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Avian Influenza H9N2 in the Middle East Countries

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Influencers "Likes": Husam Bakri
Summary

Avian influenza (AI) is a highly contagious disease caused by type A influenza viruses that are members of the family Orthomyxoviridae in the genus Influenza virus A. Middle East countries have an estimated poultry population of 3 billion broilers, 137 million commercial layers, 30 million breeders, 2x106 layer breeders and 500.000 GP broilers,180.000 GS layers. Since 1999 the region faces different health problems such as drop in egg production, close to peak production: up to 62 % during 2-3 weeks, thin – shelled, rough and misshapen eggs, moderate mortality and respiratory signs in commercial Layer and Breeder production; while in broiler it was noticed severe mortality (over 60% after 3 weeks of age), severe respiratory signs, high percentage of condemnation due to secondary bacterial infections. Different serum and tissues samples were taken from breeders, layers and broilers from different countries and analyzed by serology and virus isolation. The results showed the presence of AI H9N2 virus in the Middle East area combined with IB or ND.; different investigations were done using reduction in mortality and improvement in production as parameters. By using Nobilis Influenza H9N2, the farmers were able to control the economic impact of the infection.

 

Keywords: AIV; Middle East; Nobilis Influenza H9N2 vaccine. 

 

Introduction

The avian influenza virus (AIV) H9N2 subtype was first characterized in 1966 as causing mild respiratory diseases in turkeys (Homme and Easterday, 1970) and, for the first decade after its isolation, was found only in shorebirds and mallards (Kawaoka, et al., 1988). However, after almost 50-years evolution and propagation, the H9N2 viruses have spread across most of the earth, circulating in wild bird and domestic poultry populations worldwide. Although AIV infections commonly result in low mortality in avian populations, in immunosuppressed chickens, recent isolates of H9N2 virus have been associated with high mortality in young chicken and a severe decline in egg production in laying chickens via secondary bacterial infections of the upper respiratory tract and other viruses resulted in significant economic losses of domestic poultry.

 

AI in the Middle East

Estimated poultry population in the Middle East consists of 3 billion broilers, 137 million commercial layers, 30 million breeders, 2 million layer breeders. Since 1999 the region faces different health problems such as drop in egg production, close to peak production: up to 62 % during 2-3 weeks, thin – shelled, rough and misshapen eggs, moderate mortality and respiratory signs in commercial Layer and Breeder production; while in broiler it was noticed severe mortality (over 60% after 3 weeks of age), severe respiratory signs, high percentage of condemnation due to secondary bacterial infections. Thus, it has been believed valuable to find out what is the reason behind above mentioned respiratory problems.

 

Materials and methods

Several field visits to flocks with these clinical signs were performed in Kingdom Saudi Arabia (KSA), Jordan, Syria, Lebanon, United Arab Emirates (UAE), Kuwait, and Yemen. A large number of samples (serum and tissues) have been collected for serological testing and virus isolation. ELISA tests performed for the major respiratory diseases such as IB, ND, AI, TRT, EDS and ILT. Test results showed the presence of AI. So HI test and virus isolation from tissues, kidney, trachea, lung and ceacal tonsils was done to detect and type the strain of AI.

 

Results and discussion

More than 60%, 1790 blood samples showed positive AI antibody response in AGP and Elisa tests. Same sera tested in HI showed positive titers against AI H9 strain, (Figure 1) and IB 4/91(data not shown).

 

From tissues frequently AI H9N2 virus was isolated, (Table 1), and IB serotype 4/91 (793B) also, (data not shown).

 

Figure 1: HI results of Broilers, Breeders and Layers

Table 1: Number of virus isolation samples.

 

Discussion and Conclusion 

Field trials have been conducted in UAE at a farm, where AI H9 was isolated the first time. In this commercial layer farm one house (45,000 birds, Lohmann) was vaccinated. A second house (45,000 birds, Lohmann) was not vaccinated as control. Birds were vaccinated twice with 0.5 ml of the vaccine Nobilis® Influenza H9N2 at 12 weeks and 16 weeks of age. Production and mortality were monitored. (See figure 2). The control flock which showed a severe drop in egg production just before the peak of lay: 62% at 21 weeks of age. No drop in egg production and mortality were observed in the vaccinated flock. Intervet was the first company to introduce Nobilis® Influenza H9N2 in the area after intensive field investigation. Field trials were performed in the most endemic area and showed good protection against clinical signs. Figure 3 showed Production and mortality curves of a breeder flock, infected with AI H9N2, while figure 4 showed the egg quality of during AI problems in a commercial layer farm.

 

 

Figure 2: Results of a field trial with commercial layers in UAE: Production curve of a non-vaccinated flock (Non Vac) and a flock vaccinated with Nobilis Influenza H9N2 at 12 and 16 weeks of age (Vac).

  Figure 3: Production and Mortality curves of a breeder flock, infected with AI H9N2.

All the results from isolation, Elisa and HI tests show that H9N2 is present in the Middle East countries. Most of the governments allowed the use of vaccines containing the antigen H9N2 in order to control the economical impact of the disease.

 

In conclusion: AI H9 virus has a high prevalence in the Middle East region. The vaccine Nobilis® Influenza H9N2 helps the farmers to control the economical impact of the infection.

 

Figure 4: Egg quality during AI problems in a commercial layer farm.

Acknowledgements

  • The author would like to extend his thanks to Animal Health Service Deventer – The Netherlands.
  • Institute of Animal Health, Compton – UK.
  • R&D service laboratory, MSD-International – The Netherlands for their technical help.

 

References

1. HOMME, J. and EASTERDAY, C. (1970) Avian influenza virus infections I Characteristics of influenza A-turkey-Wisconsin-1966 virus. Avian Disease, Vol.14, pp. 66-74.

2. KAWAOKA, Y., CHAMBERS, M., SLADEN, L., and WEBSTER, G. (1988) Is the gene pool of influenza viruses in shorebirds and gulls different from that in wild ducks? Virology, Vol. 163, pp. 247-250.

 
Author/s
Mohamed Swelam
diploma degree
Re: Avian Influenza H9N2 in the Middle East Countries
12/04/2017 |

Dear Dr. Hussam Bakri;
Bases on your experience in the Middle East and avian flu (H9) problems, I would like to inquire about the effect of H9 on production in commercial layer flocks and whether the effect is different according to the age of production.
By the way, is the negative effect of the respiratory vaccination in the presence of H9 has the same response In the sense of the existence of H9 whether the vaccination by using clone or lasota vaccine.

Mustafa Ezat
Veterinary Doctor
Re: Avian Influenza H9N2 in the Middle East Countries
13/04/2017 |

Dear Husam
Thank you for your great effort.
1- What about recombinant vaccination against AI and which best inactivated vaccine or recombinant vaccination?
2- Inactivated vaccine at 7 days need at least 3 weeks to achieve protective immunity and AI influenza field infection in most cases at 18-24 days so may be filed infection come before complete immunity and also if injection at 0 day old chicks will interfere with MDA and delaying seroconversion and immunity what do?

Thanks.

Husam Bakri
record_voice_overHusam Bakri
Veterinary Doctor
Re: Avian Influenza H9N2 in the Middle East Countries
13/04/2017 | Dear Mohammed ,
Yes AI infection is playing a role in respiratory vaccines response. From our experience in the filed the most important point is before the flock comes to the production having good immunity against AI as most of the flock has been infected on the way to peak.

All the best


Bakri
Husam Bakri
record_voice_overHusam Bakri
Veterinary Doctor
Re: Avian Influenza H9N2 in the Middle East Countries
13/04/2017 | Dear Ezat,
1- Recombinant vaccine are good in general not just for AI and it will be future of the vaccines .
2- Yes I agree killed vaccine need time to get immunity from it , but what we can do as we can not use AI live vaccine. As live vaccines in general give fast immunity. That why good biosecurity need to protect birds from early infection not just AI also other diseases .

All the best

Bakri

Dr.muhammad Siddiq
General Manager
Re: Avian Influenza H9N2 in the Middle East Countries
15/04/2017 |

Dear sir, I want to ask you a question, that is there any link with that we have to shake well the killed vaccine vial during vaccinating the birds, for every ten minutes to get good titer. Or shaking the vial homogenized the killed vaccine virus?

Husam Bakri
record_voice_overHusam Bakri
Veterinary Doctor
Re: Avian Influenza H9N2 in the Middle East Countries
16/04/2017 |

Dear Mohammed,
First thank you for your question. Yes shak the killed vaccines is important during the vaccination, but also the most important is the type and quality of adjuvants is playing big role in the antigen distribution that why even if you shak the vaccine during the vaccination frequently you still not getting homoginsity in immune response if the quality of the adjuvant not good.

All the best

Bakri

Re: Avian Influenza H9N2 in the Middle East Countries
16/04/2017 |

Could you please advise the distribution of H9N2 in Middle East countries. Thanks

Mohamed Swelam
diploma degree
Re: Avian Influenza H9N2 in the Middle East Countries
16/04/2017 |

Dr.Hossam; I send you questions related to your post but no answer.

Husam Bakri
record_voice_overHusam Bakri
Veterinary Doctor
Re: Avian Influenza H9N2 in the Middle East Countries
16/04/2017 | Dear Mohamed,
I am sorry the below is my email :
Husam_bakri@hotmail.com
Mobile : 00962795553703

All the best
Husam Bakri
record_voice_overHusam Bakri
Veterinary Doctor
Re: Avian Influenza H9N2 in the Middle East Countries
16/04/2017 |

Dear Dr. Turki,
Hope you are doing well. AI H9N2 is present in most of the Middle East and North Africa countries and most of them using the vaccine to control the disease.

All the best

Bakri

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