1. ATYPICAL PNEUMONIAS: THE BASICS Nilesh Patel, DO October 8, 2008 St. Joseph’s Regional Medical Center

2. QUESTIONS WE WILL ANSWER???  What is an atypical pneumonia?  What are the organisms that compromise atypical pneumonias?  How do we test for atypical pneumonias; does it matter?  What are the antibiotic choices?  What should we think about when HIV patients present with pneumonia?

3. OBJECTIVES  We will discuss….  Mycoplasma pneumoniae  Legionella sp.  Chlamydia pneumoniae  Chlamydia psittaci  Viral pneumonias  Pneumonia in the setting of HIV/AIDS--PCP

4. ATYPICAL PNEUMONIA: WHAT IS IT???  Infection of pulmonary parenchyma  Community-acquired  Classically—do not show up on Gram stain  Characteristics  “Atypical” presentation/symptoms/diagnostics  Insidious onset  Nonproductive cough  Constitutional symptoms  Interstitial pattern on CXR  Smoldering course  The lines are “blurred”  Similar to typical organisms clinically and radiographically

5. ORGANISMS  Mycoplasma pneumonia  Viral pneumonias  RSV  Parainfluenza  Adenovirus  Influenza  Other  Chlamydia pneumonia  Chlamydia psittaci  Legionella pneumophila  Coxiella burnetti (Q fever pneumonia)  Francisella tularensis (Tularemia)

6. EPIDEMIOLOGY  4 million cases CAP/year  20-60% typical organisms  10-40% atypical organisms  Hard to quantify these organisms

7. PATHOPHYSIOLOGY

8. MYCOPLASMA PNEUMONIA  Smallest free living organisms  Prokaryotes  No cell wall  Most common cause of atypical pneumonia  “Walking” pneumonia  Community acquired  Usually occur in young to middle aged patient  Clinical symptoms  Insidious onset, protracted course  Constitutional symptoms (fevers, chills, myalgias, body aches)  Sore throat, HA  Dry cough  Chest pain/SOB

9. MYCOPLASMA: DIAGNOSTICS  CXR  Consolidation  Patchy infiltrates  Interstitial pattern  Pleural effusion  Labs  WBC  Cold agglutinin assays  Other serum assays  Cultures  Blood  Sputum

12. MYCOPLASMA: TMT  Macrolides  Azithromycin  Erythromycin  Clarithromycin  Doxycycline

13. LEGIONELLA  Gram negative intracellular rods  Fastidious  Multiple serotypes  Legionella pneumophila  Community acquired  Legionnaire’s disease  Transmission from contaminated water sources  Warm water environments  No person to person transmission  Outbreaks….Sporadic cases  High mortality if not treated

14. LEGIONELLA  Natural water habitats  Water distribution systems  Cooling towers  Hot tubs/Spas  Respiratory equipment  Humidifiers  Etc……  Travel  Hotels  Large Events  Floods/Natural Disasters

15. LEGIONELLA: SYMPTOMS  Incubation period: 2-10 days  Clinical symptoms  Pulmonary  Cough  Chest pain  Dyspnea  Extrap-pulmonary  Constitutional symptoms  GI symptoms—diarrhea, abd pain, n/v  Neuro symptoms—HA, change in mental status

16. LEGIONELLA: DIAGNOSTICS  CXR—variable  Consolidation  Patchy infiltrates/Interstitial infiltrates  Pleural effusions  Multi-lobar  Labs  CBC, SMA-7 (Hyponatremia, Elevated LFTs, ARF)  CPK  Urine antigen tests  Serum legionella antibodies  PCR  Cultures  Sputum gram stain/culture; DFA sputum  Blood cultures

18. LEGIONELLA: TMTS  Fluoroquinolones  Levaquin  Avelox  Macrolides  Zithromax  Doxycycline  Bactrim  Rifampin  Extended course  Initial IV therapy

19. CHLAMYDIA  Chlamydia 3 sp (pneumoniae, psittaci, trachomatis)  Gram negative obligate intracellular organisms (parasites)  Unique organisms  Community acquired  Chlaymydia pneumoniae  Common  Respiratory transmission (person to person)  Pneumonia  Chlaymdia psittaci  Rare  Ornithosis  Respiratory transmission (infected birds to humans)  Pneumonia/Viral illness

20. CHLAMYDIA PNEUMONIA  Clinical symptoms  Incubation period: 1-4 weeks  Acute/subacute illness  Self limited URI/bronchitis  Fever  Constitutional symptoms  Cough  Chest pain/sob  Pharyngitis  Sinusitis  Rales/Rhonchi/Wheezing

21. CHLAYMDIA PSITACCI  Risk Factors—Contact with birds  Clinical symptoms (incubation 5-30 days)  Acute viral illness/flu like symptoms  Fever  Relative bradycardia  Constitutional symptoms  Chest pain/sob  Multi-system  Neuro symptoms—HA, altered mental status  HSM (elevated LFTs)  Rash—Horder spots, EM, EN  Rales/Rhonchi/Wheezing/Clear lungs

22. CHLAMYDIA: DIAGNOSTICS  Chlamydia pneumonia  CXR  Cultures  Serologic tests  Chlamydia psitacci  CXR  Cultures  Serologic tests

24. CHLAMYDIA: TMTS  Chlamydia pneumoniae  Doxycycline/Tetracycline  Macrolides (Zithromax, Clarithromycin, E-mycin)  Quinolones (Avelox, Levaquin)  Chlamydia psitacci  Doxycycline/Tetracycline  Macrolides (Zithromax, E-mycin)

25. VIRAL PNEUMONIAS  More common in pediatric population and elderly  Up to 15% of all CAP cases  Mild>>>>Severe  Influenza A & B  RSV  Adenoviruses  Parainfluenza  SARS  Avian flu  Varicella  CMV  Herpes virus  Hanta virus

26. ANTIBIOTICS  Outpatient/Inpatient/ICU  Remember coverage for CAP  Mycoplasma—Macrolide, Doxy  Legionella—Quinolone, Macrolide  Chlaymydia pneumonia—Doxy, Macrolide  Chlaymida psitacci—Doxy, Macrolide  Viral pneumonias  Supportive care  Influenza—Tamiflu, think Staph coverage

27. HIV & PNEUMONIA  Most common infectious process in HIV + patients  Broaden differential diagnosis  CD4 count & viral load important for specific organisms and prognosis  CAP most common  Other  PCP  TB  MAC  Histoplasmosis/Coccidiomycosis  Viral pneumonias

28. PCP  Pneumocystis carinii >> Pneumocystis jiroveci  Unicellular fungus  Various morphology--cysts  Pre-HIV—few cases  Most common opportunistic infection in HIV patients  Common cause of death in HIV patients; mortality ~ 15%  Decreased incidence with prophylaxis and antiretroviral treatment  Transmission—human to human; airborne  Pneumocystis is widespread  Symptomatic disease occurs in immunosuppressed populations

29. PCP: CLINICAL SYMPTOMS  Symptoms  SOB (exertional)  Cough  Fevers  Constitutional symptoms  Chest pain  Signs  Tachypnea/Fever/Tachycardia  Rales/RhonchiWheezing  Cachexia  Lymphadenopathy  Cyanosis

30. PCP: DIAGNOSTICS  Labs  CBC, SMA-7  LDH  ABG  Imaging  CXR—variable  Normal>>Diffuse b/l infiltrates>>Perihilar infiltrates>>PTX  CT scan  Diffuse b/l infiltrates>>Ground glass appearance>>Cysts  Sputum culture  BAL  Complication—PTX!

36. PCP: TMT  Supportive treatments  Oxygen  Noninvasive/Invasive ventilation  Antibiotics (14-21 days or until clinical response achieved)  Bactrim IV  Pentamadine IV or aerosolized  Atovaquone po  Other therapies  Steroids—Hypoxemia, PaO2 < 70, Severe disease  Prophylaxis

37. PCP: COMPLICATIONS  Hypoxemic respiratory failure  ARDS  PTX  Risk for other opportunistic infections

38. SUMMARY  Atypical pneumonias  Mycoplasma  Legionella  Chlamydia  Viral pneumonias  HIV & pneumonia  PCP