Authorities in El Salvador have tightened control of its borders as contagious diseases, caused by the floodwaters left behind by Hurricane Mitch, spread across Central America.

Recorded cases of cholera have now reached more than five hundred.

El Salvadorean border guards are meant to be checking every lorry load of food products that come into the country but they say that, in the face of the huge volume of traffic, the checks have become increasingly sporadic.