Frequency of Detection and Phylogenetic Analysis of Porcine circovirus 3 (PCV-3) in Healthy Primiparous and Multiparous Sows and Their Mummified Fetuses and Stillborn

Abstract

<jats:p>Porcine circovirus 3 (PCV-3) has been suggested as a putative causal agent of swine reproductive disease. A number of different studies have pointed out this association, but there is still a lack of information regarding the normal rates of PCV-3 infection in farms with normal reproductive parameters. The objective of the present study was to assess the frequency of PCV-3 detection in primiparous and multiparous sows and in tissues from their respective fetuses from farms with average reproductive parameters. Sera from 57 primiparous and 64 multiparous sows from 3 different farms were collected at two time points. Brain and lung tissues from 49 mummies and 206 stillborn were collected at farrowing. Samples were tested by PCR, and when positive, quantified by quantitative PCR. Thirty-nine complete genomes were obtained and phylogenetically analyzed. All sera from multiparous sows were negative, while 19/57 (33.3%) primiparous sows were PCV-3 PCR positive. From the 255 tested fetuses, 86 (33.7%) had at least one tissue positive to PCV-3. The frequency of detection in fetuses from primiparous sows (73/91, 80.2%) was significantly higher than those from multiparous ones (13/164, 7.9%). It can be concluded that PCV-3 is able to cause intrauterine infections in absence of overt reproductive disorders.</jats:p>

Porcine Circovirus 3 Detection in Aborted Fetuses and Stillborn Piglets from Swine Reproductive Failure Cases

“…PCV-3 DNA has been widely detected in samples from healthy animals [ 10 , 13 , 14 , 43 , 44 ] as well as in mummified fetuses and stillborn piglets from farms without reproductive problems [ 19 ]. The simple assessment of viral DNA in cases of reproductive problems also has been widely performed [ 5 , 6 , 7 , 9 , 10 ], but the detection of a viral genome alone does not imply the causality of a disease.…”

“…However, the mere detection of an enzootic virus in animals with clinical conditions is not sufficient to demonstrate its disease causality [ 4 ]. Despite the worldwide ubiquitous distribution of PCV-3 [ 13 , 19 ], there is little evidence of PCV-3 detection within lesions of diseased animals [ 4 , 20 ]. In consequence, it is of great importance to determine the frequency of the virus in farms with reproductive problems and assess its potential causality in these problems.…”

Analysis of spread of porcine circovirus type 3 detected in Russia

“…В дальнейшем было установлено, что данная патология была ассоциирована с цирковирусом свиней 3 типа (ЦВС-3). Данный возбудитель относится к семейству Circoviridae, роду Circovirus [12]. На данный момент наличие ЦВС-3 установлено в США, Южной Америке, Европе, России, и странах Азии [1,4,6,7,11,14,15].…”

“…Однако в другом исследовании было показано, что внутриутробное инфицирование данным возбудителем не всегда сочетается с проявлением выраженной репродуктивной патологии, а мертворожденные и мумифицированные плоды содержали ДНК вируса ЦВС-3 в широком диапазоне от 0 до 87%. Наконец, было установлено, что на интенсивность циркуляции вируса оказывает зрелость свиноматок: вирус чаще обнаруживали у первоопоросных свиноматок, чем у свиноматок после 2 и более опороса [12].…”

Detection of Porcine circovirus 3 from captured wild boars in Korea

“…PCV3 was recently discovered porcine circovirus and was first reported in USA (Palinski et al., 2016). The presence of virus was subsequently reported in other Countries including Brazil (Tochetto et al., 2018), China (Ku et al., 2017; Shen et al., 2018), Colombia (Vargas‐Bermudez et al., 2019), Denmark (Franzo, Legnardi, Hjulsager, et al., 2018), Germany (Fux et al., 2018), India (Bera et al., 2020), Japan (Hayashi et al., 2018), Korea (Kim et al., 2018; Kwon et al., 2017), Malaysia (Tan et al., 2020), Poland (Stadejek et al., 2017), Russia (Yuzhakov et al., 2018), Spain (Saporiti et al., 2020), Sweden (Ye et al., 2018) and Thailand (Kedkovid et al., 2018). Since the first report, PCV3 was detected in the presence of severe diseases including porcine dermatitis and nephropathy syndrome (PDNS), reproductive disorders, respiratory signs and myocarditis and PCV3 genomes were also detected in asymptomatic animals which speculates the interpretation of this virus as potential causative agent of the disease though circoviruses are considered to be immune suppressive and increase in disease severity with co‐infecting pathogens (Shulman & Davidson, 2017).…”