We live in a 'global village' nowadays. It could happen.... And all too easily.
I remember when England held the rugby World Cup some years back. People came from all over the world - and brought their viruses with them.
The same when the EU expanded to include Eastern Europeans and many of them came here looking for work and opportunity.
If it spreads to Nigeria and Gambia we would be in trouble. Then because of the number of travellers, business and holiday, it could break out and go global.
But lets hope not ...