Playing in the ball pits found at paediatric physiotherapy centres may be a health hazard for children, with a study showing they harbour a host of pathogens.

Cultures grown from swabs of 9-15 balls from each of six physiotherapy clinics in Georgia, US, revealed numerous types of micro-organisms — including those that cause bacteraemia and sepsis.

Among the 32 micro-organsims identified, nine were opportunistic pathogens, the researchers write in the American Journal of Infection Control.

These included the bacteria Enterococcus faecalis, Staphylococcus hominis, Streptococcus oralis, Acinetobacter lwoffii, Raoultella terrigena and Klebsiella variicola, which could cause bacteraemia, sepsis or endocarditis, they said.