Genetic Analysis of Familial Onset of Trichophyton rubrum Infection

Area of Science:

• Medical Mycology
• Dermatology
• Infectious Diseases

Background:

• Trichophyton rubrum is a common cause of superficial fungal infections.
• Familial clustering of dermatophytosis can occur, but the precise transmission dynamics are often complex.
• Understanding transmission routes is crucial for effective prevention and treatment.

Purpose of the Study:

• To investigate the source and transmission routes of Trichophyton rubrum infection within a family.
• To determine if a single index case was responsible for the infections in multiple family members.
• To analyze the genetic relatedness of T. rubrum strains isolated from different affected individuals.

Main Methods:

• Mycological culture and microscopic examination of skin lesions from affected family members.
• Genetic analysis of Trichophyton rubrum strains using ITS-PCR-RFLP and non-transcribed spacer region sequencing.
• Epidemiological investigation of potential exposure and contact tracing within the household.

Main Results:

• Five out of six cohabiting family members presented with clinical signs of tinea pedis and tinea corporis.
• Mycological cultures confirmed the presence of Trichophyton rubrum in all affected individuals.
• Genetic analysis indicated distinct profiles for the T. rubrum strains, suggesting multiple independent introductions or complex transmission patterns rather than a single source.

Conclusions:

• The familial Trichophyton rubrum infection was not attributed to a single infected individual.
• Multiple sources or complex transmission dynamics likely contributed to the spread of infection within the household.
• Further investigation into environmental factors and varied exposure routes is warranted for similar cases.