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Infectious Disease Emergencies
Carol Sulis, MD
Associate Professor of Medicine
Boston University School of Medicine
Hospital Epidemiologist, Boston Medical Center
Emergency Lecture Series
Boston Medical Center, Boston, MA
7/5/13
Learning Objectives
Review the diagnosis and management of:
•
•
•
Bacterial meningitis
Necrotizing fasciitis
Infections in compromised hosts
─Asplenic
─Neutropenic
SIRS
Bacterial Meningitis - Introduction
Definition
Infection of arachnoid mater
and CSF
Pathogenesis
•Colonization of nasopharynx
•Invasion of CNS following
bacteremia (endocarditis,
urosepsis)
•Direct extension (sinus,
mastoid; trauma; surgery)
Bacterial Meningitis - Epidemiology
Common causes in adults:
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•
•
•
•
Streptococcus pneumoniae – 60%
Neisseria meningitidis – 20%
Hemophilus influenzae type B – 10%
Listeria monocytogenes (<1, >50) – 6%
Group B streptococcus – 4%
Gram negative diplococci
Gram Positive Diplococci
Listeria monocytogenes
Bacterial Meningitis – Clues from History
Recent URI
Otorrhea/rhinorrhea
Petechial rash
Recent travel to endemic area
Exposure to meningitis case
Recent head trauma
IVDU
HIV
Other immunocompromising condition
Bacterial Meningitis - Clinical
Classic triad:
• Fever +/- headache
• Nuchal rigidity
• Change in mental status
─ Confusion/lethargy 75%
─ Obtunded 25%
•
Complications:
─ Focal neuro deficits including CN palsy (1/3)
─ Seizure (1/3)
─ Papilledema
Petechial Rash
Petechiae and Purpura
Image 080_40. Meningococcal Infections This 4 month old white female infant presented with fever and
an otherwise normal examination except for a single petechia on her hip which the mother thought was a
diaper pin injury. Over the next few hours a rapidly progressive generalized petechial rash developed
resulting in several areas of cutaneous necrosis despite appropriate antibiotic administration. Neisseria
meningitidis was cultured from her spinal fluid.
Red Book Online Visual Library, 2009. Image 080_40. Available
at: http://aapredbook.aappublications.org/visual.
Copyright ©2009 American Academy of Pediatrics
Purpura fulminans
Bacterial Meningitis - Diagnosis
PEx:
• Kernig and Brudzinski (specificity 70-95%)
• Papilledema (late)
• Petechiae/purpura
Laboratory:
• CBC with differential
• BCUL (+ 50-75%)
• CSF – cell count, WBC diff, culture, protein, glucose
VDRL, cryptococcal antigen, PCR (HSV, VZV, WNV, etc.)
Bacterial Meningitis - Diagnosis
When to image prior to LP:
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•
•
•
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Hx of mass lesion or stroke
Focal neurologic deficit
Abnormal level of consciousness
New-onset seizure within 1 week
Immunocompromised
CSF Interpretation
CSF
Normal
Meningitis
WBC (cells/mm3)
<5
1000-5000
Protein (mg/dL)
<50
100 - 500
50% - 60%
> 60mg/dl
<40%
< 45mg/dl
Glucose
(% normal serum)
Bacterial Meningitis - Treatment
Ceftriaxone + vancomycin +/- ampicillin
Chloramphenicol if allergic
Decadron
Droplet precautions
Bacterial Meningitis - Prognosis
Low
Risk
Medium
Risk
High
Risk
# Risk factors*
0
1
2 or 3
Adverse outcome %
9
33
57
*baseline hypotension, change mental status, seizure
Prediction of Risk: prognostic model in 176 adults, validation in 93 adults
in four hospitals in Connecticut. In-hospital mortality – 27%, Neurologic
deficit at discharge - 9%. Ann Internal Medicine 1998; 129:862-9.
Bacterial Meningitis - Prevention
Vaccines
Chemoprophylaxis
Necrotizing Fasciitis
Introduction
• Fulminant tissue destruction
• Thrombosis
• Bacterial spread along fascial planes
• Sparse inflammatory cell infiltrate
• Systemic toxicity
• High mortality
Necrotizing Fasciitis
Type 1
Mixed infection with
aerobic and anaerobic
bacteria, especially
after surgery in patients
with diabetes and PVD
Type 2
GAS or CA-MRSA
Necrotizing Fasciitis - GAS
Risk factors: unknown
Associations: IVDU, DM, obesity, immunosuppression
Clinical clues: fever, ↑ heart rate, ↓ blood pressure
Skin: edema, disproportionate pain, blisters, bullae,
crepitus
Diagnosis: BC + 60%
Treatment: surgical debridement + antibiotics
Mortality: 24%
Image 151_22. Varicella-Zoster Infections Varicella complicated by necrotizing fasciitis. A blood
culture was positive for group A streptococcus. The disease responded to antibiotics and surgical
debridement followed by primary surgical closure.
Red Book Online Visual Library, 2009. Image 151_22. Available at:
http://aapredbook.aappublications.org/visual.
Copyright ©2009 American Academy of Pediatrics
Necrotizing Fasciitis – Type 1
Risk factors: local trauma, recent surgery
Examples: infected diabetic foot ulcer, Ludwig’s angina,
Fournier’s gangrene,
PEX findings: characteristic locations feet, head/neck,
perineum
Diagnosis
Treatment
Mortality: 20 – 40%
Necrotizing Fasciitis
Necrotizing Fasciitis – Type 1
Necrotizing Fasciitis – Type 1
Cases from BMC
#1: 40 yo F c/o N/V, abdominal pain, distension. Tachycardic, hypotensive,
tachypneic, confused. Lab - acute renal + hepatic failure. Intubated. Aggressive
attempts at resuscitation. Admit 3/27/10 @ 11:21. Expired 3/28/10 @ 03:50
#2: 43 yo F c/o 3d abdominal pain, non-bloody diarrhea, N/V X 1. Rapidly
developed tachycardia, hypotension, confusion, progressive organ dysfunction.
Intubated. Aggressive attempts at resuscitation. Admit 4/13/10 @ 05:51. Expired
4/13/10 @ 15:53
#3: 48 yo T12/L1 paraplegic M with HCV and sacral decubitus ulcer c/o 4d
malaise, chills, N/V, decreased urine output. Lab - acute renal + hepatic failure +
ARDS. Intubated. Aggressively resuscitated + urgent debridement of infected
tissue. Admit 4/14/10 @ 03:47. Discharged to rehab 5/4/10.
#4: 60 yo M c/o 5d malaise, myalgias, vomiting, diarrhea, LBP, progressive SOB,
confusion. Massive volume resuscitation, maximum ventilatory support, CVVH.
Admit 4/18/10 @ 22:38. Expired 4/19/10 @ 22:00
Diagnostic Criteria for Staphylococcal and Streptococcal Toxic Shock Syndrome
Staphylococcal Toxic Shock Syndrome*
Streptococcal Toxic Shock Syndrome
Fever
Hypotension
Diffuse macular rash with subsequent
desquamation
Isolation of Group A Streptococci from:
 Sterile site for definite case
 Nonsterile site for probable case
Three of following organ systems involved:
 Liver
 Blood
 Renal
 Mucous membranes
 Gastrointestinal
 Muscular
 Central nervous system
Hypotension
Two of the following symptoms:
 Renal dysfunction
 Liver involvement
 Coagulopathy
 Soft tissue necrosis
 Adult respiratory distress syndrome
 Generalized erythematous rash
Negative serology for measles, leptospirosis,
and Rocky Mountain spotted fever and
negative blood or cerebral spinal fluid
cultures for organisms other than S. aureus
Adapted from McCormick JK, Yarwood JM, Schlievert PM. Toxic shock syndrome and bacterial superantigens: An update. Annu Rev
Microbiol. 2001;55:77-104.
*Proposed revision of diagnostic criteria for staphylococcal toxic shock syndrome (TSS) includes: 1. isolation of S. aureus from mucosal or
normally sterile site, 2. production of TSS-associated superantigen by isolate, 3. lack of antibody to implicated toxin at time of acute illness,
4. development of antibody to toxin during convalescence.
Staphylococcal Versus Streptococcal Toxic Shock Syndrome
Feature
Staphylococcal
Streptococcal
Age
Primarily 15-35 yr
Primarily 20-50 yr
Gender
Higher frequency in women
Men and women equally affected
Severe pain
Rare
Common
Hypotension
100%
100%
Erythroderma rash
Very common
Less common
Renal failure
Common
Common
Bacteremia
Low frequency
60%
Tissue necrosis
Rare
Common
Predisposing factors
Tampons, surgery
Cuts, burns, varicella
Thrombocytopenia
Common
Common
Mortality rare
<3%
30%-70%
Adapted from Stevens DL. The toxic shock syndromes. Infect Dis Clin North Am. 1996;10:727-746.
Compromised Hosts
Postsplenectomy sepsis
Etiology: encapsulated organisms
(pneumococcus, Capnocytophaga canimorsus,
babesia)
Clinical: sudden onset high fever and
complications of high grade bacteremia
(petechiae, purpura, meningitis, hypotension)
Diagnosis
Treatment
Prevention
Howell-Jolly bodies
“Pocked” RBC
Ecthyma gangrenosum
Clostridium difficile
Systemic Inflammatory Response
Syndrome (SIRS)
SIRS (2 or more of the following):
─ T >38 or <35
─ Heart rate >90
─ RR >20 or PaCO2 <32 mm Hg
─ WBC >12000, <4000, or >10% bands
Sepsis = SIRS + infection
Severe sepsis = sepsis + organ hypoperfusion or
dysfunction
Septic shock = severe sepsis + BP <60 mm Hg