School of Veterinary Science, Massey University, Palmerston North, New Zealand.
School of Fundamental Science, Massey University, Palmerston North, New Zealand.
N Z Vet J. 2021 Jul;69(4):224-233. doi: 10.1080/00480169.2021.1915211.
The aim of this study was to identify viruses associated with canine infectious respiratory disease syndrome (CIRDS) among a population of New Zealand dogs.
Convenience samples of oropharyngeal swabs were collected from 116 dogs, including 56 CIRDS-affected and 60 healthy dogs from various locations in New Zealand between March 2014 and February 2016. Pooled samples from CIRDS-affected (n = 50) and from healthy (n = 50) dogs were tested for the presence of canine respiratory viruses using next generation sequencing (NGS). Individual samples (n = 116) were then tested by quantitative PCR (qPCR) and reverse transcriptase qPCR (RT-qPCR) for specific viruses. Groups were compared using Fisher's exact or χ tests. The effect of explanatory variables (age, sex, type of household, presence of viral infection) on the response variable (CIRDS-affected or not) was tested using RR.
Canine pneumovirus (CnPnV), canine respiratory coronavirus (CRCoV), canine herpesvirus-1 (CHV-1), canine picornavirus and influenza C virus sequences were identified by NGS in the pooled sample from CIRDS-affected but not healthy dogs. At least one virus was detected by qPCR/RT-qPCR in 20/56 (36%) samples from CIRDS dogs and in 23/60 (38%) samples from healthy dogs (p = 0.84). CIRDS-affected dogs were most commonly positive for CnPnV (14/56, 25%) followed by canine adenovirus-2 (CAdV-2, 5/56, 9%), canine parainfluenza virus (CpiV) and CHV-1 (2/56, 4% each), and CRCoV (1/56, 2%). Only CnPnV (17/60, 28%) and CAdV-2 (14/60, 23%) were identified in samples from healthy dogs, and CAdV-2 was more likely to be detected healthy than diseased dogs (RR 0.38; 95% CI = 0.15-0.99; p = 0.045).
The frequency of detection of viruses traditionally linked to CIRDS (CAdV-2 and CPiV) among diseased dogs was low. This suggests that other pathogens are likely to have contributed to development of CIRDS among sampled dogs. Our data represent the first detection of CnPnV in New Zealand, but the role of this virus in CIRDS remains unclear. On-going monitoring of canine respiratory pathogens by NGS would be beneficial, as it allows rapid detection of novel viruses that may be introduced to the New Zealand canine population in the future. Such monitoring could be done using pooled samples to minimise costs.
Testing for novel respiratory viruses such as CnPnV and CRCoV should be considered in all routine laboratory investigations of CIRDS cases, particularly in dogs vaccinated with currently available kennel cough vaccines.
本研究旨在鉴定新西兰犬群中与犬传染性呼吸道疾病综合征（CIRDS）相关的病毒。
2014 年 3 月至 2016 年 2 月期间，从新西兰各地的 56 只 CIRDS 患病犬和 60 只健康犬中采集咽拭子进行检测。将 50 只 CIRDS 患病犬和 50 只健康犬的混合样本进行下一代测序（NGS），以检测犬呼吸道病毒的存在。然后，使用定量 PCR（qPCR）和逆转录 qPCR（RT-qPCR）对 116 个单独样本（n=116）进行特定病毒的检测。使用 Fisher 确切检验或 χ 检验比较各组。使用 RR 检验年龄、性别、家庭类型、病毒感染存在等解释变量对反应变量（是否患有 CIRDS）的影响。
NGS 鉴定出混合样本中来自 CIRDS 患病犬但不来自健康犬的犬呼吸道冠状病毒（CRCoV）、犬副流感病毒（CPiV）和犬疱疹病毒-1（CHV-1）序列。qPCR/RT-qPCR 在 20/56（36%）只 CIRDS 患病犬和 23/60（38%）只健康犬的样本中检测到至少一种病毒（p=0.84）。CIRDS 患病犬最常见的病毒阳性为犬肺炎病毒（CnPnV，14/56，25%），其次是犬腺病毒-2（CAdV-2，5/56，9%）、犬副流感病毒（CPiV）和 CHV-1（2/56，各 4%），以及 CRCoV（1/56，2%）。在健康犬的样本中仅检测到 CnPnV（17/60，28%）和 CAdV-2（14/60，23%），且 CAdV-2 在健康犬中比患病犬更容易被检测到（RR 0.38；95%CI=0.15-0.99；p=0.045）。
在患病犬中，与 CIRDS 传统相关的病毒（CAdV-2 和 CPiV）的检测频率较低。这表明，其他病原体可能在采样犬中导致了 CIRDS 的发展。我们的数据代表了在新西兰首次检测到犬肺炎病毒，但该病毒在 CIRDS 中的作用仍不清楚。通过 NGS 对犬呼吸道病原体进行持续监测将是有益的，因为它可以快速检测到未来可能引入新西兰犬群的新型病毒。这种监测可以使用混合样本进行，以最大限度地降低成本。
在所有 CIRDS 病例的常规实验室检测中，均应考虑检测新型呼吸道病毒，如 CnPnV 和 CRCoV，尤其是在使用目前可用的犬窝咳疫苗接种的犬中。
