ABSTRACT
BACKGROUND: Fine tooth lice combs fall into two classes based on the material from which their teeth are made: plastic or metal. Metal combs are further divided into those that are made from a flat sheet of metal, and hence have rectangular teeth, and those that have cylindrical teeth embedded in a plastic base. METHODS: The efficacy of two fine tooth combs [Lice Meister comb (metal) and Lady Jayne comb (plastic)] in removing head lice (Pediculus humanus var. capitis) and their eggs from the hair of children was evaluated after treatment with a viscous head lice product (Lice Blaster; Emerald Forest Pharmaceuticals Pty Ltd, Currumbin, Qld, Australia). The hair of 27 children was divided into two sections sagitally, and each comb was randomly assigned to one half of the hair, and the lice and eggs removed by the combs were counted. RESULTS: In 96% of subjects, the Lice Meister comb removed more eggs than the Lady Jayne comb, with an average of three to four times more hatched, dead, and live eggs removed. The Lice Meister comb removed more lice than the Lady Jayne comb in 10 subjects, the same in eight subjects, and less in nine subjects. CONCLUSION: Overall, the Lice Meister comb is recommended as a more effective comb for use in controlling head lice infestations, whether employed with conditioner or with insecticide treatment. This appears to be the first study investigating the efficacy of nit combs in vivo. Further research is needed to determine which characteristics of fine tooth combs are the most important in removing head lice eggs.
Subject(s)
Lice Infestations/therapy , Pediculus , Scalp Dermatoses/therapy , Animals , Child , Child, Preschool , Combined Modality Therapy , Dermatologic Agents/therapeutic use , Dermatology/instrumentation , Female , Humans , Male , OvumABSTRACT
BACKGROUND: Due to a lack of evidence, controversy exists about the role of bedding in the transmission of head lice. AIMS: To determine the proportion of the head lice population found on pillowcases of people with head lice, and to test strategies available to householders to kill head lice on pillowcases. METHODS: To assess the incidence of head lice on pillowcases, people with active pediculosis had their head lice collected and counted and the pillowcase they had used the night before examined for head lice. To test strategies to kill head lice on pillowcases, live head lice were experimentally placed in miniature pillowcases, and the cases were subjected to a hot wash, a cold wash, hot dryer, and hanging out to dry on an outdoor clothes line. RESULTS: Forty-eight people and their pillowcases were recruited from Townsville, Qld, Australia (dry tropics). One thousand, eight hundred and forty-five lice were collected from their heads to give an average and median intensity of infection of 38.4 and 21 lice, respectively. Two of the 48 pillowcases contained live lice, one nymph on each, 2 h and 9 h after the pillowcases had been removed from the bed. Another pillowcase contained a dehydrated nymph. The incidence of live lice on pillowcases was 4.2% per night and the proportion of the head louse population on the pillowcases was 0.11%. Heat (hot wash and hot clothes dryer) killed head lice experimentally placed in pillowcases. Cold wash and hanging pillowcases out to dry did not kill head lice. CONCLUSIONS: Head lice transfer to pillowcases at night, but the incidence is low. Pillowcases pose a risk for re-infection with head lice, but the risk is low, and changing the pillowcase is a reasonably cost-efficient strategy to minimize this risk. Lice on pillowcases can be killed by heating the pillowcase by immersion in water at > 60 degrees C, by a hot wash, or by 15 min in a hot clothes dryer.
Subject(s)
Bedding and Linens/parasitology , Lice Infestations/prevention & control , Lice Infestations/transmission , Pediculus , Adolescent , Adult , Animals , Child , Child, Preschool , Cold Temperature , Female , Hot Temperature , Humans , Infection Control/methods , Lice Infestations/parasitology , Male , Scalp Dermatoses/parasitology , Scalp Dermatoses/prevention & control , WaterABSTRACT
BACKGROUND: The control of head lice is frequently based on perceptions rather than evidence, as illustrated by the belief that vacuuming carpets is an essential component of treating head lice, and the less common practice of application of insecticides to floors as an adjunct to head lice treatment. OBJECTIVE: To 1) evaluate the importance of floors as a source of infection for head lice in primary schools to provide evidence on which to base decisions about the need to treat floors; 2) determine the prevalence of active pediculosis and average intensity of infection in primary school children in Townsville, north Queensland. METHODS: In Townsville, north Queensland, we examined preschool and primary classroom floors for lice by using a filter on a vacuum cleaner when the children were absent from the rooms. Active pediculosis was treated, head lice were collected and counted. RESULTS: Of the 2,230 children examined from 118 classrooms, 466 had head lice, a prevalence of 20.9%. A total of 14,033 lice were collected from these children to give an average intensity of infection of 30.1 (95% CI 21.9-38.3) lice per infected child and 129.9 (95% CI 90.7-169.2) lice per infected class. Of the 118 classrooms, 108 (91.5%) had at least one child with active pediculosis. No lice were recovered from the classroom floors. CONCLUSION: Classroom floors are not a risk in the transmission of head lice and no special anti-louse measures are required.