Should We Worry about H1N1(Swine Flu) combining with H5N1(Bird Flu) ?

A Poultry outbreak in Chile sparks new alarm

The detection of an H1N1 virus in turkeys in Chile raises concern that poultry farms elsewhere in the world may also become infected with the pandemic swine flu virus, according to the United Nations FAO (Food and Agriculture Organization). Chilean authorities last week reported that the pandemic H1N1 virus, had been detected in turkeys on two farms near Valparaiso.

The flu strain found in the poultry flocks is identical to the H1N1/2009 pandemic strain currently circulating among human populations around the world.

The FAO said the discovery of the virus did not pose any immediate threat to human health and turkey meat can still be sold commercially following veterinary inspection.

However, the FAO did say that it could theoretically become more dangerous if it combines with H5N1, commonly known as bird flu, which is far more deadly but harder to pass along among humans. [See an earlier post in this blog called “Swine Flu and Bird Flu - What If They Join Forces?” http://blog.binomial.com/2009/08/swine-flu-and-bird-flu-what-if-they.html

The report describes two cases of what is described as 'influenza A virus' in turkeys in the state of Valparaiso.

One case, starting on 29 July, is in Nogales. It involved illness in 12,248 breeding turkeys of a flock of almost 30,000. An abnormal decrease in the laying rate was observed but no respiratory signs or increased mortality.

Symptoms were observed on 23 July in another flock of breeding turkeys in Valparaiso. More than 24,000 birds out of another flock of 30,000 birds were affected. Egg production fell from around 70 per cent to 31 per cent, and shell quality deteriorated. Again, no respiratory signs or increased mortality were observed. Necroscopy of the affected birds showed salpingitis, peritonitis and an interruption of the follicular development. No other lesions were observed. Samples of embryonated eggs collected from the incubation building gave negative results with real time PCR. Twenty days after the beginning of the event, a recovery in the laying rate was observed.

The affected farms are turkey breeding premises belonging to the same company, vertically integrated, where appropriate biosecurity measures are applied.

Outbreak 1 was on a farm composed of five breeding premises. The outbreak started in premises no. 1 and through horizontal transmission, it reached three other premises. In outbreak 2, two of five sectors were affected.

Chile does not yet have H5N1 flu. In South-East Asia where there is a lot of the virus circulating in poultry, the introduction of H1N1 in these populations would be of a greater concern.

The FAO is encouraging better monitoring of animals to ensure that hygienic and good farming practice guidelines are followed.

Chile is now the fourth country that is investigating the spill-over of the H1N1/2009 virus from farm workers showing flu-like illness to animals, with swine becoming infected in Canada, Argentina and, most recently, Australia.

The emergence of new influenza virus strains capable of affecting humans and domestic animals remains a broader, more general concern that is being closely monitored by FAO, the World Organization for Animal Health and the WHO (World Health Organization).

The U.S Center for Disease Control and Prevention said it was theoretically possible for the viruses to combine. That hasn't been documented but is a concern."