Evaluation of the presence of avian influenza receptors in oviducts of forced moulting birds using immunofluorescence

Good idea for partial vaccinated birds if no immunity the birds shall be high mortality

In the case of IA H7N3 of high pathogenicity the important thing was not mortality, it was the affectation to the reproductive system of the hen. The hens did not die but the oviduct was affected and production was never recovered.

I want to clarify my previous message.
When the first outbreaks of AI occurred in my country the mortalities reached 100%. Given the situation, the use of emulsified vaccines was authorized, which stopped the mortality but we had to face a fall in production, which never recovered. Dr. Ramon Lopez, expert in egg production, gave the indication of pelechar and the surprise was that the birds continued to become infected and did not die but there was no problem in egg production, we assumed what happened but we checked with immunofluorescence and the results are those that we present in the article. At present, these managements continue, the buds are partially controlled but now it is the periods of pelecha that affect the production, we are looking for alternatives to stop having unproductive flocks for so long.

Avian influenza is endemic in many countries. Without knowing the type of AI virus use of prophylactic vaccination against is prohibited since vaccination against AI does not causes sterilizing immunity. Sterilizing immunity means a vaccinated bird, if exposed to infection there should not be development of virulant virus I vaccinated flock. But in case of AI in vaccinated bird exposed to infection will lead to multiplication of virulant virus without showing clinical signs and the disease will become endemic. Before vaccination type of AI virus should be assessed. Elevated biosecurity covering feed water and environment is need of the hour. Under field conditions by clinical signs and pm lesions, prevalence AI infection can be assessed- refer atlas of avian diseases Cornell University. Further under field level prevalence of AI can be confirmed by means of screening pancreas. Examine pancreas after centrifugation of pancreas extract at 5000 rpm to produce bacteria free pancreatic extract. Do ha. If extract is positive for haemo agglutination[ha] then neutralize the extract with known new castle disease anti serum and repeat ha. Even in the presence of ND antiserum pancreas sample shows ha activity then the sample is positive for AI. On the other hand, if the sample shows inhibition it means the sample is positive for newcastle disease. As per Alexander, father of AI bacteria free filtrate howig ha activity no neutralised by ND antiserum is onl orthomixo virus and not paro mixovirus. Use only food grade chemosterilant- chlorine dioxide/acidified sodium chlorite for biosecurity against AI. LPAI is low pathogenic only in spf and not in commercial. Present problem is AI is exacerbated by bacterial agents. Feed is more often contaminated. Use of food-grade chemosterilant is a must. By elevated biosecurity covering feed water and environment vaccination after assessment, if type of AI virus is necessary for control of AI under field condition.

Control of LPAI,
Incidence of ai prior to 2005 was one outbreak for every 2 years. Present scenario is 2 outbreak per day. Over 2000 years free-living birds were harboring AI virus as carrier and source of infection to poultry. Since 2005 first incidence of AI among free-living birds was confirmed in quigai lake 700 km from Himalayan ranges. So-called LPAI can cause mortality even >90 % due to exacerbation by bacterial and viral infections. Under field conditions, there is wide prevalence of vancomycin-resistant staphylococci in litter and over carcass in processing plant. Similarly, in broiler processing plant there is wide prevalence of e.Coli o157. Further, there are multiple sero types of AI. No combined vaccine for all AI viruses. There are about 23 feed ingredients in poultry feed. On micro biological examination, most of the ingrediants are contaminated.

Over 40 years control of AI is carried out by vaccination after assessment of ai virus. No destruction or compensation. In USA and other countries type of AI virus is made available in a matter of hours. Without elevated biosecurity no control of ai. Selection of agents for bio security is chlorine di oxide/acidified sodium chlorite and per acetic acid which are food grade chemosterilants approved by national and international agencies. As on date clo2/asc are the most power full germicidal agent including viruses. At Namakkal commercial poultry farmer with 5 lkhs birds is able to maintain weekly mortality <0.05 percent per week and production drop < 1 to 2 % of standars. As such with elevated biosecurity of feed water and environment is essential. In such conditions, evaluation of the presence of AI receptors in oviducts of forced moulting birds using immuno fluorescence will be additional advantage. When infecting virus is present in free-living birds and infection spread by air a comprehensive mode of control is need of the hour.
a.T.Venugopalan/31-5-19

This H7N3 virus produces a great reaction of the tissues infected that produce abnormal levels of TNF, this citoquine may change all the metabolism in the bird that increases mortality by hipovolemian shock. When the "pelecha" is applied the production of TNF decrease and bird recover opportunities to live if serum titles (because of vaccination) are enough.

Thanks for sharing your information about AI and moulting effect. When the high pathogenic AI is prevalent in an area we see two different outcomes in pullet and layer. In pullet farms, the rate of morbidity and mortality is much slower than layer farms in production, and it seems it
is because of slower infection and shedding of agent. The important difference between these two (pullet and hens in production) is only not functional oviduct in pullets, it was suspected by many that oviduct plays important role in infection and shedding of AI and your research confirms it, but because we do stamping out of all infected flocks we never saw the outcome of its effect on production rate after recovery from disease. Again, information in this aspect is also new for me.

My experience is about many flocks of pullet and layer that were not vaccinated against AI.

For AI prophylactic vaccination is prohibited. AI vaccination does not cause sterilizing immunity. Sterilizing immunity means vaccinated birds on exposure to infection naturally or artificially there should not be development of virulent virus in vaccinated host. On the contrary, in case of AI vaccination, there will be active multiplication of virulent virus in vaccinated host without showing clinical signs. Such infected birds are likely to spread the disease to other age groups in the same flock and neighboring flock and the disease will become endemic. Vaccination is feasible only after identification of the type in the farm as well as in the area. Further in case of low pathogenic influenza due to exacerbation by bacterial and viral agents it can cause mortality even >90%. Over 2000 years free living birds were horbourng virus as carriers. Since 2005 free living birds are infected and dying. Indian scenario is poultry is not covered by any central or state animal health laws. Notification on AI is issued under act 9 of 1898. Prompt diagnosis/elevated IO security covering feed/water and environment is need of the hour.

Since October 2018, a new form of LPAI is present in Karnataka/Andhra and Tamil Nadu. Clinical signs of comb/wattles/shank are absent/congestion and bleaching of breast muscle is also not seen. But cloacal lesion typical of AI are present. On pm streaks of haemorrhages typical of AI are seen. Pancreas of such cases are positive for AI as per ha hi test. Weekly mortality is >0.2%.

Screening of kidney shows positive for IB/water sanitation/feed sanitation/environmental sanitation are very poor. Litter is positive for vancomycin resistant staphylococci/broiler carcass swab are wide of e.Coli by screening test that is material inoculated in two tubes of teepol broth one incubated at 37 degrees and another at 44.5 degrees c. Tube at 37 degrees, as well as 44.5 degrees, are positive means the sample is e.Coli.

On the contrary tube at 37 degrees c alone positive means the sample is coliforms. My contention is without elevated level of biosecurity covering feed/water/environment it is not feasible to control AI. So-called LPAI can cause mortality even >90 % due to exacerbation by bacterial and viral agents. After implementing biosecurity and weekly mortality >0.1% per week the immuno prophylaxis will be an adjunt.

Present indian scenerio is no prompt diagnosis/no official veterinarian/no animal health laws covering poultry over 108 years/international veterinary certificate signed by non veterinarian/no proper disease reporting such as IB not prevalent in India. As per OIE report bhopal confirmed AI cases mortality >o.01%. Prevalence of h4 in India was reported only by USA. AI prevalence is spoted by dipstic elisa in other countries. Without costly biosafety measures formalin fixed smears are examined for AI and the result is made available in a matter of hours. In USA and other countries type of AI virus infecting the farm is identified 0.7 the farm should be closed. Rdvk and r2b vaccine used in India the ICPI value is 1.4. All vaccine produced in India are produced in India as per indian pharmacopia except ND killed vaccine, which is produced as per british pharmacopia. Use of commercial eggs for vaccine production is the indian scenerio. The ICPI value of seed material should be zero or near o but in India Lasota ND vaccine with ICPI value 0.4 is used as vaccine. Without correcting these basic abnormalities use of immuno prophlaxis alone will be a failure.

Athangudi thanks for your comments, it is very interesting. Regards

Regarding vaccination, much has been learnt in Mexico. The most important is the following:

a) The best vaccination strategy is to use a Prime Boost Strategy (Prime with a live vectored vaccine at day of age, most widely used in Mexico is using a Pox vectored vaccine and boost with a killed vaccine applied at the farm at 10-12 days of age to decrease the neutralization of MABs from progeny coming from vaccinated breeders).
b) The live vectored vaccine seems to deliver a broader immunity and not need the update of the protein expressed with such frequency as killed vaccines.
c) Killed vaccines should be able to elicit high levels of antibodies expressing an updated vaccinal strain (either killed LPAIV or reverse genetics). Mexican experience shows the updated frequency is 1 year upon antigenic drift.
d) The industry is seeking to offer vaccines that provide with broader antigenicity. An example is Baculovirus expression along with specific genetic manipulation that enhances the antigenicity.

Is there combined vaccine-h5/h7/h9 for AI, how to predict which strain is going to infect the particular flock? Further vaccination against AI does not causes sterilising immunity. Sterilizing immunity means -vaccinated birds exposed to infection there should not be active multiplcation of virulent virus in vaccinated flock. But in case of ai vaccinated birds exposed to infection there will be active multiplication of virulant virus without clinical signs. Such infected birds will be a source of infection to other age group in the same farm and neighbouring farms. Disease will become endemic. In Vietnam, 100% vaccination was done. Highest no of world outbreak was recorded only in Vietnam. Present scenario-freeliving birds which were carriers are infected. Lpai are exacerbated by bacterial and viral agents. Most of feed ingredients are contaminated. Vancomycin resistant staphylo cocciis widely prevalent. Prevalence of e.Coli o157 among poultry is also seen.At present in tamil nadu/andhra/karnataka typical cloacal lesions of ai is seen. Prompt diagnosis and vaccination after identification of the if AI virus and elevated level of biosecurity covering feed water and environment is need of the hour.

Present field scenario is low pathogenic avian influenza exacerbated by bacterial and viral agents. Typical lesions of ai-cloacal lesions and streaks of haemorrhage in rectum are seen. This type of problem is seen among broilers in Tamil Nadu/Andhra and Karnataka. Mortality among commercial broilers is even >20 percent with in 6 weeks. Use of Lasota ND vaccine exacerbates LPAI. ND vaccine[killed vaccine] is produced as per British pharmacopia that is by use of commercial eggs in place of spf.Nephro pathogenic ib is endemic since 1995. Use of ib vaccine ma5 and 4/91 is a must. Since there is no official report of ib in India import of ib vaccine 4/91 is not feasible. Prompt diagnosis is the first step in control. First report of h9 in India was not done by bhopal. As such prompt diagnosis and use of elevated biosecurity covering feed water and enviornment is essential. After implementation of these basic measures use of immuno prophylaxis will be useful