Page 39 of articles about health in Articles

It is important to be able to identify the distinct circulating strains and to differentiate between the strains that are merely colonisers and those that have the capacity to produce disease. With this aim various methods of classification of strains or “typing” of H. parasuis have been developed.

When the clinical signs on the farm and the lesions observed in the piglets lead us to suspect that there is a Haemophilus parasuis infection we have to confirm this diagnosis in the laboratory

Haemophilus parasuis is present in all swine producing countries and its prevalence is close to 100% on conventional farms. However, only a percentage of these farms present pathologies associated to the infection.

The factors of virulence allow the pathogenic strains to survive inside the animal and cause the infection, while the non-virulent strains lack these factors and can only survive in the upper respiratory tract as colonisers.

Pig rearing practices in the country need a lot of improvement considering that about 70% of pigs are on a backyard level.

On a conventional farm with no problems with Glässer’s disease, it is possible to isolate various strains of Haemophilus parasuis which colonise piglets while being in balance with the animal’s immunity without producing pathology.

Experimentally it is difficult to demonstrate whether a pathogen can be windborne and if so how far.

H. parasuis is a gram-negative bacillus of small size, which belongs to the Pasteurellaceae family. The group characterized by fibrinous polyserositis and fibrinous arthritis became known as Glässer’s disease.

We may have some highly efficient vaccines, but we shouldn’t forget that for their application we must obtain good diagnostic information, and that in all cases we should not lose sight of good management and a good control of the concomitant diseases.

The usual pig viruses are H1N1, H3N2 and H1N2. The original H1N1 pig viruses have been largely replaced by poultry viruses in pigs. The H3N2 viruses were from humans originally. The H1N2 viruses are re-assortants from human viruses (H and N genes) and poultry viruses.

Between 1995 and 1997, at the beginning of an epizootic called “maladie de l’amagrissement du porcelet” (MAP), it was observed that the farms that were most affected and that had the most losses, generally presented obvious deviations from what we would consider to be a suitable management of the animals and facilities. This is why Dr. François Madec made a list of management practices with the aim of improving the anomalous situation observed.

There are several decisions to make before attempting an eradication programme. Firstly, which antibiotic should we use? If we have had the disease on the farm for some time, the Brachyspira will have been exposed to possibly a number of drugs and may have reduced susceptibility to some of them.

The use of diagnostics will allow producers and practitioners to work together towards the common goal of PRRS eradication

On December, the Philippine Department of Agriculture announced that the non-lethal Ebola Reston Virus previously only found in monkeys, had been detected in pigs

The first swine influenza viruses were all H1N1 and were for about 60 years in North America. In the middle 1980’s, there appeared in European pigs H3N2 viruses that were derived originally from humans and had adapted to pigs and were therefore known as human-like H3N2 viruses. These viruses have since appeared in other parts of the world most notably as H3N2 in the USA in 1998. These viruses however contained bits of human, avian and swine viruses and were therefore called triple re-assortants.

It is produced by a virus with genetic material from porcine, human and avian viruses which has shown the ability unusually for such a virus to transmit from human to human. The virus appears to have 2 of 8 gene segments that derive from eurasian swine viruses. The NA and matrix genes of the new virus have not been seen in humans or pigs before.