Vaccuuming method as a successful strategy in the diagnosis of active infestation by Pediculus humanus capitis

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Bruno Paulo Rodrigues Lustosa, Juciliane Haidamak, Camila Yumi Oishi, Ariela Both de Souza, Bruna Jacomel Favoreto de Souza Lima, Larissa Reifur, Márcia Kiyoe Shimada, Vânia Aparecida Vicente, Maria Adela Valero Aleixandre, Débora do Rocio Klisiowicz
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2020
• Subjects: Detection; Diagnosis; Effectiveness; Hair aspiration; Head lice; Pediculosis; Pediculus humanus capitis; Prevalence; Visual inspection; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1590/s1678-9946202062007; https://doaj.org/article/d602e44f075a4b59862b222ba85d5aec

ABSTRACT Most human epidemiological and clinical studies use visual inspection of the hair and scalp to diagnose Pediculus humanus capitis , however this method has low sensitivity to diagnose active infestations (presence of nymphs and adult lice). Vacuuming the hair and scalp has been used as a diagnostic method, but there are no previous data comparing its effectiveness with visual inspection. The aim of this study was to determine the prevalence of overall infestation (nits and trophic stages), of active infestation by Pediculus humanus capitis , and to evaluate the effectiveness of vacuuming in comparison with the visual inspection. Visual inspection was performed by three examiners and vacuuming of the scalp by one investigator, with an adapted vacuum cleaner. A total of 166 children aged 4 to 10 years old were randomly selected from public schools in Southern Brazil. Considering the positive results obtained by both methods, the prevalence of overall infestation was 63.3%, whereas active infestation was 18.7%. The visual inspection was more effective on diagnosing overall infestation, however, its effectiveness to detect active infestation was lower, ranging from 0.6% (RR=3%, p<0.001) to 6.6% (RR=35%, p=0.001), depending on the number of examiners. The effectiveness of vacuuming to diagnose active infestation was higher than the one of visual inspection, with a prevalence rate of 16.3% (RR=87%, p=0.332). As presented in our study, the vacuuming method was 2.74 to 7.87 times most likely to detect active infestation, thus it could be adopted as a more accurate method to diagnose active pediculosis.