Publisher Summary This chapter deals with human lice— Pediculus humanus and their management The Anoplura, or sucking lice, found as blood-feeding parasites on nearly all groups of mammals Head lice have a compact, highly sclerotized thorax and an elongate membranous abdomen with lateral paratergal plates surrounding the abdominal spiracles The first three segments of the abdomen are fused and there are seven visible segments The cuticle may be pigmented and the degree of coloration is dependent on the host or background at the time of the first blood meal The male has a stouter first tibio-tarsus, which is used to grasp the female during copulation, and a large vesicular penis The eggs are deposited either on to a hair or fabric fibre, according to the species, and held there by a glue that is produced by the female's accessory glands Head lice is cosmopolitan in their distribution and their absence from any population of humans has been attributed to behavioral, social or hygienic practices that have eradicated the insects rather than to climatic, geographical or ethnic causes The treatment of lice infections by chemical means is a recent innovation Eradication of head lice from most communities is possible but it requires regulatory input to ensure that only effective treatment products are marketed

Human lice and their management

Background Little is known about the prevalence of pediculosis among school students in northern Jordan.



Objective  To study the incidence of pediculosis among school students of different socio-economic levels in northern Jordan.



Method  A total of 2519 school students of both sexes enrolled in eight elementary governmental schools were examined for the presence of Pediculus capitis. Schools were grouped into four socio-economic classes: very low (VL), low (L), medium (M), and high (H). The chi-squared test was performed to analyze the results.



Results  Overall, 338 students (13.4%) were infested with nits, immature or adult P. capitis. Girls showed a higher prevalence (14.5%) than boys (11.1%).



Statistical analysis  for socio-economic classes and infestation rates yielded a significant effect of the four classes on infestation. This conclusion was evident among schoolgirls, where infestation rates were 28.8%, 18.9%, 6.1%, and 0.2% in VL, L, M, and H socio-economic classes, respectively. Schoolchildren in the age group 8–9 years exhibited higher prevalence rates (16% in boys and 22.1% in girls), while prevalences declined to 10.2% and 6.6% among boys and girls aged 10–12 years, respectively.



Conclusions  This study reveals that socio-economic status is a major factor influencing the occurrence of pediculosis among school students of both sexes in Jordan. A national campaign should be implemented to enhance public awareness.

Pediculosis capitis in northern Jordan

Introduccion. La pediculosis es una de las infestaciones cronicas mas importante en escolares en el mundo. Objetivo. Estimar la prevalencia y describir la estacionalidad de la pediculosis durante siete meses en un jardin infantil y explorar su asociacion con las variables socioeconomicas, las practicas de higiene y las caracteristicas del cabello. Materiales y metodos. Ciento setenta y ocho ninos entre 3 y 60 meses de edad del jardin infantil de la Universidad Nacional de Colombia participaron en el estudio. En cada nino se exploro la presencia de Pediculus humanus mensualmente por siete meses y se midio el grosor y la longitud del cabello al comienzo del seguimiento. Se realizo una encuesta a los cuidadores de los sujetos de estudio sobre practicas higienicas y condiciones socio-economicas. Se estimaron las razones de prevalencia con su respectivo IC95% para cada una de las asociaciones exploradas y, tambien, para describir las diferencias en las prevalencias por grupo de edad en cada uno de los periodos de corte. Resultados. Se encontraron mayores prevalencias en el grupo de edad entre 48 y 59 meses, al principio del ano escolar. Estos resultados sugieren una asociacion positiva entre la pediculosis y tener una longitud del cabello mayor de 11,5 cm [razon de prevalencia (RP)=2,0; intervalo de confianza (IC) del 95%: 0,82-4,8], el banarse la cabeza menos de tres veces a la semana (RP=1,58; IC95% 0,58-4,7), el compartir implementos de aseo (RP=1,31; IC95% 0,38- 4,46) y el vivir mas de cinco personas en la casa (RP=2,04; IC95% 0,8-5,06). Dado el numero limitado de la muestra estudiada, ninguna de las asociaciones fue estadisticamente significativa. Conclusion. La infestacion por P. humanus capitis tiene altas prevalencias en los escolares del jardin. Esta infestacion se encuentra asociada a las malas practicas higienicas, a convivir con mas de cinco personas en la casa y a la longitud del cabello.

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[Pediculosis prevalence and associated risk factors in a nursery school, Bogotá, Colombia].

Pediculosis by Pediculus humanus capitis is still an important health issue in school-age students worldwide. Although pediculicidal agents effectively kill head lice, the re-infestation rate is still high. This study was conducted to provide a summary of evidence about the prevalence of pediculosis capitis among school-age students worldwide. Different databases including MEDLINE/PubMed, Scopus, and Web of Science were searched for publications related to pediculosis capitis in school-age students from 1977 to 2020. All peer-reviewed original research articles describing pediculosis capitis among school-age students were included. Statistical heterogeneity of the different years among studies was assessed using the standard chi squared and I2 tests. Due to the significant heterogeneity, a random effect model was adopted to estimate the pooled, continent, and gender-specific prevalence of pediculosis. Two hundred and one papers met the inclusion criteria of this review and entered into the meta-analysis including 1,218,351 individuals. Through a random effect model, the prevalence of pediculosis capitis among school students was estimated as 19% (CI 95% = 0.18–0.20%, I2 = 99.89%). The prevalence of pediculosis capitis among boys was 7% (CI 95% = 0.05–0.10) compared to 19% (CI 95% = 0.15–0.24) in girls. The highest prevalence was in Central and South America (33%, CI 95% = 0.22–0.44, I2 = 99.81%) and the lowest was in Europe (5%, CI 95% = 4–6, I2 = 99.28%). Relatively high pediculosis capitis prevalence among school-age students observed in this study emphasizes the need for implementing screening and prophylaxis tailored to the local context.

Pediculosis capitis among school-age students worldwide as an emerging public health concern: a systematic review and meta-analysis of past five decades

Human head lice (Pediculus capitis) infest people worldwide and are most prevalent in children, the aim of this study was to determine the socioeconomic status of the family and hygienic practices in the home on prevalence of head lice infestation in children. The prevalence was investigated among 192 houses in Gaza city with 608 children. The hair was examined for head louse infestation. A total of 197 children were infested with head lice. Males had lower infestation than females. Children aged 4-9 years were the most frequently affected, there was a significant relationship between head louse infestation, family size, number of rooms in the homes, family income, frequency of shampooing and combing the hair and frequency of examination the hair for lice. It was found that 26.7% of infested children had other family members who had been infested with head lice and 52.6%of the families used insecticides, 28% used louse comb for treatment of children. There was no correlation between mothers Education and infestation of head lice that mean head louse infestation depends on hygienic practices in the home rather than socioeconomic status of the family. Key words: Pediculus humanus capitis, epidemiology, prevalence, Gaza Governorate

Pediculus capitis, infestation according to sex and social factors in Gaza Governorate

The prevalence of infestation with the head louse, Pediculus capitis, was assessed among the child population, from birth to 10 years old inclusive, of the rapidly expanding Saudi Arabian city of Jeddah. Over a period of two months, 300 consecutive children attending the general practitioner for any reason were examined specifically to identify those infested with head lice: 37 cases of active infestation were found, which is an overall prevalence of 12%. An interesting distribution, however, was noted in respect of age, ranging from less than 2% in the first year of life, rising rapidly to around 30% in ages six to eight years, thereafter declining steadily to about 16% by age 10 years. The distribution of infestation among males and females was broadly similar. These results show a high head lice infestation, particularly in the early school years, where presumably interpersonal contacts are most frequent, facilitating contagious spread. As the head lice is known to spread several viral and rickettsial diseases, such as relapsing fever and typhus, greater efforts should be made towards patient education in hygiene, and towards identifying and treating the disease when found.

Patrick Boyle

Papers

Pilot study of the prevalence of head lice infestation in a population of Saudi Arabian children.