This is how urban legends are born and I hate to let a bit of reason get in the way of a nice story.

Put a chicken feet in your mouth (Especially a spicy one) and say 4 to 6 and it comes out as forty-six. Same happens in the Chinese language: si zhi liu and si shi liu.

Or let somebody else work out your hand scribbled notes and 4-6 comes out as 46.

Still pretty old for chicken feet but things like these happen more often in unorganised storage facilities.

46 years ago was 1967. China was in the middle of the Cultural Revolution and I bet you that Frozen Food facilities didn't exist in those days in the town of the story. As technicians know a frozen food warehouse will last only a couple of years and these deep frozen chicken feed would have been replaced several times to new facilities. Very unlikely.

Pity but not a new record. Just bad journalism.

Well Liumingke1234 the drought is not over.
19 cm of rain is only in some places. The South of Kunming hardly got any. The flooding are not so much caused by the amount of rain fall but by the amount of runoff. The ground is so dry that it hardly absorbs water and the result is that it runs off. Gravity dictates that it goes to the lowest places and that is where the floodings were. Also some reservoirs might be refilled it does not mean that ground water levels are replenished. Droughts are here to stay.

Yunnan is full of travel agents. If you want to get off the beaten track or are interested in the Burma Road or trips along the Yunnan-Vietnam railroad than Tinyadventurestours is a good choice.
www.tinyadventurestours.com

Indeed as tigertiger states there is giardia which is a nasty amoeba. Can be recognized by having stomach cramps and farting and burping. Better not get it and if you have it you can use albendazole or metronidazole to get rid of it. Mostly water born so stay away from tap water and raw vegetables Alternative treatment flushing them out with large quantities of beer.

Giardia being an amoeba encapsulates itself when it doesn't like the environment it lives in (your guts) any longer and resurfaces when it things the situation is getting better, that means worse for you. So it hits you when you are fatigued, drunk, have another sickness or having your period. Avoid these and you will have less problems.

Personally I never had giardia in all my time in Yunnan and surroundings.

You are making the usual mistake. The reason you got ill was because you were not used to the local bugs. Your recent experience has resulted in you getting there. Next time you eat the bug you will not notice. My advice is to go back there; you are immune now. (Well a bit more immune than before).

Best way to build up resistance is to go to the worst place you can find lick the floor and after a nasty couple of days spend on the toilet you can from then on go wherever you like without anything. If not than you will spend the rest of your time being worried and stressed out about the possibility to get ill and not having a relaxed time and great local food at decent prices.

Don't make the mistake to think that "western style" restaurants are any better especially a'la carte restaurants. They are the worst. The need to have everything that is on the menu in stock leads to ingredients being old and often stored in a wrong way (Meat dripping on vegetables). And these places might trick you into eating western food like raw vegetables like salads which are sure no no's (At least till you have build up your resistance against the local bugs).