Infection Risk by Dermatophytes During Storage and After Domestic Laundry and Their Temperature-Dependent Inactivation

Abstract

In the developed countries infections of the feet (tinea pedis, athlete's foot) and nails (onychomycosis) with the anthropophile fungus Trichophyton rubrum are most common. We examined the propagation of dermatophytes before and during domestic laundering. About 10% of the infectious material was transferred from contaminated textiles to sterile textiles during storage in a clothes basket simulation indicating a high infection risk during storage. This was evaluated with two quantification techniques: cultivation with subsequent colony counting and tracing of radioactively labelled propagating units. Both approaches reliably revealed similar results with the latter method reducing experimental time to few minutes compared to 2 weeks with the traditional method. The tracer technique allowed favourably to directly reflect the textile-bound infectious material at the moment of skin contact. To address the infection risk during domestic laundry, bioindicators with T. rubrum or the yeast Candida albicans were introduced into common domestic washing procedures with different temperature courses. While C. albicans did not survive any of the tests, T. rubrum could be recovered after washing at 30°C, indicating the risk potential of dermatophyte infections at home. Up to 16% of the initial fungus load was detected in the rinsing water. Washing at 60°C however, eliminated both pathogens, T. rubrum and C. albicans.

Compendium of Veterinary Standard Precautions for Zoonotic Disease Prevention in Veterinary Personnel: National Association of State Public Health Veterinarians: Veterinary Infection Control Committee 2015

“…When soiled clothing is laundered at home, it should be transported in a sealed plastic bag, kept separate from household laundry, emptied from the bag directly into a washing machine, and thoroughly machine dried after completion of the wash cycle. [162][163][164] 4. Spill Response and Decontamination Spills and splashes of potentially infective substances should be immediately contained with absorbent material (eg, paper towels, sawdust, or cat litter).…”

Ringworm Infections in Anambra State of Nigeria: Epidemiologic Features and Antifungal Potentials of Local Plant Remedies

“…It should be pointed out that mycological examination of the cloths at the time the case was reported was more likely to yield organisms transferred from the patient's lesion to the fabrics, rather than confirm the cloth as source of the infection-hence we saw no benefit in doing so. However, the possibility of transmission of ringworm through clothes has been reported before [18]. Acquisition of ringworm from second-hand clothes is of dire implications in this part of the world, since majority of Nigerians, even those at the upper socio-economic stratum of the society, have significant taste for second-hand wears.…”

Dermatophyte susceptibility varies towards antimicrobial textiles

“…Antimicrobial fabrics can be a part of primary and secondary prevention strategies for skin mycoses. Nevertheless, the antimicrobial effect cannot replace efficient washing processes, which should be conducted at temperatures ≥ 60 °C 14 . The variation of dermatophyte susceptibility, however, has to be kept in mind when the efficacy of such textiles is tested.…”

“…In addition, shoes, towels and bed linen have to be considered as parts of the chain of infection. Recently, it could be shown that T. rubrum can be transferred from contaminated to non‐contaminated textiles during storage in the laundry basket and during low‐temperature domestic washing procedures 14 . This finding is especially important for persons suffering from tinea pedis, also known as athlete’s foot, where the causative pathogens can persist on the patients’ socks.…”