Transmission of porcine circovirus 2 (PCV2) by semen and viral distribution in different piglet tissues

Abstract

RESUMO.-[Transmissão do circovirus suíno 2 (PCV2) pelo sêmen e distribuição do vírus nos tecidos da leitegada.] A circovirose suína é causada pelo circovirus suíno 2 (PCV-2). Dentre seis diferentes manifestações clí-nicas envolvendo sinais respiratórios, entéricos, nervosos e reprodutivos, a síndrome multissistêmica do definhamento do suíno (SMDS) é a doença mais importante e estudada. Todavia, relatos sobre falhas reprodutivas associadas ao PCV2 tem aumentado. Alguns estudos mostraram a possibilidade de contaminação das fêmeas pelo sêmen de machos positivos para PCV2. Porcine circovirus infections are caused by the porcine circovirus 2 (PCV2). Among six different clinical manifestations involving respiratory, enteric, nervous and reproductive signs, the postweaning multisystemic wasting syndrome (PMWS) is the most important and studied disease. However, reproductive failures associated with PCV2 have been increasingly reported. Some studies have shown the possible contamination of sows by semen of PCV2 positive boars. In order to investigate the transmission of PCV2 by contaminated semen and its ability to infect the sow and piglets, 20 PCV2 negative sows were inseminated, 10 with negative boar semen and 10 with previously nested-PCR tested positive boar semen. The sows were weekly monitored and blood samples were collected. Based on the results, 4 out 20 sows were selected (1 sow was PCR negative and inseminated with a negative semen, 2 sows were PCR negative and inseminated with a positive semen and 1 sow was PCR negative and inseminated with a positive semen, but became PCR positive around the 30 days of pregnancy). After weaning, 12 male piglets, 3 of each sow, were selected and maintained under isolation. In order to investigate which organs harbored the virus, the young pigs were necropsied around 9 months of age. Samples of serum collected monthly were tested by immunocitochemistry (ICC), and all 12 pigs serum converted. Samples of lymphoid, systemic and reproductive organs were analyzed by nested-PCR and immunohistochemistry (IHC). Evaluation of the samples by nested-PCR, revealed that several tissues were positive in 10 of 12 pigs, mainly the lymph nodes, bone marrow and spleen. Various samples were positive by IHC in 8 of 12 piglets, being the lymph nodes, tonsils and bulbourethral glands the most frequently positive. Thus, the results of testing different samples, in the 3 tests (ICC, nested-PCR and IHC) were complementary. These results show that PCV2 transmission through semen to the sows and piglets may occur and may also represent a potential risk for the herd.

Genome‐wide association study of periweaning failure‐to‐thrive syndrome (PFTS) in pigs

“…Lymph node and thymus samples were also analysed by immunohistochemistry (IHC) for PCV2 antigen detection as described by Gava and others (2008). Lung samples were tested for influenza A detection by reverse transcription PCR (RT-PCR) (Fouchier and others 2000).…”

The effect of porcine circovirus type 2 (PCV2) vaccination of male piglets on sperm quality at the age of puberty

“…Groups P and PS tended to differ non-significantly (P = 0.093) suggesting that vaccination against PCV2 early in life could have a beneficial effect on the sperm quality of young boars. Other authors did not find a positive relation between boar vaccination against PCV2 and sperm quality (Gava et al 2008;Madson et al 2009). This difference in young compared to mature boars is probably due to the time of vaccination and the age of the boars.…”

Investigation of Porcine Circovirus type 2 (PCV2) antibodies in clinically healthy boars from Serbian commercial farms

“…Infections may come from secretions or contact with diseased animals. PCV2 is also present in semen and artificial insemination can contribute to virus spread (Vicente et al, 2004, Gava et al, 2008. Despite extensive research of PCV2 infection, a precise mechanism of persisting PCV2 in pigs is still unknown (Krakowka et al, 2000).…”