The bird flu It is an infectious disease which usually affects birds and is caused by a family virus Orthomyxoviridae the same family as the common flu, points out the Pan American Health Organization (PAHO).
Depending on its subtype, it can be classified as low pathogenicity (that is, it causes severe symptoms in some infected people) or high pathogenicity (it causes mild to severe symptoms in all infections) , the agency reports.
“The low pathogenic avian influenza virus can cause mild pain, which may go unnoticed, without the presence of symptoms. The highly pathogenic virus, mainly caused by subtypes (H5 and H7) of type A, can cause many diseases in birds and spread rapidly, leading to a high rate of death in various species,” said in PAHO.
According to the organization, most influenza viruses circulating in birds are not zoonotic (those from animals and can be transmitted to humans). However, some highly pathogenic strains have the capacity to infect humans and threaten public health.
Avian influenza is a notifiable disease by the World Organization for Animal Health (WHO) because of its ability to infect different types of animals and humans.
In addition to domestic and wild birds, The infection can affect rats, cats, dogs, horses, pigs and other mammals. in general, including those that do not live on land, such as wolves and sea lions, explains the Brazilian Ministry of Agriculture and Livestock on its official website.
The organization promotes that las sea birds and wild are the most common hosts of this type of flu.
However, it emphasizes that certain events, such as fairs or markets for the sale of live birds (or even illegal trafficking), contribute to increasing the possibilities of transmission and genetic recombination between different- other types of avian influenza virus.
According to the Pan-American organization, the most common way the virus enters a territory is through migratory birds. The main risk factor for transmission in humans is direct or indirect contact with infected animals or contaminated environments and surfaces through the feces of these animals.
“Plucking, handling carcasses, and preparing infected birds for consumption, especially in households, can also be risk factors,” explains PAHO.
In humans, the symptoms can be from a mild infection of the upper respiratory tract, which causes fever y cough even severe pneumonia, difficulty breathing (acute respiratory distress syndrome), shock and even death, the entity concluded.