More infoPlymouth has been named the UK's STI "blind spot" where most have never been tested. It's according to new research that found adults living in Plymouth have the lowest STI testing rates in the UK. Plymouth was found to have the highest proportion of adults who never get an STI test (78%), followed by Exeter (73%) and Sheffield (72.%). Londoners are the most likely to test, followed by Belfast (43.6%) and Edinburgh (44.7%). More than one in ten adults in Plymouth also admitted they never use condoms (12%).