Avian Influenza
Einstein Health Glossary
ICD 10 - J09
What is avian influenza?
Avian influenza, also known as bird flu, is caused by subtypes of the influenza A virus. It primarily affects birds and rarely infects humans. Human-to-human transmission is also uncommon. The most frequent form of transmission occurs through direct contact with respiratory secretions, saliva, and feces of infected birds or contaminated environments.
Although avian influenza rarely infects humans, health authorities closely monitor changes in the influenza A virus that could facilitate its transmission among people.
Symptoms
In humans, avian influenza is a viral infection that affects the nose, throat, and lungs—parts of the respiratory system. Symptoms usually appear between one and ten days after exposure to the virus and may resemble a mild flu. Common symptoms include:
Nosebleeds or bleeding gums may also occur. In severe cases, pneumonia and systemic infection (sepsis) may develop.
Types
These types vary in severity and transmissibility and are closely monitored by health authorities.
Diagnosis
Diagnosis is based on symptom analysis and confirmed through laboratory tests using samples of nasal and throat secretions (nasopharyngeal). The test detects the presence of the virus in respiratory secretions. It is important for individuals with symptoms and a history of contact with infected birds to consult an infectious disease specialist or general practitioner for proper diagnosis and treatment.
Treatment
Treatment for avian influenza includes antiviral medications that typically reduce the duration of symptoms and prevent disease progression. Additionally, medications such as antipyretics and analgesics are administered to relieve symptoms. In severe cases, intensive hospital care may be required.
Prevention
Currently, there are no vaccines available to the public against avian influenza. Key preventive measures include avoiding contact with infected birds, not handling dead birds, and ensuring poultry meat and eggs are thoroughly cooked. It is essential for poultry workers and breeders to follow health authority guidelines to minimize the risk of infection.
The first severe human infection with the H5N1 virus was recorded in December 2024 in the United States, in the state of Louisiana. The patient, a 65-year-old man, had contact with sick birds on his rural property. This case highlights the importance of epidemiological surveillance and preventive measures to avoid the spread of the virus.