Mortality Of Lice Research Articles

Detection of deltamethrin, cypermethrin and flumethrin efficacy against buffalo lice-Haematopinus tuberculatus.

The cattle and buffalo farm practices have been adopted differently by farmers in India but the infestation of ectoparasites including louse has been advocated in high population of animals across the country. The aim of this study was to identify the louse morphologically and determine the in vitro efficacy of the insecticides deltamethrin, cypermethrin and flumethrin against the buffalo louse, Haematopinus tuberculatus. The present research work was conducted using lice collected from organized buffalo dairy farms of Mhow block, Indore district of Madhya Pradesh, India. The adult's lice were collected from heavily infested regions of the body and tail of buffaloes. Some of the collected adult's lice were preserved for morphological identification in 70% alcohol. Briefly, in vitro treated surface bioassay utilizing a cloth rectangle that allows lice to move freely has been used. The concentrations were prepared as 30, 60, 90 and 120ppm for deltamethrin and flumethrin, whereas for cypermethrin, 100, 200, 300 and 400ppm concentrations were prepared in distilled water. The 600μl of each concentration was spread evenly over a cloth rectangle held in the bottom of a Petri plate. Ten adult lice were used for each concentration in triplicate (n = 30) and the same is maintained for control. The vitality of the louse was assessed at various intervals: 30, 60, 120, 180 and 240min. The lousicidal efficacy was determined by using in vitro bioassays with deltamethrin, cypermethrin and flumethrin. It is observed that as the concentration of insecticides increases with exposure time, mortality of lice is also increased. The current study reveals that cypermethrin and flumethrin were effective in their recommended doses but in the case of deltamethrin, the lice showed a low level of resistance. Furthermore, this type of study on buffalo louse has not conducted in Mhow region of Madhya Pradesh where heavy infestation of lice occurs on buffalo.

Evaluation of Lousicidal Activity of Ziziphus mauritiana Alkaloids and Eucaylptus camaldulensis Terpenoids Leaves Extracts in Chickens: An In Vitro Study

The present study aimed to highlight and assess the in vitro poultry anti-lice properties of Ziziphus mauritiana alkaloids and Eucalyptus camaldulensis terpenoids leaves extracts. In vitro poultry antilouse effects of the extracts of various concentrations (1 mg/mL, 5 mg/mL, and 10 mg/mL) using filter paper contact bioassay was applied. Results revealed that lice mortality was concentration-dependent for both studied extracts. The median lethal concentration (LC50) values were 3.687 and 1.045 for alkaloids and terpenoids extracts respectively. The results indicate that terpenoids extract has strong lousicidal activity. Further steps should be pursued to make these extracts to be tested in vivo then may be used as a novel treatment for poultry lice in future, allowing lice control in a less aggressive way to the environment.

Effectiveness of Custard Apple (Annona squamosa) Seed Extract in Treating Pediculosis Capitis

Pediculosis capitis infestation, commonly known as head lice, a worldwide public health concern affecting individuals of all age groups, and prevalence in the general population can be as high as 40 percent. The main task attained in the study was the determination of the pediculicidal effects of Annona squamosa seed extract of different concentrations. Methodology utilized a true experimental design done in 3 trials; 10 live head lice were observed under each concentration of 25%, 50%, 75% atis seeds extract for the experimentation and 75% permethrin concentration as controlled group. In vitro testing was used and the subjects were placed in prepared petri dishes for experimentation. Data results found out that there is p-value of 0.067 at α = 0.05 for mean time elapsed (secs) for 100% head lice mortality. Significant p-level of 0.002 for pediculicidal activity for the first 5 minutes has been noted. The researchers derived up with a conclusion that Custard Apple (Annona squamosa) seed extract in 75%, 50% and 25% concentration is as effective as Commercial Pediculicide (Permethrin) in killing pediculosis Capitis. 50% concentration has comparable results to Permethrin and is the most effective due to its earlier onset of pediculicidal activity.

EVALUATION OF DELTAMETHRIN 7.5 % POUR ON FOR THECONTROL OF SOME ECTOPARASITES OF CATTLE AND BUFFALOES

The results of in vivo evaluation of deltamethrin 7.5 % pour on revealed that single application caused 100% elimination of Boophilus annulatus hard ticks from naturally infested cows under treatment within 2-3 weeks. There was neither any reinfestation nor undesirable side effect up to 45 days post treatment. Deltamethrin 7.5% pour on seems to be very effective against tick infested cows, safe for use and easy for application. In vitro evaluation, B. annulatus tick species exposed to hair (10 minutes) collected from cows previously treated with deltamethrin 7.5% pour on show some degree of paralysis and mortality varies according to time of collected hair post treatment. The most effective result was observed on hair collected 14 days post treatment, while hair collected 35 days post treatment was the least, since the speed of killing activity slows down gradually with time pass. The predilection site of lice, Haematopinus tuberculatus among buffaloes were the wither region (47.6%) followed by the neck and dewlap (45%), while the cheek was (0.16%) the lowest predilection site for buffaloe lice. In vivo evaluation, of deltamethrin 7.5% pour on against buffaloe's lice was 100% on day 7 post treatment compared to control group. Animal showed relief from symptoms of itching which continued for 35 days post treatment. In vitro evaluation, the mortality of lice was started 15 minutes after exposure and completed after 30 minutes from exposure to insecticide.

Paranucleospora theridion (Microsporidia) infection dynamics in farmed Atlantic salmon Salmo salar put to sea in spring and autumn

The microsporidian Paranucleospora theridion (syn. Desmozoon lepeophtheirii) is a parasite of Atlantic salmon Salmo salar and also a hyperparasite of the salmon louse Lepeophtheirus salmonis. The parasite develops 2 types of spores in salmon, cytoplasmic spores in phagocytes and intranuclear spores in epidermal cells. The former type of development is assumed to be propagative (autoinfection), while the epidermal spores transfer the parasite to lice. Development in lice is extensive, with the formation of xenoma-like hypertrophic cells filled with microsporidian spores. We show that salmon are infected in the absence of lice, likely through waterborne spores that initiate infections in the gills. During summer and autumn the parasite propagates in the kidney, as evidenced by peaking normalised expression of P. theridion rRNA. Lice become infected during autumn, and develop extensive infections during winter. Lice mortality in winter and spring is likely responsible for a reservoir of spores in the water. Salmon transferred to sea in November (low temperature) did not show involvement of the kidney in parasite propagation and lice on such fish did not become infected. Apparently, low temperatures inhibit normal P. theridion development in salmon.

Activity of tea tree oil and nerolidol alone or in combination against Pediculus capitis (head lice) and its eggs.

Head lice infestation is an emerging social problem in undeveloped and developed countries. Because of louse resistance increasing, several long-used insecticidal compounds have lost their efficacy, and alternatives, such as essential oils, have been proposed to treat this parasitic infestation. The present study investigated the efficacy of two natural substances: tea tree (Melaleuca alternifolia) oil and nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol) against lice and its eggs. Products were used alone and in combination (ratio 1:1 and 1:2) from 8 % dilution. The in vitro effect of natural substances at different concentrations were evaluated against 69 head lice (adults and nymphs) and 187 louse eggs collected from school children in Chieti–Pescara (Central Italy) over a 6-month period. The lice mortality was evaluated for 24 h by a stereo light microscope. The ovicidal activity was monitored by microscopic inspections for 15 days. Tea tree oil was more effective than nerolidol against head lice with 100 % mortality at 30 min and 1 % concentration. On the contrary, nerolidol expressed a more pronounced ovicidal activity inducing the failure of 50 % of the eggs to hatch at 1 % concentration after 4 days; the same effect was achieved by using a twice concentration of tea tree oil. The association of the two substances both in ratios 1:1 and 1:2 combined efficaciously their insecticidal and ovicidal effect; in particular, the ratio 1:2 (tea tree oil 0.5 % plus nerolidol 1 %) acted producing both the death of all head lice at 30 min and the abortive effect of louse eggs after 5 days. These results offer new potential application of natural compounds and display a promising scenario in the treatment of pediculosis resistant cases. The development of novel pediculicides containing essential oils could be, in fact, an important tool to control the parasitic infestation.Electronic supplementary materialThe online version of this article (doi:10.1007/s00436-012-3045-0) contains supplementary material, which is available to authorized users.

Efficacy of the LouseBuster, a New Medical Device for Treating Head Lice (Anoplura: Pediculidae)

Human head lice (Pediculus humanus capitis De Geer) occur worldwide and infest millions of children and adults every year. Head lice infestations, which are known as pediculosis capitis, are psychologically stressful, physically irritating, and are one of the leading causes of K-6 school absence. The prevalence of head lice in many countries is increasing rapidly because of resistance to chemicals used in many head lice treatments. We tested the efficacy of an alternative method for controlling head lice, the LouseBuster, a custom-built medical device designed to kill head lice and their eggs using controlled, heated air. A total of 56 infested subjects was treated with the LouseBuster, and the efficacy of the treatment was evaluated by comparing the viability of lice and eggs on randomly assigned pre- and posttreatment sides of each subject's scalp. We evaluate treatment efficacy in the hands of novice versus experienced operators. We also evaluate treatment efficacy on different hair types and at different ambient humidities. Overall mortality of lice and eggs was 94.8% after treatment by experienced operators. Novice operators also achieved good results after a short training session; their results did not differ significantly from those of experienced operators. No adverse events were associated with the LouseBuster treatment. The LouseBuster is efficacious for killing head lice and their eggs. The use of heated air is appealing because it is a fast, safe, nonchemical treatment. Head lice are also unlikely to evolve resistance to desiccation, which is the apparent mode of action.

Eficácia do extrato concentrado contendo Saccharum officinarum L: Poaceae, Azadirachta indica A. Juss. Meliaceae, e Eucaliptus spp Myrtaceae, sobre Pediculus capitis De Geer, (Anoplura: Pediculidae)

O objetivo deste trabalho foi avaliar a eficácia do extrato concentrado contendo Saccharum officinarum L. Poaceae, Azadirachta indica A. Juss. Meliaceae, e Eucaliptus spp Myrtaceae sobre Pediculus capitis De Geer Pediculidae. Foram coletados mil e trinta e cinco piolhos da cabeça de crianças infestadas por Pediculus capitis de creches da Região Metropolitana do Recife, Estado de Pernambuco, Brasil. Para realização do teste utilizou-se três grupos com trezentos e quarenta e cinco piolhos cada referentes aos produtos, extrato concentrado (EC), inseticida piretróide (PI) e controle (C). Os piolhos foram imersos em solução dos produtos por três minutos e em seguida secos. A mortalidade foi monitorada em diferentes momentos, por um período de vinte e quatro horas. O extrato concentrado matou todos os piolhos antes de doze horas e uma média de 60,28% (208/345) de mortalidade do EC ocorreu entre três e seis horas, a maior parte da mortalidade do PI foi observada 24 h após o tratamento. Os resultados mostraram que o extrato contendo Saccharum officinarum, Azadirachta indica, e Eucaliptus spp constitui-se como uma potente ferramenta no controle do Pediculus capitis.

Use of Temperature and Water Immersion to Control the Human Body Louse (Anoplura: Pediculidae)

Physical methods such as high and low temperatures were used in the past for the control of human body louse, Pediculus humanus humanus L. (Anoplura: Pediculidae). In the current study, the minimum time necessary to kill all lice after exposing them to temperatures other than those described in the literature, the mortality of lice after immersing them in water, and the survival of lice whose legs were amputated were studied. All lice died after 6 d at 6 degrees C, after 11 d at 24 degrees C, and after 9 d at 31 degrees C. At -17 degrees C, all lice were dead after 35 min, whereas at -70 degrees C, all lice were dead after 1 min. All lice died after immersion in water within 19 h. The differences in mortality were significant but borderline between controls and lice whose two legs were amputated immediately or 24 h after feeding (3.3 versus 13.3% and 8.3 versus 21.7%). For lice whose leg was amputated 48 h after feeding, significant differences were found between controls and lice with one amputated leg (13.3 versus 48.3%), between controls and lice with two amputated legs (13.3 versus 68.3%), and between lice with one and two amputated legs (48.3 versus 68.3%).

Immunization of rabbits with a midgut extract of the human body louse Pediculus humanus humanus: the effect of induced resistance on the louse population.

Resistance to human body lice, Pediculus humanus humanus L, induced by feeding on rabbits immunized with an extract of louse gut was studied. The mortality of lice fed on immunized rabbits was 73%, significantly higher than that of lice fed on control rabbits (52%) (P < 0.01). The proportion of dead nymphs and female lice with ruptured guts was significantly higher in lice fed on immunized rabbits (P < 0.01). The size of the bloodmeal was 35% greater in female lice fed on control rabbits than on immunized rabbits. Lice fed on immunized rabbits laid 40% less eggs than those fed on the controls, they also demonstrated a significant decrease in the number of eggs per female over time (P < 0.01). 86% of the eggs laid by lice fed on immunized animals hatched, compared with 92% hatching of eggs laid by the lice fed on control animals (P < 0.01). With the exception of the first bloodmeal the percentage of hatched eggs which were laid between any two bloodmeals was significantly smaller (P < 0.01) in the lice fed on immunized rabbits than in the control group. The first nymphal stage of lice fed on immunized rabbits took an average of 5.2 days to moult to the second stage, compared with 4 days for those fed on control rabbits.

Tests With Systemic Insecticides in Rabbits as Toxicants for Body Lice

More than 100 selected materials were evaluated as systemic insecticides in rabbits against body lice, Pediculus h. humanus L. Thirteen caused complete mortality of lice fed on rabbits which had been given the materials orally without noticeably affecting the rabbits. Eight others caused complete mortality of lice but also affected or killed the rabbits. Butazolidin, monosodium 4-butyl-1,2-diphenyl-3,5-pyrazolidinedione, one of the most promising chemicals, caused complete mortality of all motile stages of lice fed within 5 hours after treatment on rabbits given doses as low as 20 mg/kg. Complete mortality of female lice was obtained at 10 mg/kg. There were no noticeable effects on the rabbits at dosages up to 600 mg/kg.

The ecology of Lice on sheep. 5. The influence of heavy rain on populations of Linognathus ovillus

Exposure of nymphal and adult Damalinia ovis (L.) to 100% R.H. at 37�C did not increase the death rate but immersion for 6 hr in water followed by exposure to 40% R.H. was sufficient to kill all nymphs and adults. Immersion of only 1 hr was fatal for 50-100% when followed by exposure of 7.5-24 hr to 90% R.H. Eggs continued to develop under water at 37�C and an appreciable mortality occurred only after 7 days immersion. Exposure to relative humidities of over 90% killed hatching eggs. When the fleece of a sheep infested with D. ovis is soaked by rain it may take many hours to dry and there is a resultant mortality of nymphal and adult lice and hatching eggs. In the region where the experiments were carried out, sheep were soaked periodically by thunderstorms in the autumn. The irregular mortalities of lice on different sheep was reflected 6 months later, when the lousiest sheep were shown to be those which were not soaked in the previous autumn.