Red eyes, itching, irritation and swelling of the eyelids are among the symptoms most associated with human infection with the Newcastle disease virus. Although it mainly affects birds and rarely causes illness in people, there are scientific records of more serious manifestations, including respiratory and neurological problems.
Disease that is killing birds in Portugal could affect humans
Red eyes, itching, irritation and swelling of the eyelids are among the symptoms most associated with human infection with the Newcastle disease virus. Although it mainly affects birds and rarely causes illness in people, there are...
The virus, highly contagious among birds, has caused deaths in Portugal and has already been detected on different islands in the Autonomous Region of the Azores. Local authorities monitor the spread of the disease and adopt measures to reduce the risk of new outbreaks.
- The General Directorate of Food and Veterinary (DGAV) points to birds as the main hosts.
- Information from the United States Centers for Disease Control and Prevention (CDC) indicates, however, that the agent has also been identified in other animals, such as monkeys, rabbits...
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The virus, highly contagious among birds, has caused deaths in Portugal and has already been detected on different islands in the Autonomous Region of the Azores. Local authorities monitor the spread of the disease and adopt measures to reduce the risk of new outbreaks.
The General Directorate of Food and Veterinary (DGAV) points to birds as the main hosts. Information from the United States Centers for Disease Control and Prevention (CDC) indicates, however, that the agent has also been identified in other animals, such as monkeys, rabbits and pigs.
Recent outbreak hit birds in northern Portugal
A Portuguese study published in 2025 described the circulation of pigeon paramyxovirus type 1, known as PPMV-1 and belonging to genotype VI of avian orthoavulavirus 1.
Earlier that year, an outbreak was recorded at a wildlife rehabilitation center in northern Portugal, with cases involving Turkish doves, domestic doves and pigeons.
According to researchers, birds that developed acute neurological signs died quickly. The work also pointed out that the circulation of the virus represents a threat to populations of domestic and wild birds.
Can Newcastle disease pass to humans?
Newcastle disease is a zoonosis caused by the avian paramyxovirus type
1. Transmission to humans is considered uncommon and is usually related to close contact with infected birds or contaminated materials.
In cases identified in people, ocular manifestations, especially conjunctivitis, appear more frequently. There are also reports of infections without symptoms and respiratory conditions.
Severity may vary depending on the viral strain and circumstances of exposure.
What are the symptoms in humans?
Among the signs most associated with Newcastle disease virus infection are:
redness in the eyes; eye irritation; itching; swelling of the eyelids; conjunctivitis; respiratory symptoms in some cases.
Neurological complications are considered rare. There are, however, isolated scientific reports, including a fatal case of neurological infection caused by PPMV-1 in a child in Australia.
Conditions of this type may involve inflammation of the brain, known as encephalitis, and changes in regions of the nervous system, such as the brain stem and cerebellum.
Among the neurological manifestations described are confusion, altered consciousness, difficulty speaking or swallowing, coordination problems, weakness, paralysis and, in the most severe cases, coma.
How to avoid infection with the virus
DGAV recommends reducing direct contact with birds that show signs of illness or that are found dead, especially wild animals.
People who work with raising, handling or rescuing birds must use appropriate protective equipment, such as gloves, protective glasses and a respiratory mask.
It is also recommended to carefully wash your hands after contact with birds, feces, secretions or equipment used to handle animals.
Another guideline is to avoid touching your eyes, nose or mouth after contact with birds or potentially contaminated materials.
If you experience symptoms after exposure to a suspected infected bird, the recommendation is to seek medical attention. Animals showing signs of the disease should also be isolated to reduce the risk of transmission.
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