Human Louse and Disease

“Pediculosis is a disease caused by the insect Pediculus humanus capitis that mainly occurs in childhood. A comparative study was carried out evaluating groups of schoolchildren with (group A) and without pediculosis (group B) to analyse the characteristics of the scalp microbiota. Samples were collected by swab using Stuart transport medium and incubate in Sabouraud dextrose agar with tetracycline to analyse the fungal microbiota and in blood agar to assess the bacterial microbiota. The isolates identity was confirmed by sequencing of the 16S and 18S regions of the ribosomal DNA gene for bacteria and fungi, respectively. The analysis of the 186 isolates led to the identification of 35 bacteria and 40 fungi in group A and 47 bacteria and 64 fungi in group B. The results indicate …

Scalp microbiota alterations in children with pediculosis.Read More

“Human head lice, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), are hematophagous parasites that infest human heads. They are extreme host specialists suggesting a strict selection behavior towards the human head by the parasites. Despite the public health relevance of P. humanus capitis, the role of chemical clues to select the human head is not well known. In the present study, we attempted to find out whether head lice recognize and select the odor of the head over the odor of other parts of the human body. Our results using a two-choice olfactometer demonstrated that head lice were highly attracted by the volatile compounds of the human odor air, but they did not show preference for the volatiles of head compared to the volatiles of other parts of the body (forearm or …

Head Lice Recognize and Prefer Head Odor Over Foot and Forearms OdorsRead More

“Pediculus humanus, the human body louse, is widespread where overcrowding and lack of hygiene are present, in areas of the world affected by poverty, war, famine and presence of refugees. It has recently been considered re-emerging among homeless populations in developed countries. In Italy, it was last reported in 1945. Pediculus humanus is a vector of highly relevant human pathogens.”  De Liberato C1, Magliano A2, Romiti F2, Menegon M3, Mancini F3, Ciervo A3, Di Luca M3, Toma L3. Parasit Vectors. 2019 May 3;12(1):201. doi: 10.1186/s13071-019-3458-z  See full article: Report of the human body louse (Pediculus humanus) from clothes sold in a market in central Italy. …

Report of the human body louse (Pediculus humanus) from clothes sold in a market in central ItalyRead More

“Insect antennae are sophisticated sensory organs, usually covered with sensory structures responsible for the detection of relevant signals of different modalities coming from the environment. Despite the relevance of the head louse Pediculus humanus capitis as a human parasite, the role of its antennal sensory system in the highly dependent relation established with their hosts has been barely studied. In this work, we present a functional description of the antennae of these hematophagous insects by applying different approaches, including scanning electron microscopy (SEM), anterograde antennal fluorescent backfills, and behavioral experiments with intact or differentially antennectomized lice. Results constitute a first approach to identify and describe the head louse antennal …

The Sensory Machinery of the Head Louse Pediculus humanus capitis: From the Antennae to the BrainRead More

“Skin disorders are one of the commonest conditions among school children in developing countries. There are only a few published studies available from Sri Lanka on the prevalence of skin disorders. A community-based cross-sectional study was carried out among five government-run schools randomly selected from the district of Gampaha, Sri Lanka, during 2016-2017. A total of 41 students between 5 and 16 years of age were randomly selected from each school. Sociodemographic profile and hygienic behaviors of selected students were assessed using a pretested interviewer-administered questionnaire. Students were examined by a medical officer for the presence of different skin disorders. The chi-squared test of association and binary logistic regression were used for the identification of the …

Prevalence of Ectoparasitic Infections and Other Dermatological Infections and Their Associated Factors among School Children in Gampaha District, Sri LankaRead More

“Louse-borne relapsing fever (LBRF) is an epidemic disease with a fascinating history from Hippocrates’ times, through the 6th century ‘Yellow Plague’, to epidemics in Ireland, Scotland and England in the 19th century and two large Afro-Middle Eastern pandemics in the 20th century. An endemic focus persists in Ethiopia and adjacent territories in the Horn of Africa. Since 2015, awareness of LBRF in Europe, as a re-emerging disease, has been increased dramatically by the discovery of this infection in dozens of refugees arriving from Africa.The causative spirochaete, Borrelia recurrentis, has a genome so similar to B. duttonii and B. crocidurae (causes of East and West African tick-borne relapsing fever), that they are now regarded as merely ecotypes of a single genomospecies. Transmission …

Louse-borne relapsing fever (Borrelia recurrentis infection)Read More

“The study of arthropods is still scarce in paleoparasitology, especially their molecular identification. In this experimental study, we amplify DNA using a polymerase chain reaction from 2 ectoparasite species, Rhipicephalus sanguineus and Pediculus humanus capitis, in experimentally desiccated feces. This study shows perspectives for the study of the identification of arthropods in coprolites when taxonomic identification is not possible.”  Pucu E1, Lemos E2, Rozental T2, Ogrzewalska M2, Chame M3, Machado-Silva JR4, Leles D1. J Parasitol. 2019 Feb;105(1):133-134.  See full article: Identification of Arthropods By Polymerase Chain Reaction As Probes For Infectious Disease Studies In Experimental Coprolites …

Identification of Arthropods By Polymerase Chain Reaction As Probes For Infectious Disease Studies In Experimental CoprolitesRead More

“Louseborne relapsing fever (LBRF) was once a cosmopolitan disease but it now occurs only in the Horn of Africa. Recent cases in refugees to Europe made LBRF topical again. Crowded boarding houses and church dwellings in Ethiopia are analogous to the crowded air-raid shelters of World War II. Thus, we might learn from experiments the London School of Tropical Hygiene and Medicine conducted during World War II. When the vector of Borrelia recurrentis (Pediculus humanus lice) were held away from the host for 10 days, 100% of nymphal and adult lice starved to death and 100% of eggs did not hatch. We hypothesize that holding infested clothes away from hosts in plastic shopping bags will kill enough lice to control LBRF in Ethiopia. Owning 2 sets of clothes might be useful; 1 set might be held …

Killing Clothes Lice by Holding Infested Clothes away from Hosts for 10 Days to Control Louseborne Relapsing Fever, Bahir Dah, EthiopiaRead More

“In this study, we demonstrate that the genus Rickettsia is widely distributed in Central America and that rickettsiosis could be an underestimated problem in the absence of greater diagnostic efforts in undetermined febrile cases.”  C Sergio E Bermúdez and Adriana Troyo. Res Rep Trop Med. 2018; 9: 103–112.  See full article: A review of the genus Rickettsia in Central America. …

A review of the genus Rickettsia in Central AmericaRead More