Fowl Adenovirus（FAdV）

The basic information of the avian adenovirus (FADV)

Fowl Adenovirus (FAdV) is a common infectious disease of poultry and wild birds worldwide. The virus infection after onset of fast, high case fatality rate, easy to trigger a mixed infection, to poultry, bring huge economic losses. The classified method of fowl adenovirus has updated recently, now it can be divided into three: avian adenovirus, salivary glands virus genus, thymus gland, corresponding to the original classification method of I, II, III group. And subdivided into five species of genus avian adenovirus (A, B, C, D, E), serotype 12 (type 1 to 11, of which 8 are divided into 8 A, 8 B two type), its kind of corresponding relation is: (1), B (5), C (4, 10), D (2, 3, 9, 11) and E (6, 7, 8 A, 8 B).

The spread of avian adenovirus and prevention and control

Avian adenovirus can spread through the horizontal distribution and vertical spread of two ways. Horizontal transmission mainly through the digestive tract and respiratory tract infection, vertical transmission is through the eggs. In China, the popularity of fowl adenovirus presented seasonal, although in the past mainly happens in September 7 - high temperature season, but also have happened nearly two years of the cold season, seasonal is not obvious. Main popular serotype C - 4-11, E, D - 8 a, 8 b E -, different regions or at the same time there are several different serum type. Flocks infected with serotype specific may appear after the specificity of the clinical symptoms or recessive infection, poisoned cause disease chicken and chicken continues to pollute the environment.

In order to prevent and control avian adenovirus, from the two aspects of biological vaccine safety and prevention. Strictly control the introduction, not imported from avian adenovirus the epidemic area, shang poultry seedling, select avian adenovirus sensitive disinfectant as strengthening foreign vehicles, inner environment of disinfection measures. In addition, the vaccination is important, control strategy, need to choose according to poultry breed frequency multivalent vaccines and immunization, both kinds of immune and generations.

The research progress of fowl adenovirus

In recent years, the research of avian adenovirus has made some progress. For example, research has successfully built a fowl adenovirus type 4 Fiber - 2 serum protein expression in pichia in optimizing the system, and analyzed the immunogenicity. Studies have found that by the optimized pichia expression of the preparation of Fiber - 2 protein subunit vaccine immunization chicks, can induce a higher level of antibodies and provide as much as 100% of super FAdV - 4 strains (GD616) attack protection.

Conclusions

Avian adenovirus is a serious threat to the poultry industry, and its prevention and control requires a combination of biosecurity measures and vaccination strategies. With the progress of scientific technology, the future is expected to develop more effective prevention and control measures and vaccines, to reduce the effect of fowl adenovirus to poultry industry.

What are the main routes of transmission of avian adenovirus included?

The main routes of transmission of avian adenovirus include the following:

1. Respiratory spread: avian adenovirus can be transmitted by respiratory droplets, when infected people cough, sneeze or speak, will contain virus droplets spread in the air, others after inhaling these droplets may be infected with avian adenovirus.
2. Contact: avian adenovirus can through direct contact with secretions from an infected blood, body fluids, such as transmission, can also be spread by contact with infected pollution of the surface of the object or.
3. The fecal-oral transmission: avian adenovirus can spread through infected droppings, if life diet, poor hygiene, easy to cause the fecal-oral transmission. Food, for example, are infected fecal contamination or pollution of drinking water sources, the avian adenovirus could lead to others.

In order to prevent the transmission of avian adenovirus, it is necessary to maintain good personal hygiene, such as frequent hand washing, food safety, and avoid close contact with infected people. If avian adenovirus infection symptoms, should be timely medical treatment.

Recent changes in the classification of avian adenoviruses

Avian adenovirus is a kind of pathogens that have a significant impact on birds and their classification system and constantly updated along with the development of scientific research. According to the latest research progress of fowl adenovirus can according to the characteristics of molecular structure is divided into five kinds, respectively is A, B, C, D and E. And according to the serum cross neutralization reaction, it can be divided into 12 serotype (FAdVs 1 ~ 7, 8 a, 8 b, 9 ~ 11).

In recent years, the avian adenovirus infection showed a trend of global growth, especially in China, the main popular serotype FAdVs including FAdV - 4, 8 a, 8 b, and 11. The serotype with infectious bronchitis (IBH) and pericardial effusion syndrome (HPS). Mainly related to the HPS FAdV - 4, for example, while FAdV - 2, 8 a, 8 b, and 11 are associated with IBH.

In addition, the pathogenicity of fowl adenovirus studies have also made some progress. FAdV - 11 of SPF chicken embryo, for example, most lethal, whereas FAdV - 4 HPS is the main pathogen. Vertical transmission is thought to be important biological characteristics of fowl adenovirus, but different serotype of the virus pathogenic difference of chicken embryos.

Due to the classification of fowl adenovirus and pathogenic research is still in development, it is recommended that you pay attention to the latest scientific research achievements and the classification of the official standard, in order to obtain the most accurate information.

Avian adenovirus vaccination strategy overview

Avian adenovirus vaccination strategy involves different types of vaccines, including inactivated vaccine, attenuated vaccine, subunit vaccine, synthetic vaccine and genetic engineering vaccine. The choice of these vaccines and vaccination programs often according to poultry breed, age, local disease prevalence and the characteristics of the vaccine to decide.

Vaccination program

1. Chicks: normally in the age of 1 marek's disease vaccine, 7 to 10 days of age Newcastle disease infectious bronchitis duplex seedlings inoculated, the age of 14, bursal disease vaccine, the age of 21, Newcastle disease infectious bronchitis duplex seedlings inoculated.
2. Breeding chickens: 60 to 70 days of age Newcastle disease infectious bronchitis duplex seedlings inoculated, between 90 and 100 days of age to be vaccinated against bird flu.
3. Layer chicken: open prenatal Newcastle disease infectious bronchitis duplex seedlings inoculated, a bird flu vaccine every six months.
4. Chicken: according to the growth cycle and epidemic diseases, timely vaccination Newcastle disease, infectious bronchitis, bursal disease vaccine.

Matters needing attention

1. Vaccine storage: should be under the specified temperature storage, avoid heat and direct sunlight and freeze.
2. Check: vaccination before to check if there is a crack vaccine bottles and sealing closely, vaccines have the phenomenon such as precipitation, color, odor.
3. Disinfection: vaccination used equipment (such as needles, syringes, etc.) should be strictly sterilized, avoid cross infection.
4. Inoculation methods: to choose the right means of inoculation, depending on the type of vaccine, such as injection, dripping nose, eye, etc.

conclusion

Avian adenovirus vaccination strategy is a process of a comprehensive consideration of various factors, aimed at raising poultry through vaccination, immunity, reduce the happening of the disease. The correct procedures and precautions to ensure that immunization effect is crucial.