Rare case of ‘parrot fever’ sickens English bird-keeper

Issue: October 2016

A man in England who kept many pet birds was sickened by a rare case of psittacosis, also known as “parrot fever,” according to researchers.

The sometimes deadly respiratory infection has symptoms similar to influenza and can be mistakenly diagnosed as community-acquired pneumonia (CAP). It is likely underreported, but should be considered in patients who have been exposed to birds, Anne-Marie Ionescu, MBBS, junior doctor in training at University Hospitals Coventry, United Kingdom, and colleagues said.

“Our patient did not succumb to his infection, but it was a real possibility when he required respiratory support on the intensive care unit and was developing further neurological complications as a result of the infection,” Ionescu told Infectious Disease News.

In this case, the patient had been experiencing flu-like symptoms for 1 week during a period of increased influenza activity, and initial clinical findings suggested CAP and meningoencephalitis, according to Ionescu and colleagues.

The correct diagnosis of psittacosis was made after it was discovered that the patient kept about 12 species of birds as a hobby, and that two of them recently had died.

“Our case demonstrates the importance of considering other potential causes of atypical pneumonia during the peak season for influenza by obtaining a detailed clinical history,” Ionescu and colleagues wrote in BMJ Case Reports.

Litany of symptoms

When the patient, aged 61 years, was admitted to the hospital, he already had completed a course of amoxicillin and had symptoms including fever, productive cough, malaise, breathlessness and episodes of forgetfulness, Ionescu and colleagues reported. He had no significant medical history, had not traveled recently and did not have diarrhea.

Early on he developed a fever, became increasingly drowsy, irritable and confused and his Glasgow Coma Scale score dropped to 11, according to the report. Later, his oxygen requirements rose, and he had frequent bouts of confusion. On the third day, he suffered a convulsion in the ICU with a full tonic-clonic seizure.

Figure 1. A man in England who kept several species of birds, including cockatiel, was diagnosed with a rare case of parrot fever.

Source: Shutterstock.com

Once psittacosis was suspected, the patient’s treatment — initially broad-spectrum antibiotics — was adjusted to include ceftriaxone, acyclovir and doxycycline, after which he improved markedly in the next 24 hours, the investigators reported.

Tests ruled out influenza A and B virus and other ailments. After the patient’s sputum tested positive for Chlamydia psittaci via PCR, he was prescribed doxycycline as a sole antibiotic and recovered well, they said.

Social history can prevent death

Psittacosis is a known risk for pet bird owners, poultry farmers, veterinarians and people who work in or visit zoos or pet shops, according to the researchers. Humans are infected by inhaling aerosolized C. psittaci bacteria from the feces, feather dust or respiratory secretions of infected birds, they wrote.

Fewer than 10 cases are reported annually in the United States, according to the CDC, while England and Wales see approximately 50 confirmed cases each year, Ionescu and colleagues said.

Human infection often resembles CAP, while birds may present with symptoms including lack of appetite, weight loss, difficulty breathing, watery green droppings, pink eyes, discharge from the eyes or nose, or sudden death, according to the report.

Ionescu told Infectious Disease News that clinicians should be reminded that there are other, rarer causes of pneumonia that will not respond to traditional first-line antibiotics, and that taking a good social history can prevent death in an otherwise treatable infection.

Bird species kept by the man included cockatiel, parrotlet, kakareki, turquisine, budgie, canary, Bengalese finch, diamond doves, lovebirds, chickens and red rump parrots, according to Ionescu and colleagues. The report did not specify which birds had died, and Ionescu said it was unclear if the man’s wife took them to a veterinarian to be investigated, as was recommended.

“We are not sure which of the birds were likely the primary source of the infection,” Ionescu said. “It is likely there was one infected bird originally, which then spread to the other and also to our patient.” – by Gerard Gallagher

Reference:

Ionescu A-M, et al. BMJ Case Rep. 2016;doi:10.1136/bcr-2016-216879.

Disclosure: The researchers report no relevant financial disclosures.