Avian influenza virus H7N9 in stool
Avian influenza virus H7N9 detected in fecal samples
Since the first detection of an infection with the deadly avian influenza virus H7N9 in China, according to the Chinese health authorities, 45 people died of the novel pathogen. A total of 134 cases of H7N9 infection have been confirmed in the mainland of China, said Yu Wang, Director of the National Health Service. Despite intense research, "there are still many unknown aspects of the H7N9 avian influenza virus, including the source of the virus, the pathways and mutation," Wang Yu continued. In a recent study, scientists at Yuen Kwok-Yun from the University of Hong Kong have now shown that the pathogens are also detectable in patients' stool samples and could possibly be transmitted from person to person in this way.
Although there was a long-term suspicion that a human-to-human transmission of the H7N9 viruses is also possible, the evidence for an interpersonal spread of the pathogens is missing. The research team around the microbiologist Yuen Kwok-Yung has now published in the journal "Clinical Infectious Diseases" a study that shows that even fecal samples can contain the infected H7N9 viruses. The researchers examined fecal, urine, and blood samples as well as the sputum and a nasopharyngeal mucosa smear from 12 patients who had to be treated for an infection with the avian flu virus in the intensive care unit. Six of the patients had died as a result of the infection. They also performed a post mortem biopsy of the lung, liver, kidney, spleen, bone marrow and the heart.
More than two-thirds of stool samples with H7N9 viruses loaded
The researchers made some surprising discoveries during their studies. For example, the H7N9 virus was detectable in four of the six faeces( 67 per cent) of the deceased. Also in the chair of two survivors( 33 percent) the pathogens were detected. In addition, a significantly higher virus load was found in the sputum( ejection) of the infected than in the swab from the nasopharynx mucosa. The tests of urine, blood and brain fluid were negative. No bird flu virus could be detected. The possibility of interpersonal transmission of the pathogens via the sputum or contaminated stool must now be tested in further studies. The Director of the Chinese Health Authority concludes that "the future development of the new bird flu virus is still unclear".The risks of an influenza pandemic should not be underestimated, stressed Wang. Also the study director Yuen Kwok-Yung sees the risk of a renewed increase of infections in the winter of this year.(fp)
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