“The NPA’s model of educating the community and combing: ‘Effect of a health education program on reduction of pediculosis in school girls at Amphoe Muang, Khon Kaen Province, Thailand.'” PLoS One See full article: Effect of a health education program on reduction of pediculosis in school girls at Amphoe Muang, Khon Kaen Province, Thailand. …
New approaches in the systematics of rickettsiae
“The development of a formal order analysis (FOA) allowed constructing a classification of 49 genomes of Rickettsiaceae family representatives. Recently FOA has been extended with new tools—‘Map of genes,’ ‘Matrix of similarity’ and ‘Locality-sensitive hashing’—for a more in-depth study of the structure of rickettsial genomes. The new classification confirmed and supplemented the previously constructed one by determining the position of Rickettsia africae str. ESF-5, R. heilongjiangensis 054, R. monacensis str. IrR/Munich, R. montanensis str. OSU 85- 930, R. raoultii str. Khabarovsk, R. rhipicephali str. 3-7-female6-CWPP and Rickettsiales bacterium str. Ac37b. The ‘Map of genes’ demonstrated the complete genomes and their components in a graphical form. The ‘Matrix of similarity’ was …
Detection of bacterial pathogens in clade E head lice collected from Niger’s refugees in Algeria
“Head lice, Pediculus humanus capitis, are obligate blood-sucking parasites. Phylogenetically, they occur in five divergent mitochondrial clades (A, D, B, C and E), each having a particular geographical distribution. Recent studies have revealed that head lice, as is the case of body lice, can act as a vector for louse-borne diseases. Here, we aimed to study the genetic diversity of head lice collected from Niger’s refugees (migrant population) arriving in Algeria, northern Africa, and to look for louse-borne pathogens. Comparative head lice samples collected from indigenous population of schoolchildren (non-immigrant) were also analyzed to frame the study.” Parasit Vectors. 2018 Jun 15. See full article: Detection of bacterial pathogens in clade E head lice collected from Niger’s …
Molecular Survey of Head and Body Lice, Pediculus humanus, in France
“Human lice, Pediculus humanus, are obligate blood-sucking parasites. Phylogenetically, they belong to several mitochondrial clades exhibiting some geographic differences. Currently, the body louse is the only recognized disease vector, with the head louse being proposed as an additional vector. In this article, we study the genetic diversity of head and body lice collected from Bobigny, a town located close to Paris (France), and look for louse-borne pathogens.” Vector Borne Zoonotic Dis. 2018 May. See full article: "Molecular Survey of Head and Body Lice, Pediculus humanus, in France." …
Molecular Survey of Head and Body Lice, Pediculus humanus, in FranceRead More
Body lice of homeless people reveal the presence of several emerging bacterial pathogens in northern Algeria
“Recently, head lice belonging to different mitochondrial clades were found to carry the DNA of several bacterial body louse-borne pathogens, such as B. quintana, B. recurrentis, Acinetobacter species and Y. pestis in natural settings [14,16,20,33±38]. Experimental studies have also demonstrated that head lice may also act as a vector of louse-borne diseases” PLoS Negl Trop Dis. 2018 Apr 17. See full article: "Body lice of homeless people reveal the presence of several emerging bacterial pathogens in northern Algeria." …
Insights About Head Lice Transmission From Field Data and Mathematical Modeling
“Head lice infest millions of school-age children every year, both in developed and developing countries. However, little is known about the number of lice transferred among children during school activities, because direct methods to study this are almost impossible to implement. This issue has been addressed following an indirect method, which consist in collecting data of real infestation from several children groups and using a mathematical model of lice colonies to infer how the infestation observed might have evolved. By determining the events that would most likely lead to infestations as those observed, we find that severe infestations are most likely initiated by a relatively large number of lice transferred at the same moment or within relatively short time spans. In turn, …
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Response of Pediculus humanus capitis (Phthiraptera: Pediculidae) to Volatiles of Whole and Individual Components of the Human Scalp
“The head louse Pediculus humanus capitis (De Geer) (Phthiraptera: Pediculidae) is a cosmopolitan human ectoparasite causing pediculosis, one of the most common arthropod parasitic conditions of humans. The mechanisms and/or chemicals involved in host environment recognition by head lice are still unknown. In this study, we evaluated the response of head lice to volatiles that emanate from the human scalp. In addition, we identified the volatile components of the odor and evaluated the attractive or repellent activity of their pure main components. The volatiles were collected by means of Solid Phase microextraction and the extract obtained was chemically analyzed by gas chromatograph-mass spectrometer. Twenty-four volatile were identified in the human scalp odor, with the main …
Detection of bacterial pathogens including potential new species in human head lice from Mali
“In poor African countries, where no medical and biological facilities are available, the identification of potential emerging pathogens of concern at an early stage is challenging. Head lice, Pediculus humanus capitis, have a short life, feed only on human blood and do not transmit pathogens to their progeny. They are, therefore, a perfect tool for the xenodiagnosis of current or recent human infection. This study assessed the occurrence of bacterial pathogens from head lice collected in two rural villages from Mali, where a high frequency of head lice infestation had previously been reported, using molecular methods. Results show that all 600 head lice, collected from 117 individuals, belonged to clade E, specific to West Africa. Bartonella quintana, the causative agent of trench fever, …
Rickettsia Prowazekii (Epidemic Typhus)
“The human body louse is only a vector and not a reservoir because infected lice die five to seven days after they become infected with R. prowazekii. R. prowazekii multiplies in the gut epithelium of the louse which then detaches, ruptures, and releases rickettsiae into the feces. Rickettsiae from the infected feces enter the skin via abrasions or bite site and access the human host.”Sami M. Akram; Vidhya Prakash. See full article: "Rickettsia Prowazekii (Epidemic Typhus)." …