bacterial infections Flashcards
-rash
-diffusely erythematous and resembles a sunburn with superimposed fine red papules giving skin a sandpaper consistency
-may appear 1-2 days after onset of GAS pharyngitis (strep throat)
Scarlett fever
hallmark of Scarlett fever
strawberry tongue
bacteria of Scarlett fever
group A streptococci (gram pos)
How to diagnose rheumatic fever
JONES criteria – at least two major criteria OR one major and two minor criteria
PLUS, evidence of recent GAS infection
what is Jones criteria for rheumatic fever
Major: polyarthritis, carditis, chorea, rash
Minor: fever, arthralgia, inflammatory markers, PR segment prolongation
treatment of rheumatic fever and Scarlett fever
penicillin
common pathogens of skin and soft tissue infections
staph aureus
skin and soft tissue infections lab findings
-culture of wound
-blood cultures
example of purulent skin and soft tissue infection
abscess, furuncle, carbuncle, cellulitis with purulence
treatment of purulent skin and soft tissue infection
primary treatment: I & D
treatment of purulent skin and soft tissue infection if they also have:
-severe disease
-signs of systemic illness
- purulent cellulitis/wound infection
-comorbidities/old age
-abscess in difficult area
-septic phlebitis
-I&D didn’t work
I&D plus:
can add oral antibiotics: dicloxacillin, clindamycin
if MRSA: clindamycin, Bactrim, doxycycline
IV antibiotics: nafcillin or cefazolin
if MRSA: vancomycin
examples of non purulent skin and soft tissue infection
cellulitis
erysipelas
common pathogens of non purulent skin and soft tissue infections
beta hemolytic streptococci
treatment of non purulent skin and soft tissue infections
oral abx: amoxicillin, cephalexin or clindamycin
IV abx: nafcillin or cefazolin, vancomycin
usual sites of osteomyelitis
long bones and vertebrae
what could be concerning if vertebral osteomyelitis is present with fever, sever back or neck pain, radicular pain, or evidence of spinal cord compression
epidural abscess
-associated with sickle cell disease, injection drug use, DM, older age
hematogenous osteomyelitis (bacteria in blood that goes to bone)
big risk factors for hematogenous osteomyelitis
injection drug users
sickle cell anemia
older patients
-prosthetic joint replacement or other orthopedic surgery, neurosurgery, and trauma most frequently cause soft tissue infections that can spread to bone
-MC pathogens: S. aureus and staphylococcus epidermis
osteomyelitis (contiguous focus of infection) (injury/surgery/trauma)
-MC sites: foot and ankle, hip and sacrum (pressure)
-bone pain is often absent or muted by associated neuropathy
-ability to easily advance a sterile probe to bone through a skin ulcer
- large skin ulcer
osteomyelitis (vascular insufficiency) (skin breakdown)
how to diagnose osteomyelitis
- isolation of organism from blood, bone, or contiguous focus
- blood culture
- elevated ESR and CRP
- bone biopsy
(have to get from bone or blood)
(for diagnosis you have to find the causative organism!!)
what will you find on osteomyelitis x-ray (early findings) – Initial step
-soft tissue swelling
-loss of tissue planes
-periarticular demineralization of bone
what is seen on osteomyelitis x-ray (after 2 weeks)
-erosion of bone
-alteration of cancellous bone
-periostitis
what (better, more definitive) imaging for osteomyelitis
CT and bone scan
what imaging for osteomyelitis if epidural abscess is suspected
MRI
osteomyelitis treatment
-identify causative organism
-consult ID specialist
prolonged therapy (4-6 weeks or longer)
Not MRSA: IV cefazolin, nafcillin
MRSA: IV vancomycin
osteomyelitis treatment if epidural abscess and spinal cord compression, or other abscesses
or if they’re not getting better
surgery
S aureus readily invades the bloodstream and infects sites distant from the primary site of infection
- endocarditis
-osteomyelitis
-other deep infection
staphylococcal bacteremia
what to do if they have staph aureus in bloodstream that makes you suspicious for infective endocarditis
transesophageal echocardiogram
staphylococcal bacteremia treatment
IV vancomycin or daptomycin
-S. aureus produces toxins
-abrupt onset high fever, vomiting, watery diarrhea
-sore throat, myalgia, HA
-hypotension with kidney and heart failure
-diffuse macular erythematous rash and nonpurulent conjunctivitis
-desquamation of palms and soles
toxic shock syndrome
toxic shock syndrome is associated with what that harbors a toxin producing S aureus strain
tampons
TSS treatment
- remove source (tampon)
-rapid rehydration
-antistaphylococcal therpay
-IV clindamycin
important cause of infections of:
-intravascular devices
-prosthetic devices
-wound infection following cardiothoracic surgery
signs/symptoms:
-purulent or serosanguineous drainage, erythema, pain, tenderness at site of foreign body or device
-joint instability and pain of prosthetic joint
infections by coagulase negative staphylococci
infections by coagulase negative staphylococci treatment
-remove device or foreign body suspected of being infected
-IV vancomycin
-caused by neurotoxin tetanospasmin which is found in soil (clostridium tetani)
-puncture wound
tetanus
why does tetanus cause uncontrolled spasms and exaggerated reflexes
interferes with neurotransmission at spinal synapses of inhibitory neurons
tetanus complications
-airway obstruction
-urinary retention and constipation
-respiratory arrest and cardiac failure
MC cause of death of tetanus
respiratory failure
Tetanus prevention (active immunization for adults)
Td vaccine
when is booster Td given
every 10 years or at the time of injury if it has been greater than 5 years after a dose
immunization schedule of children (DTaP)
- 2 months
- 4 months
- 6 months
- 15-18 months
- 4-6 years
what 3 forms does botulism exist in
-Foodborne: canned, smoked, or vacuum packed foods
-Infant: ingestion of honey
-Wound: injection drug use
paralytic disease caused by botulism toxin (produced by clostridium botulinum)
botulism
tetanus treatment
- human tetanus immune globulin within 24 hours of presentation
- debride wound
- metronidazole IV or PO
Hallmark of botulism
-symmetric, descending flaccid paralysis progressing to respiratory failure
-visual disturbances
botulism treatment
-equine serum heptavalent botulism antitoxin
-intubation/mechanical ventilation
-fluids
-caused by corynebacterium diphtheria
-attacks respiratory tract but may involve any mucous membrane or skin wound
-mostly spread respiratory secretions
-exotoxin can lead to myocarditis and neuropathy
diptheria
MC sign of diphtheria (pharyngeal)
tenacious gray membrane covers tonsils and pharynx
diphtheria labs
clinical
for confirmation:
- culture from respiratory secretions
- PCR detection of the toxin
diphtheria prevention
active immunization with diphtheria toxoid with appropriate booster injections
what should susceptible people exposed to diphtheria do
receive a booster of diphtheria toxoid (or complete series if not immunized) and a dose of PCN G benzathine or course of erythromycin
diphtheria treatment
-removal of membrane by direct laryngoscopy or bronchoscopy
- antitoxin (from horse serum)
-PCN or erythromycin x14 days
-isolate patient
-caused by listeria monocytogenes, a motile gram + rod
- can come from contaminated food:
Unpasteurized dairy products
hot dogs
deli meats
cantaloupes
soft cheese
listeriosis
5 infections of listeriosis
- infection during pregnancy
- granulomatosis infantisepticum
- bacteremia
- meningitis
- focal infections
what diagnostic to do with listeriosis with neutrophils, increased protein and meningitis
lumbar puncture
listeriosis treatment
ampicillin IV
what causes pertussis
bordetella pertussis transmitted via respiratory droplets
pertussis also called
whooping cough
symptoms of catarrhal stage of pertussis
lacrimation, sneezing, coryza, anorexia, hacking night cough that becomes diurnal
symptoms of paroxysmal stage of pertussis
bursts of rapid, consecutive coughs followed by deep, high-pitched inspiration (whoop)
symptoms of convalescent stage of pertussis
decrease in frequency and severity of paroxysms
what is seen on pertussis labs
elevated WBC
how to establish diagnosis of pertussis
isolating organisms from nasopharyngeal culture (special agar)
pertussis prevention
vaccine for infants with DtaP
what ages do young children get DTaP vaccine
-2,4, and 6 months
-15 through 18 months
-4 through 6 years
what age do preteens get Tdap
11 through 12 years
when do pregnant women get Tdap
during 27-36th week of pregnancy
when do adults get Tdap
anytime if they’ve never received it
pertussis treatment
azithromycin (abx treatment)
when do you get Hib dose 1
2 months
when do you get Hib dose 2
4 months
when do you get Hib dose 3
6 months
may cause sinusitis, otitis, bronchitis, epiglottis, pneumonia, cellulitis, meningitis, septic arthritis, endocarditis
H. flu and hemophilus
when do you get Hib dose 4
12-15 months
Hemophilus Treatment (pts with sinusitis, otitis, or respiratory tract infections)
amoxicillin or amoxicillin/clavulanate
hemophilus treatment (more seriously ill pts) (toxic clinical features with multiline pneumonia)
IV ceftriaxone or fluoroquinolone
-abrupt onset of high fever, drooling, and inability to handle secretions
-severe sore throat
-stridor and respiratory distress from obstruction
epiglottitis
how to diagnose epiglottitis
direct visualization of the cherry red swollen epiglottitis at laryngoscopy
epiglottitis treatment
IV ceftriaxone
complication of H. influenza
meningitis
meningitis treatment
ceftriaxone 4g/day in two divided doses
-MC form of salmonellosis
-incubation period 6-72 hours after ingestion of contaminated food or liquid
salmonella gastroenteritis
signs and symptoms of salmonella gastroenteritis
-fever (chills)
-nausea and vomiting
-cramping abdominal pain
-bloody diarrhea lasting 4-7 days
how to diagnose salmonella gastroenteritis
culture of organism from the stool
salmonella gastroenteritis treatment
self limited
salmonella gastroenteritis treatment for patients who are malnourished, severely ill, sickle cell disease, or immunocompromised
ciprofloxacin 500mg BID or levofloxacin 500mg
- prolonged or recurrent fevers accompanied by bacteremia and local infection (bone, joints,pleura,pericardium,lungs,etc)
- mycotic aortic aneurysms may occur
salmonella bacteremia
salmonella bacteremia treatment
systemic antimicrobial therapy plus drainage of any abscesses
- Highly transmissible via the fecal oral route
S/S:
-abrupt onset of diarrhea, lower abdominal cramps, tenesmus
-stool mixed with blood and mucus
-fever,chills,anorexia,malaise,HA
-tender abdomen
-sigmoidoscopy shows inflamed, engorged mucosa with punctuate and sometimes large areas of ulceration
shigellosis
shigellosis lab findings from stool culture
-stool shows many leukocytes and red cells
shigellosis treatment
self resolving
treat dehydration and hypotension
-acute diarrheal illness caused by certain serotypes of vibrio cholerae
-toxin mediated
-MASSIVE watery diarrhea
-occurs in conditions of crowding, war, famine
-ingestion of contaminated food/water
-dehydration and hypotension
cholera
hallmark of cholera
gray stool, turbid, without fecal odor, blood, or pus
“rice water stool”
how to get definitive diagnosis of cholera
positive stool culture
cholera treatment
mild/moderate:
-fluid replacement
-oral rehydration (gatorade,pedialyte)
severe hypovolemia:
-IV fluids (lactated ringers)
-microaerophilic, motile, gram neg rods
-caused by C jejuna or C coli
-dairy cattle and poultry are main reservoir
campylobacter
campylobacter outbreaks associated with
consumption of raw milk
campylobacter virulence factors
-fimbriae like filaments and cell surface proteins
-attach to surface of small intestine and colon
-spiral shaped and long flagella
-can drill into the colon, releasing cytolethal distending toxins
cytolethal distending toxins from campylobacter causes what complication
inflammation –> toxic megacolon
campylobacter symptoms
symptoms appear after 1-7 days of infection:
-fever, muscle pain, malaise, HA
followed by:
crampy abdominal pain, diarrhea (water and ill smelling and bloody)
campylobacter treatment
self limited
hydration and correction of electrolyte abnormalities (shortens duration one day)
zoonotic infection carried by wild rodents and caused by yersina pestis
the plague
how is plague transmitted
transmitted among rodents and humans by bites of fleas
following fleabite, the organisms spread through the lymphatics to the…
lymph nodes
(they become greatly enlarged–> buboes)
complications of the plague that can be fatal
pneumonia or meningitis
the plague signs and symptoms
-sudden onset of high fever, malaise, tachycardia, intense HA, delirium, severe myalgias
-axillary, inguinal, cervical lymph nodes become enlarged and tender and may suppurate and drain
-purpuric spots (black plague)
the plague lab findings
-smears from aspirates of buboes examined with gram stain
-cultures from aspirate or pus, CSF, and sputum
The plague prevention
-avoid exposure to rodents and fleas in endemic areas
-Drug prophylaxis with doxycycline and ciprofloxacin
The plague treatment
fluoroquinolone:
- ciprofloxacin, levofloxacin IV or PO
OR
aminoglycoside:
- streptomycin IV, Gentamycin IV
OR
doxycycline
duration of treatment for the plague
10-14 days
what causes gonococcal infections
neisseria gonorrhoeae
how are gonococcal infections transmitted
sexual activity
penile infections symptoms
-initial: dysuria and serous or milky discharge
-1-3 days later: urethral pain, yellow, creamy, profuse, blood tinged discharge
may regress and become chronic or progress to involve the prostate, epididymis, and periurethral glands with painful inflammation
cervicovaginal infections symptoms
-dysuria, urinary frequency, urgency, purulent discharge
-vaginitis and cervicitis with inflammation of bartholins glands
preferred method of diagnosis for urethritis and cervicitis
nucleic acid amplification tests at all mucosal sites
what systemic complications follow the dissemination of gonococci from primary mucosal site via bloodstream
-purulent arthritis
-triad of rash, tenosynovitis, and polyarthralgia
how to diagnose urethral infection of men
first catch am urine
gonococcal infection prevention
-condom
-partner notification and referral of sexual contact for treatment
most common form of eye involvement is direct inoculation into the conjunctival sac
conjunctivitis
uncomplicated gonorrhea treatment
IM ceftriaxone
with chlamydia –> add oral doxycycline (non pregnant), oral azithromycin (pregnant)
complicated gonorrhea treatment
arthritis dermatitis syndromes:
ceftraixone IV or IM
endocarditis:
ceftriaxone IV
- STI caused by short gram-neg bacillus haemophilus ducreyi
- at site of inoculation, a vesicopustule develops that breaks down to form a painful, soft ulcer with a necrotic base, surrounding erythema, and undermined edges
chancroid
chancroid treatment
single dose of oral azithromycin OR ceftriaxone IM
- acute infection of children and young adults that is transmitted from cats to humans as the result of a scratch or bite
cat scratch disease
bartonella henselae
cat scratch disease diagnosis
clinical
hallmark of cat scratch disease
cat scratch
regional lymphadenitis (treat with azithromycin)
cat scratch disease treatment
self limited
(treat lymphadenitis with azithromycin)
-acute and chronic STI caused by chlamydia trachomatis
-initial papular or ulcerative lesion on external genitalia often unnoticed
-patients engaging in anal sex present with symptoms of proctocolitis*
-inguinal or femoral buboes appear 1-4 weeks after exposure
lymphogranuloma venereum
diagnosis for lymphogranuloma venereum
positive nucleic amplification test for chlamydia trachomatis
chlamydia urethritis and cervicitis has common coinfection with…
gonococci and chlamydia
treatment for lymphogranuloma venereum
doxycycline
chlamydia urethritis and cervicitis clinical findings
-most often no symptoms
-urethral or cervical discharge
-less painful, less purulent, and more watery compared to gonococcal infection
chlamydia urethritis and cervicitis lab findings
a patient with clinical signs and symptoms of urethritis and cervicitis is assumed to have chlamydia infection until proven otherwise
chlamydia urethritis and cervicitis diagnosis
highly sensitive nucleic amplification test for urine or cervical/vaginal swabs
chlamydia urethritis and cervicitis screening recommended for
-all sexually active women 25 years or younger
-women > 25 years with risk factors for STIs
-pregnant women
-HIV
-men with risk factors for STI
chlamydia urethritis and cervicitis treatment
doxycycline 100mg BID x7 days
chlamydia urethritis and cervicitis treatment for pregnant women
single dose of azithromycin
what to also screen for with chlamydia
HIV, gonorrhea, syphilis
who should also be treated for chlamydial infections
the sexual partners of the patients
