The environmentally friendly trend of washing clothes in lower water temperatures could be failing to eliminate fungal pathogens from dirty socks, a study from Israel shows.

The researchers took samples from 81 socks worn by patients with tinea pedis, caused by the fungus Trichophyton rubrum, and washed them at 40°C and 60°C.

Taking fungal samples from the heel and toe of the washed socks, they found that 36% of the socks washed at 40°C had positive fungal cultures; 70% of these were caused by Aspergillus.

This compared to only 6% of socks washed at 60°C being positive for fungal cultures and all were caused by Aspergillus.

Trichophyton rubrum was found in four of the socks washed at 40°C, but none of the socks washed at 60°C.

The authors said the study confirmed that washing clothes at high temperatures was essential for completely eradicating fungal pathogens.

“We consider that uses of other modes of disinfection, such as UV devices, should be considered as standard applications in domestic washing machines,” they said.

Catherine Hanrahan
Medical Observer