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Infectious Disease Emergencies
Carol Sulis, MDAssociate Professor of Medicine
Boston University School of MedicineHospital Epidemiologist, Boston Medical Center
Emergency Lecture SeriesBoston 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
DefinitionInfection 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:
• 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 URIOtorrhea/rhinorrheaPetechial rash Recent travel to endemic areaExposure to meningitis caseRecent head traumaIVDUHIVOther 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
Copyright ©2009 American Academy of Pediatrics
Red Book Online Visual Library, 2009. Image 080_40. Available at: http://aapredbook.aappublications.org/visual.
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.
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, glucoseVDRL, cryptococcal antigen, PCR (HSV, VZV, WNV, etc.)
Bacterial Meningitis - Diagnosis
When to image prior to LP:
• 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
Glucose (% normal serum)
50% - 60%> 60mg/dl
<40% < 45mg/dl
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%
Copyright ©2009 American Academy of Pediatrics
Red Book Online Visual Library, 2009. Image 151_22. Available at: http://aapredbook.aappublications.org/visual.
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.
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 Isolation of Group A Streptococci from: Hypotension Sterile site for definite case Diffuse macular rash with subsequent desquamation
Nonsterile site for probable case
Three of following organ systems involved: Hypotension
Liver Blood Two of the following symptoms: Renal Renal dysfunction Mucous membranes Liver involvement Gastrointestinal Coagulopathy Muscular Soft tissue necrosis Central nervous system 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.
Adapted from Stevens DL. The toxic shock syndromes. Infect Dis Clin North Am. 1996;10:727-746.
30%-70%<3%Mortality rare
CommonCommonThrombocytopenia
Cuts, burns, varicellaTampons, surgeryPredisposing factors
CommonRareTissue necrosis
60%Low frequencyBacteremia
CommonCommonRenal failure
Less commonVery commonErythroderma rash
100%100%Hypotension
CommonRareSevere pain
Men and women equally affectedHigher frequency in womenGender
Primarily 20-50 yrPrimarily 15-35 yrAge
StreptococcalStaphylococcalFeature
Staphylococcal Versus Streptococcal Toxic Shock Syndrome
Adapted from Stevens DL. The toxic shock syndromes. Infect Dis Clin North Am. 1996;10:727-746.
30%-70%<3%Mortality rare
CommonCommonThrombocytopenia
Cuts, burns, varicellaTampons, surgeryPredisposing factors
CommonRareTissue necrosis
60%Low frequencyBacteremia
CommonCommonRenal failure
Less commonVery commonErythroderma rash
100%100%Hypotension
CommonRareSevere pain
Men and women equally affectedHigher frequency in womenGender
Primarily 20-50 yrPrimarily 15-35 yrAge
StreptococcalStaphylococcalFeature
Staphylococcal Versus Streptococcal Toxic Shock Syndrome
Compromised Hosts
Postsplenectomy sepsisEtiology: encapsulated organisms
(pneumococcus, Capnocytophaga canimorsus, babesia)
Clinical: sudden onset high fever and complications of high grade bacteremia (petechiae, purpura, meningitis, hypotension)
DiagnosisTreatmentPrevention
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
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