Scabies is a skin infestation caused by tiny mites, Sarcoptes scabiei, which burrow into the skin’s top layer to live and lay eggs. This microscopic parasite triggers a reaction in the skin, leading to an intensely itchy rash. The condition is highly contagious, affecting people across all ages and backgrounds.
How Scabies Mites Spread
Scabies primarily spreads through prolonged, direct skin-to-skin contact with an infested person. This often occurs during close physical interactions, such as living in the same household or intimate contact. While direct contact is the most common way for mites to transfer, transmission can also occur less frequently through shared items.
Inanimate objects, known as fomites, like clothing, towels, and bedding, can harbor scabies mites. It is possible to contract scabies from bed sheets, although this is not the primary mode of transmission. Scabies mites survive off a human host for 2 to 3 days, and up to a week in cool, humid conditions.
Understanding Scabies Transmission from Objects
Transmission from objects like bed sheets is more likely under specific circumstances, such as crusted scabies, a severe infestation where an individual harbors millions of mites. This significantly increases the chance of mites transferring to surfaces. A heavy mite load, even in typical scabies cases, also increases the risk of mites on environmental surfaces.
A period of prolonged contact is required for mites to transfer from an object to a new host. Brief contact, such as quickly touching an infested item, carries less risk compared to extended exposure, like sleeping in a bed used by an infested person.
Practical Steps to Prevent Scabies Spread
To prevent the spread of scabies, particularly from items like bed sheets and clothing, specific cleaning measures are necessary. All bedding, clothing, and towels used by an infested person should be machine washed in hot water, at temperatures above 50°C (122°F), and dried on a hot cycle. This is effective in killing mites and their eggs.
Items that cannot be washed, such as certain stuffed animals or delicate fabrics, can be disinfested by sealing them in a plastic bag. These items should remain sealed for at least 72 hours, which starves the mites of a host. Additionally, vacuuming carpets and upholstered furniture can help remove any mites that may have transferred from an infested individual.
Recognizing Scabies Symptoms and Next Steps
The most common signs of scabies include intense itching, which often worsens at night, and a rash that may appear as tiny red bumps or blisters. In some cases, thin, wavy lines, known as burrows, may be visible on the skin. Symptoms can develop 2 to 6 weeks after initial exposure. For those previously infected, symptoms may appear within 1 to 4 days. If scabies is suspected, seek medical attention for diagnosis and treatment.