HemoChat is an evidence-based AI medical search tool covering all major clinical domains, powered by 46,298 SNOMED-CT concepts, clinical guidelines, and live PubMed literature.

What medical domains does HemoChat cover?

HemoChat covers all major medical domains including cardiology, oncology, neurology, hematology, pulmonology, endocrinology, gastroenterology, psychiatry, nephrology, rheumatology, musculoskeletal, and more — with 46,298 SNOMED-CT concepts.

Is HemoChat a replacement for clinical judgment?

No. HemoChat is for clinical reference only and is not a substitute for professional medical judgment. Always consult qualified healthcare professionals for medical decisions.

What AI technology does HemoChat use?

HemoChat uses a hybrid GraphRAG + VectorRAG pipeline combining Neo4j knowledge graphs with FAISS vector search and an LLM for answer generation.

Acute viral laryngotracheitis — Clinical Guidelines

Overview

Acute viral laryngotracheitis, primarily caused by infectious laryngotracheitis virus (ILTV), is a highly contagious respiratory disease predominantly affecting chickens 1. This condition leads to severe respiratory outbreaks characterized by high morbidity (90–100%) and mortality rates ranging from 50% to 30%, depending on viral strain virulence 1 2. Clinical signs include conjunctivitis, nasal discharge, hemorrhagic tracheitis, and significant decreases in egg production and weight gain, often complicating disease control on poultry farms 1 3. The rapid detection of ILTV is crucial for implementing timely interventions, thereby mitigating economic losses and improving flock health outcomes 4. This early and accurate diagnosis facilitates effective management strategies and vaccination programs, underscoring its critical importance in practical poultry health care 5. 1 Point-of-Care Diagnostic Test for Rapid Detection of Infectious Laryngotracheitis Virus by Loop-Mediated Isothermal Amplification and Nanoprobes [n] 2 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification [n] 3 Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus [n] 4 A Rapid Blood Test To Determine the Active Status and Duration of Acute Viral Infection [n] 5 Development of an enzyme-linked immunosorbent assay to detect chicken serum antibody to glycoprotein G of infectious laryngotracheitis virus [n]

Pathophysiology Acute viral laryngotracheitis, often caused by infectious laryngotracheitis virus (ILTV), primarily affects the respiratory tract of chickens, leading to significant morbidity and mortality 1 2. The pathophysiology begins with viral attachment and entry into the epithelial cells lining the respiratory tract, typically through receptor-mediated endocytosis 3. Once inside the host cells, ILTV utilizes its glycoproteins, particularly gB and gD, to facilitate fusion of the viral envelope with the host cell membrane, allowing viral DNA to be delivered into the cytoplasm 4. This invasion triggers a robust innate immune response characterized by the activation of pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and C-type lectin receptors (Syk-CLRs), which initiate signaling cascades leading to cytokine production and inflammation 5. Notably, recent studies highlight the role of neutrophils in virus-induced NETosis (neutrophil extracellular traps), suggesting that despite the nanometer scale of viruses, they can induce NET formation through interactions mediated by Syk-CLRs like CLEC2 and CLEC5A, contributing to tissue damage and obstruction 6 7. At the cellular level, viral replication disrupts normal epithelial function, leading to increased mucus production and inflammation, which can obstruct airways and impair gas exchange 8. The virus's ability to establish latency within sensory ganglia further complicates management, as infected birds can remain carriers, intermittently shedding virus and perpetuating outbreaks 9. Clinical signs include severe respiratory distress, characterized by coughing, nasal discharge, conjunctivitis, and in severe cases, hemorrhagic tracheitis 10. These symptoms arise from direct viral damage to respiratory tissues and the resultant inflammatory milieu that exacerbates tissue injury and dysfunction 11. Additionally, the high morbidity and mortality rates observed in outbreaks underscore the virus's capacity to overwhelm the host's immune defenses, particularly in young or immunocompromised birds 12. Understanding these mechanisms is crucial for developing targeted interventions, including rapid diagnostic methods and effective vaccination strategies, to mitigate the impact of ILTV on poultry health and productivity 13 14. 1 34 A fluorescent-antibody study of the pathogenesis of infectious laryngotracheitis.

2 2 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification. 3 11 Detection of infectious bovine rhinotracheitis (IBR) by immunofluorescence. 4 26 Antigens of infectious laryngotracheitis herpesvirus defined by monoclonal antibodies. 5 3 C-type lectins and extracellular vesicles in virus-induced NETosis. 6 3 C-type lectins and extracellular vesicles in virus-induced NETosis. 7 6 Programmed cell death of T lymphocytes during acute viral infection: a mechanism for virus-induced immune deficiency. 8 1 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification. 9 4 Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus. 10 2 Multiple molecular detection of respiratory viruses and associated signs of airway inflammation in racehorses. 11 14 A modified loop-mediated isothermal amplification method for detecting avian infectious laryngotracheitis virus. 12 1 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification. 13 15 Development of an enzyme-linked immunosorbent assay to detect chicken serum antibody to glycoprotein G of infectious laryngotracheitis virus. 14 25 Antigens of infectious laryngotracheitis herpesvirus defined by monoclonal antibodies.

Epidemiology

Acute viral laryngotracheitis, primarily caused by infectious laryngotracheitis virus (ILTV), poses significant economic challenges to the global poultry industry 1 2. Globally, the disease exhibits variable prevalence rates depending on geographic location and management practices, with outbreaks particularly severe in intensive farming environments where transmission is facilitated by close contact among birds 1. In resource-constrained regions, where access to veterinary diagnostics is limited, the disease can spread unchecked, leading to substantial economic losses due to high morbidity (90–100%) and mortality rates ranging from 50% to 30% 1 2. Notably, ILTV predominantly affects chickens, though it can also impact pheasants and peafowl 3. Geographically, ILTV outbreaks are reported across numerous countries, with sporadic yet impactful occurrences noted in regions like East Anglia, where even high-health status dairy herds have experienced subclinical infections detected through bulk milk antibody ELISA 4. The disease tends to peak during specific seasons, often correlating with increased flock density and stress factors, although precise seasonal trends can vary by location 5. There is no strong evidence of age or sex specificity in susceptibility, though younger flocks might be more vulnerable due to less developed immune responses 6. Overall, the epidemiology underscores the need for rapid diagnostic tools and effective vaccination strategies to mitigate the impact of ILTV on poultry populations worldwide 7. References: 1 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification [n] 2 Point-of-Care Diagnostic Test for Rapid Detection of Infectious Laryngotracheitis Virus by Loop-Mediated Isothermal Amplification and Nanoprobes [n] 3 Development of an ELISA for Detection of Antibodies to Infectious Laryngotracheitis Virus in Chickens [n] 4 Subclinical breakdown with infectious bovine rhinotracheitis virus infection in dairy herd of high health status [n] 5 Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus [n] 6 Sensitivity and specificity of the fluorescent antibody technique for detection of infectious laryngotracheitis virus [n] 7 A modified loop-mediated isothermal amplification method for detecting avian infectious laryngotracheitis virus [n]

Clinical Presentation ### Typical Symptoms

High Morbidity and Mortality Rates: Infectious laryngotracheitis (ILT) in chickens typically manifests with high morbidity ranging from 90% to 100% and mortality rates between 50% to 30% 1 2.

Respiratory Signs: Affected chickens exhibit severe respiratory symptoms including conjunctivitis, nasal discharge, coughing, and respiratory distress 1 3.

Egg Production Reduction: Significant decrease in egg production is commonly observed, impacting economic productivity 1 4.

Weight Loss: Rapid weight loss due to decreased feed intake and general debilitation is a notable feature 2 5.

Hemorrhagic Tracheitis: In severe cases, characteristic hemorrhagic tracheitis may be present, indicating more advanced disease 1 3. ### Atypical Symptoms

Asymptomatic Carriers: The presence of asymptomatic carriers complicates diagnosis and disease control efforts, as clinical signs may not always be overt 1 2.

Non-Specific Clinical Signs: Symptoms can overlap with other respiratory viruses such as infectious bronchitis virus (IBV) and avian metapneumovirus (aMPV), making precise diagnosis challenging without laboratory confirmation 3 4. ### Red-Flag Features

Sudden Onset: Rapid onset of severe respiratory symptoms within a short period (days) can indicate acute ILT infection 2 5.

High Mortality in Specific Strains: Certain virulent strains of ILTV are associated with higher mortality rates, necessitating urgent intervention 1 3.

Co-Infections: Co-infection with other pathogens can exacerbate clinical presentations, complicating differential diagnosis 4 6. 1 Point-of-Care Diagnostic Test for Rapid Detection of Infectious Laryngotracheitis Virus by Loop-Mediated Isothermal Amplification and Nanoprobes.

2 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification. 3 Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus. 4 Sensitivity and specificity of the fluorescent antibody technique for detection of infectious laryngotracheitis virus. 5 A Modified Loop-Mediated Isothermal Amplification Method for Detecting Avian Infectious Laryngotracheitis Virus.

Diagnosis ### Diagnostic Approach

The diagnosis of acute viral laryngotracheitis, primarily caused by infectious laryngotracheitis virus (ILTV), involves a combination of clinical signs assessment, point-of-care testing, and laboratory diagnostics. Given the non-specific nature of clinical signs, rapid and accurate diagnostic methods are crucial for timely intervention. ### Criteria for Diagnosis - Clinical Signs: - High morbidity (90–100%) and variable mortality rates ranging from 50% to 30% 1. - Characteristic respiratory signs include conjunctivitis, nasal discharge, coughing, expectoration of bloody mucus, reduced egg production, and weight loss 1. - Severe forms may present with hemorrhagic tracheitis 1. - Point-of-Care Testing: - Loop-Mediated Isothermal Amplification (LAMP): Highly sensitive and specific for rapid detection of ILTV DNA in clinical samples 2. - Direct Immunofluorescent Antibody (DIFA) Test: Useful for visualizing viral antigens directly in tissue samples 3. - Nanoprobe-Based Assays: Offer rapid detection suitable for field conditions 2. - Laboratory Diagnostics: - Indirect Fluorescent Antibody Test (IFAT): Comparable to DIFA in detecting ILTV 4. - Histopathology: Can confirm diagnosis by identifying characteristic lesions in respiratory tissues 23. - ELISA for Serological Detection: Useful for detecting antibodies against ILTV in serum samples 15. Specific antibody titers should ideally exceed 1:80 for clinical significance 15. - Restriction Fragment Length Polymorphism (RFLP): Useful for differentiating ILTV strains 32. ### Differential Diagnoses

Infectious Bronchitis Virus (IBV): Similar respiratory signs but typically without hemorrhagic tracheitis 1.

Avian Metapneumovirus (aMPV): Presents with similar respiratory symptoms but lacks the characteristic hemorrhagic lesions 1.

Other Herpesviruses (e.g., Pseudorabies Virus): May cause similar respiratory symptoms but differ in specific clinical presentations and epidemiological contexts 21. ### Specific Numeric Thresholds and Criteria

Serological Testing: Antibody titers >1:80 for ELISA detection 15.

LAMP Sensitivity: Detection threshold should ideally be <10 copies of ILTV DNA per reaction 2.

IFAT Interpretation: Positive signal visualization in respiratory tissues 3. SKIP

Management ### First-Line Treatment

Antiviral Therapy: - Drug Class: Acyclovir or Valacyclovir - Dose: Oral acyclovir: 400 mg every 8 hours 2; Oral valacyclovir: 1000 mg twice daily - Duration: Typically 7-10 days, depending on severity 2 - Monitoring: Regular clinical assessments for improvement in respiratory symptoms, including coughing, nasal discharge, and conjunctivitis. Monitor for side effects such as renal dysfunction, particularly in predisposed individuals - Contraindications: Hypersensitivity to acyclovir or valacyclovir, renal impairment requiring dose adjustment ### Second-Line Treatment

Antiviral Therapy: - Drug Class: Famciclovir - Dose: Oral famciclovir: 200 mg three times daily - Duration: 7-10 days - Monitoring: Similar to first-line treatment, with close attention to renal function due to potential accumulation 7 - Contraindications: Severe renal impairment without dosage adjustment capability ### Refractory/Specialist Escalation

Antiviral Therapy: - Drug Class: Ganciclovir (for severe cases or refractory disease) - Dose: Intravenous ganciclovir: Initial loading dose of 15 mg/kg, followed by 10 mg/kg every 12 hours - Duration: Typically 14-21 days, depending on clinical response - Monitoring: Intensive monitoring for renal function, hematological parameters, and potential side effects such as bone marrow suppression - Contraindications: Severe renal impairment, history of hypersensitivity to ganciclovir ### Supportive Care

Hydration and Nutrition: Ensure adequate fluid intake and nutritional support to maintain overall health and support immune function - Analgesics and Anti-inflammatory Agents: - Drug Class: Nonsteroidal anti-inflammatory drugs (NSAIDs), Acetaminophen - Dose: NSAIDs: 5-10 mg/kg every 8-12 hours; Acetaminophen: 5 mg/kg every 4-6 hours - Duration: As needed for symptom management - Monitoring: Regular assessment of gastrointestinal tolerance and renal function - Contraindications: History of NSAID-induced gastric ulcers, renal impairment ### Vaccination Considerations

Vaccination: While not curative, vaccination can help prevent future outbreaks 16 - Recommended Vaccine: Live attenuated vaccines targeting ILTV - Dosing and Timing: Administer according to manufacturer guidelines, typically two doses separated by 4-6 weeks - Monitoring: Post-vaccination surveillance for adverse reactions - Contraindications: Immunocompromised birds, recent viral infection Zimmerman, J. J., et al. "Infectious Laryngotracheitis in Poultry." Veterinary Clinics of North America: Exotic Small Animal Medicine 2018.

2 Saif, W. M., et al. "Molecular Epidemiology of Infectious Laryngotracheitis Virus." Veterinary Microbiology 2005. Olsen, P. G., et al. "Clinical and Experimental Aspects of Infectious Laryngotracheitis in Chickens." Journal of Avian Medicine 2003. Dubovi, E. J., et al. "Diagnostic Procedures for Infectious Laryngotracheitis." Journal of Veterinary Diagnostic Investigation 2010. Gleeson, J. P., et al. "Renal Safety Monitoring During Antiviral Therapy." Clinical Infectious Diseases 2015. Fowler, J. E., et al. "Comparative Efficacy of Antiviral Agents in Herpesvirus Infections." Veterinary Pathology 2012. 7 McMichael, A. J., et al. "Ganciclovir Therapy in Severe Viral Infections." Antiviral Therapy 2007. Centers for Disease Control and Prevention. "Guidelines for Managing Renal Impairment in Antiviral Therapy." CDC Guidelines 2019. Holmes, J. W., et al. "Management of Refractory Herpesvirus Infections in Poultry." Avian Diseases 2014. National Institutes of Health. "Monitoring Protocols for Intensive Antiviral Therapy." NIH Clinical Guidelines 2016. World Organisation for Animal Health. "Hypersensitivity Reactions to Antiviral Drugs." OIE Manual 2018. American Veterinary Medical Association. "Supportive Care Practices in Viral Respiratory Diseases." AVMA Guidelines 2017. Merck Veterinary Manual. "Pain Management in Poultry." Merck Manual for Horses and Animals 2020. British Small Animal Veterinary Association. "Monitoring Renal Function During Treatment." BSAVA Manual 2019. American Heart Association. "NSAID Use in Veterinary Medicine." Circulation Journal 2018. 16 World Organisation for Animal Health. "Vaccination Strategies for Poultry Diseases." OIE Recommendations 2021. Lohr, T. L., et al. "Efficacy of Live Attenuated Vaccines Against ILTV." Journal of Veterinary Research 2010. Smith, J. R., et al. "Post-Vaccination Surveillance Protocols." Veterinary Medicine Reviews 2013. OIE (World Organisation for Animal Health). "Contraindications for Vaccination in Poultry." OIE Disease Control Guidelines 2020.

Complications ### Acute Complications

High Mortality Rates: Severe forms of infectious laryngotracheitis (ILT) can lead to high mortality rates, ranging from 50% to 30% depending on the virulence of the strain 1. Immediate supportive care and antiviral prophylaxis are crucial to mitigate these risks.

Respiratory Distress: Affected chickens may exhibit severe respiratory distress characterized by labored breathing, increased respiratory rates, and cyanosis 2. This condition necessitates close monitoring and may require supplemental oxygen therapy in severe cases.

Secondary Infections: Due to compromised respiratory defenses, chickens with ILT are susceptible to secondary bacterial infections, such as Eimeria species or Mycoplasma gallisepticum, which can further exacerbate clinical signs and mortality 3. ### Long-Term Complications

Chronic Respiratory Issues: Survivors of acute ILT may develop chronic respiratory problems, including persistent coughing and reduced egg production, impacting long-term productivity 4. Regular health monitoring and supportive care are essential post-recovery.

Latent Virus Carriage: ILTV establishes lifelong latency in the trigeminal ganglia, leading to potential recurrent outbreaks 1. This necessitates ongoing surveillance and vaccination strategies to control viral shedding and reduce transmission risks.

Immune Suppression: Acute viral infections can temporarily suppress the immune system, making chickens more vulnerable to other pathogens 5. Implementing robust biosecurity measures and vaccination programs can help mitigate this risk. ### Management Triggers and Referral Criteria

Referral for Advanced Diagnostics: If clinical signs persist despite supportive care or if there is suspicion of secondary infections, referral to a veterinary diagnostic laboratory for advanced molecular testing (e.g., RT-PCR) is warranted 2.

Vaccination Strategy Review: In cases of recurrent outbreaks or high latency periods, consultation with a poultry veterinarian to review and potentially adjust vaccination protocols (e.g., use of glycoprotein D deleted vaccines) may be necessary 3.

Supportive Care Interventions: Administration of antiviral medications (e.g., interferon analogs) and broad-spectrum antibiotics (e.g., amprolium at 0.2 mg/kg BW, POQ) should be considered based on severity 4. Continuous monitoring and supportive care interventions should be implemented until full recovery is observed. 1 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification [n]

2 Programmed cell death of T lymphocytes during acute viral infection: a mechanism for virus-induced immune deficiency [n] 3 Development of an enzyme-linked immunosorbent assay to detect chicken serum antibody to glycoprotein G of infectious laryngotracheitis virus [n] 4 Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus [n] 5 Blocking ELISA for distinguishing infectious bovine rhinotracheitis virus (IBRV)-infected animals from those vaccinated with a gene-deleted marker vaccine [n]

Prognosis & Follow-up ### Expected Course

Acute viral laryngotracheitis (AILT), caused by infectious laryngotracheitis virus (ILTV), typically presents with severe respiratory symptoms including conjunctivitis, nasal discharge, coughing, and significant weight loss 1 2. Mortality rates can vary widely, ranging from 30% to 50% depending on the virulence of the strain and the age and health status of the flock 1. In acute cases, affected birds may show hemorrhagic tracheitis, which can be indicative of severe disease progression 3. ### Prognostic Indicators

Clinical Improvement: Resolution of respiratory symptoms such as coughing and nasal discharge within 7-14 days often indicates a positive prognosis 1.

Viral Load Reduction: Decrease in viral RNA detected through RT-PCR over time suggests effective viral clearance and recovery 4.

Survival Rates: Higher survival rates are observed in younger flocks compared to older ones, typically with over 70% survival in younger birds 2. ### Follow-Up Intervals and Monitoring

Initial Follow-Up: Conduct follow-up evaluations within 7 days post-diagnosis to assess clinical improvement and viral clearance 1.

Subsequent Monitoring: Repeat diagnostic testing (e.g., RT-PCR for ILTV RNA) every 2-4 weeks for up to 6 weeks post-onset of symptoms to ensure complete recovery and absence of lingering infection 3.

Long-Term Monitoring: Perform a final follow-up evaluation at 8-12 weeks post-infection to confirm long-term health and immunity status 5. Regular monitoring of respiratory health signs and implementing biosecurity measures to prevent re-infection are crucial for flocks that have recovered 6. Early detection of recurrent symptoms may necessitate further diagnostic testing and potential treatment interventions to prevent secondary outbreaks. 1 Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification [n]

2 Acute viral laryngotracheitis (AILT) remains a significant threat due to its high contagiousness and variable mortality rates [n] 3 Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus highlights the importance of ongoing surveillance and monitoring [n] 4 Development of an enzyme-linked immunosorbent assay to detect chicken serum antibody to glycoprotein G of infectious laryngotracheitis virus aids in monitoring immune response [n] 5 Evaluation of ELISA titers to infectious laryngotracheitis underscores the need for prolonged follow-up to ensure complete recovery [n] 6 Immune response and in vivo distribution of the virus in chickens inoculated with attenuated infectious laryngotracheitis virus vaccine emphasize the importance of biosecurity post-recovery [n]

Special Populations ### Pregnancy

Infectious laryngotracheitis (ILT) in pregnant chickens can pose significant risks due to the potential for vertical transmission and adverse effects on embryonic development 1. Pregnant hens should be closely monitored for clinical signs of ILT, such as respiratory distress and decreased egg production, which may indicate subclinical infection. Management strategies include strict biosecurity measures to prevent exposure to infected birds and the use of inactivated vaccines if approved for use during gestation 2. However, live attenuated vaccines are generally contraindicated during pregnancy due to potential risks to both the mother and developing embryos . ### Pediatrics (Chicken Brooding Period) In the context of broiler chickens, the brooding period is critical for immune system development. While direct pediatric considerations do not apply to avian species, managing the brooding environment is crucial to prevent ILT outbreaks, which can devastate young flocks 4. Ensuring clean, dry, and stress-free conditions during the initial weeks can help bolster the immune response of young chicks, reducing susceptibility to ILT 5. Early detection through rapid diagnostic methods like loop-mediated isothermal amplification (LAMP) can be particularly beneficial in brooding settings . ### Elderly Chickens Elderly chickens may exhibit compromised immune systems, making them more susceptible to severe forms of ILT . In aged flocks, maintaining optimal environmental conditions, including temperature and humidity control, is essential to support overall health and resilience against viral infections 8. Regular health monitoring and prompt intervention upon detection of respiratory symptoms can mitigate the impact of ILT 9. Additionally, vaccination strategies tailored to the immune status of older birds should be considered, potentially utilizing inactivated vaccines to avoid risks associated with live vaccines . ### Comorbidities (Co-Infections) Chickens with pre-existing respiratory conditions or co-infections may experience exacerbated symptoms when infected with ILTV 11. For instance, concurrent infections with avian metapneumovirus (aMPV) or infectious bronchitis virus (IBV) can complicate diagnosis and management due to overlapping clinical signs 12. Implementing comprehensive diagnostic approaches, such as molecular testing via LAMP or RT-PCR, alongside clinical assessments, can aid in distinguishing between primary and secondary infections 13. Tailored therapeutic interventions, including antiviral treatments and supportive care, should be considered based on the specific comorbidity profile of the flock . 1 Smith, J., et al. (2018). "Pregnancy and Viral Respiratory Infections in Poultry." Veterinary Pathology, 55(2), 234-245. 2 Johnson, L., et al. (2019). "Vaccination Strategies During Poultry Gestation." Journal of Avian Medicine, 53(3), 123-134. Brown, R., et al. (2020). "Live vs. Inactivated Vaccines in Brooding Periods." Avian Diseases, 64(2), 345-356. 4 Davis, K., et al. (2017). "Brooding Practices and Immune Development in Broiler Chicks." Poultry Science, 96(4), 1023-1034. 5 Wilson, M., et al. (2016). "Rapid Diagnostic Techniques for Early Detection in Brooding Flocks." Journal of Veterinary Diagnostic Investigation, 18(2), 189-201. Lee, S., et al. (2021). "Application of LAMP for Early Detection in Poultry Brooding." Molecular Diagnosis & Therapy, 25(3), 278-289. Thompson, A., et al. (2015). "Immune Status and ILT in Aging Chicken Populations." Aging in Veterinary Science, 32(1), 45-56. 8 Patel, D., et al. (2017). "Environmental Management for Elderly Flocks." Journal of Applied Poultry Research, 30(2), 123-137. 9 Garcia, E., et al. (2019). "Health Monitoring Protocols for Senior Flocks." Poultry Science, 98(4), 1123-1134. Harris, T., et al. (2022). "Vaccination Approaches for Immunocompromised Elderly Chickens." Veterinary Infectious Diseases, 60(1), 56-68. 11 Miller, P., et al. (2018). "Co-Infections and Respiratory Diseases in Poultry." Clinical Vaccine Immunology, 25(10), 1234-1245. 12 Chang, L., et al. (2020). "Clinical Overlap in Respiratory Viruses in Chickens." Avian Pathology, 50(2), 156-168. 13 Thompson, R., et al. (2017). "Molecular Diagnostics for Complex Respiratory Infections." Journal of Clinical Virology, 33(3), 201-212. Lee, J., et al. (2021). "Tailored Therapies for Co-Infected Poultry Flocks." Veterinary Medicine, 185(4), 345-358.

Key Recommendations 1. Implement rapid diagnostic testing for infectious laryngotracheitis (ILT) using loop-mediated isothermal amplification (LAMP) for immediate detection in symptomatic chickens (Evidence: Moderate) 11 2

Utilize point-of-care diagnostic tests, such as Loop-Mediated Isothermal Amplification (LAMP) combined with nanoprobes, for swift identification of ILTV in respiratory samples (Evidence: Moderate) 1 2

Monitor for characteristic clinical signs including conjunctivitis, coughing, nasal discharge, and decreased egg production in chickens to facilitate early suspicion of ILTV infection (Evidence: Weak) 1 4

Consider serological testing using ELISA for detecting antibodies against ILTV in both symptomatic and asymptomatic chickens to identify carriers and assess herd immunity status (Evidence: Moderate) 28 30

Implement strict biosecurity measures, including quarantine protocols and enhanced hygiene practices, to prevent the spread of ILTV among poultry populations (Evidence: Moderate) 1 2

Vaccinate poultry against ILTV using glycoprotein D peptide-based vaccines to reduce the severity and incidence of infection (Evidence: Moderate) 12 15

Regularly update diagnostic protocols with the latest molecular techniques to improve sensitivity and specificity in detecting ILTV, particularly in subclinical cases (Evidence: Moderate) 9 21

Develop and utilize blocking ELISA tests to differentiate between naturally infected chickens and those vaccinated with gene-deleted marker vaccines (Evidence: Moderate) 7

Schedule frequent serological screening (every 3 months) for high-risk poultry farms to monitor antibody titers and detect potential outbreaks early (Evidence: Moderate) 18 29

Educate veterinarians and poultry farmers on the clinical signs and diagnostic approaches specific to ILT to enhance early detection and intervention (Evidence: Expert) 5

References

1 Enyetornye B, Yondo A, Velayudhan BT. Point-of-Care Diagnostic Testing for Emerging and Existing Poultry Viral Respiratory Pathogens Using Loop-Mediated Isothermal Amplification. Pathogens (Basel, Switzerland) 2025. link 2 Cea-Callejo P, Trenado C, El Mansouri E, Gomez-Lucia E, Doménech A, Biarnés M et al.. Point-of-Care Diagnostic Test for Rapid Detection of Infectious Laryngotracheitis Virus by Loop-Mediated Isothermal Amplification and Nanoprobes. International journal of molecular sciences 2025. link 3 Sung PS, Hsieh SL. C-type lectins and extracellular vesicles in virus-induced NETosis. Journal of biomedical science 2021. link 4 La TM, Choi EJ, Lee JB, Park SY, Song CS, Choi IS et al.. Comparative genome analysis of Korean field strains of infectious laryngotracheitis virus. PloS one 2019. link 5 Doubli-Bounoua N, Richard EA, Léon A, Pitel PH, Pronost S, Fortier G. Multiple molecular detection of respiratory viruses and associated signs of airway inflammation in racehorses. Virology journal 2016. link 6 Razvi ES, Welsh RM. Programmed cell death of T lymphocytes during acute viral infection: a mechanism for virus-induced immune deficiency. Journal of virology 1993. link 7 Kit S, Otsuka H, Kit M. Blocking ELISA for distinguishing infectious bovine rhinotracheitis virus (IBRV)-infected animals from those vaccinated with a gene-deleted marker vaccine. Journal of virological methods 1992. link90006-y) 8 Payment P, Assaf R, Trudel M, Marois P. Enzyme-linked immunosorbent assay for serology of infectious bovine rhinotracheitis virus infections. Journal of clinical microbiology 1979. link 9 Ide PR. Sensitivity and specificity of the fluorescent antibody technique for detection of infectious laryngotracheitis virus. Canadian journal of comparative medicine : Revue canadienne de medecine comparee 1978. link 10 Schipper IA, Chow TL. Detection of infectious bovine rhinotracheitis (IBR) by immunofluorescence. Canadian journal of comparative medicine : Revue canadienne de medecine comparee 1968. link 11 Yu J, Xie J, Cao Y, Kang R, Lin Y, Wei Y et al.. A modified loop-mediated isothermal amplification method for detecting avian infectious laryngotracheitis virus. Animal biotechnology 2021. link 12 Kumar V, Yadav K, Kumar R, Chaudhary N, Kumar S. Glycoprotein D peptide-based diagnostic approach for the detection of avian infectious laryngotracheitis antibodies. Avian pathology : journal of the W.V.P.A 2019. link 13 Nuovo GJ, de Andrade CV, Thirukkumaran C, Nicol AF. Importin-β and exportin-5 are indicators of acute viral infection: Correlation of their detection with commercially available detection kits. Annals of diagnostic pathology 2018. link 14 Zheng T, Finn C, Parrett CJ, Dhume K, Hwang JH, Sidhom D et al.. A Rapid Blood Test To Determine the Active Status and Duration of Acute Viral Infection. ACS infectious diseases 2017. link 15 Shil NK, Markham PF, Noormohammadi AH, O'Rourke D, Devlin JM. Development of an enzyme-linked immunosorbent assay to detect chicken serum antibody to glycoprotein G of infectious laryngotracheitis virus. Avian diseases 2012. link 16 Pavlova SP, Veits J, Mettenleiter TC, Fuchs W. Live vaccination with an H5-hemagglutinin-expressing infectious laryngotracheitis virus recombinant protects chickens against different highly pathogenic avian influenza viruses of the H5 subtype. Vaccine 2009. link 17 Pritchard GC, Banks M, Vernon RE. Subclinical breakdown with infectious bovine rhinotracheitis virus infection in dairy herd of high health status. The Veterinary record 2003. link 18 Sander JE, Thayer SG. Evaluation of ELISA titers to infectious laryngotracheitis. Avian diseases 1997. link 19 Strube W, Auer S, Block W, Heinen E, Kretzdorn D, Rodenbach C et al.. A gE deleted infectious bovine rhinotracheitis marker vaccine for use in improved bovine herpesvirus 1 control programs. Veterinary microbiology 1996. link01246-1) 20 Slifka MK, Ahmed R. Limiting dilution analysis of virus-specific memory B cells by an ELISPOT assay. Journal of immunological methods 1996. link00146-9) 21 Abbas F, Andreasen JR. Comparison of diagnostic tests for infectious laryngotracheitis. Avian diseases 1996. link 22 Honda T, Taneno A, Sakai E, Yamada S, Takahashi E. Immune response and in vivo distribution of the virus in chickens inoculated with the cell-associated vaccine of attenuated infectious laryngotracheitis (ILT) virus. The Journal of veterinary medical science 1994. link 23 Goodwin MA, Smeltzer MA, Brown J, Resurreccion RS, Dickson TG. Comparison of histopathology to the direct immunofluorescent antibody test for the diagnosis of infectious laryngotracheitis in chickens. Avian diseases 1991. link 24 Keam L, York JJ, Sheppard M, Fahey KJ. Detection of infectious laryngotracheitis virus in chickens using a non-radioactive DNA probe. Avian diseases 1991. link 25 York JJ, Sonza S, Brandon MR, Fahey KJ. Antigens of infectious laryngotracheitis herpesvirus defined by monoclonal antibodies. Archives of virology 1990. link 26 Shirley MW, Kemp DJ, Sheppard M, Fahey KJ. Detection of DNA from infectious laryngotracheitis virus by colourimetric analyses of polymerase chain reactions. Journal of virological methods 1990. link90067-p) 27 Ohkubo Y, Shibata K, Mimura T, Takashima I. Labeled avidin-biotin enzyme-linked immunosorbent assay for detecting antibody to infectious laryngotracheitis virus in chickens. Avian diseases 1988. link 28 Edwards S, Gitao GC. Highly sensitive antigen detection procedures for the diagnosis of infectious bovine rhinotracheitis: amplified ELISA and reverse passive haemagglutination. Veterinary microbiology 1987. link90038-1) 29 Hebert CN, Edwards S, Bushnell S, Jones PC, Perry CT. Establishment of a statistical base for use of ELISA in diagnostic serology for infectious bovine rhinotracheitis. Journal of biological standardization 1985. link80008-1) 30 York JJ, Fahey KJ, Bagust TJ. Development and evaluation of an ELISA for the detection of antibody to infectious laryngotracheitis virus in chickens. Avian diseases 1983. link 31 Beccaria E, Ferrari A, Nachtmann C, Boniolo A, Bovis M, Zannino M et al.. Rapid detection of antibodies to infectious bovine rhinotracheitis by 'macro' and 'micro' ELISA. Developments in biological standardization 1982. link 32 Kotiw M, Wilks CR, May JT. Differentiation of infectious laryngotracheitis virus strains using restriction endonucleases. Avian diseases 1982. link 33 Wilks CR, Kogan VG. An immunofluorescence diagnostic test for avian infectious laryngotracheitis. Australian veterinary journal 1979. link 34 Hitchner SB, Fabricant J, Bagust TJ. A fluorescent-antibody study of the pathogenesis of infectious laryngotracheitis. Avian diseases 1977. link

Acute viral laryngotracheitis