Background: The human head louse, Pediculus humanus capitis, is a cosmopolitan blood-sucking ectoparasite affecting mostly schoolchildren in both developed and developing countries. In Honduras, chemical pediculicides are the first line of treatment, with permethrin as their main active ingredient. Despite the extended use of these products, there is currently no research investigating insecticide resistance in Honduran head lice. In head lice, the most common mechanism is knockdown resistance (kdr), which is the result of two point mutations and the associated amino acid substitutions, T917I and L920F, within the voltage-sensitive sodium channel (VSSC)......To our knowledge, this is the first study showing the presence of the C/T mutation responsible of the T917I kdr allele associated …
NPA asks CDC to improve guidance on head lice
"The National Pediculosis Association (NPA) appreciates the complexity of these times with COVID-19. Our intent here is to minimize pediculosis as an additional public health burden when children return to school and other group settings. We would be pleased to lend our assistance to the CDC in updating its published information on head lice in order to help achieve this goal." Please see the National Pediculosis Association's letter to the Centers for Disease Control concerning the CDC's guidance on head lice. Please also see press release. …
A World Gone Viral
Pathogens still have the power to change the course of history. We may say we're fighting a war against the coronavirus, but it might be more accurate to say the coronavirus is waging a war against us. Microbes are changing our lives, our economy, our culture. You should know – though it will provide no consolation – that it has ever been thus.Perhaps you assumed that the ability of pestilence to transform the course of history was… well, history, in the sense that modern science, modern public health systems, and such modern bureaucracies as the Centers for Disease Control and Prevention, the National Institutes of Health, and the World Health Organization would show those nasty little germs who's boss.The Ebola outbreak of 2014-16, the most severe in recorded history, only confirmed …
Ectoparasites: Pediculosis and Tungiasis
Pediculosis is an infestation of lice on the body, head, or pubic region that occurs worldwide. Lice are ectoparasites of the order Phthiraptera that feed on the blood of infested hosts. Their morphotype dictates their clinical features. Body lice may transmit bacterial pathogens that cause trench fever, relapsing fever, and epidemic typhus, which are potentially life-threatening diseases that remain relevant in contemporary times. Recent data from some settings suggest that head lice may harbor pathogens. The epidemiology, clinical manifestations, and management of body, head, and pubic louse infestation are reviewed. New therapies for head lice and screening considerations for pubic lice are discussed. Tungiasis is an ectoparasitic disease caused by skin penetration by the …
National Pediculosis Association Petition Leads to FDA Website Updates on Treating Head Lice
Lice and Nit Combing Acknowledged as A Valid Treatment Strategy NEWTON, Mass.--(BUSINESS WIRE)--The National Pediculosis Association (NPA) of Newton, Mass. today announced a milestone in its mission to educate parents on chemical-free ways to screen and treat children with head lice. Following review of a citizen petition from the NPA, the U.S. Food and Drug Administration (FDA) has updated its website, Treating and Preventing Head Lice, noting that lice removal kits, which are “comb or comb-like” devices, are a treatment option, and stating that combing may be used alone. “We appreciate the FDA’s careful consideration. While combs have been mentioned passively through the years, the FDA is now recognizing combing as a treatment strategy on its own,” said …
Rickettsia Prowazekii (Epidemic Typhus)
Rickettsia prowazekii is an intracellular, gram-negative coccobacillus. It is an obligate parasite. R. prowazekii belongs to the genus Rickettsia and is the causative agent of epidemic typhus. The genus Rickettsia is composed of gram-negative bacteria. Rickettsiae are the closest known relatives of mitochondria in eukaryotic cells.The vector for epidemic typhus is the human body louse. R. prowazekii multiplies in the gut epithelium of the body louse and explodes into the gastrointestinal (GI) tract, eventually killing the body louse in the process. In this regard, R. prowazekii is unique because no other known members of Rickettsia kill their vector. The R. prowazekii remain viable in the dead louse as well as in the louse feces. Viable R. prowazekii have been detected in dried feces of …
Where Are We With Human Lice? A Review of the Current State of Knowledge
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 …
Where Are We With Human Lice? A Review of the Current State of KnowledgeRead More
Severe pediculosis capitis in a nursery school girl
Pediculosis capitis is the most frequent ectoparasitosis around the world. The infestation is caused by Pediculus humanus capitis (head louse), which affects hair, scalp, and skin. It rarely presents with more symptoms and in the majority of the cases, it shows a benign course if treated properly. We present the case of a nursery school girl with head lice infestation for 18 months. She did not improve after the shampoo treatment. This case was associated with furunculosis, skin lesions, multiple adenopathies, and anemia. Initially, the presence of boils, alopecia, and lymphadenopathy was evident. The persistence of pediculosis capitis and intense scratching induced changes on skin integrity, facilitating opportunistic bacterial superinfection that led to impetiginization, furunculosis, …
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Head lice can be a pesky problem
"I’m starting to see a few cases of head lice now that kids have been in school awhile. The critters are white and about the size of a sesame seed. They are known as "obligate ectoparasites." Obligate means they require a placental mammal host to survive (i.e. humans) and ectoparasites means they live outside the human body and need a host to survive. They do this by feeding on the host’s blood and can't live off of a body for more than a day or so. Lice are spread by direct contact of a person's head or hair with an infested individual or through sharing personal items such as hats, towels, brushes, helmets, hair ties or even car seat headrests. They do not jump or fly and are not transmitted by pets... Treatment of lice requires a lot of patience. There really is no substitute for …