bacterial infections Flashcards
botulism
neuroparalytic disease (unique from others)
produced by clostridium botulinum (anaerobic, spore-forming bacillus found in soil)
three forms of botulism:
food-borne
infant botulism
wound botulism
mechanism of action of botulinum toxin
toxin blocks release of ACH from vesicles at neurons, preventing use of muscles
botulism: clinical findings
Visual Disturbance (within 36 hours):
-Diplopia
-Loss of accommodation
-Fixed dilated pupils
-Ptosis (eyelid droop)
-Extraocular movement palsy
Dry mouth
Dysphagia/dysphonia (difficulty swallowing, not pain)
Nausea and vomiting
botulism clinical findings cont.
Acute, bilateral cranial nerve neuropathy (unique part):
-Symmetric descending weakness (only thing that will cause symmetric descending weakness)
-Paralysis progressing to respiratory failure and death
The sensory examination is normal (can feel face, just can’t move it)
-MOTOR NEURONS ONLY
note on emphasis:
stroke will knock out everything
botulism: sensory is fine, but paralysis and symmetrical descending weakness
botulism is very serious and can cause death
botulism
diagnostic findings: toxin analysis of serum, stool, vomit, food
Treatment: serum antitoxin
In most cases will make something like this a test question:
do you eat a lot of jarred or self-canned foods? Botulism!!
Campylobacter jejuni infection
One of the most frequently occurring bacterial agents of gastroenteritis
Occurs worldwide (diarrhea in children in underdeveloped countries)
Highest incidence <5 years old, especially in resource-limiting settings
Estimated 1.3 million cases annually in US
Campylobacter jejuni sources of contamination
Poultry
Unpasteurized milk
Contaminated drinking water (Traveler’s Diarrhea)
-(Traveler went (camp)ing in costa rica)
Campylobacter jejuni risk factors
International travel in the week prior to onset
Use of proton pump inhibitors and histamine-2 receptor antagonists (why?)
Campylobacter jejuni symptoms
-Arise 1-3 days after exposure; typical duration 1 week
-Watery diarrhea which may be bloody
-Abdominal pain/cramps
-Nausea
-Occasional vomiting
-Weight loss
Campylobacter jejuni Diagnosis
Gold standard: Stool culture
not usually done in clinical practice
-takes too long, symptoms only last a week
Campylobacter jejuni management
Self-limiting
Supportive therapy: Fluid and electrolyte replacement
Campylobacter jejuni: traveler’s diarrhea
Antibiotics are usually recommended
Either azithromycin, 1 g orally as single dose
Or Ciprofloxacin, 500 mg twice daily orally for 3 days
note: there are reasons why you would choose one over the other (heart issues for ex.)
rare complications of campy jejuni
-Bacteremia
-Guillain-Barre syndrome
-Reactive arthritis
GB syndrome: (“out of the blue stroke kind of” where nerves break down [ex. if they get a cold] but can regenerate back to normal [so severe patient must learn to walk again])
Chlamydia Trachomatis
Sexually transmitted disease caused by Chlamydia trachomatis
-Often asymptomatic
-Common cause of urethritis, cervicitis, and post-gonococcal urethritis.
-Occasionally causes epididymitis, prostatitis, or proctitis
Leading cause of infertility in females in the US
Symptoms causing suspect of Chlamydia
-Vaginal discharge
-Postcoital or intermenstrual bleeding or dysuria in women
-Urethral discharge, dysuria, scrotal pain or swelling in men
-dysuria: painful urination
Chlamydia: Diagnostic findings
-Highly sensitive nucleic acid amplification tests (NAAT)
-In women: Vaginal swab
-In men: Use first-void urine
-Rectal and oropharyngeal swabs may be performed, if necessary
Chlamydia: treatment (meds)
Doxycycline orally 100 mg twice daily for 7 days
-Preferred
-DO NOT USE in pregnancy
A single oral 1-g dose of azithromycin 500 mg
-Preferred for pregnancy or with concern of
adherence
levofloxacin once daily for 7 days.
Chlamydia treatment (without meds)
-Abstinence from sexual intercourse for 1 week after completion of medication
-Retesting is not recommended except in pregnancy
-Screening for reinfection is recommended in all patients 3 months after treatment
-Test and treat sexual partners (within 60 days)
Chlamydia treatment (without meds)
-Abstinence from sexual intercourse for 1 week after completion of medication
-Retesting is not recommended except in pregnancy
-Screening for reinfection is recommended in all patients 3 months after treatment
-Test and treat sexual partners (within 60 days)
Cholera (risk factors)
An acute diarrheal illness caused by Vibrio cholerae
-The disease is toxin-mediated (getting sick off the
toxin, not the bacteria)
Risk factors: Travel endemic area, contact with infected person, crowding, war, famine, refugee camps
Cholera: Clinical Findings
-The toxin produces hypersecretion of water and chloride ion in the small intestine
-Sudden onset of severe, frequent watery diarrhea(!!)
-Massive diarrhea of up to 15 L/day.
-Liquid stool is gray; turbid; and without fecal odor, blood, or pus (“rice water stool”).
-Severe dehydration may lead to hypotension and shock within hours
-Fever is rare
-Can kill you