when/and then I got a bad case of malaria

[user_gary]

It was halfway through the year and then I got a bad case of malaria.

Is the "and then" means "when" in this sentence?

[Casiopea]

Nope, but you're right about it referring to sequencing time.

It means,

First, I got halfway through the year, and then, after having done that, I got malaria.

[user_gary]

Thank you casiopea. But I can't understand what you mean by this:

First, I got halfway through the year, and then, after having done that, I got malaria.

Could you explain it to me again? [Particularly I can't understand the highlighted parts]

[Anglika]

Taking the year as starting in January, you have reached June [which is halfway through the year] and have now developed malaria.