Page 4 of articles about influenza in Articles

Summary of swine influenza (1/2)

Normally, in pigs influenza is an acute respiratory infection with pyrexia, lethargy, prostration, reluctance to eat and drink. Indoor housed pigs are usually affected simultaneously, with recovery within 1-2 weeks. No adverse effects occur unless there is secondary infection.

North American H1N1 influenza update

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.

Swine influenza: epidemiology and emergence of new viruses

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.

North-American human influenza

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.

Epidemiolology and control of swine influenza

Considering the current situation we are reproducing an article by Tom Alexander previously published by 3tres3.com on 30/dec/2005. A key factor in the epidemiology of influenza is the ability of the virus to mutate or, when cells are infected by two different strains, to recombine to produce new viruses. Either of these genetic changes results in the repeated appearance of new strains with different immunogenic structures and/or virulence, including their ability to infect different hosts.

What causes coughing in pigs?

12-Nov-2008
Any factor that irritates or inflames the respiratory system will elicit the physiological response of either sneezing or coughing or both. Although alarming and indicative of disease, coughing is at least a sign that normal physiological responses are taking place and should not in isolation be necessarily seen as a bad thing. We may have sudden or generalized outbreaks of coughing as well as a constant coughing in pig groups. There are infectious pathogenic agents that are normally associated with coughing or laboured breathing in pigs such as Actinobacillus, Bordetella, Haemophilus, Pasteurella Streptococcus, Mycoplasma, SIV, PRRSV or PCV2.