BLOG: Viral matters
There have been a number of matters relating to viral infections in pigs that have tickled my interest recently.
Swine influenza – It is the time of year when the seasons are changing and soon we will be entering the darker, colder six months of the year, when respiratory infections are rife. Last December I visited a pig farm that had just broken with pandemic H1N1 flu and managed to pick up a respiratory infection that lasted for six weeks and finally I was treated with antibiotics to get rid of the secondary bronchitis. The farm had broken down with H3N2 the previous year. I am of an age now when I am invited for free flu vaccines on our National Health and I will take them up on their offer. It made me think of the sow herds and stock persons working on these farms, should they not be vaccinating themselves and also their stock against this common problem now that there is a vaccine that protects against the three major strains (Grippovac 3– Merial/IDT-B). The infections can go both ways.
PRRSV – We have been trying to carry out PRRSV elimination on a closed sow herd, using a triple vaccination approach. After stockpiling a large number of gilts brought in from the infected finishing units, we started with a killed PRRSV vaccine (Progressis – Merial) and then followed up with two live vaccine shots (Porcilis PRRS – Merck) at monthly intervals. Biosecurity was tightened up dramatically, to stop any outsiders, cars and lorries from entering directly on to the farm and gilts will be reared on site in future. Semen is still brought in but hopefully that will remain free of contamination. So far, six months into the programme, piglets appear free of the field virus by blood test and the new ‘rope test’, which collects their saliva and is then tested by PCR. Fingers crossed the pigs will continue to remain negative in the finishing barns.
ASF – African swine fever still seems to be a problem in the East of the EU, up against the Byelorussian border. In my naivety, as it is a ‘notifiable’ disease and is being used politically to limit EU exports of pork to Russia, I thought this would be resolved rapidly but no. It is not so easy. If you Google Earth and look at the borders between the countries you can see a small river and extensive forest either side – an ideal habitat for wild boar. The river is no barrier either. One imagined that there were probably the large impervious fences between the countries as in the old ‘Cold War’ days but there were not. Something major needs to be done, such as build a fence and possibly clear some of the forest for a kilometre or two along the border to stop the ready migration of infected animals; otherwise the risk of spread will continue and possibly grow.
PEDV – Porcine Epidemic Diarrhoea, which has been a highly contagious plague in the US particularly but also other neighbouring countries has shown a slowing down of the disease spread during the summer, falling to 53 new farms a week last week, down from a peak of over 300 new cases/week in the winter months. Don’t be lulled into a false sense of security, as I suspect when the cold kicks in, the Northern States won’t be able to clean down trucks etc like last winter and the level of disease will pick up again, possibly to the 200 mark. What completely disappointed me was to find out a UK breeding company had brought in over 100 boars from the US. Testing and quarantine procedures were carried out but the potential risk is too frightening to contemplate. For it to happen in the UK, an island and therefore potentially protected, rather than in mainland Europe, was also a major surprise and shock. I hope it won’t be repeated.
On this note, the UK (United Kingdom) may change shortly to become ‘EWNI’ (England, Wales and Northern Ireland) and the new ‘USSR’ (United Scottish Socialist Republic) if Scotland votes for independence this month. What exciting times we live in.
