How long can a scabies mite live? - briefly
On a human host, a scabies mite usually survives for roughly four to six weeks, while off‑host it endures only a few days under optimal conditions.
How long can a scabies mite live? - in detail
The female Sarcoptes scabiei typically survives on the human skin for 4‑6 days, during which it lays up to 30 eggs. After hatching, the larva remains attached to the host for about 2‑3 days before molting into the protonymph stage, which lasts another 2‑3 days. The subsequent deutonymph stage persists for roughly 2 days before maturing into an adult mite. In total, the complete life cycle from egg to reproducing adult spans 10‑14 days.
When detached from a human host, the mite’s viability declines sharply. Under ambient indoor conditions (20‑22 °C, 40‑60 % relative humidity), an unfed mite can survive up to 48 hours. Cooler, drier environments reduce survival to less than 24 hours, while higher humidity modestly extends it to about 72 hours. Direct sunlight and temperatures above 30 °C are lethal within a few hours.
Key factors influencing longevity:
- Temperature: optimal range 20‑25 °C; extremes accelerate death.
- Humidity: 50‑70 % maintains cuticular integrity; low humidity causes desiccation.
- Host availability: feeding required for reproduction; without blood meals, survival is limited to a few days.
- Life stage: eggs and early larvae are more resistant to environmental stress than adult mites.
Consequently, the parasite’s lifespan on a person is measured in days, while its off‑host endurance does not exceed three days under typical household conditions. Effective control measures must therefore focus on rapid eradication of infestations and thorough decontamination of bedding and clothing within this time window.