With the AeroCollect method it is possible to measure Adeno virus in a flock. With the use of a killed vaccine, it is still possible to the collection of air samples to monitor if a wild strain occurs in the flock.
Adenovirus is divided into a further 3 groups of viruses, all of which give rise to different disease in different types of birds.
In this group there are 12 different adenovirus strains that are primarily pathogenic in chickens. These strains are called fowl adenovirus 1-12 (FAdV 1-12). Animals of all ages are susceptible to infection by these virus strains that can infect both vertically and horizontally. That is, chickens may already be infected from the egg hatch if the chicken is infected. When the animal reaches 2-4 weeks of age, it begins to secrete viruses itself with the stool, saliva, urine and other secretions. Viruses can hide latently in the animal and later give rise to disease again and are again excreted to other animals in the herd. In addition, viruses can be transmitted via personnel and other objects in the environment. Symptoms of FAdV vary by specific virus strain, but include liver and heart disease, among others. Some strains cause acute infection and death in young chicks, while other strains result in milder symptoms. However, the mild infections can be exacerbated by prior infection with, for example, gumboro or blue-wing disease, which has weakened the immune system of the animals. Below is a brief description of selected diseases caused by FAdV.
Inclusion body hepatitis (IBH) is a form of hepatitis seen primarily in poultry. As a result of this disease affecting the liver, a sudden death of some individuals in the herd occurs.
Hydropericardium syndrome is believed to be caused by FAdV 4 and causes fluid retention around the animal’s heart, which impairs the pumping capacity of the heart. This disorder is seen more frequently than IBH and causes a much higher mortality rate.
Quail bronchitis is a lung infection in quail caused by FAdV 1. Chickens can carry this infection and thus infect quail. The clinical symptoms are coughing, sneezing, rattle and flooding of the nose and eyes. In acute cases, aqueous diarrhea is also seen. Mortality can be very high in birds under 2 weeks, which is why the disease is of great economic importance to breeders of this type of bird.
Among this group are the viruses that cause the diseases turkey haemorrhagic enteritis and marble spleen disease. These diseases occur in turkeys and pheasants, respectively, where a third disease of avian adenovirus group II splenomegaly causes an exacerbation of spleen in broilers.
Egg drop syndrome ’76 is caused by duck adenovirus 1 (DAdV 1). In addition to ducks, this virus can also infect chickens that may be infected already from the egg if the parent animals have the infection. However, viruses can also be transmitted by horizontal infection, where infected chickens can infect their flocks via the stool. The disease is manifested in laying hens by the production of pale, thin and soft eggshells or partially or completely missing eggshells. In addition, in geese and ducks which are the natural hosts of this virus, coughing and difficulty breathing can be seen as typical symptoms.