I work in this particular arena and these issues are not just happening in the UK. CSE problems are rife across Europe and beyond. In particular sex trafficking is a very significant problem in Cambodia and Vietnam. Brazil and Thailand have the worst issues with child prostitution - source. Belarus, Russia, China, North Korea are some of the countries with the worst sex trafficking statistics. Source
The USA also has problems with sex trafficking and child prostitution - source source 2. However the US is now classed as going from having a tier 3 to a tier 1 problem. This means that they have now acknowledged the issue and are taking steps to address this.
These issues are currently being better reported in the media in the UK but they are in fact a world wide issue. Furthermore this is a hidden crime and a large percentage of offences go unreported, making it very difficult to estimate the full scale of the problem. It is important to know how wide scale this is. The only way this is going to stop is by people knowing about this problem, being vigilant to any issues in their area, and reporting concerns to the authorities.