"Children's ball pit play areas contain dozens of killer germs," reports the Mail Online.
Ball pits, a popular form of play for children, are sometimes used by physiotherapists working with children, especially those with autism. But commercial ball pits in shopping centres and restaurants have previously been found to be contaminated with dirt, urine and faeces. A survey of 6 ball pits in physiotherapy clinics found many of these also contained large numbers of micro-organisms, including 9 bacteria or yeasts known to cause potentially serious illness.
The researchers found wide variation between the amounts of bacteria in the different ball pits, which may reflect different cleaning regimes. They report that some clinics "may go days or even weeks" between cleaning of ball pits.
The study didn't look at whether any children had become infected or ill as a result of using the ball pits. However, they warn that children could pick up infections, especially if they have cuts or grazes to their skin, and if they have weakened immune systems.
They suggest that further research needs to be done on how often ball pits, used in a clinical setting, need to be cleaned.
If you are concerned about exposure to germs, a potentially useful step to take is to encourage your child to wash their hands after they finish playing.
Where did the story come from?
The researchers who carried out the study were from the University of North Georgia in the US. The study was funded by the university. It was published in the peer-reviewed American Journal of Infection Control on an open-access basis, so it is free to read online.
The study was covered in The Sun and the Mail Online, which carried accurate and balanced reports of the study that were sadly let down by over-alarmist headlines. We don't know whether the same results would have been found in UK clinics, which might have different cleaning regimes.
What kind of research was this?
This was a survey of ball pits in which randomly selected balls were taken for microbiological analysis. The study can give an estimate of the numbers and types of bacteria in each individual ball pit, but the results don't necessarily apply to all ball pits.
What did the research involve?
Researchers sampled 6 ball pits in physiotherapy clinics in Georgia, US. They sampled 9 to 15 balls from each pit, randomly chosen from different depths of the pit. They swabbed the entire surface of each selected ball, then sent the swabs for analysis.
They used agar plates to grow the micro-organisms found on the balls. They then identified the bacteria and yeasts, and calculated how many colonies were found on each ball, and the average number of colonies found on balls from each clinic.
What were the basic results?
Researchers identified 31 species of bacteria and 1 yeast. The yeast and 9 of the bacteria were known to have the ability to cause disease in humans.
Diseases that could be caused by the micro-organisms found included:
- endocarditis (an infection of the inner membrane around the heart and valves)
- septicaemia (a blood infection that can cause sepsis)
- urinary tract infections
- skin infections
The researchers said there was "considerable variability" between the clinics. They found 97% of balls sampled from one clinic had a particularly high number of colonies, while 37% of balls from another reached the same level of contamination. They said bacterial colonisation "was found to be as high as thousands of cells per ball".
How did the researchers interpret the results?
The researchers said the contaminated ball pits demonstrated "an increased potential for transmission of these organisms to patients and the possibility of infection in those exposed individuals".
They added: "Although it is normal to see human microbes wherever humans are present, further study of the amount of colonisation should be performed" and perhaps "standardised cleaning protocols developed".
As the authors say, it's not surprising to find bacteria where you find people. We're all covered with micro-organisms, inside and out, and most of the time they don't cause us any harm – in fact, they are essential to the normal functioning of our bodies. It would be surprising if the balls in ball pits didn't contain any bacteria after children have played in them.
However, you would hope that ball pits used in clinical settings would be regularly cleaned to keep down the levels of potentially harmful bacteria. The widely differing levels of bacteria found suggest a lack of standardisation of cleaning regimes.
The study is very limited. It only included 6 ball pits in clinics in Georgia, so we don't know whether the results are relevant to the UK.
It is of concern that the researchers found bacteria and yeast that can cause serious diseases. However, we don't know whether the presence of these micro-organisms caused illness in any of the children playing in the ball pits. Diseases such as endocarditis and septicaemia are relatively rare.
If your child is using a ball pit at a clinic run by the NHS, you might ask staff how often the pit gets cleaned. The small risk of infection needs to be set against the potential benefit and pleasure that children get from using these play areas.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
Mail Online, 22 March 2019
The Sun, 23 March 2019
Links to the science
American Journal of Infection Control. Published online November 22 2018