Comparison of tracheal and choanal cleft swabs and poultry dust samples for detection of Newcastle disease virus and infectious bronchitis virus genome in vaccinated meat chicken flocks

PLoS One. 2021 Apr 16;16(4):e0247729. doi: 10.1371/journal.pone.0247729. eCollection 2021.

Abstract

This study assessed different methods (tracheal and choanal cleft swabs from individual birds, and poultry dust as a population level measure) to evaluate the shedding kinetics of infectious bronchitis virus (IBV) and Newcastle disease virus (NDV) genome in meat chicken flocks after spray vaccination at hatchery. Dust samples and tracheal and choanal cleft swabs were collected from four meat chicken flocks at 10, 14, 21 and 31 days post vaccination (dpv) and tested for IBV and NDV genome copies (GC) by reverse transcriptase (RT)-PCR. IBV and NDV GC were detected in all sample types throughout the study period. Detection rates for choanal cleft and tracheal swabs were comparable, with moderate and fair agreement between sample types for IBV (McNemar's = 0.27, kappa = 0.44) and NDV (McNemar's = 0.09; kappa = 0.31) GC respectively. There was no significant association for IBV GC in swabs and dust samples (R2 = 0.15, P = 0.13) but NDV detection rates and viral load in swabs were strongly associated with NDV GC in dust samples (R2 = 0.86 and R2 = 0.90, P<0.001). There was no difference in IBV and NDV GC in dust samples collected from different locations within a poultry house. In conclusion, dust samples collected from any location within poultry house show promise for monitoring IBV and NDV GC in meat chickens at a population level and choanal cleft swabs can be used for detection of IBV and NDV GC instead of tracheal swabs in individual birds.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens / virology
  • Coronavirus Infections / diagnosis
  • Coronavirus Infections / prevention & control
  • Coronavirus Infections / veterinary*
  • Genome, Viral
  • Infectious bronchitis virus / genetics
  • Infectious bronchitis virus / isolation & purification*
  • Newcastle Disease / diagnosis*
  • Newcastle Disease / prevention & control
  • Newcastle disease virus / genetics
  • Newcastle disease virus / isolation & purification*
  • Poultry Diseases / diagnosis*
  • Poultry Diseases / prevention & control
  • Vaccination

Grants and funding

This study was partially funded by AgriFutures Australia (grant number PRJ-010639) and by PoultryHub Australia (grant number 18-424) for authors SWB and PFG. Baiada Poultry Pty Limited provided support in the form of salary for authors MS and SA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.