13. Gastrointestinal Infections Flashcards
what are some common gastrointestinal infections
- infectious diarrhea
- C. diff
- intra-abdominal infections such as cholangitis, cholecysitits, peritonitis, abscess
the normal stomach contains very few bacteria due to gastric _______ and gastric ______. if either of these are altered, infections may occur
acidity, and motility
which part of the intestines, duodenum, jejunum or ilium has the most bacteria present
ilium is the transitional area between the stomach and colon therefore has more bacteria present (aerobic gram-neg, e.coli, enterococcus)
- duodenum and jejunum have very few bacteria
trauma to which area of the GI tract causes infection more often:
a. stomach
b. colon
c. duodenum
d. jejunum
colon
this is caused by ingestion of water or food products contaminated by pathogenic organisms &/or their individual toxins; is characterized by three or more loose stools or any loose stools with blood in it. involves a disrupted balance between bacterial virulence factors, host factors and ores disposing factors to infection
infectious diarrhea
these are bacteria causing GI disease and have virulence factors that can make infection worse. some can cause a significant host-inflammatory response producing diarrhea
enteropathogens
these cause fluid movement into the gut lumen, leading to fever and diarrhea
enterotoxins
these cause direct mucosal damage, leading to fever and bloody diarrhea. invasive properties of shigella and e.coli allow these bacteria to invade and destroy epithelial cells causing bloody and mucoid stools
cytotoxins
what are some predisposing factors that can contribute to infectious diarrhea
- poor sanitation/hygiene
- immunocompromised
- medications (e.g. PPIs, antibiotics, chemo)
what are some ways to prevent getting infectious diarrhea
- good hygiene
- proper food handling, cooking, storage
what is one of the most important ways to treat infectious diarrhea
rehydration!!!!!
when are stool cultures recommended for infectious diarrhea
- severe acute diarrhea or with high temperature (> 38.5º)
- dysentry (bloody mucoid stools with cramping)
- substantial watery diarrhea
- dehydration
- elderly or immunocompromised
- nursing home patients
- food handlers
- daycare workers
what are some medications used for infectious diarrhea
- antimotility agents (loperamide)
- bismuth subsalicylate
- probiotics (may be questionable)
- antimicrobials (only in specific situations including severely ill, immunocompromised, and patients with conditions that compromise the GI tract)
this causes infectious diarrhea. they are gram negative organisms that live in environmental waters throughout the world. presents with watery, colourless stools with “white flecks” of mucus (“rice water stool”).
cholera (vibrio cholera)
how long after the ingestion of contaminated food does infectious diarrhea with cholera usually occur
12 hours - 5 days
what is the treatment for infectious diarrhea with cholera for adults
high one dose: doxy or azithromycin PO x 1 day
three day dose: cipro, tetracycline or erythromycin PO x 3 days
what is the treatment for infectious diarrhea with cholera for children
azithromycin PO x 1 dose
erythromycin PO x 3 days
cipro PO x 3 days (don’t use cipro in small children)
this is a group of gram negative bacilli found in nature but colonizes hosts including mammals, reptiles and birds. twi main groups: typhoidal and non-typhoidal but typhoidal is not usually seen. illness by this group is caused by consuming contaminated foods including poultry and dairy products
salmonella
how long after ingestion of contaminated food does symptoms of infectious diarrhea with salmonella occur
6 to 72 hours
symptoms include fever, diarrhea (if severe: bloody diarrhea and dehydration)
are antibiotics recommended in non-typhoidal salmonella infectious diarrhea
no! they do not reduce the duration and severity of the illness and may be problematic (adverse effects, prolonging asymptomatic carriage of salmonella, resistance)
true or false: anti motility agents can be used for non-typhoid salmonella infectious diarrhea
if being used they should be used with caution
what should be recommended for someone with non-typhoid salmonella infectious diarrhea
- most need fluid replacement
- specific diets (BRAT)
when are antibiotics indicated for non-typhoid salmonella infectious diarrhea
- cancer
- diabetes
- RA disorders
- HIV infection
- people on immunosuppressive therapies
- very young age
- low gastric pH
- severe infection
what antibiotics are used in non-typhoid salmonella infectious diarrhea
oral FQ PO for 7 days
azithromycin PO for 7 days
cerftiaxone IM/IV 7-10 days (if immunocompromised 14 days)
what is the recommended duration of treatment for patients with HIV and gastroenteritis without bacteremia and have elevated CD4 levels (>200)
7 to 14 days
what is the recommended duration of treatment for patients with HIV and gastroenteritis without bacteremia and have decreased CD4 levels (<200)
2 to 6 weeks
for patients who develop ________________ the treatment is IV and more aggressive
extraintestinal infection
this is a group of gram negative intracellular bacteria consisting of 4 species. is spread through the fecal oral route and can be spread through sexual contact; is the most common cause of dysentry
shigella
this is most commonly caused by shigella dysenteriae and shigella flexneri
severe dysentry
this is most commonly caused by shigella sonnei and shigella boydii
milder illness
what is the incubation period of shigella infectious diarrhea
1-7 days
what are the symptoms of shigella infectious diarrhea
- malaise
- fever
- anorexia
- initial diarrhea is watery but subsequently may contain blood and mucus
in shigella infectious diarrhea, _______ production causes fluid secretion into the intestinal lumen and __________ productions causes cell deaths. both toxins lead to the severe clinical manifestation of the disease
enterotoxin, cytotoxin
this syndrome can occur secondary to infections caused by shigella. this is rare but serious and affects the kidneys and clotting. it is a consequence of the production of shiga-toxin 1 and occurs in 13% of patients with dysentry caused by S. dysenteriae type 1
hemolytic uremic syndrome (HUS)
what is the treatment used for mild shigella illness?
- hydration imp
- anti motility usually avoided
- usually don’t require antibiotics (unless e.g. immunocompromised, nursing home, etc)
- prevention = good hygiene
what is the treatment for severe shigella illness?
- levofloxacin or ciprofloxacin PO for 3 days
- azithromycin PO for 3 days
- Cefixime PO for 3 days
- Ceftriaxone IV for 5 days
TMP/SMX and Ampicillin are used orally for 5 days but only used for infections with documented susceptibility due to high resistance rates
how long should patents with HIV confection along with severe shigella illness be treated
5-7 days
how quickly should improvement in symptoms be seen in shigella infectious diarrhea if the correct antibiotic has been chosen
1-2 days (fewer stools, less blood in stools, lower fever, improved appetite)
this is often indistinguishable from Salmonella or Shigella. commonly contracted from undercooked poultry, dairy products, unpasteurized foods or contaminated water. early symptoms include abrupt onset of abdominal pain and diarrhea. 1/3 cases can have a prodromal period which involves a high fever with rigours, aches, dizziness,. diarrhea is self-limiting and lasts ~ 7 days
campylobacter jejuni enteritis infectious diarrhea
what is the average incubation period of campylobacter jejuni enteritis infectious diarrhea
3 days
what is the main treatment recommendation for someone with campylobacter jejuni enteritis infectious diarrhea
maintenance of proper hydration and correction of electrolyte abnormalities
antibiotics are not indicated unless it is severe (bloody stools, high fever, extraintestinal infection, symptoms > 7 days, immunocompromised, elderly)
what antibiotics, if indicated, are used in campylobacter jejuni enteritis infectious diarrhea
azithromycin PO x 3 days or single dose
levofloxacin or ciprofloxacin PO x 3 days
this is a specific strain of e.coli that produces shiga toxins. these e.coli cause asymptomatic carriage, mild and non-bloody diarrhea, bloody diarrhea (hemorrhagic colitis), HUS. occurs from consumption of undercooked beef products that are contaminated with he e.coli. illness usually removes in 5-8 days
shiga toxin-producing E.coli (STEC)
are antibiotics used in STEC infectious diarrhea
no - there is no specific drug therapy required and use for antibiotics is controversial and not recommended
are antimotility agents used in STEC infectious diarrhea
no - increases risk of HUS
most of these cases occur when taking an antibiotic or just after taking an antibiotic
c. diff
what are some frequently associated antibiotics that cause C. diff
- FQs
- Clindamycin
- broad spectrum cephalosporins e.g. ceftriaxone
- penicillins
what are some risk factors for getting C. diff
- > 65 y.o
- recent stay at hospital or nursing home
- weakened immune system (e.g. HIV, cancer, immunosuppressive drugs, previous infection with C. diff)
what are the s/s of C. diff
- nausea
- diarrhea
- fever
- stomach tenderness or pain
- loss of appetite
true or false: confirmed diagnosis of CDI needs to occur in order to be treated for C. diff
true - stool culture, enzyme-immunoassay
what medications are used in non-severe and severe C. diff and the duration
Vancomycin PO or Fidaxomicin PO or metronidazole PO x 10 days
what is the treatment for Fulminant C. diff
vancomycin PO + metronidazole IV + vancomycin PR
if metronidazole was used for initial episode of C. diff what should be used this time
Vancomycin x 10 days
if vancomycin was used for initial episode of C. diff what should be used this time
Fidaxomicin x 10 days
this is an infection contained within the peritoneal cavity. many are secondary infections that are polymicrobial and are caused by a defect in the GI tract. can be non-complicated (single organ) or complicated (make it to the peritoneum causing peritonitis). includes infections of the biliary tract, peritonitis and abscess
intra-abdominal infections
these two intra-abdominal infections occur in the biliary tract
cholecystitis (infection of the gall bladder) and cholangitis (infection of the common bile duct)
this intra-abdominal infection is not by an evident source of bacteria from the abdomen - it is common in alcoholics or any form of ascites
primary peritonitis
this intra-abdominal infection is caused by a focal process evident within the abdomen; abdominal perforation, post-op peritonitis, traumatic peritonitis; abscess is a common feature
secondary peritonitis
this intra-abdominal infection occurs in critically ill patients 48 hours after apparent adequate treatment for secondary peritonitis
tertiary peritonits
this intra-abdominal infection consists of a purulent collection of fluid separated from surrounding tissue by a wall of inflammatory cells and adjacent organs; occurs due to chronic inflammation and contains necrotic debris, bacteria and inflammatory cells
abscess
true or false: the common bile duct is not sterile
false - it is usually sterile and the bile is bacteriostatic
what are s/s of biliary tract intra-abdominal infections (cholecystitis or cholangitis)
fever, jaundice, right upper quadrant pain
- may see elevated WBCs, ALP and liver transanimases
what pathogens usually cause acute cholecystitis and acute cholangitis
E. coli, k. pneumoniae, sometimes enterococcus and anaerobes
what is used to treat acute cholecystitis and acute cholangitis
- pip/tazo IV
- amoxicillin/clav IV
- ertapenem IV
- cefotaxime IV
- ciprofloxacin IV
- moxifloxacin IV
TREAT FOR 5-7 DAYS
what are s/s of peritonitis
- decreased cardiac output and hypovolemic shock therefore sweating, tachycardia
- fever, vomiting, diarrhea
what pathogens usually cause primary peritonitis
S. pneumoniae, E. coli, group A strep (often caused by single organism)
what is used to treat primary peritonitis
- pip/tazo IV
- ertapenem IV
- cefotaxime IV
- ciprofloxacin IV
- moxifloxacin IV
TREAT FOR 5-7 DAYS (only 5 days if repeat paracentesis ,0.25 x 10^9 /L and cultures are negative)
what pathogens usually treat secondary peritonitis
often polymicrobial - mixtures of aerobic and anaerobic bacteria
what is used to treat mild/moderate secondary peritonitis
- ertapenem IV
- cefotaxime IV
- ciprofloxacin IV
- moxifloxacin IV
USUALLY 5-7 DAYS OR UNTIL RESOLUTION OF CLINICAL SIGNS OF INFECTION
what is used to treat severe/life-threatening secondary peritonitis
- pip/tazo IV
- imipenem IV
- meropenem IV
USUALLY 5-7 DAYS OR UNTIL RESOLUTION OF CLINICAL SIGNS OF INFECTION
