You can find scabies all over the world and it's assumed scabies outbreaks occur due to overcrowding, poverty and poor sanitation. I know when I did some sexual health as a trainee I saw patients with new infestations who had been staying in backpacker hostels. They told me they had been enjoying sexual activities with other guests of the hostels, and doing quite a bit of bed hopping. I suppose it's one way for a parasite to travel the world.