Transcript ATYPICAL PNEUMONIAS AND BEYOND!!!

ATYPICAL PNEUMONIAS:
THE BASICS
Nilesh Patel, DO
October 8, 2008
St. Joseph’s Regional Medical Center
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?
OBJECTIVES

We will discuss….

Mycoplasma pneumoniae
Legionella sp.
Chlamydia pneumoniae
Chlamydia psittaci
Viral pneumonias
Pneumonia in the setting of HIV/AIDS--PCP





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
ORGANISMS


Mycoplasma pneumonia
Viral pneumonias










RSV
Parainfluenza
Adenovirus
Influenza
Other
Chlamydia pneumonia
Chlamydia psittaci
Legionella pneumophila
Coxiella burnetti (Q fever pneumonia)
Francisella tularensis (Tularemia)
EPIDEMIOLOGY

4 million cases CAP/year

20-60% typical organisms

10-40% atypical organisms

Hard to quantify these organisms
PATHOPHYSIOLOGY
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
MYCOPLASMA: DIAGNOSTICS

CXR





Labs




Consolidation
Patchy infiltrates
Interstitial pattern
Pleural effusion
WBC
Cold agglutinin assays
Other serum assays
Cultures


Blood
Sputum
MYCOPLASMA: TMT

Macrolides




Azithromycin
Erythromycin
Clarithromycin
Doxycycline
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
LEGIONELLA











Natural water habitats
Water distribution systems
Cooling towers
Hot tubs/Spas
Respiratory equipment
Humidifiers
Etc……
Travel
Hotels
Large Events
Floods/Natural Disasters
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
LEGIONELLA: DIAGNOSTICS

CXR—variable





Labs






Consolidation
Patchy infiltrates/Interstitial infiltrates
Pleural effusions
Multi-lobar
CBC, SMA-7 (Hyponatremia, Elevated LFTs, ARF)
CPK
Urine antigen tests
Serum legionella antibodies
PCR
Cultures


Sputum gram stain/culture; DFA sputum
Blood cultures
LEGIONELLA: TMTS

Fluoroquinolones



Macrolides






Levaquin
Avelox
Zithromax
Doxycycline
Bactrim
Rifampin
Extended course
Initial IV therapy
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
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






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







CHLAMYDIA: DIAGNOSTICS

Chlamydia pneumonia




CXR
Cultures
Serologic tests
Chlamydia psitacci



CXR
Cultures
Serologic tests
CHLAMYDIA: TMTS

Chlamydia pneumoniae




Doxycycline/Tetracycline
Macrolides (Zithromax, Clarithromycin, E-mycin)
Quinolones (Avelox, Levaquin)
Chlamydia psitacci


Doxycycline/Tetracycline
Macrolides (Zithromax, E-mycin)
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
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
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
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
PCP: CLINICAL SYMPTOMS

Symptoms






SOB (exertional)
Cough
Fevers
Constitutional symptoms
Chest pain
Signs





Tachypnea/Fever/Tachycardia
Rales/RhonchiWheezing
Cachexia
Lymphadenopathy
Cyanosis
PCP: DIAGNOSTICS

Labs




CBC, SMA-7
LDH
ABG
Imaging

CXR—variable


CT scan




Normal>>Diffuse b/l infiltrates>>Perihilar infiltrates>>PTX
Diffuse b/l infiltrates>>Ground glass appearance>>Cysts
Sputum culture
BAL
Complication—PTX!
PCP: TMT

Supportive treatments



Antibiotics (14-21 days or until clinical response
achieved)




Bactrim IV
Pentamadine IV or aerosolized
Atovaquone po
Other therapies


Oxygen
Noninvasive/Invasive ventilation
Steroids—Hypoxemia, PaO2 < 70, Severe disease
Prophylaxis
PCP: COMPLICATIONS

Hypoxemic respiratory failure

ARDS

PTX

Risk for other opportunistic infections
SUMMARY

Atypical pneumonias

Mycoplasma

Legionella

Chlamydia

Viral pneumonias

HIV & pneumonia
PCP
