Removing your shoes when you enter a house to prevent the spread of germs can be annoying - but it also may not be enough. Even if you don't come from a household with a zero tolerance policy towards shoes indoors, it's likely that you've visited a home that does.

As you wrestle off the offending footwear, praying that you wore a decent pair of socks, you may wonder if all this is really necessary... but it seems that the answer is yes.

Shoe shelf
There is an average of 421,000 types of bacteria on 96% of shoes

According to a recent survey from The University of Houston, there is an average of 421,000 types of bacteria on 96% of shoes, with E. coli lingering on 27% of soles. 

Speaking to the Journal of cleaning, restoration and inspection,  Dr. Charles Gerba, a microbiologist at the University of Arizona said, "The common occurrence (96%) of coliform and E. coli bacteria on the outside of the shoes indicates frequent contact with fecal material, which most likely originates from floors in public restrooms or contact with animal fecal material outdoors".

As if that wasn't revolting enough, there was a 90-99% transfer rate of germs from shoe to floor. If this doesn't make you lose confidence in the 5-second rule from childhood nothing will.

However, there is still hope. According to the study, washing shoes in the washing machine will kill 90% of the bacteria present and all of the fecal matter - hurrah! Just try not to let your mind fester on that final 10% or on the practicality of regularly washing your shoes. 

On another note, a survey released today commissioned by UK company Modern Rugs found that shoes are not the main cause of bacteria in the home - meaning that even when you leave your shoes at the door, more bacteria can enter in other ways! (Screams internally) 

Germs on shoes
There is a 90-99% transfer rate of germs from shoe to floor

The survey found that ineffective cleaning was the greatest cause of the presence of bacteria in the home, and that bad practice can spread it from room to room. 

"The key to reducing bacteria in the home is by effective cleaning. Ineffective cleaning can actually increase numbers as it spreads bacteria around the house. Effective cleaning usually means using the correct products in the correct order." Dawn Mellors, Technical Director at Melbec Microbiology told Open PR

If you're unsure about the calibre of your cleaning regime, experts advise using a dry, clean cloth, a dehumidifier, a steam cleaner and a hoover with a filter to prevent further spreading of bacteria. Wooden floors also offer the best platform for effective cleaning. 

So it seems shoe-less strategies alone are not the answer. To really banish bacteria, you also need to be sure you're being clever when it comes to cleaning.