Mode of Transmission of Plantar Warts
Plantar warts are transmitted through both direct skin-to-skin contact with infected tissue and indirect contact with contaminated environmental surfaces, with the virus remaining infectious on surfaces for months to years. 1
Primary Transmission Routes
Direct Transmission
- Person-to-person spread occurs through direct contact with infected skin tissue. 1
- HPV spreads from one individual to another through direct skin-to-skin contact with wart lesions. 1
Indirect Environmental Transmission
- The virus can persist and remain infectious on surfaces for extended periods—potentially months or even years outside the human body. 1
- Contaminated floors, particularly in changing rooms, serve as a prime source of transmission. 2
- Kitchen towels and bathroom mats can harbor infectious HPV, especially types HPV1 and HPV2, which are frequently found (>50%) on household linens when present in warts. 3
High-Risk Environments and Behaviors
Critical Exposure Settings
- Walking barefoot in communal shower areas, locker rooms, and pool decks significantly increases transmission risk. 1, 4
- The floor of changing rooms has been identified as the primary cause of transmission in outbreak investigations. 2
- Swimming pools and communal bathing facilities are documented transmission sites. 1
Quantified Risk Factors
- Walking barefoot in changing rooms increases disease risk with an adjusted odds ratio of 1.97 (95% CI, 1.39-2.79). 2
- In one study, 27% of adolescents using communal showers regularly had plantar warts versus only 1.25% of those only using locker rooms. 4
- The risk of disease increases with the number of activities taking place in these environments. 2
Transmission Through Shared Items
- Sharing towels, shoes, or other personal items that contact feet facilitates HPV spread. 1
- Sharing athletic equipment can facilitate transmission. 1, 4
- Treatment instruments should not be shared between individuals to prevent cross-contamination. 1
Important Clinical Considerations
Viral Persistence
- Warts can persist for years with little or no inflammation while remaining highly infectious. 1
- Even after treatment or spontaneous clearance, individuals may harbor HPV in surrounding normal-appearing tissue. 1
- Plantar warts shed HPV, which can then infect other sites in the plantar region or spread to other people. 5