front 1 What is the 2nd most common illness category in the U.S.? | back 1 Digestive system diseases (mostly fecal‑oral transmission). |
front 2 What breaks the fecal‑oral cycle? | back 2 Proper sewage disposal, water disinfection, and safe food handling. |
front 3 Where are the highest bacterial counts in the GI tract? | back 3 Large intestine (>100 billion/g; up to 40% of fecal mass is bacteria). |
front 4 Why do the stomach and small intestine have few microbes? | back 4 Acidity of the stomach. |
front 5 What organism is the primary cause of dental caries? | back 5 Streptococcus mutans — forms dextran from sucrose; produces lactic acid → enamel destruction. |
front 6 Which sugars do NOT promote caries? | back 6 Starch, mannitol, sorbitol (not used to make dextran). |
front 7 What is gingivitis vs periodontitis? | back 7
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front 8 What causes acute necrotizing ulcerative gingivitis (“Trench Mouth”)? | back 8 Prevotella intermedia + spirochetes (Borrelia vincentii). |
front 9 Infection vs intoxication — key differences? | back 9
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front 10 What is dysentery? | back 10 Severe diarrhea with blood or mucus. |
front 11 What food poisoning toxin is heat‑stable (not destroyed by boiling 30 min)? | back 11 Staph aureus enterotoxin. |
front 12 Classic foods for Staph food poisoning? | back 12 Custards, cream pies, ham (high osmotic pressure). |
front 13 What Shigella species produces Shiga toxin and causes severe dysentery? | back 13 Shigella dysenteriae. |
front 14 What finding suggests invasive diarrhea (not toxin‑mediated)? | back 14 WBCs in stool. |
front 15 Common sources of Salmonella? | back 15 Chicken and eggs. |
front 16 What causes fever in Salmonella gastroenteritis? | back 16 Endotoxin. |
front 17 What organism causes typhoid fever? | back 17 Salmonella typhi — human‑only pathogen. |
front 18 Who is the classic chronic carrier? | back 18 Typhoid Mary (gallbladder colonization). |
front 19 What does cholera toxin do? | back 19 Activates secretion of Cl⁻ and HCO₃⁻, causing massive watery diarrhea. Mortality untreated: 50%. |
front 20 What foods are associated with V. parahaemolyticus and V. vulnificus? | back 20
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front 21 What strain causes hemorrhagic colitis and HUS? | back 21 E. coli O157:H7 — produces Shiga‑like toxin. |
front 22 What is the 2nd most common cause of diarrhea in the U.S.? | back 22 Campylobacter jejuni. |
front 23 What syndrome is associated with Campylobacter? | back 23 Guillain‑Barré syndrome. |
front 24 What enzyme allows H. pylori to survive stomach acid? | back 24 Urease → produces ammonia. |
front 25 What foods commonly cause C. perfringens gastroenteritis? | back 25 Meats left at room temperature (spores germinate). |
front 26 What food is classically associated with B. cereus? | back 26 Fried rice. Two toxins:
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front 27 What gland is swollen in mumps? | back 27 Parotid glands. Orchitis may occur in post‑pubertal males. |
front 28 Which hepatitis viruses are fecal‑oral? | back 28 Hepatitis A virus , Hepatitis E virus |
front 29 Which hepatitis requires HBsAg to infect? | back 29 Hepatitis D (HDV) — coinfection or superinfection. |
front 30 Which hepatitis is most associated with chronic infection and cirrhosis? | back 30 HCV (slow, progressive liver damage). |
front 31 Most common cause of viral gastroenteritis in children? | back 31 Rotavirus. |
front 32 What virus causes outbreaks on cruise ships? | back 32 Norovirus (Norwalk agent) — highly infectious, hardy. |
front 33 What protozoan causes foul‑smelling, greasy diarrhea? | back 33 Giardia lamblia — cysts resist chlorine; treat with metronidazole. |
front 34 What stain identifies Cryptosporidium oocysts? | back 34 Acid‑fast stain (oocysts stain red). |
front 35 What foods commonly transmit Cyclospora? | back 35 Imported berries and produce. |
front 36 What organism causes amoebic dysentery? | back 36 Entamoeba histolytica — eats Red blood cells ; can cause liver abscess. |
front 37 Which tapeworm causes neurocysticercosis? | back 37 Taenia solium (pork tapeworm). |
front 38 What organism causes hydatid cysts? | back 38 Echinococcus granulosus — dog definitive host; sheep intermediate. Cysts can reach 15 liters; rupture → anaphylaxis. |
front 39 How is Enterobius vermicularis diagnosed? | back 39 Tape test (perianal eggs). |
front 40 How do hookworms infect? | back 40 Larvae penetrate skin → blood → lungs → swallowed → intestine. Causes iron‑deficiency anemia + pica. |
front 41 What is the migration pattern of Ascaris lumbricoides? | back 41 Eggs → intestine → blood → lungs → throat → swallowed → intestine. Adults up to 1 foot long. |
front 42 What causes trichinosis? | back 42 Trichinella spiralis — larvae encyst in muscle (esp. diaphragm, eye). Symptoms: fever, periorbital edema, myalgia, eosinophilia. |