catchy complaints

[shaymaa Elreedy]

This passage is from «The Railway Children»:
"If I was you, Mum," said Mrs. Viney, "I should take and send for the doctor. There's a lot of catchy complaints a-going about just now. My sister's eldest—she took a chill and it went to her inside, two years ago come Christmas, and she's never been the same gell since."
Here mother is suffering from a strong headache and high temperature, so Mrs. Viney suggests that she should send for a doctor. As for the first sentence in bold, I can't understand what is the meaning of catchy. Does it mean tricky, in the sense that a lot of complaints can be dangerous but one don't realize that, or it means endemic.
As for the other sentence in bold, I can't understand it at all. would you please help me to understand?
thanks in advance.

 

[lingobingo]

I think catchy is used here in the sense of a cold or flu being “easy to catch”, i.e. contagious/infectious. And “two years come Christmas” (= by Christmas, it will be two years since it happened) means a time exactly two years before the forthcoming Christmas.

 

[shaymaa Elreedy]

I think catchy is used here in the sense of a cold or flu being “easy to catch”, i.e. contagious/infectious. And “two years come Christmas” (= by Christmas, it will be two years since it happened) means a time exactly two years before the forthcoming Christmas.

thank you so much.