Invasive GAS disease

Question 1

RF for invasive GAS in adults:

Answer 1

HIV
diabetes
postpartum
cancer
heart disease
lung disease
alcohol abuse
injection drug use

RF for IGAS in children and adults
NSAIDS
Recent soft tissue trauma

Question 2

RF for IGAS in children

Answer 2

recent pharyngitis
varicella

RF for IGAS in children and adults
NSAIDS
Recent soft tissue trauma

Question 3

RF for IGAS in children and adults

Answer 3

recent soft tissue trauma

NSAIDS

Question 4

Most secondary cases of GAS occur within __ days of the index case

Answer 4

7

Question 5

What is the definition of IGAS?

Answer 5

Laboratory confirmation: Isolation of GAS from a normally sterile site, with or without clinical evidence of severe invasive disease.

Question 6

What is the definition of severe IGAS?

Answer 6

• Streptococcal TSS
  
  • hypotension (SBP =< 90 in adult or <5th %ile in children) and at least 2 of:
    
    • renal impairment (Cr 2x ULN or 2x baseline)
    • coagulopathy (plt =< 100 or DIC)
    • liver function abnormality (AST, ALT or total bili >= 2x ULN for age)
    • ARDS
    • generalized erythematous macular rash that may later desquamate
• Soft-tissue necrosis (NF, myositis, gangrene)
• meningitis
• pneumonia (isolation of GAS from pleural fluid, not from BAL)

Question 7

What is the definition of non-severe IGAS?

Answer 7

bacteremia
cellulitis
wound infections
soft tissue abscess
lymphadenitis
septic arthritis
osteomyelitis 

(above without evidence of strep TSS or soft tissue necrosis)

Question 8

What is the definition of probable case of IGAS?

Answer 8

• invasive disease in absence of another identified etiology and with isolation of GAS from a non-sterile site (eg BAL)
  
  • pneumonia with isolation of GAS from BAL with no other cause would be considered IGAS for pt management but isn’t nationally notifable

Question 9

What factors make GAS-related nec fasc more likely?

Answer 9

generalized rash
pharyngitis
conjunctivitis
strawberry tongue

Question 10

What antimicrobials do you give for confirmed GAS?

Answer 10

penicillin + clindamycin
- discontinue clinda after 48-72 hours

TSS: beta-lactamase stable beta-lactam (clox) + clinda +/- empiric vanco

NF:

• empiric piptazo or carbapenem + clinda +/- vanco
• healthy children with no RF for organisms other than GAS: pen + clinda

RF for clostridial/polymicrobial organisms:

• chemotherapy
• recent GI surgery
• penetrating trauma
• intra-abdominal or pelvic focus of infection
• pregnancy complications

Question 11

What are RF for clostridial/polymicrobial myonecrosis?

Answer 11

CRAPP

• chemotherapy
• recent GI surgery
• intra-abdominal or pelvic focus of infection
• penetrating trauma
• pregnancy complications

Question 12

What is a non-antimicrobial treatment for IGAS?

Answer 12

IVIG - consider on day of clinical presentation of streptococcal TSS or other severe invasive (toxin-mediated) disease
* 150-500 mg/kg/day x 5-6 d or 1g/kg-2g/kg x 1dose

• discontinue clindamycin after 48-72 hours if: pt hemodynamically stable, blood sterile, no further progression of necrosis (stable, sterile, standstill)

Question 13

Who gets prophylaxis for coming in contact with a GAS case?

Answer 13

• Routine for SEVERE IGAS (not routinely recommended for non-severe IGAS)
• contacts exposed 7d before onset of symptoms in index case to 24 h after initiating antimicrobial therapy
• start within 24 hr but up to 7 day after LAST contact with case
• alert all contacts of confirmed IGAS cases to be alert to S&S of GAS

Close contacts:

• household contacts who spent 4h/d or 20 hr in past 7 days with contact
• shared a bed or sexual relations with case
• direct contact with mucous membranes
• injection drug user who shared needle
• contacts in child care settings (family or home child care settings but not in group or institutional child care centres)
• selected hospital contacts
• selected contacts in long-term care homes
• consider in institutional child care centres if >1 case of IGAS or varicella ourbtreak

Question 14

What abx for chemoprophylaxis for IGAS?

What about allergic to first line?

Answer 14

Keflex preferred for 10 days (alternatives: second and third gen cephalosporins like cefurox and cefixime)

Pen allergic: macrolides (erythro, clarithro, azithro)
- consider clinda

• routine cultures not required for follow-up of contacts receiving abx proph

Question 15

What kind of GAS infection is nationally reportable?

Answer 15

all invasive GAS cases