In England we are too polite to refer to lice, nits, crabs, fleas, etc. Also, there is a huge head lice problem in the UK, and has been since my DC were small, 20-30 years ago. There are often MN threads about this problem. DD, aged 15, having been clear for ages, came home with lice caught in a mosh pit 
The nearest insult I can think is "lousy" but it just means bad.
However, from Across the Pond the Other Way, we would probably agree that Trump has the lurgie. This means a) a mild infection of unknown origin, and (b) the equavalent of "cooties" in school playground use, usually only in primary schools ie up to age of 11. If someone has given you the lurgie, the only way to get rid of it is to give it to someone else, accompanied by a cry of "You've got the lurgie."
But mainly we call Trump an idiot and laugh at him. The laughs are tinged with horror that he might get in again...