Dermophytes and guinea pigs. An underestimated danger?

For several years, an increasing number of human infections, mainly affecting children, with the zoophilic dermatophyte Trichophyton benhamiae has been observed. It is predominantly transmitted by pet guinea pigs. The prevalence of the dermatophyte on guinea pigs which are for sale in pet shops is unknown. Therefore, the aim of this study was to analyze the frequency of T. benhamiae on symptomatic and asymptomatic guinea pigs from pet shops in Berlin. We sampled 59 guinea pigs from 15 pet shops using toothbrushes (MacKenzie brush technique) and FLOQswabs (TM) and analyzed the material for the presence of T. benhamiae with polymerase chain reaction (PCR) and culture. We detected T. benhamiae on more than 90% of the guinea pigs; 9% of which showed visible tinea symptoms. The majority was identified as asymptomatic carriers of the dermatophyte. Pet shop guinea pigs have a high risk of being carriers of T. benhamiae, which can be transmitted to humans via physical contact, even though there is no visible infection in most cases. It is therefore recommended to have newly purchased animals examined by a veterinarian.