paedophilia       
noun [ U ] UK (US pedophilia) uk/ˌpiː.dəˈfɪl.i.ə/ us/ˌped.oʊˈfiː.li.ə/
 恋童癖
the condition of being sexually interested in children, or sexual activity with children
  This initiative is aimed at stamping out internet paedophilia. 这项新举措的目的在于杜绝网上的恋童罪行。 
 See: paedophile
 - More examples
 - This is the largest ever police investigation into online paedophilia and child pornography.
 - He has convictions for paedophilia and child abuse.