The lethal effects of high-frequency ultrasound waves in Pediculus humanus capitis (Anoplura: Pediculidae) nymphs and adults
Öz
Purpose: This study aimed to assess the efficacy of high-frequency ultrasound waves as a non-chemical alternative for controlling head lice (Pediculus humanus capitis) by evaluating mortality rates in adult and nymphal stages exposed to various ultrasound frequencies.
Materials and Methods: A total of 1,000 head lice (adults and nymphs) collected from infested children were exposed under controlled laboratory conditions to five ultrasound frequencies (0.5, 1.0, 1.5, 2.0, and 2.5 MHz) for up to 24 hours. A control group of 200 lice was maintained under the same laboratory conditions without ultrasound exposure. Mortality was recorded at 1, 2, 4, 8, 16, and 24 hours.
Results: Among the 1,000 head lice tested, ultrasonic frequencies of 1.5, 2.0, and 2.5 MHz caused the highest mortality, reaching ≥90% in adults and ≥98.3% in nymphs. In contrast, 0.5 MHz produced the lowest mortality (20–21.7%), while the control groups showed only 8.3% (nymphs) and 15.0% (adults) mortality. Most deaths occurred within 8–24 hours post-exposure. Correlation analysis revealed a strong positive relationship between mortality and exposure time (r = 0.710, p < 0.001). ANOVA confirmed significant effects of frequency on mortality (F(5, 330) = 6.845, p < 0.001), with mortality plateauing at 2.5 MHz. Probit regression estimated LT₅₀ values of 12.1–13.4 hours for adults and 15.4–17.6 hours for nymphs at higher frequencies, compared to 22.2 and 27.3 hours, respectively, at 0.5 MHz.
Conclusion: This study is the first to demonstrate the direct effect of ultrasonic sound frequencies on Pediculus humanus capitis. High-frequency ultrasound (1.5–2.5 MHz) effectively controlled head lice without the need for additional chemicals, highlighting its potential as a non-chemical pediculosis management strategy. These findings provide a basis for future research and the development of portable devices, such as hair clips or necklaces, designed to repel or inactivate lice. Incorporating high-frequency ultrasound alongside routine combing may enhance head lice control, and further studies are warranted to optimize device design and exposure parameters.
Anahtar Kelimeler
Pediculus humanus capitis, head lice, ultrasonic frequencies, mortality, pediculosis control, non-chemical methods
Destekleyen Kurum
TÜBİTAK
Proje Numarası
219S203
Etik Beyan
The study was approved by the ethical committee of Cukurova University Medical School. Furthermore, official permission to conduct the studies in schools was received from the district governorship, informed consent was obtained from the participants.
Teşekkür
All authors would like to express their gratitude to the administrations of the three schools in the Karaisalı District of Adana where the head lice screening was conducted.
Kaynakça
- Oh JM, Lee IY, Lee WJ, Seo M, Park SA, Lee SH et al. Prevalence of pediculosis capitis among Korean children. Parasitol Res. 2010;107:1415–19.
- Cummings C, Finlay JC, MacDonald NE. Head lice infestations: A clinical update. J Paediatr Child Health. 2018;23:e18-e24.
- Özsürekçi Y, Kara A. Infestations of lices. Klin tıp pediatr derg. 2018;10:38-43.
- Kurt Ö, Tabak T, Kavur H, Muslu H, Limoncu ME, Bilaç C et al. Comparison of two combs in the detection of head lice in school children. Turkiye Parazitol Derg. 2009;33:50-53.
- Özkan Ö, Hamzaoğlu O, Yavuz M. The prevalence and management of Pediculosis capitis in Türkiye: A systematic review. Turkiye Parazitol Derg. 2015;39:135-46.
- Nejati J, Keyhani A, Kareshk AT, Mahmoudvand H, Saghafipour A, Khoraminasab M et al. Prevalence and risk factors of pediculosis in primary school children in South West of Iran. Iran J Public Health. 2018;47:1923.
- Falagas ME, Matthaiou DK, Rafailidis PI, Panos G. Pappas G. Worldwide prevalence of head lice. Emerg Infect Dis. 2008;14:1493–94.
- Najjari M, Gorouhi MA, Zarrinfar H, Hosseini Farash BR, Jamali J et al. Impact of a health educational interventional program on reducing the head lice infestation among pupils in an elementary school of a sub-tropical region: a quasi-experimental study. BMC Pediatr. 2022;22:1–9.
- Devore CD, Schutze GE, Council on School Health and Committee on Infectious Diseases. Head lice. Pediatrics. 2015;135:e1355–e1365.
- Gratz NG, World Health Organization. Human lice: Their prevalence, control and resistance to insecticides: A review 1985–1997.
