Most people involved in the current parrot fever outbreak developed the disease after being exposed to infected wild or pet birds, the WHO said.
An outbreak of a respiratory infection that most often affects birds has killed five people in Europe, the World Health Organization (WHO) warns.
During 2023 and the start of 2024, Austria, Denmark, Germany, Sweden and the Netherlands have reported an "unusual and unexpected increase" in cases of so-called parrot fever, beyond what's been seen in previous years, the WHO said in a statement Tuesday (March 5). In all, the illness has affected almost 90 people, with five deaths reported among them.
Parrot fever, or psittacosis, is caused by a species of bacteria called Chlamydia psittaci (also spelled Chlamydophila psittaci). The bacteria can infect many mammals — including dogs, cats and horses — but most often infects birds.
Humans can catch psittacosis by inhaling airborne particles containing C. psittaci, but human-to-human transmission of the disease is very rare, with only a handful of cases ever reported. Instead, most people develop psittacosis by inhaling particles that waft from the breath, poop or feather dust of infected birds, especially pets such as parrots, finches or canaries.
The disease is thus more common in people who come into close contact with birds — such as poultry workers, veterinarians and pet-bird owners.
That said, C. psittaci infection is possible without having direct contact with birds, and there's no evidence that the bacteria can be spread by preparing or eating poultry.
Appropriate treatment with antibiotics can reduce the death rate of psittacosis from between 15% and 20% to just 1%.
The five countries affected by the current psittacosis uptick have reported far more cases than usual. Some of these cases were suspected, based on symptoms, and others were confirmed with various diagnostic tests. Notably, most cases involved contact with infected wild or pet birds. But in some cases, recent contact with birds wasn't reported at all.
