02194nas a2200217 4500008004100000022002500041245014400066210006900210260001600279300001400295490000700309520144600316653001501762653002401777653002201801100002101823700001801844700002701862700002801889856005901917 2022 eng d a0022-2585, 1938-292800aThe Attractivity of the Head Louse, Pediculus humanus capitis (Pediculidae: Anoplura) to Isolated Compounds and Blends of Human Skin0 aAttractivity of the Head Louse iPediculus humanus capitisi Pedic cApr-28-2022 a1171-11760 v593 a

Human head lice Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae) are ectoparasites that cause pediculosis, a global scale disease mainly found in school-age children. Previous works from our laboratory found nonanal, sulcatone, and geranylacetone as the main human scalp volatile components, and individually evaluated their attraction to head lice using an olfactometer. In this work, we compared how their blends at different concentrations attract head lice, and how their blended effect compares to the effect of isolated compounds. At the concentrations evaluated, individual components did not show attraction towards head lice, but a ternary mixture of them was attractive. Moreover, a solvent extract from the human head scalp was analyzed by GC-MS, finding that tetradecanoic acid, palmitic acid, oleic acid, palmitoleic acid, and squalene are the most abundant components. Attraction to these individual compounds at natural concentrations was tested by bioassays in a circular experimental arena. No attraction was observed when the components were tested individually, but when they were evaluated as a blend they attracted head lice. This work presents new information about how chemical signals are attractive at certain concentrations and proportions. This information could be used to better understand communication mechanisms in head lice and for the development of louse repellents.

10aHead louse10ahead scalp compound10ainsect attraction1 aAdjemian, Victor1 aGalassi, F.G.1 aPicollo, María, Inés1 aGonzález-Audino, Paola uhttps://academic.oup.com/jme/article/59/4/1171/657555602502nas a2200265 4500008004100000022001400041245011600055210006900171260001200240300001200252490000800264520168300272653001701955653001301972653001301985653001301998653001602011100001802027700003102045700002102076700002802097700002702125700002802152856005602180 2021 eng d a0932-011300aHead lice were also affected by COVID-19: a decrease on Pediculosis infestation during lockdown in Buenos Aires0 aHead lice were also affected by COVID19 a decrease on Pediculosi c01-2021 a443-4500 v1203 a

Pediculosis is a worldwide disease affecting school-aged children produced by the presence of the head louse,Pediculushumanus capitisDe Geer, an obligate ectoparasite on the human scalp feeding exclusively on blood. Transmission occursprimarily through direct physical head-to-head contact. In March 2020, the World Health Organization (WHO) declared theCOVID-19 outbreak as a pandemic. COVID-19 is caused by SARS-CoV-2, a variant of the coronavirus. Therefore, on March 18,2020, the Argentinean government established mandatory isolation for an indefinite period. This obligatory isolation interruptedregular classes avoiding direct contact between children, thus affecting the dispersal route of individuals and the evolution of headlouse populations. In this study, we evaluated through an online survey how confinement affected the prevalence of lice duringlockdown compared to the situation prior to confinement. The survey allowed to discriminate the different control strategies, thenumber of treatments, and the amount of insects recorded by parents. Data of 1118 children obtained from 627 surveys wereanalyzed. As the main result, it was observed that prevalence of lice decreased significantly from before (69.6%) to during(43.9%) COVID-19 lockdown. Moreover, head lice infestation was more effectively controlled in households with up to 2children in comparison to households with 3 or more children. This is the first study that analyzed the prevalence of head liceduring COVID-19 pandemic. In addition, this work demonstrated the impact of social distance in the population dynamics ofhead lice and how it could affect the control strategies in the future

10aBuenos Aires10aCovid-1910aHead lic10aLockdown10aPediculosis1 aGalassi, F.G.1 aOrtega-Insaurralde, Isabel1 aAdjemian, Victor1 aGonzález-Audino, Paola1 aPicollo, María, Inés1 aToloza, Ariel, Ceferino uhttp://link.springer.com/10.1007/s00436-020-07038-y02513nas a2200217 4500008004100000022001400041245006400055210006300119260001100182300001200193490000700205520186000212653002402072653002202096653001002118653001402128100001802142700002702160700002802187856008002215 2020 eng d a0022-258500aHead Louse Feces: Chemical Analysis and Behavioral Activity0 aHead Louse Feces Chemical Analysis and Behavioral Activity c3-2020 a336-3420 v573 a

Human head lice Pediculus humanus capitis (De Geer) (Phthiraptera: Pediculidae) are insect parasites closely associated with humans, feeding on the blood of their hosts and causing them skin irritation and probable secondary infections. Despite being a severe nuisance, very few studies have reported on intraspecific chemical communication in head lice. Here, we evaluated the attractive response of head lice to the volatile compounds and solvent extracts from their feces. We also chemically analyzed the main volatile components of these feces and those of the feces’ extracts. Head lice were attracted to the methanol extract of their feces but not to the hexane or dichloromethane extracts, suggesting the polar nature of bioactive chemicals present in head louse feces. Follow-up chemical identifications, in fact, showed the presence of hypoxanthine, uric acid, and another purine tentatively identified as either guanine or iso-guanine. Additionally, head lice were significantly attracted by volatiles emitted from samples containing feces. The volatiles emanated from feces alone contained 19 identified substances: 2-pentanone, hexanal, heptanal, 3-methyl-3-buten-1-ol, octanal, sulcatone, nonanal, acetic acid, 2-ethyl-1-hexanol, decanal, 1-octanol, butyric acid, 1-nonanol, hexanoic acid, octanoic acid, 2,6-dimethyl-7-octen-2-ol, 2-undecanone, geranylacetone, and hexadecane. The major compounds found were decanal, nonanal, hexanal, and acetic acid, together representing approximately 60% of the identified compounds. This work represents the first chemical evidence of intraspecies communication among head lice. The results support the existence of active substances present in the feces of P. humanus capitis that may be involved in its aggregation behavior.

Attached pdf file is e-print ahead of printed version

10abehavioral activity10achemical analysis10afeces10ahead lice1 aGalassi, F.G.1 aPicollo, María, Inés1 aGonzález-Audino, Paola uhttps://academic.oup.com/jme/advance-article/doi/10.1093/jme/tjz184/560735601827nas a2200205 4500008004100000022001400041245007400055210006900129260001200198300001600210490000700226520121300233653001401446653001401460653001501474100001801489700002801507700002701535856005901562 2019 eng d a0022-258500aHead Lice Recognize and Prefer Head Odor Over Foot and Forearms Odors0 aHead Lice Recognize and Prefer Head Odor Over Foot and Forearms  c05-2020 a1204 - 12070 v563 a

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 foot). Conversely, when head lice were exposed in an experimental arena to the whole human odor of different parts of the body, they showed a preferential response to the whole head odor compared with the whole foot or forearm odors. These results suggest that head lice can at short distance of the host, be oriented towards the head odor of the human host in the selection of the scalp environment.

10ahead lice10ahead odor10apreference1 aGalassi, F.G.1 aGonzález-Audino, Paola1 aPicollo, María, Inés uhttps://academic.oup.com/jme/article/56/5/1204/548872701203nas a2200157 4500008004100000245004700041210004700088260003300135520064500168100003100813700002800844700002800872700002700900700002000927856009800947 2018 eng d00aEL SISTEMA OLFATIVO DEL PIOJO DE LA CABEZA0 aEL SISTEMA OLFATIVO DEL PIOJO DE LA CABEZA aMendoza, ArgentinacMay 20183 a

Conference Poster

 

Description:

El piojo de la cabeza Pediculus humanus capitis (Phthiraptera: Pediculidae) es un insecto hematófago cosmopolita que parasita exclusivamente a humanos. Debido a la alta dependencia por su huésped, su comportamiento y fisiología se ven afectados durante la evaluación de alimento y refugio. Nuestro objetivo principal fue caracterizar el sistema olfativo del piojo de la cabeza. En particular, estudiamos el rol de la antena de manera morfológica y comportamental en la evaluación de estímulos olfativos.

1 aOrtega-Insaurralde, Isabel1 aToloza, Ariel, Ceferino1 aGonzález-Audino, Paola1 aPicollo, María, Inés1 aBarrozo, R., B. uhttps://www.researchgate.net/publication/325722564_EL_SISTEMA_OLFATIVO_DEL_PIOJO_DE_LA_CABEZA02078nas a2200217 4500008004100000022001400041245013700055210006900192300001400261490000700275520132500282653002401607653002601631653002301657100001801680700002101698700002801719700002701747700002801774856005801802 2018 eng d a0022-258500aResponse of Pediculus humanus capitis (Phthiraptera: Pediculidae) to Volatiles of Whole and Individual Components of the Human Scalp0 aResponse of Pediculus humanus capitis Phthiraptera Pediculidae t a527 - 5330 v553 a

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 compounds being the following: nonanal, sulcatone, geranylacetone, and palmitic acid. Head lice were highly attracted by the blend human scalp volatiles, as well as by the individual major components. A significant finding of our study was to demonstrate that nonanal activity depends on the mass of the compound as it is repellent at high concentrations and an attractant at low concentrations.The results of this study indicate that head lice may use chemical signals in addition to other mechanisms to remain on the host.

10aattractant activity10ahuman scalp volatiles10arepellent activity1 aGalassi, F.G.1 aFronza, Georgina1 aToloza, Ariel, Ceferino1 aPicollo, María, Inés1 aGonzález-Audino, Paola uhttps://academic.oup.com/jme/article/55/3/527/481792402498nas a2200253 4500008004100000245014000041210006900181260000900250300001400259490000700273520154300280653001401823653001201837653001601849653001401865653001501879100002501894700003301919700002801952700002201980700002902002700002702031856018602058 2003 eng d00aPrevalence and levels of Permethrin resistance in Pediculus humanus capitis DeGeer (Anoplura: Pediculidae) from Buenos Aires, Argentina0 aPrevalence and levels of Permethrin resistance in Pediculus huma c2003 a447 - 4500 v403 a

Permethrin has been used extensively for control of Pediculus humanus capitis De Geer(Anoplura: Pediculidae) in Argentina since 1990, resulting in the development of resistance to this and other pyrethroids. This resistance was Þrst detected in some Þeld populations in 1997. A survey for resistance in Buenos Aires in 2001 revealed signifcant resistance levels in lice on children at 24 of 26 (92.3%) schools. When compared with a previously unexposed reference population, resistance ratios (RRs) obtained by exposing the insects to Þlter papers impregnated with permethrin ranged from 2 to 60 in 10 (39%) of the schools. RRs in the remaining 14 (61%) populations were too great to not be measured with the Þlter paper method (RR 88.7). As an alternative, we used topical applications of 0.1 l of acetone solution of permethrin on the dorsal abdomen of adults and third instars. This topical method, which has not been previously reported for head lice, was capable of quantifying higher levels of resistance. Highly resistant populations had RRs from 162.5 to 655.2. When applied to populations with low and intermediate levels of resistance, results from the Þlter paper and topical application methods were highly correlated, and RRs from topical application were higher than those from the Þlter paper method. Results from the combination of the two methods indicated that head lice among Buenos Aries school children are highly resistant to permethrin, and the resistance is widespread.

10aArgentina10acapitis10aPediculosis10aPediculus10aPermethrin1 aVassena, Claudia, V.1 aMougabure-Cueto, Gastón, A.1 aGonzález-Audino, Paola1 aAlzogaray, R., A.1 aZerba, Eduardo, Nicolás1 aPicollo, María, Inés uhttps://www.researchgate.net/publication/8955671_Prevalence_and_Levels_of_Permethrin_Resistance_in_Pediculus_humanus_capitis_De_Geer_Anoplura_Pediculidae_from_Buenos_Aires_Argentina01220nas a2200313 4500008004100000020001400041245013400055210006900189260000900258300001400267490000700281520019000288653002600478653001200504653003200516653001900548653002700567653002600594653001400620653001500634653003700649653002100686100003300707700002800740700002500768700002700793700002900820856005700849 2002 eng d a0022-258500aToxic effect of aliphatic alcohols against susceptible and permethrin-resistant Pediculus humanus capitis (Anoplura: Pediculidae)0 aToxic effect of aliphatic alcohols against susceptible and perme c2002 a457 - 4600 v393 a

The effectiveness of 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, and 1-dodecanol was evaluated by immersion method against susceptible and permethrin-resistant head lice, Ped

10aAlcohols/pharmacology10aanimals10aFatty Alcohols/pharmacology10aInsect Control10aInsecticide resistance10aOctanols/pharmacology10aPediculus10aPermethrin10aResearch Support, Non-U.S. Gov't10ascalp dermatoses1 aMougabure-Cueto, Gastón, A.1 aGonzález-Audino, Paola1 aVassena, Claudia, V.1 aPicollo, María, Inés1 aZerba, Eduardo, Nicolás uhttps://academic.oup.com/jme/article/39/3/457/83497501149nas a2200301 4500008004100000245014600041210006900187260000900256300001400265490000700279520019000286653001200476653001400488653001000502653001100512653002700523653001600550653001400566653001500580653003700595100002800632700001600660700002500676700003300701700002900734700002700763856005700790 2005 eng d00aIncreased monooxygenase activity associated with resistance to permethrin in Pediculus humanus capitis (Anoplura: Pediculidae) from Argentina0 aIncreased monooxygenase activity associated with resistance to p c2005 a342 - 3450 v423 a

We studied the profile of permethrin resistance in populations of head lice infesting children 6-12 yr old in schools and their homes in and around Buenos Aires, Argentina. Fiv

10aanimals10aArgentina10achild10ahumans10aInsecticide resistance10aPediculosis10aPediculus10aPermethrin10aResearch Support, Non-U.S. Gov't1 aGonzález-Audino, Paola1 aBarrios, S.1 aVassena, Claudia, V.1 aMougabure-Cueto, Gastón, A.1 aZerba, Eduardo, Nicolás1 aPicollo, María, Inés uhttps://academic.oup.com/jme/article/42/3/342/849058