Mikey - Leptospirosis is rife where we live at the moment, with some deaths even, so I'm not going to drop having this done. Just as if I saw a big jump in the number of Parvo cases locally, I'd be taking mine in for that to be boostered too. I'd always consider local conditions when deciding whether or not to booster to be honest.
Quote from my vet's reminder "We have seen cases of Leptospirosis recently which are usually fatal. This part of the vaccine only lasts for 12 months so please ask your owner (this reminder is addressed to Dear Frankie and Teazel!!) to contact your surgery to make an appointment." I am a cynic and always think 'kerching', but ................