PMWS Transmission: Pig-to-Pig Transmission
This report in the June 2008 issue of the newsletter from the EU PCVD Consortium demonstrates that Post-Weaning Multisystemic Wasting Syndrome (PMWS) can be passed to healthy pigs from infected herds.Pigs were obtained from two (1-2) PMWS non-affected herds and four herds (A-D) that were PMWS-affected according to the EU definition.
The herds were matched on health status and were all infected with Porcine Reproductive and Respiratory Syndrome virus (PRRSV).
The PMWS non-affected herds selected had a low mortality rate and no clinical signs of PMWS in the weaning unit before the start of the study. The mortality was recorded in all herds during the study and for 2 months after the end of the study.
A veterinarian selected 27 pigs with clinical signs of PMWS 2-3 days before start of the study from the weaning units of each PMWS-affected herd. 144 pigs aged 4-5 weeks were obtained from each of the PMWS non-affected herds.
The animals were distributed to research facilities I and II consisting of 8 separated units as shown in table 1. All pigs in units 5-8 served as controls.
At research facility I the pigs from PMWS-affected and PMWS non-affected herds were mingled according to figure 1.
During the 48 days of the transmission study 27 pigs from PMWS-affected herds were euthanased and 16 were diagnosed with PMWS according to the EU definition by laboratory examination.
Of the pigs from PMWS non-affected herds 25 were euthanased due to clinical signs of PMWS.
The PMWS diagnosis was confirmed in 14 pigs, 10 by direct contact (same pen), 3 by close indirect contact (neighbouring pen) and 1 by indirect contact (across the aisle).
None of the control pigs developed any clinical signs of PMWS during the study.
Based on this study it can be concluded that PMWS can be transmitted to healthy pigs after mingling with pigs from PMWS-affected herds.
October 2008
- | You can view the EU PCVD Consortium report on aerial transmission of PMWS by clicking here. |
Further Reading
- | Find out more information on PMWS by clicking here. |