This guideline is an interim update of the 2015 guidelines to reflect recent changes in epidemiology, testing and treatment. We have added new advice on hepatitis A testing and vaccination in response to the recent HAV outbreak in MSM, updated the definition of chronic hepatitis B and advice on vaccination of HIV patients. We have also updated advice on hepatitis C testing and treatment. This is accompanied by expansion of the relevant background sections in the main text (sections 2-5). Changes to the 2015 guideline are highlighted in yellow. This update was performed by a small subgroup of the 2015 writing committee but using the same methodology as below.