by Tanya Melillo Fenech MD MSc

Chairperson of the National Influenza Pandemic Standing Committee

 The situation regarding avian H5N1 virus is only getting worse. Since the
beginning of February 2006 affected wild birds – mainly swans – have been recorded in 14 European countries, without involvement of domestic poultry (Austria, Bosnia, Bulgaria, Croatia, Germany, Greece, Hungary, Italy, Poland, Slovakia, Slovenia, Sweden
& Switzerland). In France, a commercial turkey farm, adjacent to a site where infected swans were located, has also been found infected.

Other countries like Albania, Azerbaijan, China, Egypt, India, Indonesia, Malaysia, Niger, Russia and Romania have poultry affected with the virus. The situation in Africa is of particular concern. It is now obvious that H5N1 has become significantly endemic and widespread in poultry populations outside South East Asia.

The discovery in Germany and Austria of H5N1 virus affecting also domestic cats has only complicated the picture. Other animals that have been infected with H5N1 include tigers, pigs, civets and ferrets. In Germany, on the 10th of March it was also discovered in a stone marten (a member of the weasel family). To date only domestic poultry have been shown to play a role in the transmission cycle of the virus from animals to humans. Further investigation is needed to determine whether evidence of H5N1 infection in new mammalian species has any significance for the risk of human infection or the potential of this virus to adapt to mammals, including humans.

Studies done this year on H5N1 viruses show that multiple lineages of the virus are now established in poultry in parts of Asia. Poultry to poultry transmission is thought to sustain endemicity of the virus in this region. H5N1 virus has been isolated from apparently healthy migratory birds in southern China suggesting that migratory birds can carry the virus for long distances.

According to the WHO, the cumulative number of confirmed cases of human avian virus  up to 10th March is 176 cases and 97 deaths (case fatality rate of 55%).

Seasonal Influenza Surveillance

From October 2005 to date there has been low reporting of influenza cases in Europe compared to previous years. Virological studies have shown that 68% of cases where found to be Influenza B while 32% where found to be influenza A (H3N2 and H1N1).

Infact, it has been recommended that the 2006-07 influenza vaccine will consist of “Wisconsin” strain for Influenza A (H3N2) replacing “California” strain, and “Malaysia’ strain for Influenza B replacing “Shanghai” strain. The “New Caledonia” strain of H1N1 used for this year’s vaccine will be used again as the third component of the trivalent vaccine.

For further information check the Disease Surveillance Unit Web Portal on http://www.health.gov.mt/dsu/ and TheSYNAPSE Web Portal on http://www.thesynapse.net/ (MAKE A SECTION ON THIS)

The information is correct as on 13/3/06.