A 61-year old man was admitted feeling generally unwell. It was peak flu season and he was admitted with a 1-week history of flu like symptoms, developing a fever, productive cough, malaise, breathlessness and episodes of forgetfulness . He had no other significant past medical history.
On admission, he was hemodynamically stable with a GCS of 15. chest X-rays and CT scan showed a right middle lobe and left lower lobe consolidation .He also had an acute kidney injury Other routine investigations were unremarkable. Shortly after admission, he became increasingly drowsy, irritable and confused with his GCS deteriorating to 11. Oxygen requirements continued to rise, He was managed in ICU with high flow oxygen and intermittent Non-invasive ventilation (NIV). On the third day, he suffered a full tonic-clonic seizure which self-terminated.
During his stay in ICU it became known that he was a hobbyist bird-keeper. He kept several species of birds including: Cockatiel, Parrolet, Kakareki, Turquisine, Budgie, Canary, Bengalese finch, Diamond doves, love-birds, Chickens and Red rump parrots. Two of these birds had unexpectedly died very recently since the patient’s admission
Management : He was initially started on broad-spectrum antibiotics, Ertepenem and Clarithromycin (given the potential penicillin allergy) and Oseltamivir. Once Influenzae virus infection was excluded and the diagnosis of Psittacosis was more likely, he was treated with Ceftriaxone, Acyclovir and Doxycycline. Once C Psittaci was detected in the sputum sample, Doxycycline was continued as the sole antimicrobial agent for three weeks. The patient recovered well, suffering no further convulsions. .
Sputum: Chlamydia psittaci DNA detected by PCR.
Serology: Positive for antibody to Chlamydia psittaci at a titer of 1 in 128.
Microscopy of CSF: Moderate (118 x 106) lymphocytosis of 83%., RBC 90 x 106, No organism seen on Gram staining.
Biochemistry of CSF: Protein raised at 0.93(units required), glucose 4.3( units required), CMV < 180 copies per ml.
PCR tests on CSF: Negative for, HSV, VZV and enterovirus.
Psittacosis, also known as parrot fever and ornithosis, is a rare cause of pneumonia in humans who are exposed to infected birds. It is caused by an infection with Chlamidophilia Psittacai, which is an obligate intracellular organism 1,2. It is a known risk for pet bird owners, zoo and pet shop workers/visitors poultry farmers as well as veterinarians. Transmission is through the inhalation of aerosolized bacteria from the faeces, feather dust or respiratory secretions of infected birds. Human to human transmission is extremely rare.
Psittacosis is a systemic infection but patients classically present as a CAP and up to 70% have flu-like symptoms. Symptoms can range from mild coryzal symptoms to severe respiratory failure and meningio-encephalitis. Dermatological manifestations include a facial macular rash (Horder’s spots).
Other end-organ complications such as endocarditis, renal disease, myocarditis, hepatitis, kerato-conjunctivitis, arthritis, and encephalitis have also been described . Laboratory diagnosis is usually by serological methods, though rapid molecular tests are available in some centers. Culture of this hazardous organism is not attempted in any UK diagnostic laboratories.
Reporting of psittacosis is uncommon in the literature. An observational study in Holland of 147 patients admitted with CAP found 4.8% had laboratory evidence of psittacosis 3.
Following a large outbreak of community-acquired psittacosis in 2002 in residents of the Blue Mountains, New South Wales, Australia, a review of new cases in this area over a 7-year period from 2003 to 2009 was undertaken4. 48 patients met the diagnosis of psittacosis. 60% patients had no direct contact with birds. Lawn-mowing without the use of grass catcher was suggested as one of the risk factors .