Diseases of the Digestive System

Question 1

Bacterial Deases of the Digestive System

Answer 1

dental caries, gingivitus, periodontal disease
peptic ulcers
bacterial gastroeneteritis: cholera (fatal diarrheal disease), shigellosis (bacillary dysentery), traveler’s diarrhea, Campylobacter (diarrheal disease), C. difficile, salmonellosis and typhoid fever
bacterial intoxication

Question 2

Dental Caries

Answer 2

tooth decay/cavity
bacteria cause dimineralization and destruction of hard tissues

causative agent: Streptococcus mutants

symptoms: initially a small, chalky area which may develop into large cavitation

treatment: small lesions: topical fluoride to encourage reminaralization
for larger lesions, progression of dental caries can be stopped by filling

Question 3

Peptic Ulcers

Answer 3

mucosal erosions equal to or greater than 0.5 cm in the stomach or duodenum

causative agent: Helicobacter pylori

treatment: combinations of 2 antibiotics Clarithromycin, Amoxicillin, Tetracycline, Metrinidazole and 1 proton-pump inhibitor sometimes together w/ a bismuth compound

Dx:
smears
X-ray
urease test

symptoms:
abdominal pain
bloating and abdominal fullness
waterbrash (GERD)
nausea and copious vomiting
loss of appetite and weight loss
hematoemesis
melena (dark spots)
rarely, gastric or duodenal perforation

Question 4

Shigellosis

Answer 4

Bacillary dysentery

causative agent: Shigella sp.
found in water polluted w/ human feces and is transmitted via fecal-oral route

symptoms:
cramps
diarrhea
fever
vomiting
blood, pus, or mucus in stools

infective dose: 10 to 200 organisms is sufficient to cause an infection

treatment:
fluids
Trimethoprim-sulfamethoxazole
Norfloxacin

Dx: culture

Question 5

Traveler’s diarrhea

Answer 5

usually occurs within the first week of travel

causative agent: Escherichia coli
(ETEC: Enterotoxigenic E.coli
EAEC: Enteroagglugative E. coli)
Salmonella
Shigella
Campylobacter

symptoms:
watery or bloody diarrhea
abdominal cramps w/ or w/o fever

treatment: fluids

Dx: based on symptoms

Question 6

Clostridium difficile diarrhea

Answer 6

healthcare-associated infections; toxin A & B pruduction by bacteria leads to colon damage

causative agent: Clostridium difficile

symptoms: significant diarrhea, recent antibiotic exposure, abdominal pain, fever (up to 40.5 C)
distinctive foul stool odor

treatment: Metronidazole

Dx: toxigenic culture
PCR

Question 7

Bacterial Intoxication (Food poisoning)

Answer 7

caused by toxins
symptoms show within few hours
causative agent (ex.): S. aureus

symptoms:
nausea
vomiting
cramping
loss of appetite
fever

treatment:
fluids
anti-emetics

Question 8

Viral Digestive Infedction

Answer 8

Norovirus

Question 9

Norovirus

Answer 9

viral gastroenteritis

causative agent: Norovirus aka Norwalk virus

symptoms: diarrhea
vomiting
nausea
stomach pain
stomach pain
fever
headache
body aches

treatment: fluids

Dx: PCR of stool

Question 10

Parasitic Infections

Answer 10

Giardiasis
Amebiasis
Tapeworm infection
Hydatid disease
Pinworm infection

Question 11

Giardiasis

Answer 11

causative agent: Giardia lamblia

symptoms: diarrhea
gas
greasy stools that tend to float
stomach or abdominal cramps
upset stomach or nausea/vomiting
dehydration (loss of fluids)

treatment: Metronidazole
Tinidazole
Nitazoxanide

Dx: stool wet mount

Question 12

Amebiasis

Answer 12

causative agent: Entamoeba hystolitica

symptoms: dysentery, colitis, appendicitis, toxic megacolon, amebomas, liver abscess, cutaneous and genital amebic lesions

treatment: for symptomatic intestinal disease or extraintestinal infections: metronidazole or tinidazole
immediately followed by treatment with: iodoquinol, paromomycin, or diloxanide furoate

Dx: stool wet mount

Question 13

Tapeworm Infection

Answer 13

causative agent: ceastodes, Taenia saginata (beef tapeworm) and Taenia solium (pork tapeworm)

symptoms: none or mild
can cause digestive problems including abdominal pain, loss of appetite, weight loss, and upset stomach
neurocystececrosis (brain infection caused by larval tapeworm; cysts are formed; inflammation of tissue)

treatment: praziquantel
niclosamide

Dx: stool wet mount

Question 14

Hydatid Disease

Answer 14

Echinococcus granulosus (tapeworm)

tissue damage

intermediate host: humans

definitive host: dogs

liver, lungs

serology, X-ray exam

surgical removal, albendazole

Question 15

Pinworm Infection

Answer 15

nematode

causative agent: Enterobius vermicularis

symptoms: itchy and anal region
infection of genital tract that has been well reported

treatment: Merbendazole
Pyrantel pamoate
Albendazole

Dx: look for the worms in the perianal region 2 to 3 hours after the infected person is asleep
touch the perianal skin w/ transparent tape to collect possible pinworm eggs around the anus first thing in the morning