1. 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

2. Learning Objectives Review the diagnosis and management of: Bacterial meningitis Necrotizing fasciitis Infections in compromised hosts ─Asplenic ─Neutropenic SIRS

3. 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)

4. 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%

5. Gram negative diplococci

6. Gram Positive Diplococci

7. Listeria monocytogenes

8. 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

9. 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

10. Petechial Rash

11. Petechiae and Purpura

12. 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.

13. Purpura fulminans

14. 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.)

15. 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

16. CSF Interpretation CSFNormalMeningitis WBC (cells/mm3)<51000-5000 Protein (mg/dL)<50100 - 500 Glucose (% normal serum) 50% - 60% > 60mg/dl <40% < 45mg/dl

17. Bacterial Meningitis - Treatment Ceftriaxone + vancomycin +/- ampicillin Chloramphenicol if allergic Decadron Droplet precautions

18. 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.

19. Bacterial Meningitis - Prevention Vaccines Chemoprophylaxis

20. Necrotizing Fasciitis Introduction Fulminant tissue destruction Thrombosis Bacterial spread along fascial planes Sparse inflammatory cell infiltrate Systemic toxicity High mortality

21. 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

22. 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%

23. 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.

24. 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%

25. Necrotizing Fasciitis

26. Necrotizing Fasciitis – Type 1

28. Cases from BMC

31. 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

32. Howell-Jolly bodies “Pocked” RBC

35. Ecthyma gangrenosum

36. Clostridium difficile

37. 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