TY - JOUR
T1 - Transmission of different variants of PCV2 and viral dynamics in a research facility with pigs mingled from PMWS-affected herds and non-affected herds
AU - Dupont, Kitt
AU - Hjulsager, Charlotte Kristiane
AU - Kristensen, C.S.
AU - Baekbo, Poul
AU - Larsen, Lars Erik
PY - 2009
Y1 - 2009
N2 - Post-weaning Multisystemic Wasting Syndrome (PMWS) has been identified in most swine-producing countries worldwide. The disease has resulted in significant health
challenges and economic damage to the swine industry. The aim of this study was to determine horizontal transmission of porcine circovirus type 2 (PCV2) and to examine
viral dynamics in pigs in a controlled PMWS transmission study. In the study pigs from PMWS-affected herds and non-affected herds were permitted to have close contact (same
pen), nose-to-nose contact (to pigs in neighbouring pens) or no physical contact (pen across the aisle and pens in other compartments). By DNA sequence analysis, eight
variants of genotype PCV-2b were identified in the research facility. From the spread of these PCV2-variants it was concluded that PCV2 primarily infects through close contact and nose-to-nose contact. PCV2 genome sequences were obtained from selected pigs at arrival to the research facility and again when the same pigs developed PMWS. This analysis showed that pigs from PMWS-affected herds developed PMWS caused by the same variant of PCV2 as they carried when entering the research facility. In contrast, pigs from non-affected herds developed PMWS with PCV2-variants identified in pigs from PMWS-affected herds. This was probably connected to at least 103 higher mean serumtiter of PCV2 in pigs from PMWS-affected herds as compared to pigs from non-affected herds at the beginning of the transmission study. The study further showed that pigs able to control the PCV2 infection, as measured by the PCV2-titer in serum, recovered clinically(pigs from PMWS-affected herds) or stayed healthy (pigs from non-affected herds). Likethis, pigs with a PCV2 titer below 5 108 copies/ml serum during the study period had a
chance of recover from the PCV2 infection whereas pigs with PCV2 titers above 5 108 copies/ml serum at any time point generally died from PMWS.
AB - Post-weaning Multisystemic Wasting Syndrome (PMWS) has been identified in most swine-producing countries worldwide. The disease has resulted in significant health
challenges and economic damage to the swine industry. The aim of this study was to determine horizontal transmission of porcine circovirus type 2 (PCV2) and to examine
viral dynamics in pigs in a controlled PMWS transmission study. In the study pigs from PMWS-affected herds and non-affected herds were permitted to have close contact (same
pen), nose-to-nose contact (to pigs in neighbouring pens) or no physical contact (pen across the aisle and pens in other compartments). By DNA sequence analysis, eight
variants of genotype PCV-2b were identified in the research facility. From the spread of these PCV2-variants it was concluded that PCV2 primarily infects through close contact and nose-to-nose contact. PCV2 genome sequences were obtained from selected pigs at arrival to the research facility and again when the same pigs developed PMWS. This analysis showed that pigs from PMWS-affected herds developed PMWS caused by the same variant of PCV2 as they carried when entering the research facility. In contrast, pigs from non-affected herds developed PMWS with PCV2-variants identified in pigs from PMWS-affected herds. This was probably connected to at least 103 higher mean serumtiter of PCV2 in pigs from PMWS-affected herds as compared to pigs from non-affected herds at the beginning of the transmission study. The study further showed that pigs able to control the PCV2 infection, as measured by the PCV2-titer in serum, recovered clinically(pigs from PMWS-affected herds) or stayed healthy (pigs from non-affected herds). Likethis, pigs with a PCV2 titer below 5 108 copies/ml serum during the study period had a
chance of recover from the PCV2 infection whereas pigs with PCV2 titers above 5 108 copies/ml serum at any time point generally died from PMWS.
U2 - 10.1016/j.vetmic.2009.06.001
DO - 10.1016/j.vetmic.2009.06.001
M3 - Journal article
C2 - 19576705
SN - 0378-1135
VL - 139
SP - 219
EP - 226
JO - Veterinary Microbiology
JF - Veterinary Microbiology
IS - 3-4
ER -