Abstract
Infectious laryngotracheitis (ILT) is an acute, highly contagious infectious disease of the upper respiratory tract in chickens and other poultry species that causes significant economic losses in countries worldwide. Between 2017 and 2019, seven outbreaks of mild to severe respiratory disorders with high suspicion of ILT occurred in commercial and backyard poultry flocks in Slovenia. In all submissions, infection with ILT virus (ILTV) was confirmed by PCR, which is the first report of ILT in Slovenia. Circulating ILT strains were characterized by the sequence and phylogenetic analysis of two fragments of the ICP4 gene. Four strains—three detected in non-vaccinated flocks and one in a flock vaccinated against ILT—were identical or very similar to the chicken embryo–origin live virus vaccines, and the other three were closely related to Russian, Chinese, Australian, and American field strains and to tissue culture origin vaccine strains. As in other diseases, coinfections with other respiratory pathogens in confirmed ILT cases may cause a more severe condition and prolong the course of the disease. In our study, coinfections with Mycoplasma synoviae (7/7 tested flocks), infectious bronchitis virus (5/5 tested flocks), Mycoplasma gallisepticum (4/7 tested flocks), Ornithobacterium rhinotracheale (3/4 tested flocks), and avian pox virus (1/2 tested flocks) were confirmed, indicating the importance of these pathogens in the occurrence of ILT infections.
Highlights
Infectious laryngotracheitis (ILT) is an acute and highly contagious respiratory disease of chickens, pheasants, peafowl, and turkeys [1,2]
We report the detection of ILT virus (ILTV) by PCR in poultry flocks with respiratory clinical signs between 2017 and 2019
Until 2017, ILT had never been reported in Slovenia, and a non-vaccination policy against ILT had been applied in commercial flocks [11]
Summary
Infectious laryngotracheitis (ILT) is an acute and highly contagious respiratory disease of chickens, pheasants, peafowl, and turkeys [1,2]. The virus has a dsDNA genome of approximately 150 kb that encodes 80 viral proteins [3]. Infection with ILT virus (ILTV) results in an economically important respiratory disease with high morbidity and variable mortality. Sources of the viral transmission include clinically ill chickens, contaminated dust, litter, beetles, drinking water and fomites. Birds that recover from GaHV-1 infection do become long-term carriers of the virus. ILTV can establish latency in the trigeminal ganglion of the central nervous system after 7 days of acute infection [6]. Intermittent viral shedding into the trachea has been demonstrated in recovered or vaccinated chickens [8,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
