The question often arises on forums and in thrift stores: can a garment worn by someone else transmit a sexually transmitted infection? To answer this, we need to examine what the biology of pathogens says about their survival on textiles, and then distinguish STIs from other infections that can actually be transmitted through fibers.
Survival of pathogens on textiles: STIs vs. skin infections
The confusion comes from a mix-up between two categories of microorganisms that behave very differently outside the human body. The table below contrasts the main agents involved.
| Pathogen | Type | Survival on dry textile | Transmission via clothing |
|---|---|---|---|
| HIV | Virus (STI) | Several minutes in open air | Not documented |
| Chlamydia | Bacteria (STI) | Very brief, requires host cell | Not documented |
| Gonococcus | Bacteria (STI) | Very brief, fragile outside mucosa | Not documented |
| Mycoplasma genitalium | Bacteria (STI) | Does not survive in open air | Not documented |
| HPV (human papillomavirus) | Virus (STI) | Possible on moist surface | Theoretical, not confirmed by dry textile |
| Staphylococcus aureus | Skin bacteria | Several days to weeks | Yes, if skin is damaged |
| Dermatophytes (fungal infections) | Fungus | Several weeks | Yes, especially shoes and underwear |
| Sarcoptes (scabies) | Parasite | Up to several days | Yes, through prolonged contact with contaminated linen |
The conclusion is clear: the agents responsible for STIs do not survive on dry textiles. Their transmission requires direct contact between mucous membranes or an exchange of bodily fluids. HIV, gonococcus, chlamydia, and Mycoplasma genitalium are too fragile to remain viable on a fiber exposed to air, light, and temperature variations.
When discussing health risks of second-hand clothing, the real issue concerns skin infections: fungal infections, staphylococci, scabies. These agents are much better at surviving in the textile environment.
Fungal infections, staphylococci, and scabies: the real risks of second-hand textiles
Dermatophytes, responsible for foot or groin fungal infections, can persist for several weeks in the fibers of a shoe or underwear. Staphylococcus aureus also survives on textile surfaces for days, or even longer in a humid environment.
Scabies is transmitted through prolonged contact with contaminated linen, not through a quick try-on. The sarcoptes remains viable for a few days in the fibers, which explains the decontamination protocols for linen in hospital settings.
Two conditions favor the transmission of these agents through clothing:
- The textile is worn directly on damaged skin (cut, eczema, irritation), providing an entry point for bacteria and fungi
- The garment has not been washed between wearers, or has been stored in a humid environment promoting fungal proliferation
- The person wearing the garment has a weakened immune system, lowering the contamination threshold necessary to trigger an infection
In contrast, a brief try-on in a store or thrift shop, on intact skin, poses a negligible risk for a healthy person.
Washing temperature and elimination of microorganisms
Washing is the determining factor. A low-temperature cycle with standard detergent removes most visible dirt, but does not destroy all pathogenic microorganisms.
Dermatophytes and staphylococcus aureus are more resistant to lukewarm cycles. For second-hand clothing in direct contact with the skin (underwear, socks, swimsuits), washing at a higher temperature significantly reduces the microbial load.
Washing recommendations for second-hand linen
- Wash all second-hand clothing before first use, even if it appears clean
- Prefer a high washing temperature for textiles in direct contact with the skin, within the limits of the care label
- Completely dry the linen before storing: residual moisture promotes fungal proliferation
- For second-hand shoes, use a disinfectant spray and let them air dry for several hours
A properly washed and dried second-hand garment does not present a higher infectious risk than a new garment tried on in a fitting room by multiple people before purchase. This detail is often overlooked: new clothes in stores also pass through many hands and over many skins.
Immunocompromised individuals: a different threshold of vigilance
For the majority of the population, the risk associated with second-hand clothing can be managed by simple washing. The situation is different for individuals with weakened immune systems: infants, the elderly, patients on immunosuppressive therapy.
In these individuals, the contamination threshold necessary to trigger a skin infection is lower. A staphylococcus or dermatophyte that would cause no symptoms in a healthy adult can lead to an infection requiring treatment in an immunocompromised patient.
For these profiles, systematic washing at high temperatures and complete drying before any wear remain the most effective precaution. Ironing at high temperatures provides additional safety for textiles that can withstand it.
The answer to the initial question comes down to a simple distinction: no documented STI is transmitted through second-hand clothing. Infections that can be transmitted through textiles (fungal infections, staphylococci, scabies) are not STIs. They can be eliminated through appropriate washing before first use, a practice that should indeed apply to all garments, new or second-hand.