Veterinary authorities in Bulgaria have called for culling of nearly 8,000 ducks according to a food safety agency yesterday after two more regions there have reported avian flu infection. According to the agency a total of four outbreaks of bird flu have been registered in Bulgaria at this time.
The ducks were all culled following an outbreak in a farm in the southern village of Zimnitsa in Yambol region. Other susceptible animals on the farm and in the neighborhood also had to be put down to prevent the spread of the highly virulent infection. Glushnik in the southern region of Sliven also reported an outbreak meanwhile. Only last month two more outbreaks were reported from a farm in the village of Stefanovo in the northeastern region of Dobric and in the yard in Uzundzhovo in the southern region of Haskovo.
Bird flu (Avian influenza)
Bird flu or avian influenza is a highly contagious viral infection that is transmitted between birds and on rare occasions, from birds to humans. This comes in several varieties. Most important of these are the H5N1 virus, which was found to infect humans in 1997 and the H7N9 virus which infected humans in 2013.
Although these viruses are not usually spread between humans, they have claimed the lives of a number of people. Other strains of the bird flu virus that can infect humans include H7N7 and H9N2, although these strains do not usually cause severe illness.
The H5N1 virus affects a wide variety of bird species including chickens, ducks, geese and turkeys. It can be passed between commercial, wild and pet birds. Birds do not always develop symptoms of infection, so seemingly healthy birds may still pose a risk to people who come into contact with them.
Humans are unlikely to transmit bird flu unless they have been in contact with birds from an area where there has been an outbreak of the infection. The birds can spread the virus to other birds through their droppings, nasal secretion and saliva. This can occur if direct contact is made with these bodily secretions or if contact is made with contaminated surfaces.
As with other forms of flu, bird flu is typically gives rise to symptoms such as –
- a high fever
- muscle pain
- a runny nose and
- a cough. People who develop a cough generally go on to develop more severe respiratory symptoms such as pneumonia or acute respiratory distress syndrome.
- Serious respiratory problems can lead to respiratory failure and require mechanical ventilation.
- Other symptoms include diarrhea, nausea, vomiting, chest pain, abdominal pain and bleeding from the nose and gums.
Symptoms generally appear within a week after exposure and can last for up to a week.
The bird flu virus evolves very fast and thus development of a vaccine against this virus is a challenge. Each year a vaccine is developed to combat the outbreaks.
One well-known drug that has been used to protect against H5N1 is oseltamivir, which is marketed by Roche as Tamiflu. Oseltamivir can prevent the spread of the bird flu virus within the body. Another drug being used is zanamivir brand name Relenza, that can protect against H5N1, H9N2 and H6N1.
Good hygiene including hand washing, covering mouth and nose while coughing and sneezing, adequate disposal of tissues after use and routine vaccination among vulnerable population can prevent this infection. Persons with the infection are barred from cross country travel or travelling abroad. Live farms and live animal market visits should be avoided if visiting an area where a bird flu outbreak has occurred.