March 9th, 2006 11:35 EST
Deadly bird flu strain confirmed in Germany for second time in two weeks
ATLANTA - A fourth H5N1 avian influenza infection has been confirmed in a second non-human mammalian species, German officials said Thursday.
The animal, a stone marten, was found alive March 2 on the Baltic island of Ruegen, but showed signs of serious illness. Samples from the large, tree-dwelling creature were sent to Germany’s Friedrich-Loeffler Institute for Animal Health, where tests confirmed the presence of the H5N1 virus.
This marks the second time in two weeks German officials have confirmed H5N1 infection in non-human mammals on Ruegen. They announced Feb. 26 the presence of the virus in a dead domestic cat. Since then, two other cases have been confirmed in domestic cats on the island.
Officials suspect the cats and the stone marten, which has predatory feeding patterns similar to that of cats, were infected with the virus after feeding on dead birds. More than 100 dead birds have been found on Ruegen since the middle of February. Among those, there have been several confirmations of H5N1 infection.
To date, there have been no confirmed cases of H5N1 being transmitted from mammalian species to humans. All human cases have been linked to exposure to infected poultry. However, an H5N1 outbreak among captive tigers in Thailand in Oct. 2004 showed evidence of tiger-to-tiger virus transmission. The tigers were infected with the virus after being fed raw meat from infected chickens.
The avian influenza virus resides in the intestines of most bird species, with wild birds having a general immunity to it. The H5N1 strain has proven to be a particularly virulent one to which wild birds do not have the same immunity.
Health officials are worried about the possibility of this deadly strain becoming a pandemic, such as the 1918 H1N1 Spanish flu, which killed an estimated 50 million to 100 million people worldwide. One slight mutation in the H5N1 virus’ genetic code, which is similar to that of H1N1, could give it the ability to spread through human-to-human contact.
H5N1 was first confirmed in humans in 1997 in Hong Kong. The current outbreak of the virus began in December 2003 in Vietnam, and has resulted in 175 confirmed infections and 96 deaths.
Source: World Health Organization