Scabies is a skin condition caused by a tiny mite, Sarcoptes scabiei var. hominis, which burrows into the upper layer of human skin. This infestation leads to intense itching, especially at night, and a rash. Understanding how scabies spreads is important, particularly regarding concerns about contracting it from inanimate objects like furniture.
How Scabies Spreads
Scabies primarily spreads through direct, prolonged skin-to-skin contact with an infected person. Casual contact, like a quick handshake, is generally insufficient; the mite needs extended physical contact to transfer. This close contact often occurs within households, among sexual partners, or in crowded settings like nursing homes or childcare facilities.
The human itch mite burrows into the skin, living for one to two months and laying eggs. Symptoms, including itching and a rash, may take four to eight weeks to develop after initial infestation. Despite this delay, an infested person can still spread scabies during the asymptomatic period.
Scabies Mite Life on Surfaces
While direct skin-to-skin contact is the primary mode of transmission, concerns exist about contracting scabies from inanimate objects like furniture or bedding. Scabies mites are adapted to human skin and generally cannot survive long away from a human host, typically dying within two to three days.
Temperature and humidity influence mite survival; higher humidity and lower temperatures prolong it, while higher temperatures and lower humidity lead to earlier death. Even if mites are present on surfaces, their ability to cause an infestation is significantly reduced due to their limited survival time and adaptation to human skin. Transmission from objects like clothing, towels, or bedding is less common, though more likely in cases of crusted scabies, a severe form where an infected person carries thousands of mites.
Preventing Indirect Transmission
To minimize the risk of indirect transmission, especially when someone in the household has scabies, certain measures can be taken. All clothing, bedding, and towels used by an infested person during the three days prior to treatment should be machine washed using hot water (exceeding 50°C or 122°F) and dried on a hot cycle, as high heat effectively kills mites and eggs.
For items that cannot be machine washed, seal them in a closed plastic bag for several days to a week; mites will die without a human host. Vacuuming furniture and carpets where an infected person has spent time can also help remove any mites. These cleaning actions are primarily precautionary steps to reduce the already low risk of indirect spread.