In this study, The PCR molecular test was performed on samples gathered from local laying farms that exhibited symptoms of ILT. With the wild strain, ILTV was positive, and subsequently, AI, ND, and IB were tested and all negative findings were found. ECE was inoculated with the prepared positive sample using the CAM method for three separate passages. PCR testing and viral titration, in the same manner, was carried out again once the cytopathic impact occurred. The EID50 is the fourth dilution. An ELISA test for maternal ABs was performed on four groups of broiler chickens (A, B, C, and D), each group containing 50 birds, and an experimental infection was made for three groups, with group D remaining as control negative. Group A was infected at one day, Group B at 15 days, and Group C at 30 days, clinical signs and pathological lesions, both macroscopic and microscopic in nature, were observed. After clinical indicators, affected groups performed the histopathological test. And then all groups had 3 ELISA tests at 1, 2, and 3 weeks following infection. The experiment indicated that group A was the least affected. Group B was more impacted than A, whereas group C had more clinical indications and mortalities, indicating that broiler chickens of all ages are vulnerable to infection, although maternal immunity may offer some protection for at most two weeks. This research was done to provide information to the scientific library of broiler chickens infected with ILT, which has been more investigated in laying hens and breeders.


ILTV infectious laryngotracheitis chorioallantoic membrane


How to Cite
Mustafa Badr Hussein, & Sameer Mezher Abdullah. (2022). Pathological investigation of local infectious laryngotracheitis virus isolated from layers on broiler Chicks. Texas Journal of Agriculture and Biological Sciences, 8, 79–100. Retrieved from https://zienjournals.com/index.php/tjabs/article/view/2340


  1. Abdul-Aziz, Tahseen, and H. John Barnes. 2018. “Infectious Laryngotracheitis (ILT).” In Gross Pathology of Avian Diseases:Text and Atles, 1st ed., 74.
  2. Al-Khidr, Ahmed, and Harith Al-Hayali. 2000. “Isolation , Identification and Pathogensis of Herpes Virus That Causes Infectious Laryngotracheitis in Chickens.” baghdad.
  3. Alaraji, Furkan, Hasan Hammadi, Alaa Abdulaziz Abed, and Yahia Ismail Khudhair. 2019. “Molecular Detection and Phylogenetic Tree of Infectious Laryngotracheitis Virus in Layers in Al-Diwaniyah Province, Iraq.” Veterinary World 12 (4): 605–8. https://doi.org/10.14202/vetworld.2019.605-608.
  4. Ali, A, S Mansour, M Mohamed, Haythm Ali, and Abeer Shahin. 2014. “Molecular Characterization of Thymidine Kinase and Glycoprotein G Genes from a Possible Vaccine Induced Infectious Laryngotracheitis Outbreak in Egypt.” Pak. Vet. J 34: 381–85.
  5. Allawe, Aida Bara, Amer Abdulameer Abbas, Zaid Haddam Taha, and Shony M. Odisho. 2016. “Molecular Characterization of Field Isolates of Avian Infectious Laryngeotracheitis Virus from Different Farms in Iraqle.” The Iraqi Journal of Veterinary Medicine 40(2):31.
  6. Arnaout, M Y, M M Fadel, and I M Mohra. 2010. “Characterization of Syrian Isolates of Avian Infectious Laryngotracheitis Virus By Restriction Fragment Length Polymorphism.” Assiut Veterinary Medical Journal 56 (127): 1–11. https://doi.org/10.21608/avmj.2010.174260.
  7. Bayoumi, Mahmoud, Mohamed El-Saied, Haitham Amer, Mostafa Bastami, Ezz Eldein Sakr, and Magdy El-Mahdy. 2020. “Molecular Characterization and Genetic Diversity of the Infectious Laryngotracheitis Virus Strains Circulating in Egypt during the Outbreaks of 2018 and 2019.” Archives of Virology 165 (3): 661–70.
  8. Beker, A, S L Vanhooser, J H Swartzlander, and R G Teeter. 2004. “Atmospheric Ammonia Concentration Effects on Broiler Growth and Performance.” Journal of Applied Poultry Research 13 (1): 5–9.
  9. Carnaccini, Silvia, Chiara Palmieri, Simone Stoute, Manuela Crispo, and H L Shivaprasad. 2022. “Infectious Laryngotracheitis of Chickens: Pathologic and Immunohistochemistry Findings.” Veterinary Pathology 59 (1): 112–19. https://doi.org/10.1177/03009858211035388.
  10. Dufour-Zavala, Louise. 2008. “Epizootiology of Infectious Laryngotracheitis and Presentation of an Industry Control Program.” Avian Diseases 52 (1): 1–7.
  11. Emadi Chashmi, Seyed Hesamodin, Hamid Staji, Iradj Ashrafi Tamai, and Sahar Ghaffari Khaligh. 2021. “Molecular Identification of Infectious Laryngotracheitis Virus in Backyard and Broiler Chickens in Iran.” Iranian Veterinary Journal 17 (3): 24–33.
  12. Farag, Shaimaa Ibrahim, and Ahmed Eissa. 2021. “Molecular Characterization and Isolation of Infectious Laryngotracheitis Virus (ILTV) Strains Causing Outbreaks in Layer Chicken Farms of Kalubia Province, Egypt.” Benha Veterinary Medical Journal 40 (2): 126–30.
  13. García, Maricarmen, Stephen Spatz, and James S. Guy. 2013. Infectious Laryngotracheitis. Diseases of Poultry: Thirteenth Edition. Wiley-Blackwell. https://doi.org/10.1002/9781119421481.ch5.
  14. Gopal, Prashanth Anur, H D Narayanaswamy, M L Sathyanarayana, Suguna Rao, D Rathnamma, and Divakar Hemadri. 2022. “Studies on Molecular Diagnosis and Respiractory Tract Pathology of Infectious Laryngo-Tracheitis Disease in Chickens in Karnataka.” The Pharma Innovation Journal, 1124–29.
  15. Gustavohenrique, Schneiders. 2016. “Potential of an Infectious Laryngotracheitis (Ilt) Recombinant Virus Depleted of Open Reading Frame (Orf) c Gene as a Live Attenuated Vaccine For.” University of Georgia.
  16. Guy, J S, T J Bagust, Y M Saif, H J Barnes, A M Fadly, J R Glisson, L R McDougald, and D E Swayne. 2003. “Laryngotracheitis.” In Diseases of Poultry, 121–34. Iowa State University Press: Ames, IA.
  17. Islam, M S, M S R Khan, M A Islam, and J Hassan. 2010. “Isolation and Characterization of Infectious Laryngotracheitis Virus in Layer Chickens.” Bangladesh Journal of Veterinary Medicine 8 (2): 123–30.
  18. Kaur, Jagmeet. 2021. “Infectious Laryngotracheitis in Avian Species: A Review.” The Pharma Innovation Journal 2021;, 450–54.
  19. Loncoman, Carlos A. 2018. “Recombination of Infectious Laryngotracheitis Virus (ILTV) and the Role of Vaccination.” The University of Melbourne.
  20. Magouz, A. 2015. “Isolation and Molecular Characterization of Infectious Laryngotracheitis Virus from Naturally Infected Layer Chicken Flocks in Egypt.” Global Veterinaria 14 (6): 929–34.
  21. Menendez, Kimberly R, Maricarmen García, Stephen Spatz, and Nathaniel L Tablante. 2014. “Molecular Epidemiology of Infectious Laryngotracheitis: A Review.” Avian Pathology 43 (2): 108–17. https://doi.org/10.1080/03079457.2014.886004.
  22. Nagy, Nourhan, Sherif Mahmoud Ibrahim, Amina Radwan, and Rafik Hamed Sayed. 2020. “Isolation and Molecular Characteraization of Circulating Infectious Laryngotracheitis (ILT) Virus in Egypt, 2018.” The Journal of the Egyptian Medical Association, 1–9.
  23. OIE. 2021. Avian Infectious Laryngotracheitis.
  24. Ou, Shan-Chia, and Joseph J Giambrone. 2012. “Infectious Laryngotracheitis Virus in Chickens.” World Journal of Virology 1 (5): 142–49. https://doi.org/10.5501/wjv.v1.i5.142.
  25. Ponnusamy, P, K Sukumar, A Raja, S Saravanan, and P Srinivasan. 2021. “Histopathological and Molecular Confirmation of Infectious Laryngotracheitis Virus in Desi Chicken.” The Pharma Innovation Journal, 2852–56.
  26. Portz, Cristiana, Nilzane Beltrao, Thales Quedi Furian, Alfredo Bianco Júnior, Marisa Macagnan, Josiane Griebeler, Carlos André Veiga Lima Rosa, Edson Moleta Colodel, David Driemeier, and Alberto Back. 2008. “Natural Infection of Turkeys by Infectious Laryngotracheitis Virus.” Veterinary Microbiology 131 (1–2): 57–64.
  27. Ravi, V, A Desa, and S N Madhusudana. 2010. “Virology Manual of the Department of Neurovirology.” Nimhans, Bangalore, 8–10.
  28. Razmyar, Jamshid, Sara Shokrpoor, Abbas Barin, Jamshid Gheshlaghi, Peyman Nakhaee, Moein Khodayari, and Seyed Mostafa Peighambari. 2021. “Isolation of Infectious Laryngotracheitis Virus in Broiler Chicken in Iran: First Report.” In Veterinary Research Forum, 12:259. Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
  29. Reddy, Vishwanatha R A P, Lennert Steukers, Yewei Li, Walter Fuchs, Alain Vanderplasschen, and Hans J Nauwynck. 2014. “Replication Characteristics of Infectious Laryngotracheitis Virus in the Respiratory and Conjunctival Mucosa.” Avian Pathology 43 (5): 450–57. https://doi.org/10.1080/03079457.2014.956285.
  30. Reed, L. J., and H. Muench. 1938. “A Simple Method of Estimating Fifty per Cent Endpoints.” American Journal of Hygiene, 493–97. https://doi.org/10.1093/oxfordjournals.aje.a118408.
  31. Rojas, M Florencia, Guido A König, Ariel E Vagnozzi, Federico S Vera, Luis A Scolaro, and M Isabel Craig. 2021. “Optimization and Application of a High-Resolution Melting Protocol in the Characterization of Avian Infectious Laryngotracheitis Virus.” Revista Argentina de Microbiologia 53 (2): 89–97. https://doi.org/10.1016/j.ram.2020.04.008.
  32. Solis, Barboza. 2021. “Infectious Laryngotracheitis Infection in Chickens Raised in Western Canada : Molecular Characterization and Vaccine Efficacy Studies.” University of Calgary.
  33. Taher, MT, MM Amer, and FE Saad. 2017. “Epidemiology of Viral Components Causing Respiratory Problems in Broilers in Six Egyptian Governorates.” Journal of Veterinary Medical Research 24 (1): 71–83.
  34. Thilakarathne, Dulari S, Carol A Hartley, Andrés Diaz-Méndez, Mauricio J C Coppo, and Joanne M Devlin. 2020. “Development and Application of a Combined Molecular and Tissue Culture-Based Approach to Detect Latent Infectious Laryngotracheitis Virus (ILTV) in Chickens.” Journal of Virological Methods, 1–48. https://doi.org/https://doi.org/10.1016/j.jviromet.2019.113797.
  35. Tsiouris, Vasileios, Natalia Mavromati, Konstantinos Kiskinis, Tilemachos Mantzios, G. Zalan Homonnay, Tamas Mato, Mihaly Albert, Istvan Kiss, and Ioanna Georgopoulou. 2021. “A Case of Infectious Laryngotracheitis in an Organic Broiler Chicken Farm in Greece.” Veterinary Sciences, 2–11.
  36. Vagnozzi, Ariel, Sylva M Riblet, Susan M Williams, Guillermo Zavala, and Maricarmen García. 2015. “Infection of Broilers with Two Virulent Strains of Infectious Laryngotracheitis Virus: Criteria for Evaluation of Experimental Infections.” Avian Diseases 59 (3): 394–99. https://doi.org/10.1637/11075-033115-Reg.1.
  37. Veretsun, A., B. Stegniy, O. Rula, V. Bolotin, A. Stegniy, A. Gerilovych, and D. Muzyka. 2021. “Molecular and Genetic Characterization of Avian Laryngotracheitis Virus Isolates Obtained in Ukraine.” Agricultural Science and Practice 8 (1): 37–46. https://doi.org/10.15407/agrisp8.01.032.