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