No all-clear for bird flu virus H7N9

Doctors give no all-clear for the H7N9 bird flu virus

The previously unknown bird flu virus H7N9 has cost seven lives in China. Other infections have been confirmed, and there are now 24 patients. Chinese authorities and the World Health Organization (WHO) are assessing the situation.
What does H7N9 mean?
The new bird flu virus is called "A (H7N9)", the A stands for type A flu. The proteins in the virus envelope (hemagglutinin and neuraminidase), of which there are different structures, are abbreviated to H and N. Infection with these virus combinations usually occurs in birds. Infections from sub-group H7 have already been identified in humans, but not in combination with N9. This variant, which has been found frequently in China in the past few days, had not previously occurred in humans.

Contagion options
It has not yet been possible to determine exactly how the affected people became infected because the source of the infections is still unknown. The virus was detected in various birds: in pigeons in Shanghai, China, and in quails in other cities. Much of China's population is rural, which often comes into contact with various animals. There are often various live birds to buy in Chinese markets. In some of the infected patients, close contact with animals is considered safe. A special WHO website provides information on cases that have become known so far.

What is the danger of the new virus?
Theoretically, there is a pandemic risk for every flu virus in an animal that can also infect humans. This means the spread of a disease across countries or continents. However, animal influenza viruses have not yet led to a pandemic in humans, despite individual evidence. But to assume that they are harmless would be wrong and the fear that has arisen is understandable. For example, there have been more than 600 people infected with the H5N1 avian influenza virus since 2003. There were 371 deaths. It is still unclear whether a pandemic could be triggered by H7N9. But if there was evidence of human-to-human transmission, the risk would skyrocket. However, according to the Chinese authorities, there is no evidence of this.

Is there a danger when traveling to China?
There have been few confirmed infections so far and the World Health Organization has not issued travel restrictions. Despite this, Chinese airlines are already experiencing significant drops in passenger numbers to the cities concerned. Since there are no indications of possible connections between Chinese products and the cases of illness, the WHO does not recommend any trade restrictions.

No vaccination so far
There is still little information available about the patient's symptoms. It is known that most infected people developed severe pneumonia. You can usually treat type A flu with medication (neuraminidase inhibitors). There is also evidence that these work at an early stage of, for example, A (H5N1) infections. For the virus combination H7N9, however, there is as yet no information as to whether such drugs are effective. So far there is no vaccination against the virus.

Information from the World Health Authority
If people with suspicious flu symptoms are reported to the Chinese authorities and the infection is confirmed, contact people are also tested and monitored. In China, the sale and trade in birds has been severely restricted or banned, markets have also been closed and thousands of animals culled as a precaution. According to the WHO, it is harmless to eat well-cooked meat from healthy birds, as flu viruses usually do not survive at temperatures above 70 degrees Celsius. However, it is warned about the consumption of sick animals and also the direct contact with animals in markets. In some cities in China, hospitals were placed on alert and advised to store necessary medicines in large quantities. So far there are no known cases of infected people in Germany. Further developments must be closely monitored in order to identify possible dangers at an early stage. The World Health Authority provides detailed information on the bird flu virus on a website. (ad)

Image: Gerd Altmann /

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Video: ScienceLIVE: The Threat of H7N9 Bird Flu

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