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>promotes abdominal bleeding </li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li> "uremic" refers to kidney failure </li></ul></li></ul> <ul><li><ul><li>problems with the brain - seizures </li></ul></li></ul> <ul><li><ul><li>coma may occur </li></ul></li></ul> <p> 10. Thrombotic Thrombocytopenic Purpura </p> <ul><li><ul><li>caused in the elderly</li></ul></li></ul> <ul><li><ul><li>clotting of blood within small blood vessels </li></ul></li></ul> <ul><li><ul><li>fragmentation of red blood cells </li></ul></li></ul> <ul><li><ul><li><ul><li>leads to anemia </li></ul></li></ul></li></ul> <ul><li><ul><li>shortage of platelets </li></ul></li></ul> <ul><li><ul><li><ul><li>causes easy bruising </li></ul></li></ul></li></ul> <ul><li><ul><li>neurologic abnormalities </li></ul></li></ul> <ul><li><ul><li>impaired kidney functions </li></ul></li></ul> <ul><li><ul><li>fever </li></ul></li></ul> <p> 11. Diagnosis </p> <ul><li><ul><li> 2 methods of testing stool specimens </li></ul></li></ul> <ul><li><ul><li><ul><li>growing bacteria in culture dishes </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>testing for Shiga Toxin produced by the bacteria </li></ul></li></ul></li></ul> <ul><li><ul><li>Blood Tests</li></ul></li></ul> <ul><li><ul><li><ul><li>performed periodically to look for the development of HUS</li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>CBC - complete blood count</li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>Blood levels of electrolytes </li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>BUN - blood urea nitrogen </li></ul></li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li><ul><li>Creatinine - measure the function of the kidney </li></ul></li></ul></li></ul></li></ul> <p> 12. Prognosis </p> <ul><li><ul><li>generally good </li></ul></li></ul> <ul><li><ul><li>most patients recover within 10 days just by treating the symptoms </li></ul></li></ul> <ul><li><ul><li>becomes more serious if HUS develops </li></ul></li></ul> <ul><li><ul><li><ul><li>high survival rate but possibly fatal </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>most patients are under 5 yrs old so their body might not be not strong enough to fight </li></ul></li></ul></li></ul> <p> 13. Treatment </p> <ul><li><ul><li>antibiotics not proven useful </li></ul></li></ul> <ul><li><ul><li><ul><li>studies have shown they may increase chances of developing HUS </li></ul></li></ul></li></ul> <ul><li><ul><li>replacement of fluids and electrolytes to prevent dehydration </li></ul></li></ul> <ul><li><ul><li>HUS and TTP require otherwise specific care </li></ul></li></ul> <ul><li><ul><li><ul><li>may need dialysis </li></ul></li></ul></li></ul> <p> 14. Activity </p> <ul><li>Break up into groups of three and create one skit. Each skit should demonstrate one way in which the spread of E. coli can be prevented. You have 3 minutes to discuss and 2 minutes to perform. </li></ul> <ul><li>Example: McDonalds employee does not wash his hands and patron gets sick. Re-do shows employee washing his hands after using the restroom. </li></ul> <p> 15. Prevention </p> <ul><li><ul><li>WASH YOUR HANDS </li></ul></li></ul> <ul><li><ul><li>COOK meats thoroughly </li></ul></li></ul> <ul><li><ul><li>AVOID raw milk, unpasteurized dairy products and juices </li></ul></li></ul> <ul><li><ul><li>AVOID swallowing water while swimming </li></ul></li></ul> <p> 16. History </p> <ul><li><ul><li>from 1982 to 2002 - 350 outbreaks in the US </li></ul></li></ul> <ul><li><ul><li><ul><li>52 % foodborne </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>21% unknown </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>6% recreational water </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>3% animal contact </li></ul></li></ul></li></ul> <ul><li><ul><li><ul><li>3 % drinking water</li></ul></li></ul></li></ul> <ul><li><ul><li>40 deaths </li></ul></li></ul> <ul><li><ul><li>despite regulations outbreaks remain common </li></ul></li></ul> <ul><li><ul><li>food transmission still the highest percentage </li></ul></li></ul> <ul><li><ul><li>person-to-person transmission happening most commonly in daycare centers </li></ul></li></ul> <ul><li><ul><li>total recall when source identified </li></ul></li></ul> <ul><li><ul><li><ul><li>approximately 25 million pounds of beef recalled </li></ul></li></ul></li></ul> <p> 17. History II </p> <ul><li><ul><li>outbreaks provided information about the inadequacy of processing methods </li></ul></li></ul> <ul><li><ul><li><ul><li>U.S. Department of Agriculture created regulations for processed meats </li></ul></li></ul></li></ul> <ul><li><ul><li>U.S. Food and Drug Administration revised Model Food Code for restaurants </li></ul></li></ul> <ul><li><ul><li>prevention methods targeting food preparers </li></ul></li></ul>


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