Pediculus humanus is an obligate bloodsucking ectoparasite of human that includes two ecotypes, head louse and body louse, which differ slightly in morphology and biology, but have distinct ecologies. Phylogenetically, they are classified on six mitochondrial clades (A, B, C, D, E, and F), head louse encompasses the full genetic diversity of clades, while body louse belongs to clades A and D. Recent studies suggested that not only body louse, but also head louse can transmit disease, which warrants greater attention as a serious public health problem…
Head louse infestation is very common worldwide, especially among schoolchildren, whatever their hygiene status, and the transmission occurs mainly by head-to-head contact. Adults with poor personal hygiene are also commonly affected (Chosidow, 2000). Body louse infestation is less prevalent and is related with poor hygiene and a lack of sanitation, overcrowding, damp, and cold weather conditions. For that reason, homeless, jail, and refugee populations are predominantly affected. In addition to their role as a dangerous disease vector (we will discuss this point in greater detail later in the review), louse infestations cause itching that may lead to intense irritation. Severe itching can lead to excoriations in which a secondary bacterial infection is likely to occur. Post inflammatory pigmentation is also common in chronically infested persons (Chosidow, 2000).
Frontiers in Cellular and Infection Microbiology, 21 January 2020 | https://doi.org/10.3389/fcimb.2019.00474. Nadia Amanzougaghene1,2, Florence Fenollar2,3, Didier Raoult1,2 and Oleg Mediannikov1,2.