How can you know that there are no more lice? - briefly
Examine the hair and scalp with a fine‑tooth comb under bright light, searching for live insects and nits attached within 1 cm of the scalp. Repeat the combing after 7–10 days; absence of any findings confirms that no lice remain.
How can you know that there are no more lice? - in detail
To verify that an infestation has been fully eradicated, follow a systematic approach that combines direct observation, mechanical removal, chemical treatment verification, and environmental control.
First, conduct a thorough visual inspection of the hair and scalp. Use a magnifying device or a bright light to look for live insects, nymphs, or viable eggs. Examine the hair close to the scalp, behind the ears, and at the nape of the neck. Any detection of live specimens indicates that treatment has not succeeded.
Second, employ a fine-toothed comb specifically designed for lice removal. Comb the hair in sections, starting from the scalp and moving outward. After each pass, wipe the comb on a white tissue; the presence of insects or eggs confirms residual infestation. Repeat the combing process at least three times over a 24‑hour period to ensure that newly hatched nymphs are captured.
Third, confirm the effectiveness of any chemical or topical product used. Follow the manufacturer’s instructions regarding the required waiting period before a second application. After the recommended interval, repeat the visual inspection and combing steps. If no lice or viable eggs are observed, the product can be considered effective.
Fourth, address the environment. Wash all bedding, clothing, and personal items that have been in contact with the head in hot water (minimum 130 °F/54 °C) and dry on high heat. Vacuum carpets, upholstered furniture, and car seats to remove any detached eggs. Seal non‑washable items in plastic bags for two weeks to deprive any surviving eggs of a suitable environment.
Fifth, schedule follow‑up checks. Perform a brief inspection and combing session every 48 hours for one week after the last treatment. Absence of live lice or viable eggs during this monitoring period provides strong evidence that the infestation is cleared.
Finally, consider laboratory verification only if uncertainty remains. Collect a sample of any suspect material and submit it to a medical laboratory for microscopic analysis. A negative result confirms complete eradication.
By combining meticulous inspection, repeated mechanical removal, verification of treatment efficacy, thorough environmental sanitation, and systematic follow‑up, one can confidently determine that no lice remain.