Bird flu spreads through the air

Spread of the bird flu virus H7N9 mainly through close contact

05/25/2013

Just now, the wave of infection with the bird flu virus H7N9 in China seems to be down, as an international research team has already announced the next disturbing message: The new virus should also spread through the air. In a study with ferrets on the one hand the infection from animal to animal but also the distribution via the airway has been demonstrated.

Bird flu virus could spread widely
In the trade magazine „Science“ A group of researchers from China, Canada and the US report that the new bird flu virus is not only transmitted from animal to animal, but also less effectively via the air.

For their investigation, the researchers had isolated the virus from a deceased female patient and dripped it into the nose of ferrets. The next day, three healthy animals were placed in the cage to the infected. Then they placed a second cage with three other healthy ferrets right next to the other cage. After a short time, all the animals in the cage had been infected with the infected ferrets. In the second cage, on the other hand, only one of the three previously healthy animals became infected.

The researchers also found that the pathogens were already in the nose of the animals at least one day before the onset of the first disease symptoms. The virus could therefore be transmitted by humans before they even get the bird flu. This would make an epidemic much harder to control. If, in fact, transmission of the virus from human to human is possible, it could spread widely, researchers suggest.

Despite the possible spread of the bird flu virus over the air no reason to panic
„This animal study shows us that close contact is needed for the virus to spread and that there is a risk of infection for healthcare workers because they are in close contact with humans“, said scientist David Kelvin of the University of Toronto in Canada in a statement from his institute. „It was also found that transmission through the air was very difficult in animals, which is probably the case in humans as well.“

Ferrets are often used for such studies because they are mammals and human-to-human transmissions are derivable. Therefore, the researchers conclude from the study that under certain conditions, too „transmission between humans is presumably possible. "A transmission of the current virus through the air „However, it does not seem to be very easy“, stressed Kelvin.

However, the study results should not be hastily transferred to humans, warned the virologist Professor Hans-Dieter Klenk of the University of Marburg, who with the news agency „dpa“ spoke. „The study is based on strictly controlled experiments on ferrets. So far, there is no evidence that the virus is transmitted from person to person. "Nevertheless, the pathogen must be well monitored, as some of its properties are similar to typical human influenza viruses." The bird flu symptoms are also similar to seasonal flu.

Wave of infection in China with bird flu virus H7N9 ebbs
According to the World Health Organization (WHO), 131 people have been infected nationwide since the end of March, when Chinese authorities first reported infections with the bird flu virus in humans. For 36 people, the infection ended fatally. However, there have been no other cases since 8 May so precautionary measures, including the killing of many birds and poultry, seem to be working.

Meanwhile, drug companies such as Novartis, Sanofi and Baxter are working hard on a vaccine against the bird flu virus H7N9. Because the virus could reach other regions outside of China such as the USA or Europe via migratory birds. According to Klenk, a bulk vaccine could be available in about three months. (Ag)

Picture: Gerd Altmann, Pixelio