Guangzhou, China: The cacophony of squawking, clucking, honking and quacking that two football fields' worth of live poultry makes is the first thing you notice approaching the Baixing Free-Range Bird Wholesale Market.
Then the smell of feathers, feed, dirt and faeces hits.
Tens of thousands of birds from all over southern China are trucked each day to the market in a dust-covered suburb of Guangzhou where they are stocked temporarily in small pens and sold live or butchered to retailers or restaurants. It is a massive one-stop shop for all kinds of poultry, including chickens, ducks, geese and pigeons. It is also possibly the ideal place for avian influenza to spread.
The H5N1 strain of bird flu has spread with surprising speed. Since January, more than 30 countries have reported outbreaks.
Sitting in the middle of the market, duck vendor Li Jingwen seems oblivious to the noise and stench, and brushes off suggestions that bird flu might be something to fear.
As his colleagues toss ducks into a basket to be weighed and sold, Li loads a wad of tobacco into a bamboo water pipe and explains.
"So few people have been infected by bird flu," he says, squinting to avoid dust and feathers stirred up by a janitor. "The common cold infects and kills more people around the world."
A woman who runs the tiny convenience store next to the feed depot by the market's exit feels the same way. "The chickens aren't afraid, so why should we be?"
Markets like Baixing, and smaller "wet markets" that are ubiquitous in Chinese villages, towns and cities, are worrisome.
"The mix of different species and the way in which live markets operate clearly is something which we need to look at," Julie Hall, in charge of the WHO's efforts against bird flu in China.
The Chinese government is taking measures to better regulate its markets. In some places, like Shanghai, the sale of live poultry has been banned in city wet markets. China has also been vaccinating farmed poultry in the past few years.