Human patients infected with the A(H7N9) strain of avian influenza are not able transmit the virus to animals, including birds, according to the UN’s Food and Agriculture Organisation.
A Chinese tourist from Guangdong province on a visit to Malaysia was found to have contracted the poultry-sourced low pathogenic virus, and has since been hospitalised.
Guangdong is one of the Chinese provinces that has been most affected by the A(H7N9) virus.
“This case does not come as a surprise and should not be a cause for increased concern, but should remind the world to remain vigilant," said FAO chief veterinary officer Juan Lubroth, adding that humans who become ill with the strain constitute no threat to poultry populations.
“In fact, we have no evidence that affected people could transmit the virus to other species, including birds. The highest risk of virus introduction is uncontrolled live poultry trade between affected and unaffected areas.”
People, on the other hand, become infected following close contact with infected live poultry, mostly in live bird markets or when slaughtering birds at home.
Risk assessments by the World Health Organisation show that should infected people from affected areas travel internationally, community level spread is unlikely since the virus does not have the ability to transmit easily among humans.
Lubroth added: "Such 'imported’ human cases, like the one reported in Malaysia last week, have been found in the past in previously unaffected areas of China, like Guizhou, Taiwan Province of China and Hong Kong SAR, and we will likely continue to see this in the not too distant future again. To date the virus has not been found in poultry populations outside affected areas in China.”
Birds that have contracted A(H7N9) do not show clinical signs, which renders early detection of the virus in poultry populations more difficult. The FAO has urged countries to adapt their surveillance programmes to include this recently emerged virus.
One of its main recommendations is to target surveillance at critical points of entry, where direct or indirect live poultry trade with infected areas might occur.
In order to reduce human exposure to zoonotic pathogens in general, the FAO recommends that biosecurity measures should be introduced or reinforced at live bird markets, including frequent cleaning and disinfection, establishing market rest days with no poultry present and applying good hygiene standards.
The organisation is currently assisting a number of member countries to prepare for a potential introduction of A(H7N9) into their poultry populations.