Psittacosis
GLOBAL HEALTH ELECTIVE
LEON, NICARAGUA
JUNE 8, 2010
DAVID MING, MD
Case Presentation
 HPI:
 7 year old male p/w dry cough + fevers + fatigue x 2 weeks and
been persistent
 (+) decreased appetite but no chills/NS/wt loss
 Multiple sick contacts – 11 yo brother, father, and 3 other
siblings all with similar acute febrile respiratory illness with
onset around the same time
 Was in usual state of health before presentation
 11 yo brother had been admitted with 8-10 days of similar sx
but also developed SOB/DOE and difficulty with performing
regular activities
Was admitted 3 days earlier and developed fever + hypoxic
respiratory failure in setting of ARDS
Case Presentation
 HPI (continued):

Father (40 yo) admitted 5 days earlier with similar illness but much
milder than 11 yo brother – treated for CAP on ward
 PMHx: unremarkable
 Medications: none
 Immunizations: UTD (including BCG as infant)
 SHx: very rural community outside Leon (El Sauce) –
lives with 6 siblings and parents in small 2 room home
without running water or electricity; multiple animals
in close proximity including chicken, birds, pigs,
dogs, cattle, and rats; no recent disease outbreaks in
the community and no recent travel
Case Presentation
 VS – T 38.5 / P 100 / R 28 / Sat 95-97% RA / 21 kg
 Gen – AxOx3; NAD; comfortable and interactive young








boy in NAD
HEENT – no jaundice or pallor; MMM; OP clear
Neck – supple; no LAD
Lungs – coarse BS bilat; no signs of focal consolidation;
no accessory muscle use
CV – normal
Abd – normal; no HSM; no ascites
Skin – no rash and no jaundice
Ext – 2+ pulses; no edema; nl CR <2 sec
Neuro – non-focal
Case Presentation
12.3
 6 >--------< 517

38.5

 Malaria smear neg
Cl 106 / Cr 0.9 / Glu 90
INR 1.9
LDH 1053
 Ucx/Bcx neg
PPD neg
AFB neg x 3
 AST/ALT: 79 / 70
HIV Ab neg
 Leptospirosis IgM neg
Dengue IgM neg
Admission CXR
Admission CXR – Older Brother
Follow-Up – Comparing the Brothers
Hospital Course
 Persistently febrile 39-40C without any significant




increased WOB, HD changes, or clinical worsening –
overall clinical appearance out of proportion to CXR
findings
Completed 7 days of empiric IV PCN G for possible
leptospirosis without resolution of fever
PPD for admitted 1 1 yo brother and both parents were
negative
Unable to obtain bronch/BAL
11 yo brother who was initially critically ill, eventually
responded with complete resolution of CXR findings ~45 days after receiving ampho B + steroids

Continues to improve but then develops relative bradycardia
Hospital Course
 With patient remaining persistently febrile with atypical
PNA clinical pattern (CXR out of proportion to
essentially normal exam) + older brother with new
relative bradycardia + no other identifiable cause 
attention turned to zoonotic atypical PNA given animal
exposures
 Empically started on clarithromycin for possible
psittacosis + continued on oral fluconazole for possible
histoplasmosis
 Seen in ID clinic 2 weeks post-discharge – both afebrile
on outpatient course of macrolide + fluconazole
 Presumed diagnosis: psittacosis
Our Differential Diagnosis
 “Outbreak” Illnesses
 MTB
 Histoplasmosis
 Leptospirosis with pulmonary hemorrhage
 Hypersensitivity pneumonitis
 H1N1
 Hantavirus
 Cryptococcus
 Atypical Pneumonias
Psittacosis
 Q Fever
 Legionella

Overview
 Introduction/Epidemiology
 Microbiology
 Clinical Features
 Lab Features
 Differentiation from other Atypical Pneumonias
 Diagnostic testing
 Treatment
 Prognosis
Introduction/Epidemiology
 AKA Ornithosis or Parrot Fever
 Birds are major reservoir – any type can be infected
 Infected birds usually asymptomatic but could be sick
 Transmission to humans via inhalation of dried feces or
respiratory secretions or direct bird contact
 History of exposure to birds key to raise suspicion
 Can be sporadic cases or outbreak situations
 Middle-age adults most commonly affected
 Children less commonly develop clinical illness
Microbiology
 Chlamydia psittaci
 Gram negative intracellular bacteria
 Ability to operate intracellularly allows it to evade
host defenses and is rationale for using antibiotics
like tetracyclines and macrolides
Clinical Features
 Symptoms develop over weeks after exposure
 Almost any organ system may be involved
 Pulmonary symptoms tend to be mild initially
 Headache typically a prominent feature

Other common sx include cough, myalgias, fever
 Relative bradycardia may be present
 Disease severity variable - typically mild illness but can cause fulminant
sepsis with multiorgan failure
 Presence/absence of these features neither confirms nor excludes dx
Differentiation from other Atypical Pneumonias
 Atypical PNA account for ~15% of cases of CAP
 Atypical PNA


Pulmonary + Extrapulmonary findings (hepatic/GI, CNS, renal, etc)
Zoonotic vs Non-zoonotic infections
 History key for identifying zoonotic infections – these do
not occur randomly…look for an exposure
 Relative bradycardia classic for Legionella but also may
suggest certain zoonotic atypical PNAs
Differentiation from other Atypical PNAs
Cunha BA, Clin Microbiol Infect 2006;12(S3:12-24)
Lab Features
 Abnormal CXR in up to 80% of patients
 Lobar consolidation common but no pathognomonic findings
 CXR findings may be more dramatic than exam findings
 Liver function test abnormalities common
 No characteristic hematologic pattern described
Diagnostic Testing
 Serology
 4-fold rise in acute and convalescent titers
 Elevated IgM titer
 Culture – very difficult to isolate organism
Treatment
 Doxycycline
 Macrolides (kids, pregnant women)
 Treat for 10-21 days
 Contact a vet and treat the birds
 No need to eliminate birds from the home if they get treated
Prognosis
 Most defervesce within 48 hours after doxycycline
 Capable of causing severe disease with high mortality
if left untreated
References
 Cunha BA. “The Atypical Pneumonias: Clinical Diagnosis
and Importance,” Clin Microbiol Infect, 2006;12(S3):1224.
 Fischer GB, et al. “Histoplasmosis in Children,” Paed
Resp Reviews 2009; 10: 172-177.
 Stewardson AJ. “Psittacosis,” Infect Dis Clin N Am 2010;
24:7-25.
 Vinetz J, et al. “Chlamydia psittaci,” Hopkins On-Line
Abx Guide; www.hopkins-abxguide.org