Do you have a special liking for poultry? Be careful of "parrot fever" knocking on your door! Here are some tips on how to prevent it~

Experts from Yiyang Central Hospital remind people who have chickens, ducks or birds as pets at home to be careful. In the autumn and winter, they are most likely to suffer from respiratory diseases such as headaches and fever. They thought it was just a common cold, but it never got better. After a few weeks, it became more and more serious. When they went to see a doctor, they were told that the condition was very serious and required hospitalization. This may be psittacosis.

1. What is psittacosis?

It is a highly pathogenic zoonosis. The pathogen of psittacosis is neither bacteria nor virus, but a chlamydia, which is mainly transmitted among birds . Because the disease was first discovered in people who played with parrots, it was named psittacosis. Later, it was discovered that many other birds (such as ducks, pigeons, etc.) besides parrots can carry the disease and it is contagious, so it is also called "bird fever."

Psittacosis has broken out in more than 20 countries around the world, posing a serious threat to human health. According to statistics from the past 10 years, the distribution range of psittacosis chlamydia infection has continued to expand with the activities of the intermediate hosts, and the infection rate has continued to increase.

2. Risk factors for infection with psittacosis

(1) Contact with infected or diseased birds or poultry, and inhalation of environments, feathers, and dust contaminated by secretions or excretions containing bacteria.

(2) Farms, slaughterhouses, down processing plants, poultry markets, bird distribution centers, transfer sites or transportation vehicles, and pigeon training bases that are contaminated by infected or diseased poultry . Bird keepers may be infected when cleaning bird cages, cleaning bird droppings, feeding or petting their birds.

(3) Patients with the disease or carriers . Although human-to-human transmission has been reported, it is rare.

Symptoms of parrot fever

The average incubation period after human infection is 1-2 weeks, and can be up to 45 days. The clinical manifestations of the disease lack specificity. The most common symptoms are fever, chills, muscle aches, and dry coughs . It can manifest as simple pneumonia or pneumonia combined with multiple extrapulmonary system damage. The nervous system is affected by headaches, dizziness, delirium, etc. The digestive system is affected by liver involvement (significant increase in transaminase), hepatosplenomegaly, nausea and vomiting, etc. Severe infection can cause systemic poisoning symptoms, myocarditis, pericarditis, etc., leading to multiple organ failure or even death.

4. Diagnosis of psittacosis

After being inhaled through the respiratory tract, Chlamydia psittaci first invades the respiratory system and can easily cause symptoms of pneumonia.

(1) Imaging examination

Chest X-ray and lung CT examinations are the first choice. Imaging examinations are highly sensitive to pneumonia. Lung CT mainly shows consolidation, with characteristic air bronchograms. Unilateral single-lobe consolidation is common, followed by unilateral multi-lobe consolidation and bilateral multi-lobe consolidation. The extent of consolidation is positively correlated with the severity of the disease. Patients with multi-lobe consolidation have a high risk of respiratory failure, accompanied by pleural effusion, splenomegaly and other manifestations.

(2) Laboratory testing

Through blood analysis, we observe changes in inflammatory indicators, such as increased neutrophil ratio and C-reactive protein, decreased lymphocyte ratio, and multiple organ systemic involvement after infection with psittacosis. Examination of heart and liver function may show a certain degree of decline, leading to increased lactate dehydrogenase and creatine kinase, and significantly reduced albumin. The most advanced mNGS (megagene next-generation sequencing) technology, based on the ompA gene of Chlamydia psittaci, simultaneously sequences all nucleic acid sequences in the specimen, with the highest sensitivity.

(3) Inform medical history

Promptly reporting any history of contact with birds to your doctor is essential for a confirmed diagnosis.

5. How to prevent parrot fever?

For non-professional people, raising birds at home and raising chickens and ducks in captivity are the main ways to be infected with psittacosis. For the health and safety of yourself and your family, a friendly reminder to bird lovers and those who raise poultry in captivity:

(1) Purchase through formal channels and do not bring home birds of unknown origin.

(2) When raising birds, avoid overcrowding . Adjacent bird cages can be separated by partitions to prevent the accumulation of food, feathers, or secretions and excrement, which can cause cross-transmission of diseases between birds.

(3) Bird cages, food cans, water bowls, etc. should be cleaned every day. Before cleaning, wet the surface with water or disinfectant to prevent dust. When handling excrement, personal protection should be taken , and masks and gloves should be worn properly. Wash hands thoroughly with running water and soap after handling.

(4) If you are scratched or bitten by a bird, you need to disinfect and clean the wound promptly and seek medical advice if necessary.

(5) If you find any suspicious symptoms in poultry or birds, please isolate and treat them promptly.

(6) If you develop corresponding clinical symptoms and have a history of exposure to poultry, you should go to the hospital for treatment in time and inform the doctor of the relevant epidemiological history.

References

[1] Chinese expert consensus on the diagnosis and treatment of psittacosis[J]. Chinese Journal of Clinical Infectious Diseases, 2024, 17(3): 191-204.

[2] Epidemiology and prevention of psittacosis[J]. Advances in Veterinary Medicine, 2023, 44(06): 105-110.

[3] Chest HRCT features of severe pneumonia caused by Chlamydia psittaci[J]. Radiological Practice, 2023, 38(05): 571-575.

Hunan Medical Chat Special Author: Cao Jing from Yiyang Central Hospital

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(Edited by YT)