Mira Francesco, Schirò Giorgia, Franzo Giovanni, Canuti Marta, Purpari Giuseppa, Giudice Elisabetta, Decaro Nicola, Vicari Domenico, Antoci Francesco, Castronovo Calogero, Guercio Annalisa
Istituto Zooprofilattico Sperimentale della Sicilia "A. Mirri", Via Gino Marinuzzi 3, 90129, Palermo, Italy.
Department of Veterinary Science, University of Messina, Polo Universitario dell'Annunziata, 98168, Messina, Italy.
Heliyon. 2024 Feb 17;10(4):e26561. doi: 10.1016/j.heliyon.2024.e26561. eCollection 2024 Feb 29.
Since it emerged as a major dog pathogen, canine parvovirus type 2 (CPV-2) has featured a remarkable genetic and phenotypic heterogeneity, whose biological, epidemiological, and clinical impact is still debated. The continuous monitoring of this pathogen is thus of pivotal importance. In the present study, the molecular epidemiology of CPV-2 in Sicily, southern Italy, has been updated by analysing 215 nearly complete sequences of the capsid protein VP2, obtained from rectal swabs/faeces or tissue samples collected between 2019 and 2022 from 346 dogs with suspected infectious gastrointestinal disease. The presence of the original CPV-2 type (4%) and CPV-2a (9%), CPV-2b (18%), or CPV-2c (69%) variants was documented. Over the years, we observed a decrease in the frequency of CPV-2a/-2b and a rapid increase of CPV-2c frequency, with a progressive replacement of the European lineage of CPV-2c by the Asian lineage. The observed scenario, besides confirming epidemiological relevance of CPV-2, highlights the occurrence of antigenic variant shifts over time, with a trend toward the replacement of CPV-2a, CPV-2b, and the European lineage of CPV-2c by the emerging Asian CPV-2c lineage. The comparison with other Italian and international sequences suggests the occurrence of viral exchange with other Italian regions and different countries, although the directionality of such viral flows could not be often established with confidence. In several instances, potential CPV-2 introductions led to epidemiological dead ends. However, major, long-lasting clades were also identified, supporting successful infection establishment, local spreading, and evolution. These results, besides demonstrating the need for implementing more effective control measures to prevent viral introductions and minimize circulation, stress the relevance of routine monitoring activities as the only tool to effectively understand CPV-2 epidemiology and evolution, and develop adequate countermeasures.
自犬细小病毒2型（CPV-2）成为主要的犬类病原体以来，它呈现出显著的遗传和表型异质性，其生物学、流行病学和临床影响仍存在争议。因此，对这种病原体的持续监测至关重要。在本研究中，通过分析215个衣壳蛋白VP2的近乎完整序列，更新了意大利南部西西里岛CPV-2的分子流行病学情况，这些序列来自2019年至2022年间从346只疑似感染性胃肠疾病犬的直肠拭子/粪便或组织样本中获得。记录了原始CPV-2型（4%）、CPV-2a（9%）、CPV-2b（18%）或CPV-2c（69%）变体的存在。多年来，我们观察到CPV-2a/-2b的频率下降，CPV-2c频率迅速增加，亚洲谱系逐渐取代了欧洲谱系的CPV-2c。观察到的情况，除了证实CPV-2的流行病学相关性外，还突出了随着时间推移抗原变体的转变，呈现出新兴的亚洲CPV-2c谱系取代CPV-2a、CPV-2b和欧洲谱系CPV-2c的趋势。与其他意大利和国际序列的比较表明，尽管这种病毒流动的方向性往往难以确定，但与其他意大利地区和不同国家之间存在病毒交换。在一些情况下，潜在的CPV-2引入导致了流行病学上的死胡同。然而，也确定了主要的、持久的进化枝，支持了成功的感染建立、局部传播和进化。这些结果，除了表明需要实施更有效的控制措施以防止病毒引入并尽量减少传播外，还强调了常规监测活动作为有效了解CPV-2流行病学和进化并制定适当对策的唯一工具的相关性。
