When Animals Bite

Question 1

Who is most likely to get bit by a dog?

Answer 1

9 year old boy

Question 2

Who is most likely to get bit by a cat?

Answer 2

75 year of women

Question 3

Dog bites

Answer 3

• 60% of animal bites
• mostly young boys
• Inc in sexually intact male gods
• Inc in purebred status
• More often hand and face attacked

Question 4

Type of dog that is #1 cause of human death?

Answer 4

Pit bull breed: Staffordshire terrier

Question 5

Cat bites

Answer 5

1. Less destructive/life threatening
2. Deeper puncture wounds (may cause osteomyletis)
3. Inc risk of infection/soft tissue abscess (Rapid progression to infection)
4. More often upper extremities

Question 6

Most common pathogens in Dog/care bite wound infections

Answer 6

1. Pasturella (cat>dogs)
2. Capnocytophagia canimorsus (dog>cat)
3. Anaerobes: Bacteroides, Fusobacteria, Porphyromonas, Prevotella
4. Skin flora: Staphylococci, Streptococci

Question 7

Tell me about Pasturella structure?

Answer 7

Gm (-) bacilli, facultative anaerobe, catalase (+), oxidase (+)

Question 8

What does it look like when stained? What do you grow it on?

Answer 8

Growth on 5% sheep’s blood agar.

Shows bipolar staining (safety pin like yersinia!)

Question 9

Where do we get Pasturella from (soft ball)

Answer 9

Source: respiratory tract of cats and dogs. Transmission: BITES

Question 10

Sx of Pasturella infection

Answer 10

soft tissue infections (cellulitis) w/in 24 hours of bite.
May develop into necrotizing fasciitis or osteomyelitis. Systemic spread (pneumonia, endocarditis, meningitis) and lymphadenopathy esp in those with COPD or liver dz.

Question 11

Tx for Pasturella infections?

Answer 11

PCN + beta lactamase inhibitor (amoxicillin + clavulanate)

Question 12

Tell me about Capnocytophaga canimorsus structure?

Answer 12

Gm(-) rod

Question 13

Where do we find Capnocytophaga canimorsus and how do we get it?

Answer 13

It’s normal flora in dog>cats and we get it from bites

Question 14

Management of animal bite wounds?

Answer 14

1. Irrigate the shit out of it, debridgement
2. X-rays to make sure surgical eval is not needed. Look for fractures.
3. Elevate extremity
4. Antibiotics
5. Tetanus (if human bite)

Question 15

When do you give antibiotic prophylaxis?

Answer 15

1. Deep puncture wounds
2. Crush injuries
3. Wounds involving venous/lymphatic compromise
4. Wounds close to hand/joint/bone
5. Wounds needing surgical repair
6. Immunocompromised pt

Question 16

Go to drug for dog/cat bites?

Answer 16

Amoxicillin-clavulanate

Question 17

What drugs should you avoid?

Answer 17

1. Cephalexin
2. Dicloxacillin
3. Erythromycin

Question 18

Alternative drugs if PCN allergy?

Answer 18

Fluoroquinolone+metronidazole or clindamycin

DON’T USE CLINDAMYCIN ALONE–misses pasturella

Question 19

Pregnant lady with PCN allergy gets bit by a cat. NOOOOO! What do you treat her with??

Answer 19

Azithromycin.

Can’t use PCN cuz of allergy
Can’t use fluoroquinolones/metronidazole in pregnant ladies

Question 20

Common pathogens transmitted through human bites

Answer 20

1. Staph/Strep
2. Anaerobes: Eikenella, Fusobacterium, Peptostreptococcus, Prevotella, Porphyromonas
3. Viral: HBV, HCV, HSV

Question 21

Human bite should make you think of

Answer 21

Eikenella corrodens

Question 22

Structure of Eikenella corrodens

Answer 22

Fastidious Gram(-) facultative anaerobic bacillus

Question 23

Tx for Eikenella corrodens

Answer 23

PCN (amox/clav), fluoroquinolones, TMP/SMX, doxy

Question 24

What bacteria is associated with bites in the Middle East?

Answer 24

Acinetobacter baumannii

Question 25

Structure of Acinetobacter baumannii

Answer 25

Gram(-) coccobacillus

Question 26

Common infection from rats?

Answer 26

Streptobacillus moniliformis

Question 27

Structure of Streptobacillus moniliformis

Answer 27

Gm (-) branching bacilli

Question 28

Who gets Streptobacillus moniliformis?

Answer 28

children, low SES, labs, pet shops

Question 29

What does Streptobacillus moniliformis cause?

Answer 29

rat bite fever”: relapsing fever, pustular rash, migratory polyarthritis Common complication: endocarditis

Question 30

Tx for Streptobacillus moniliformis?

Answer 30

PCN + beta lactamase inhibitor (amoxicillin + clavulanate= augmentin) , doxycycline

Question 31

Where will you get a Mycobacterium marinum infection from?

Answer 31

FISHYSSS | lives free in fresh/salt water

Question 32

What does Mycobacterium marinum cause?

Answer 32

Fish tank granuloma” after minor injury/abrasion while cleaning fish tank. Soft skin papules, pustules and ulcers weeks after exposure

Question 33

Tx options for Mycobacterium marinum

Answer 33

Rifampin + ethambutol, tetracyclines, TMP-SMX, clarithromycin and fluoroquinolones

Question 34

Where will you get a Vibrio vulnificus infection from?

Answer 34

shellfish/oysters, brackish water in the summer

Question 35

What doe Vibrio vulnificus cause?

Answer 35

red, painful hemorrhagic bullae, GI distress | can lead to: septicemia, death

Question 36

What does vibrio vulnificus look like?

Answer 36

Gram (-), comma shaped

Question 37

If you get bit by a snake what bacterial infection will you likely get?

Answer 37

Salmonella from the snake's oral flora

Question 38

Antibiotic to treat salmonella infection from snake bite?

Answer 38

ceftriaxone, B-lactamase inhibitors