From the Guidelines
Avian Influenza (AI) Definition
Avian influenza, also known as bird flu, is a viral infection that can be transmitted from birds to humans, causing a range of clinical illnesses from mild to severe respiratory diseases, and even death in some cases 1.
Characteristics of Avian Influenza
The infection can be caused by different avian influenza A subtype viruses, including both low pathogenic and highly pathogenic viruses. Highly pathogenic avian influenza A (H5N1) virus, for example, has been associated with severe illness and a high case-fatality proportion of approximately 60% in many countries 1. Human infections with low pathogenic avian influenza viruses have also been reported, with symptoms ranging from conjunctivitis to uncomplicated influenza-like illness (ILI) 1.
Transmission and Prevention
Transmission of avian influenza from birds to humans typically occurs through direct or close unprotected contact with sick or dead birds 1. Preventive measures include:
- Avoiding contact with infected birds
- Washing hands frequently
- Avoiding close contact with anyone diagnosed with bird flu
- Wearing personal protective equipment (PPE) like masks and gloves for those at high risk of exposure
Clinical Manifestation and Treatment
The clinical manifestation of avian influenza in humans can vary, with symptoms including severe lower respiratory illness, multiorgan failure, and in some cases, asymptomatic infection or mild clinical illness 1. Treatment may involve antiviral medications, such as oseltamivir (Tamiflu) or zanamivir (Relenza), and supportive care like rest, hydration, and management of symptoms. In severe cases, hospitalization may be necessary for close monitoring and oxygen therapy if required.
From the Research
Definition of Avian Influenza (AI)
Avian Influenza (AI) is a disease caused by the avian influenza virus, which has a broad host range in birds and mammals, although its natural reservoir is wild birds where it typically causes an asymptomatic to mild infection 2. The virus can cause a range of clinical diseases in poultry and is defined as either low pathogenic AI (LPAI) or highly pathogenic AI (HPAI) depending on the type of disease it causes in chickens 2, 3.
Types of Avian Influenza
- Low pathogenic AI (LPAI): causes mild disease with low mortality in chickens 2, 3
- Highly pathogenic AI (HPAI): causes severe disease with a mortality rate of 75% or greater in experimentally infected chickens 2, 3
Transmission and Host Range
- The virus can be transmitted through inhalation, direct or indirect contact, and can infect a wide range of birds and mammals 4, 5
- The natural host range of the virus is in wild ducks, gulls, and shorebirds, but it can also infect poultry and other domestic birds 6, 5
Public Health Threat
- Avian influenza virus also represents a public health threat, with some infected humans having severe disease and a high case fatality rate 2, 4
- The virus has the potential to spread to humans through close contact with infected birds or contaminated surfaces 4