Jacques Vallee pointed out how UFO patterns seem to vary according to the area where they are located.
For example in the US aliens are monsters or freaks; in Latin America they are impulsive and often aggressive (more on this later); in France they seem to behave like peaceful foreign tourists; in Russia they are usually malevolent creatures.
Abductions seem to be confined to the USA, that's true but this doesn't mean it's the only place in the world where aliens physically interacted with humans.
In Brazil one of the best cases regards the farmer Antonio Villas-Boas. In 1957, while working in his field, he was allegedely kidnapped by four "spacemen" who took him to a spacecraft, gave him a through medical check-up and then left him alone with an alien woman who proceeded to have sex with him. Villas-Boas' experience may sound far-fetched and fantastic but it left physical traces on him. Immediately after the experience he fell violently ill and had to be hospitalized: his symptoms were consistent with acute radioactive poisoning. Another Brazilian phenomenon are the so called "chupas", which allegedly killed a number of persons in the early '80s.
And Britain? You are right, there doesn't appear a single case where an alien physically interacted with a human. The celebrated Rendlesham Incident was probably some kind of weird experiment carried out jointly by US and British agencies. But Britain has another tradition in which it is second to none: fairy abductions. As Vallee pointed out in "Passport to Magonia" can't UFOs and fairies be two sides of the same coin?