Objective and the Methodology of the Study Multicentric
the Egyptian and foreign experts agreed to identify the objective of the study which is to determine the most important pathogens that contribute effectively in respiratory infections in broiler flocks,
Study Methodology
-
The survey population cover Egypt, the samples collected ranged from 200-250 sample in each governorate over a period of six months, starting from June 2010 to August 2013 (a total of about 1,500 samples were collected) of Broiler flocks, and geographical distribution, which ensures the fact that samples are representative of all Egyptian governorates.
-
Defining the principle causes of disease in the isolated samples in Egyptian universities and research institutes, and afterwards sends isolates to reference laboratories in Italy and the United Kingdom, to confirm the results.
-
The reference laboratories characterize the genetic makeup of the isolated virus, and thus determine the strain pathogenesis of these viruses, and which of these strains are more prevalent in Egypt, to determine which strain represent a part of the problem.
The results of the research, was quite surprising, which was contrary to many expectations and assumptions that prevailed in field in Egypt. Such results reaffirm the importance of taking a systematic approach towards epidemic problems.
​
The Most Important Findings of the Study.. And Many Surprises
Study Findings
-
First: The study proved that respiratory infections in broiler farms, resulting from mixed infection of at least two viruses in more than 75 % of cases, and three viruses combined in 25%.
-
Second: The study proved that the bronchitis contribute mainly to the problem, which was isolated in 80% of the infected samples, followed by Newcastle disease virus, which was isolated in 65 % of cases, and then the avian influenza which was isolated from 33 % of the cases.
Although the study results illustrate the growing importance of infectious bronchitis and Newcastle as a causative agent to the mixed infection, it does not diminish the importance of the influenza virus.
-
One third of the sample population is infected, which is considered a big percentage.
-
The samples affected with influenza occur in a form of waves varying in intensity and spread from year to year.
-
Influenza virus is a disease shared with human, and thus poses a threat to public health.
-
Third: The study proved that the prevalent strain of avian flu currently in Egypt , belong 100% to group (A), there was no strains isolated from group (B) that appeared before and then vanished, which means that the epidemiological situation of avian influenza, has became similar to the situation of 2006 to 2008.
-
Fourth: the study shows there is no presence of a different strains of bronchitis disease in Egypt, all the identified strains from isolates, had existed before, however, the spread of two strains that had been previously isolated in the Middle East (IS/885) and (IS/1494). These two strains are now spreading due to mixed infections accompanied by influenza and other diseases.
-
Fifth: while making Pathogenicity Test for the newly isolated strains of bronchitis and the most prevailing in field. The experiment has shown that the strains has weak virulence. Where it caused mortality rates ranging from 2.5% to 14 %. These mortality rates are high as a result of mixed infections with bronchitis epidemic virus and Newcastle disease, or avian influenza, or both.
-
Sixth: as for Newcastle virus, it is scientifically proven and commonly know that the virus has fixed Ontegian, and that all viruses in the field belong to a single type, and therefore were is no need to study the pathogenesis of its strain.
Additional Independent Study to Provide Solutions to Face the Problem
Based on these results, which were an outcome to the collaborative work of the professors from four Egyptian university and Animal Health Research Institute, and with the reference laboratories in Italy and Britain, it was necessary to make further studies, to discuss the vaccination programs and there ability to deal with the problem and face the causative agents that proven to be found.
For this reason IFT Corporation supported a new study, that was carried out by the head of the virus at the University of Cairo, in collaboration with the Reference Laboratory of the FAO and the Organization for Animal Health World in their field of specialty which is influenza and Newcastle disease, as well as the laboratory of Professor " Canan Janabathe " in Liverpool (Britain) in his field of specialty bronchitis contagious. The objective of the study is to provide vaccination programs proposed for poultry farmers, proving its ability against avian influenza, as well as programs against infections bronchitis, these programs based on vaccines that already recorded and traded on the Egyptian market.
The study describes the methodology of successful vaccination programs against the latest Egyptian isolates of avian influenza and infections bronchitis
First, Vaccination Programs Against Avian Influenza
-
The study relied on challenge test for avian influenza vaccines using the latest Egyptian isolates, and measure the efficiency of the vaccine in blocking infection and preventing mortality, as well as in the prevention of re- producing the virus.
Three vaccines had been tested already in market and manufactured by multinational companies in the field of poultry vaccines:
a vaccine strain (H5N1), and the vaccine prepared from strain (H5N2), and the vaccine Integrated strain (H5N3) (through merging two strains H5N1 + H7N3).
-
The study proved the efficiency of the three vaccines, with a 100% protection against infections and vaccinated flocks in the challenge tests for the latest Egyptian isolates. In addition, test the ability of these vaccines to prevent the reproduction of the virus completely. These tests were repeated in a local study in Egypt in the Animal Health Research Institute, as well as the Reference Laboratory in Italy.
Second, Vaccination Programs Against Infectious Bronchitis
Through experimenting many protocols, and various vaccines available in Egypt , the challenge tests proved its efficiency against the prevailing strains currently in Egypt, that was previously mentioned, the vaccination program, consisting of two doses:
-
First dose: using a vaccine composed from 2 strains (H120) and (D274) at the age of day
-
Second dose: using a vaccine strain (CR88), at the age of 12-14 days.
​
Although the scientific study was a multicentric that was important to clarify the fact about the epidemiological status in Egypt. However, the importance of the second experiment complements it, to translate the scientific facts reached by the first experiment, to tips and instructions to guide and to be beneficial poultry producers.