It may seem like a subject ripe for toilet humour — but whether you close the lavatory lid before you flush could have an impact on the spread of disease, according to an expert.
Professor Mark Wilcox, Clinical Director of Microbiology at Leeds Teaching Hospitals NHS Trust, said leaving the lid up can allow a cloud of bacteria to explode into the air, settling on nearby surfaces.
This increases the risk of viruses like the winter vomiting bug transmitting to another person.
“It is very clear from our work that the lid is there for a reason,” Professor Wilcox said.
Professor Wilcox and colleagues from Leeds University conducted a study to see how using a toilet lid could affect the spread of disease, specifically in hospitals.
They used a sterilised toilet cubicle and created a “diarrhoea effect” in the bowl using stool samples that had been infected with the hospital superbug C. difficile.
They found C difficile was transported up to 10 inches above the toilet seat when it was open and a reduced rate was still detected in the air up to 90 minutes later. Although C difficile did travel through the gap when the lid was down it was found in far lower concentrations in the air.
When the lid was closed no C. difficile was recovered on any surface, but when it was open it was found on the cistern, to the right and left of the toilet seat and on the floor.
Professor Wilcox said: “We then put vegetable colour dye in the water bowl, lifted the lid and put cling film over the toilet seat. After we flushed the toilet we found it sprayed a large amount. By placing the film onto filter paper we found that the toilet could spray up to 50 droplets per flush.”
They noted that many hospital toilets don’t have lids — ironically in an attempt to stop cross-contamination from handling a lid.
The professor said that although it was unlikely that keeping the lid up would be a “huge” health hazard, their findings suggested patients with a superbug should at least have a dedicated toilet.
He added that their research also had wider implications, adding: “It would be prudent if there is a lid to put it down after flushing.
“This contains smells and droplets that can become aerolised. Some bugs spread more easily to surfaces this way and the norovirus is thought to be one of them.
“Our advice — put down the lid if it’s there and wash your hands afterwards.