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24 Cards in this Set
- Front
- Back
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What is the treatment for Cryptosporidia?
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Antidiarrheals are used, although no specific curative antimicrobial exists.
occasionally, paromomycin, an aminoglycoside can be effective against protozoa. |
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What is Rotavirus?
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It is a member of the Reovirus group which consists of a double stranded RNA genome. It is the primary cause of morbidity and mortality resulting from diarrhea, accounting for nearly 50% of all cases.
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How is Rotavirus found?
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Stool samples from infected persons contain large amounts of virus. An Elisa test is also available.
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Rotavirus is transmitted by the fecal oral route and contaminated food , water and fomites. TRUE/FALSE
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TRUE. babies from 6-24 months of age lacking maternal antibodies have the greatest risk for fatal disease. Watery diarrhea, fever, vomiting, and dehydration are common symptoms. Adults may contract it from children, though its course is self limiting.
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What is the treatment protocol for Rotavirus?
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Oral replacement fluid and electrolytes. A vaccine was introduced in 1998, but withdrawn due to its potential ability to cause intussception.
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List three other types of viruses that cause diarrhea, and are often overlooked as a cause.
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Adenovirus, Norovirus(Norwalk) and Astroviruses.
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What is the common scenario associated with "food poisoning"?
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If a patient presents with severe nausea, vomiting, with/without diarrhea, is seen in individuals who shared or ate the same foods, food poisoning intoxication is the likely cause.
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What does food poisoning mean?
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It refers to symptoms in the gut that are caused by a preformed toxin of some sort. Often, the toxin comes from Staph aureus.
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What other organisms may cause food poisoning?
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bacillus cereus or Clostridium perfringens. The toxin often originates from nonmicrobial sources such as fish, shellfish, or mushrooms.
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What would initiate a Staph aureus exotoxin reaction?
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It is associated with eating foods such as custards, sauces, craem pastries, processed meats, chicken salad or ham, especially when foods are left unrefrigerated.
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Despite the high salt content of some foods, why is Staph still able to attck these substrates?
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Staph. aureus has a high salt tolerance. The exotoxin is heat stable, and inactivation requires 100C for 30 min. Even this is no guarantee.
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How does the ingested toxin work?
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It acts upon the GI epithelium and stimulates nerves, with symptoms of cramping, nausea and vomiting and diarrhea. recovery is rapid.
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The illness is caused by the toxin and does not require S. aureus to be present, or alive in the contaminated food. TRUE/FALSE
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TRUE. Even if the bacteria are destroyed by heating the preformed toxin will act quickly once it is ingested.
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What is bacillus cereus exotoxin?
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It is a sporulating Gram + bacterium that is naturally present in soil. It is a common resident on vegetables and other products in close contact with soil.
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Does Bacillus cereus secrete exotoxins?
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Yes. It produces two, one of which causes a diarrheal type disease, the other of which causes an emetic disease.
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Where is the emetic form found?
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Though not exclusively, it is frequently linked to fried rice, especially when it has been cooked and kept warm for long periods.
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Where is the diarrheal form found?
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It is often associated with cooked meats or vegetables that are held at warm temperatures for extended periods. These conditions favor the production of the high molecular weight, heat labile exotoxin.
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How is diagnosis acheived?
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In the emetic form finding the bacterium in the implicated food source is often sufficient.
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Can Clostridium cause digestive disturbances?
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Yes? It can contaminate foods, especially in animal flesh, vegetables and fish, as well as beans that contain active endospores.
C. perfringens cells enter the small intestine and release exotoxin, initiating abdominal pain diarrhea and vomiting. Recovery is usually rapid. |
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What constitutes chronic diarrhea?
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It is defined as lasting longer than 14 days. It can be infectious or not. irritable bowel syndrome, Crohn's disease and ulcerative colitis can cause chronic diarrhea, and do not have an infectious source as far as is believed.
people suffering from AIDS almost universally suffer from this. Diseases like Cryptosporidium, Mycobacterium avium and others are often suspected. |
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Enteroaggregative E. coli(EAEC) is particularly associated with chronic disease, especially in children. TRUE/FALSE
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TRUE. it does not produce a heat labile or stable toxin, and is distinguished by its ability to adhere to human cells in aggregates rather than in single cells.
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What is Cyclospora cayetanensis?
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It is an emerging protozoan pathogen. Its mode of transmission is fecal oral and associated with fresh produce and water contaminated with feces.
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How does the disease begin?
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It begins when oocysts enter the small intestine and release invasive sporozoites that invade the mucosa. After an incubation of app. 1 week, watery diarrhea, cramps, bloating fever and muscle aches appear.
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How is Cyclospora treated?
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Most infections are treated with trimethoprim-Sulfamethoxazole lasting 1 week.
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