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: Streptococcus pneumoniae – 60% Neisseria meningitidis – 20% Hemophilus influenzae type B – 10% Listeria monocytogenes ( 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

Copyright ©2009 American Academy of Pediatrics Red Book Online Visual Library, Image 080_40. Available at: 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 ( %) 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: Hx of mass lesion or stroke Focal neurologic deficit Abnormal level of consciousness New-onset seizure within 1 week Immunocompromised

CSF Interpretation CSFNormalMeningitis WBC (cells/mm3)< Protein (mg/dL)< 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*012 or 3 Adverse outcome %93357 * 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, Image 151_22. Available at: 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

Cases from BMC

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, 10% bands Sepsis = SIRS + infection Severe sepsis = sepsis + organ hypoperfusion or dysfunction Septic shock = severe sepsis + BP <60 mm Hg