Diseases Flashcards
Human Papillomavirus (HPV)
Type: DNA virus
Disease: genital warts–> cervical cancer (possible)
Pathogenesis:
- virus transmitted by physical contact, binds to epithelial cells
- stimulates cell proliferation–> warts
- viral proteins (E6/E7) binds to tumor suppressor gene product =tumors
Treatment: ca be self-limiting, topical treatments to destroy infected tissue
Human Immunodeficiency Virus (HIV)
Type: RNA virus, enveloped
Disease: Lymphadenopathy: enlarged lymph nodes, fever, sweats, myalgia, vomiting, diarrhea
- AIDS: dramatic loss of CD4 cells (>200), immunodeficiency - opportunistic
Pathogenesis:
- exposure to blood/blood products
- virus binds to CD4 receptors on T helper cells and macrophages
- virus used reverse transcriptase and HIV integrates to integrate into host DNA
- virus gets latent (asymptomatic)
- when reactivated–>kill CD4 cells–> loss of cell mediated immunity
Treatment: antiretroviral therapy (3 or more drug combinations)
Poliovirus
Type: RNA virus
Disease: poliomyelitis: permanent paralysis of muscles
Pathogenesis:
- virus binds to intestinal mucosa
- spreads to lymphatic tissue –> blood –> multiple organs
- if reaches brain of spinal cord –> destroys nerve cells
Treatment:
-none- supportive care, vaccine available (working to eradication)
Streptococcus mutans
Type: bacteria, Gram (+) cocci Disease: dental carries (cavities) -holes in tooth enamel, pain Pathogenesis: -breaks down sucrose into glucose and fructose -glucose forms dextran (sticky polysaccharide) -allows bacteria to stick to enamel -contributes to plaque -fructose: fermented into lactic acid -erodes tooth enamel Food Implicated: -sucrose Treatment/ Prevention -brush and floss teeth -fluoride helps prevent degradation by lactic acid
Helicobacter pylori
Type: bacteria, Gram (-) spiral Disease: peptic ulcers -abdominal cramps, black stool Pathogenesis -produces high amounts of urease -urease converts urea to ammonia -ammonia neutralizes stomach acid, allowing for infection -bacteria colonize in stomach lining, degrading linings --> ulcers Treatment/ Prevention -bismuth subsalicylate- coats stomach to prevent bacteria from adhering -antibiotics
Staphylococcus aureus
Type: bacteria, Gram positive cocci Disease: Staphylococcal food poisoning -vomiting, abdominal cramps, diarrhea, soon after ingestion Pathogenesis -heat stable enterotoxin -stimulates vomiting and abdominal cramps, shortly after ingestion Food Implicated -high salt, sugar, or protein based foods -ex. custards, cream pies, ham Treatment: -fluid replacement -self-limiting within 24 hours
Shigella dysenteriae
Type: bacteria, gram (-) rod
Disease: Shigellosis (Bacillary dysentery)
-dysentery (bad- 20/day)
-Abdominal cramps and fever
Pathogenesis:
-infective dose extremely low (10-100 cells)
-resistant to stomach acidity, replicates in small intestines, infects large intestines
-epithelial cells ingest bacteria, bacteria multiples inside, spread
-shiga toxin: destroys tissue, extremely virulent
Food Implicated:
-contaminated water (fecal-oral route)
Treatment/ Prevention:
-rehydration
-antibiotics: fluoroquinolones
Salmonella enterica
Type: bacteria, Gram negative rod
Disease: Salmonellosis- gastroenteritis
-diarrhea, abdominal cramps, nausea, moderate fever (possible)
Pathogenesis:
-infects intestinal mucosa, ingested by epithelial cell
-multiplies in cells –> inflammation –> diarrhea
-produces enterotoxin
Food Implicated
-undercooked poultry products
-ex Chicken, eggs
Treatment/ Prevention:
-fully cook poultry, and apply proper sanitation practices
-rehydration
Salmonella typhi
Type: bacteria, gram (-) rod Disease: Typhoid fever -high fever 40C, headache -Rose spot rash -diarrhea Pathogenesis -multiplies within phagocytes, spread to multiple organs -phagocytes lyse --> bacteremia -recovering patients still shed organism from gall bladder Food implicated: -contaminated water (fecal-oral route) Treatment/ Prevention: -rehydration -antibiotics: doxycycline
Vibrio cholerae
Type: bacteria, Gram (-) curved rod Disease: Cholera -rice water stool -Severe dehydration (12-20 liters per day) -Can lead to shock or death Pathogenesis: -infect small intestines and produce enterotoxin -enterotoxin binds to epithelium causing host to secrete Cl- -water and other electrolytes follow Food implicated: -contaminated water (fecal-oral route) Treatment/ Prevention: -intravenous replacement of fluids -antibiotics: doxycycline
Escherichia coli
Type: bacteria, Gram negative rod (various types)
1. ETEC- enterotoxigenic E. coli
2. EHEC- enterohemorrhagic E. coli (E. coli O157:H7)
Disease ETEC: Traveler’s Diarrhea
-diarrhea from enterotoxin
Food implicated: contaminated water (fecal-oral route)
Treatment: fluids
Disease (EHEC) -dysentery inflamed colon -hemoltic uremic syndrome: blood in urine, kidney failure Pathogenesis: -enterotoxin, similar to shiga toxin Food Implicated: -contaminated meats, ground meats Treatment/Prevention: -antibiotics, cook meat thoroughly
Bacillus cereus
Type: bacteria, gram positive rod (endospore former) Disease: gastroenteritis -vomiting and nausea (2-5 hours after ingestion) -diarrhea (8-16 hours) Pathogenesis -endospores survive cooking process -as food cools, spore germinate and toxins released -ingested Food implicated -high carbohydrate foods -ex. cereal, rice, pasta Treatment/Prevention: -self-limiting
Clostridium perfringens
Type: bacteria, gram positive rod (endospore former) Disease: mild gastroenteritis -mild upset stomach Pathogenesis: -endospores resist cooking -vegetative cells germinate during serving r inadequate refrigeration Food implicated -several foods Treatment/Prevention: -self-limiting
Clostridium botulinum
Type: bacteria Gram Positive rod (endospore former)
Disease: botulism
-double vision, paralysis, blinding and flashing lights
-death is paralysis of diaphragm
Pathogenesis:
-potent paralytic neurotoxin (tasteless, colorless)
Food implicated:
-canned meats and vegetables
-honey (infant botulism)
Treatment/Prevention
-anti-toxin against specific strain
Norovirus
Type: virus, RNA
Disease: diarrhea, vomiting, nausea, stomach pain
Pathogenesis:
-extremel contagious (5 viral particles –> infection)
-virus enters through contaminated foods or air
-infects small intestines –> inflammation
Food implicated: contaminated water (fecal-oral route)
Treatment/Prevention: self-limiting