In an alert bulletin published on Tuesday, the WHO is concerned about an “increase in psittacosis cases seen in 2023 and early 2024” and “particularly marked since November”.
What is psittacosis?
This is a respiratory infection called bacteria chlamydophila psittaci (C. psittaci), which mostly infect birds, both wild and domestic: 450 species have been identified as likely to infect humans.
The disease does not cause the appearance of any visible clinical signs in birds. Vs. psittaci It is also associated with various species of mammals, including dogs, cats, horses, pigs, and ruminants as well as reptiles. And it can infect humans.
How does it spread?
Humans are primarily contaminated by birds, often through direct contact, airborne particles from respiratory secretions, dried excrement, or inhalation of dust from bird feathers.
Among the people most at risk are poultry farmers, veterinarians, pet bird owners, gardeners, etc. Psittacosis is known as an occupational disease. According to the WHO, “the possibility of human-to-human transmission of the disease is low.”
Is it a serious illness?
In most cases, according to the WHO, psittacosis is benign: it is characterized by flu-like symptoms (fever and chills, headache, muscle pain and dry cough). Therefore only one specific test can be formally recognized. The first symptoms appear 5 to 14 days after exposure to the bacteria.
Prompt administration of the appropriate antibiotic (tetracycline) usually avoids complications and limits the risk of death to 1% of patients. But otherwise, respiratory complications (severe atypical pneumonia) or not (cardiac, neurological, hepatic, renal damage, etc.) can lead to the death of the patient.
How many cases and where?
Psittacosis is a surveillance animal disease, requiring mandatory notification in the countries concerned. During 2023 and the first months of 2024, several dozen cases were reported in at least five countries, an “unusual and unexpected increase” according to the WHO.
In detail, Austria announced 14 new cases in 2023 and four new cases in early 2024. In Denmark, 23 people were diagnosed between the end of 2023 and 27 February: 17 patients were hospitalized and 15 of them developed pneumonia. . Four of these patients did not survive. Five more cases were reported in Germany in 2023 between February 14 and 20. Almost all patients suffered from pneumonia. Sweden reported seven cases in November 2023, 19 in December, 10 in January and three in February.
Finally, of the 21 people registered in the Netherlands between December 2023 and February (double the normal figure), one died. No common source of infection has been identified. All recent cases have been hospitalized. Patients ranged in age from 37 to 86 years (mean age: 67 years), and 76% of them were men (16 cases). Six reported contact with wild bird droppings, seven had contact with domestic bird droppings, and eight reported no contact with birds.
For the moment, no cases have been found in France.
What does WHO recommend?
The organization believes the risk of spread to other countries is low, although it does not rule out the possibility of contaminated wild birds crossing borders. She makes sure to closely monitor epidemiological investigations linked to samples taken from patients. WHO asks doctors to be vigilant and advises people in contact with birds to maintain impeccable hygiene.
