Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Infectious Disease 2 > Bites, MRSA and Fasciitis > Flashcards

Bites, MRSA and Fasciitis Flashcards

1
Q

infectious complications of bites

A

-breach of protective skin barrier –> innoculation of microorganisms into deeper tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the microbiology make up reflected by an animal bite?

A
  • oropharyngeal flora
  • soil
  • skin/feces of animal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

white type of bites have higher rates of infection?

A

cat and human bites > dog bites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the determinants of infection in bites?

A
  • the animal
  • location
  • type of injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what location of a bite is of particular concern?

A

hand - b/c closed spaced infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Dog bite prevalence

A
  • 80% of all animal bites

- 5-20% become infected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

characteristics of dog bites

A

-usu by victims pet or dog known to victim
-most often upper extremity
- <4 yo most to head/neck
-most are provoked
(if not provoked, consider rabies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what percent of cat bites become infected?

A

30-50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what located of bites are more commonly infected?

A

bites to extremities > head, neck, face

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the single MC isolate species in bites?

A

pasteurella**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

infection 8-24 hrs after a bite w/ P. multocida results in what?

A

rapidly progressive cellulitis w/ purulent drainage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

common reasons for human bites

A
  • self inflicted
  • medical personnel
  • fights
  • domestic abuse
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a common location for a human bite during a fight?

A

a wound over MCP joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

percentage of infection in human bites

A

10-30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

common infective agent in human bites

A

viridans streptococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when do you refer to ortho for a human bite?

A
  • injury to extensor tendon

- joint capsule over MCP joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

essential w/u of bite

A
  • culture and gram stain of all infected wounds
  • vigorous cleansing and irrigation
  • radiographs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

closure of bite wounds

A
  • this is controversial
  • don’t suture if infected
  • don’t suture puncture cat wounds
  • sm uninfected wounds may close by secondary intention
  • facial wounds usu sutured
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

indications for abx prophylaxis after a bite

A
  • cat bites any location
  • all hand bites
  • comorbidities (DM, liver dz, etc)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

tx of choice for prophylaxis after bite

A

augmentin 500 mg TID x 5-7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

alternative tx options for prophylaxis after bite

A
  • clindamycins
  • doxy
  • bactrim
  • moxifoxacin
  • dicloxacillin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

rabies

A
  • rapidly progressive infectious dz of CNS caused by rabies virus
  • transmitted via animal vector
  • most occur in wild animals: raccoons, skunks, bats, foxes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

rabies virus family

A

-of family rhabdoviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what 2 genera of rabies viruses cause human disease?

A
  • lyssavirus

- vesicularvirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

transmission route of rabies virus

A

-viral infection of salivary glands of the biting animal

26
Q

incubation period of rabies

A

20-90 days - remains close to site of exposure

27
Q

pathogenesis of rabies virus

A
  • virus binds to nicotinic Ach receptor in muscle on postsynaptic membrane of neuromuscular junction
  • spreads and replicated along PNS to dorsal root ganglia, SC, and CNS then to all organs and tissue
  • leads to acute encephalitis of gray matter of CNS, basal ganglia and SC
28
Q

pathognomonic histology for rabies

A

negri bodies**

29
Q

what are the 2 clinical forms of rabies

A
  • encephalitis (furious) - 80%

- paralytic (dumb/apathetic) - 20%

30
Q

encephalitic rabies

A
  • episodes of generalized hyperexcitiabilty, disorientation, hallucinations, bizarre behavior
  • autonomic dysfunction: hypersalivation, hyperthermia, tachy, HTN, piloerection, cardiac arrythmias, priapism
31
Q

paralytic rabies

A
  • paresis of bitten extremity
  • spread to quadriparesis
  • facial weakness
  • progressing to coma and organ failure
32
Q

w/u for rabies once sx are evident

A
  • Ag and Ab testing (DFA)
  • CSF, saliva, and tissue testing
  • brain bx
  • skin bx
  • RNA by RT-PCR
33
Q

therapy for rabies

A
  • thorough wound cleansing is vital
  • tetanus prophylaxis
  • no specific tx has showed benefit in clinical rabies
34
Q

contraindicated tx in rabies

A
  • steroids**

- shortened incubation time and increased mortality in animal models

35
Q

indication for rabies postexposure prophylaxis (PEP)

A

-consider the animal and the bite - if provoked or not and consult w/ public health authority

36
Q

rabies vaccines

A
  • Imogram/HyperRab: passive immunity w/ human rabies immune globulin (HRIG)
  • Imovax/RabAvert: purified inactivated rabies vaccines
37
Q

dosing/schedule of rabies vaccines

A
  • Imogram/HyperRab: no later than 7 days after 1st vaccine at site of bite - 20IU/kg
  • Imovax/RabAvert: 4 separate 1 ml doses IM deltoid days 0, 3, 7, 14
38
Q

considerations on rabies PEP

A

never administer HRIG and vaccine in same syringe or into same anatomic site

39
Q

2 clinically important spider bites in North America

A
  • lacrodectism (Black Widow - lacrodectus species)

- loxoscelism (brown recluse - loxosceles species)

40
Q

lactrodecism

A
  • resides in dark places
  • shiny black w/ red hourglass marking on ventral abdomen
  • F more potent
  • summer and early autumn
  • bite perceived as sharp pinprick or unnoticed
41
Q

lactrodecism bite pathogenesis

A
  • venom contains toxin causing Ach & NE release/depletion from presynaptic terminals
  • painful cramps w/ rigidity from bite site to large muscles of extremities and trunk
42
Q

other sequelae of lactrodecism bite

A
  • salivation
  • lacrimation
  • diaphoresis
  • urination
  • defecation
  • GI upset
  • emesis
  • renal failure
  • rhabdo
  • resp arrest
  • cerebral hemorrhage
  • cardiac failure
43
Q

tx for lactrodecism bite

A
  • RICE and tetanus prophylaxis
  • if severe: hospital admin for IV pain control and muscle spasms
  • antivenom available but questionable efficacy
44
Q

loxoscelism

A
  • south-central US
  • dark brown violin shape on the cephalothorax (violin neck points back)
  • 6 eyes in pairs
  • live in dark places
  • not aggressive
45
Q

active enzymatic components of loxoscelism venom

A
  • sphingomyelinase D

- hyaluronidase

46
Q

outcome of loxoscelism bite

A
  • usu only cause minor injuries w/ edema and erythema

- occasionally causes severe necrosis of skin/subQ tissue and more rarely causes systemic hemolysis

47
Q

loxoscelism bite characteristics

A
  • initially is painless or may produce a stinging sensation - often unaware of bite
  • w/i hours becomes painful and pruritic w/ central induration surrounded by zones of ischemia and erythema
  • if severe: erythema spreads and the center of the lesion becomes hemorrhagic w/ bulla or necrotic
  • black eschar forms and sloughs weeks later
48
Q

systemic variant of loxoscelism bite

A
  • may occur in about 10%
  • renal failure, rhabdo, hemolysis
  • 24-72 hrs after bite
49
Q

MRSA

A

-strain of staph aureus resistant to all beta lactam abx currently available

50
Q

hospital associated MRSA

A

-invasive disease in debilitated or immunocompromised individuals, including pneumonia, bloodstream infections such as endocarditis, deep wound infection and osteomyelitis

51
Q

community acquired MRSA

A
  • MC causes pyogenic skin and soft tissue infection in the form of boils, deep abscesses, and cellulitis
  • capable of potentially lethal infection such as necrotizing fasciitis, necrotizing pneumonia and bacteremia
52
Q

tx of HA-MRSA

A

IV vancomycin, daptomycin or tigecycline

-use contact precaustions

53
Q

primary tx of CA-MRSA

A

I&D

54
Q

tx of MRSA for pts who have abscesses to multiple sites or rapid progession of associated cellulitis

A
  • abx x 5-10 days

- options: bactrim, tetracyclines, linezolid, clindamycin

55
Q

tx for MRSA if recurrent infection or if other household members develop infections

A
  • nasal decolonized w/ mupirocin twice per day x 5-10 days

- or same tx + topical body decolonization w/ skin antiseptic solution x 5-14 days

56
Q

necrotizing fasciitis

A

rapidly progressive infection of the deep fascia w/ necrosis of the subQ tissue

57
Q

type 1 necrotizing fasciitis

A
  • polymicrobial
  • usu delivered into SQ via surgery, trauma, bowel perf or IV drug use
  • MC form (90%)
  • MC to extremity, abd wall, perineum or near operative wounds
58
Q

type 2necrotizing fasciitis

A
  • monomicrobial
  • usu GAS “flesh eating bacteria”
  • MRSA becoming more prominent cause
59
Q

what are the 2 greatest risk factors for necrotizing fasciitis?

A
  • DM

- severe peripheral vascular dz

60
Q

progression of necrotizing fasciitis

A
  • rapid progression of erythema, ecchymosis w/ bullae, and necrosis or gangrene
  • edematous induration of SQ tissues extending beyond margin of erythema
  • high fevers and unrelenting pain out of proportion to cutaneous findings
  • anesthesia of skin d/t infarction of cutaneous nerves
61
Q

gold standard for diagnosis of necrotizing fasciitis

A
  • open surgical exploration

- histology and culture of deep tissue bx

62
Q

primary therapeutic modality in necrotizing fasciitis

A

surgical debridement

  • frist one w/i 24 hrs from onset of sx
  • repeat until all devitalized tissue removed
  • start abx immediately

Infectious Disease 2 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions