Out of the samples taken, 11 per cent of hands, 8 per cent of bank cards and 6 per cent of banknotes showed gross contamination, the study found.
In Britain, 10 per cent of bank cards and 14 per cent of notes were found to be contaminated with some faecal organisms, the research, carried out at Queen Mary, University of London and the London School of Hygiene & Tropical Medicine, showed.
More than a quarter (26 per cent) of hands sampled showed traces of faecal contamination, including bacteria such as E coli.
The 272 participants in the study were asked to fill out a questionnaire. Only 39 per cent said they washed their hands before eating.
The vast majority (91 per cent) said they washed their hands after using the toilet, although the levels of faecal organisms found suggested otherwise, researchers said.
Washing hands with soap can reduce diarrhoeal infections by up to 42 per cent, but only 69 per cent of people reported doing this whenever possible.