Sarcoptic mange in the Scandinavian wolf Canis lupus population.

BACKGROUND: Sarcoptic mange, a parasitic disease caused by the mite Sarcoptes scabiei, is regularly reported on wolves Canis lupus in Scandinavia. We describe the distribution and transmission of this parasite within the small but recovering wolf population by analysing 269 necropsy reports and performing a serological survey on 198 serum samples collected from free-ranging wolves between 1998 and 2013. RESULTS: The serological survey among 145 individual captured Scandinavian wolves (53 recaptures) shows a consistent presence of antibodies against sarcoptic mange. Seropositivity among all captured wolves was 10.1 % (CI. 6.4 %-15.1 %). Sarcoptic mange-related mortality reported at necropsy was 5.6 % and due to secondary causes, predominantly starvation. In the southern range of the population, seroprevalence was higher, consistent with higher red fox densities. Female wolves had a lower probability of being seropositive than males, but for both sexes the probability increased with pack size. Recaptured individuals changing from seropositive to seronegative suggest recovery from sarcoptic mange. The lack of seropositive pups (8-10 months, N = 56) and the occurrence of seropositive and seronegative individuals in the same pack indicates interspecific transmission of S. scabiei into this wolf population. CONCLUSIONS: We consider sarcoptic mange to have little effect on the recovery of the Scandinavian wolf population. Heterogenic infection patterns on the pack level in combination with the importance of individual-based factors (sex, pack size) and the north-south gradient for seroprevalence suggests low probability of wolf-to-wolf transmission of S. scabiei in Scandinavia.

Superficial fibrin thrombi and other findings: a review of the histopathology of human scabietic infections.

BACKGROUND: Cutaneous infection with the mite Sarcoptes scabiei var. hominis is associated with epidermal and dermal changes. After noting superficial fibrin thrombi in two biopsies with scabies mites, we comprehensively reviewed the histopathologic findings in scabietic infections to determine the frequency of this finding. METHODS: Twenty five biopsies of scabies infection were retrieved from the archives of our institution; only cases containing scabietic mite parts or scybala were included. The microscopic features were documented. RESULTS: Nearly half (40%) of the cases showed fibrin thrombi within vessels of the superficial dermis. Other frequent findings included dermal eosinophils (88% of cases), epidermal spongiosis (76% of cases), lymphocyte atypia (64%), a superficial and deep infiltrate (52% of cases), dermal neutrophils (52%) and endothelial cell swelling (52%). Half of the cases contained polarizable mite elements. Less commonly encountered features included extravasated erythrocytes (44%), dermal edema (32%), pink 'pigtails'(28%), intraepidermal pustules (24%), plasma cells (20%) and vasculitis (4%). CONCLUSIONS: The pathologic characteristics of scabietic infection are wide-ranging. Spongiosis, superficial and deep inflammation, and dermal eosinophils and neutrophils are seen in the majority of cases. Superficial fibrin thrombi are not uncommon in scabietic infection, and may provide a helpful diagnostic clue when mites are not visible on initial sections.

Crusted scabies is associated with increased IL-17 secretion by skin T cells.

Scabies is an ectoparasitic infestation by the mite Sarcoptes scabiei. Although commonly self-limiting, a fraction of patients develop severely debilitating crusted scabies. The immune mechanisms underlying the development of crusted scabies are unclear, and undertaking longitudinal infection studies in humans is difficult. We utilized a porcine model to compare cellular immune responses in peripheral blood and skin of pigs with different clinical manifestations of scabies (n = 12), and in uninfected controls (n = 6). Although clinical symptoms were not evident until at least 4 weeks post-infestation, the numbers of peripheral IFNγ-secreting CD4(+) T cells and γδ T cells increased in infected pigs from week 1 post-infestation. γδ T cells remained increased in the blood at week 15 post-infestation. At week 15, skin cell infiltrates from pigs with crusted scabies had significantly higher CD8(+) T cell, γδ T cell and IL-17(+) cell numbers than those with ordinary scabies. Peripheral IL-17 levels were not increased, suggesting that localized skin IL-17-secreting T cells may play a critical role in the pathogenesis of crusted scabies development. Given the potential of anti-IL-17 immunotherapy demonstrated for other inflammatory skin diseases, this study may provide a novel therapeutic avenue for patients with recurrent crusted scabies.

Association of ABO and Rhesus blood groups with symptom emergence in scabies: a cross-sectional study.

Scabies is a contagious skin condition caused by the Sarcoptes scabiei mite. It can lead to various clinical reactions, ranging from no symptoms at all to noticeable skin lesions and severe itching within the same household. We aimed to investigate the potential role of blood groups in the emergence of disease symptoms by comparing the scabies patients with asymptomatic co-residents. This study comprised 102 patients infected with scabies from index cases and 111 asymptomatic co-residents. The index cases where symptoms first appeared were excluded. Among patients with scabies, 34 individuals (33.3%) had type A blood group, 12 (11.8%) had type B, 27 (26.5%) had type AB, and 29 (28.4%) had type O. Of these patients, 101 (99%) were Rh+, while 1 (1%) was Rh-. In asymptomatic contacts, 61 individuals (55%) had type A, 9 (8.1%) had type B, 1 (0.9%) had type AB, and 40 (36%) had type O blood group. Of these, 102 (91.9%) were Rh+, and 9 (8.1%) were Rh-. A significant difference was observed between the two groups concerning the frequency of ABO, Rh, and ABO*Rh blood groups (p < 0.05). The prevalence of B + and AB + blood groups was higher in scabies patients compared to asymptomatic contacts. The study results showed a significant association between the emergence of scabies symptoms with blood groups. Our results highlight the importance of more research into the roles of blood group antigens in normal skin epithelium and their involvement in the etiopathogenesis of scabies.

Characterisation of Sarcoptes scabiei antigens.

In pig herds, the status of Sarcoptes scabiei infections is routinely monitored by serodiagnosis. Crude antigen for ELISA is usually prepared from S. scabiei var. canis or other variations and may lead to variations in the outcome of different tests, making assay standardisation difficult. This study was performed to investigate the antigen profiles of S. scabiei, including differences between hydrophilic and more hydrophobic protein fractions, by Western blotting with sera from pigs with defined infection status. Potential cross-reactivity among S. scabiei (var. canis, suis and bovis), Dermatophagoides farinae and Tyrophagus putrescentiae was also analysed. Hydrophobic S. scabiei antigens were detectable in the range of 40-50 kDa, whilst the hydrophilic fraction showed no specific antigenicity. In the hydrophobic fractions of D. farinae and T. putrescentiae, two major protein fractions in a similar size range could be identified, but no cross-reactivity with Sarcoptes-positive sera was detectable. However, examination of the hydrophilic fractions revealed cross-reactivity between Sarcoptes-positive sera and both the house dust mite and the storage mite in the range of 115 and 28/38 kDa. Specific bands in the same range (42 and 48 kDa) could be detected in blots from hydrophobic fractions of all three tested variations of S. scabiei (var. canis, bovis and suis). These results show that there are considerable differences in mange antibody reactivity, including reactions with proteins from free-living mites, which may interfere with tests based on hydrophilic antigens. Further refinement of antigen and the use of specific hydrophobic proteins could improve ELISA performance and standardisation.

Evaluation of organ function and oxidant/antioxidant status in goats with sarcoptic mange.

The objective of the present study was to investigate the hemato-biochemical changes and status of oxidative stress in goats with scabies infection. The study was conducted on 12 Jamunapari goats; six clinically infected with scabies (group I) and six healthy goats as control (group II). The examination of skin scraping revealed the presence of Sarcoptes scabiei in the infected group. In hemato-biochemical indicators, hemoglobin%, packed cell volume, total erythrocyte count, albumin and albumin: globulin ratio decreased whereas, globulin, alanine aminotransferase, bilirubin, creatinine, and blood urea nitrogen increased significantly (p<0.05) in group I animals as compared to group II healthy goats. Among the oxidative stress indices, plasma nitrate and erythrocytic lipid peroxidation were increased and reduced glutathione levels decreased significantly (p<0.05) in group I goats as compared to group II healthy goats. The results of the present study suggest that scabies infection alters the hemato-biochemical indicators, increases oxidative stress and decreases antioxidant status in goat.

SEROLOGY AS A TOOL TO INVESTIGATE SARCOPTIC MANGE IN AMERICAN BLACK BEARS (URSUS AMERICANUS).

Black bears (Ursus americanus) have historically been considered an uncommon host for sarcoptic mange. However, over the last 25 yr, sarcoptic mange has been increasingly reported in black bears in the northeastern US. Syndromic monitoring is the most common surveillance approach for mange in bears, but tools to monitor exposure to Sarcoptes scabiei in bear populations have not been thoroughly evaluated under field conditions. In this study, we validated a commercially available enzyme-linked immunosorbent assay (ELISA), designed to detect antibodies against S. scabiei in dogs, for use in black bears with a sensitivity and specificity of 95.6% and 96.6%, respectively. To further examine the performance of this assay, serial serum samples from seven black bears with confirmed sarcoptic mange were collected posttreatment to determine the persistence of detectable antibody response with the ELISA. Antibodies in black bears waned to below the limit of detection between 4 and 14 wk, suggesting that serology studies might underestimate the number of exposed black bears after antibodies have waned. State-wide serosurveys in Pennsylvania from hunter-harvested black bears in 2017 and 2018 showed a significant difference in seroprevalence between regions with high occurrence of mange (mean seroprevalence 6.7%, range of 6.6-6.8%) and low occurrence of mange (no seropositive black bears were detected). Within Pennsylvania, these data indicate that the geographic distribution of exposure to S. scabiei, based on serologic testing, generally reflects the distribution of overt disease, as determined by syndromic surveillance. Collectively, these results indicate the evaluated ELISA is an effective tool for monitoring S. scabiei exposure in bear populations and provides the framework for additional studies regarding sarcoptic mange epidemiology in black bears.

Evaluation of blood oxidant/antioxidant balance in dogs with sarcoptic mange.

The aim of this study was to investigate of oxidant/antioxidant balance in dogs with sarcoptic mange. The study materials consisted of totally 30 cross-breed male dogs; 15 with sarcoptic mange (study group) and 15 healthy as control. Blood samples for analyses were taken from control and study group. In study group, microscopic examination of dermal scrapings of 15 dogs revealed S. scabies. Lipid hydroperoxide level, total oxidant status and oxidative stress index in dogs with sarcoptic mange were higher (P<0.01, P<0.01 and P<0.05, respectively) than the control. Otherwise; sulphydril levels in dogs with sarcoptic mange were lower (P<0.05) than that of control. No significant differences were observed in total antioxidant capacity between groups. Our results suggest a possible relationship between oxidant/antioxidant imbalance and sarcoptic mange infestation in dogs.

Hematologic and Serum Chemistry values of Endangered San Joaquin Kit Foxes ( Vulpes macrotis mutica) with Sarcoptic Mange.

A fatal outbreak of sarcoptic mange caused by Sarcoptes scabiei in San Joaquin kit foxes ( Vulpes macrotis mutica) in Bakersfield, California, US is causing the once-stable population to decline. Given the fatality of the disease in this already-endangered species experiencing continued population declines, city-wide interventions are underway. To optimize medical management of mange-infested kit foxes, we documented serum biochemistry and hematology values for 11 kit foxes with mange collected from January-May 2015 and compared them to historical data from 18 healthy Bakersfield kit foxes. Results from kit foxes with mange were consistent with chronic illness and inflammation, protein loss, hypoglycemia, and dehydration. These findings contribute to our understanding of this debilitating, multisystemic disease that can progress to death in individuals without intervention and will aid in the treatment and care of rehabilitated individuals.

Comparative effect of topical application of lindane and permethrin on oxidative stress parameters in adult scabies patients.

OBJECTIVES: The insecticides lindane and permethrin are commonly used for treatment of scabies. Animal studies have shown the presence of insecticide induced oxidative stress. Hence, this study was undertaken to assess and compare the effects of topical application of lindane and permethrin on oxidative stress parameters in scabies patients. DESIGN AND METHODS: Patients were alternatively assigned to treatment by either 1% lindane lotion or 5% permethrin cream. Blood samples were collected before and 12-14 h after the application of the drugs and evaluated for oxidative stress parameters and compared with healthy controls. RESULTS: Serum malondialdehyde (MDA) levels, erythrocyte superoxide dismutase (SOD) and catalase (CAT) activity were significantly increased while blood glutathione (GSH) levels were significantly decreased in the lindane group as compared to controls and the permethrin group. The permethrin treated group showed a non significant alteration in the oxidative stress parameters. CONCLUSION: Topical application of lindane induced significant oxidative stress as compared to permethrin which appears to be a safer option for the treatment of scabies.

Evaluation of oxidant/antioxidant balance in Iberian ibex (Capra pyrenaica) experimentally infested with Sarcoptes scabiei.

Oxidative stress (OS) is an imbalance between radical-generating and radical scavenging activity, resulting in oxidation products and tissue damage. Although some studies have been done in other species, there is a lack of information about the oxidative/antioxidant status in the Iberian ibex (Capra pyrenaica) affected by sarcoptic mange. To clarify this fact, albumin, catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), paraoxonase-1 (PON-1), glutathione reductase (GR), reduced glutathione (GSH): oxidized glutathione (GSSG) ratio, thiobarbituric acid reactive substances (TBARS) and total oxidant status (TOS) concentrations were measured in peripheral blood of ibexes experimentally infested with Sarcoptes scabiei (n=25), as well as in the healthy control group (n=14). During the course of the experiment, the infected ibexes were visually assigned to four categories according to the percentage of skin surface affected by mites. In the infested ibexes, the levels of albumin, PON-1, CAT, SOD, GSH-Px and GSH:GSSG ratio showed a significant (p<0.01) decrease with disease progression. With respect to the control group, this decrease was significantly (p<0.001) lower in the more severe clinical stages. No significant changes were observed in GR activity during disease or with respect to the control group. Conversely, the concentrations of TOS and TBARS increased with lesion severity, and with respect to the control group, this increase was significant (p<0.01) in the more advanced stages of the infection. Additionally, to explore the possible effects of sex, age, haplotype, mange status, and days post infection (dpi) on each of the OS biomarkers, generalized additive mixed models were applied. According to our results, the mange status and dpi explained the highest percentages in the observed changes in the biomarkers analyzed, whereas the haplotype only influenced the observed variability of albumin and TOS. The contribution of sex and age was not significant in any of the OS biomarkers. From the present study, it may be concluded that sarcoptic mange infestation increases OS and decreases antioxidant status in ibex. This imbalance may contribute to the pathogenesis of this disease.

Sarcoptic mange in dogs: Its effect on liver, oxidative stress, trace minerals and vitamins.

The present study was aimed to determine the effect on liver, associated oxidative stress, trace element and vitamin alteration in dogs with sarcoptic mange. A total of 24 dogs with clinically established diagnosis of sarcoptic mange, divided into two groups, severely infested group (n=9) and mild/moderately infested group (n=15), according to the extent of skin lesions caused by sarcoptic mange and 6 dogs as control group were included in the present study. In comparison to healthy control hemoglobin, PCV, and TEC were significantly (P<0.05) decreased in dogs with sarcoptic mange however, significant increase in TLC along with neutrophilia and lymphopenia was observed only in severely infested dogs. The albumin, glucose and cholesterol were significantly (P<0.05) decreased and globulin, ALT, AST and bilirubin were significantly (P<0.05) increased in severely infested dogs when compared to other two groups. Malondialdehyde (MDA) levels were significantly (P<0.01) higher in dogs with sarcoptic mange, with levels highest in severely infested groups. Activity of superoxide dismutase (SOD) (P<0.05) and catalase were significantly (P<0.01) lower in sarcoptic infested dogs when compared with the healthy control group. Zinc and copper levels in dogs with sarcoptic mange were significantly (P<0.05) lower when compared with healthy control group with the levels lowest in severely infested group. Vitamin A and vitamin C levels were significantly (P<0.05) lower in sarcoptic infested dogs when compared to healthy control. From the present study, it was concluded that sarcoptic mange in dogs affects the liver and the infestation is associated with oxidant/anti-oxidant imbalance, significant alteration in trace elements and vitamins.

Distinguishing disease effects from environmental effects in a mountain ungulate: seasonal variation in body weight, hematology, and serum chemistry among Iberian ibex (Capra pyrenaica) affected by sarcoptic mange.

Our study focuses on the Iberian ibex (Capra pyrenaica) from the Sierra Nevada Natural Space (southern Spain), where sarcoptic mange is an endemic disease and animals are affected by a highly seasonal environment. Our aim was to distinguish between disease and environmental influences on seasonal variation in body weight, hematology, and serum biochemistry in Iberian ibex. We sampled 136 chemically immobilized male ibexes. The single effect of mange influenced hemoglobin, hematocrit, mean corpuscular volume, leukocytes, band neutrophils, monocytes, cholesterol, urea, creatine, and aspartate aminotransferase. Both mange and the period of the year also affected values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils, glucose, and serum proteins. Scabietic animals showed a marked reduction in body weight (21.4 kg on average), which was more pronounced in winter. These results reveal that 1) infested animals are anemic, 2) secondary infections likely occur, and 3) sarcoptic mange is catabolic.

Evaluation of an ELISA using recombinant Ssλ20ΔB3 antigen for the serological diagnosis of Sarcoptes scabiei infestation in domestic and wild rabbits.

An ELISA, based on the Sarcoptes scabiei Ssλ20ΔB3 inmunodominant antigen, was evaluated for the detection of antibodies to S. scabiei in experimentally infested (n=10), farm (n=109), and wild (n=78) rabbit sera. The S. scabiei antigen Ssλ20ΔB3, a major structural protein present over the entire mite's body, was produced as a recombinant protein in Escherichia coli and purified for its use in the ELISA. The resulting ELISA showed, in experimentally infested domestic rabbits, detectable specific antibody responses (IgG) above the cut off level from week three post-infestation indicating that the assay is able to detect positive rabbits very early during the course of the infestation. The ELISA was validated on a panel of 109 domestic breeding rabbit sera collected from 26 Spanish farms, of which 41 were obtained from rabbits with skin lesions compatible with sarcoptic mange, 26 with skin lesions compatible with psoroptic mange, and 42 from unexposed individuals from mange-free farms. The ELISA in this group was characterized by 95% sensitivity, 97% specificity, and a high degree of repeatability. In the psoroptic mange compatible lesions group, included in the study as control group for cross-reactivity with the closely related mite Psoroptes cuniculi, cross-reacting antibodies to Ssλ20ΔB3 S. scabiei antigen were detected in 42.30% of the rabbit sera. However, mean% OD values of the sarcoptic-mange group (55.61 ± 39.20%) were significantly higher (p<0.001) than OD values of the psoroptic-mange (3.64% ± 5.4%) and also of the free-mange (0.21% ± 0.67%) groups. In addition, the ELISA was also evaluated in serum samples obtained from both naturally infested and non-infested wild rabbits from Mallorca Island. The sensitivity of the assay for this group was 100% (4 out of the 4 rabbits with sarcoptic mange compatible lesions and presence of S. scabiei mites were seropositive) and the specificity was 90% (67 out of 74 wild rabbits without detectable mange lesions were seronegative). Although, the total number of tested samples from experimentally infested, farm and wild rabbits was limited, our study showed that the ELISA is able to differentiate between infested and non-infested animals in all tested groups with very high sensitivity and specificity indicating that recombinant Ssλ20ΔB3 is a reliable diagnostic antigen. This assay might be a cost-effective tool for detecting the presence of mangy animals and therefore helping prevent spread of mange among domestic rabbits, reducing potential transmission from female breeding rabbits to other farms, and detecting infestation with sarcoptic mange in the wild.

Transcutaneous gamma benzene hexachloride absorption and toxicity in infants and children.

A premature, malnourished infant had seizures and abnormal neurological function associated with topical gamma benzene hexachloride (lindane) therapy. The level of gamma benzene hexachloride in his blood was 17 times greater than expected after a single topical application of 1% gamma benzene hexachloride. Significant levels developed in another child's blood after repeated applications of small amounts to areas of dermatitis and excoriations on the skin. The use of topical gamma benzene hexachloride in pediatric patients is reviewed because of increased evidence of unpredictable absorption and toxicity.

Circulating IgE in patients with ordinary and crusted scabies.

Serum from seven patients with ordinary scabies and six with crusted scabies were screened by immunoblotting for IgE- and IgG-specific proteins in an extract of the mite, Sarcoptes scabiei variety canis. Sera from atopic individuals without sensitivity to house dust mites were used as controls. Serum from all of the patients with crusted scabies showed strong IgE binding to 11-21 and IgG binding to 1-7 scabies proteins. In contrast, three of the seven patients with ordinary scabies showed IgE binding to one to six scabies proteins, and their antibody binding was much weaker. Patients with crusted scabies had serum antibody that reacted with larger molecular weight proteins compared with patients with ordinary scabies. The results of this study indicate that patients with crusted scabies showed a pronounced IgE response to scabies mites, whereas patients with ordinary scabies did not.

Effects of Psoroptes ovis (Acarina:Psoroptidae) on certain biochemical constituents of cattle serum.

Sera from Psoroptes ovis-infested calves were examined for 17 selected biochemical constituents to determine if P. ovis caused changes in any of these constituents. In order to recognize a scabies effect, there had to be a statistically significant (P less than or equal to 0.10) scabies exposure X time interaction and the changes in the biochemical constituents should have been correlated with the changes in the mite infestation. Five serum biochemical constituents fulfilled these criteria. Total protein, alpha-, beta-, and gamma-globulin were increased and total cholesterol was decreased at the peak of the scabies infestation. Precipitating antibodies to a P. ovis antigen were detected by immunodiffusion in some of the stored sera of the infested calves just after the peak of the infestation. Total protein, beta-, and gamma-globulin values were probably increased as a result of antibody production; alpha-globulin values were probably increased as a result of inflammation. As the scabies infestation declined, the mean values of all the above constituents from the infested calves, except cholesterol, began declining. Decreases in total cholesterol occurred, but they could not be entirely attributed to scabies. Examination of the serum biochemical constituents from a heavily infested calf that died during the test suggested that, in addition to antibody production and inflammation, kidney and liver damage may have occurred.

The effect of sarcoptic mange on growth performance, leukocytes and lymphocyte proliferative responses in pigs.

The effects of a single artificial infestation with sarcoptic mite (Sarcoptes scabiei var. suis DeGeer) on weight gain and lymphocyte blastogenic responses were studied in untreated and fenvalerate-treated pigs. Average daily feed intake, average daily gain and feed efficiency were monitored for 5 weeks in 32 infested and 16 uninfested pigs. Total and differential leukocyte counts were determined and lymphocyte proliferative responses, using a mitogen-stimulated lymphocyte blastogenesis assay, were evaluated in 24 pigs. Sarcoptic mite infestation or treatment for sarcoptic mange did not affect total or differential leukocyte counts (P greater than 0.10). Differences were not observed in weight gain or lymphocyte blastogenic responses between infested and uninfested pigs.

Effects of sarcoptic mange on serum proteins and immunoglobulin G levels in chamois (Rupicapra pyrenaica) and Spanish ibex (Capra pyrenaica).

Three groups of chamois (Rupicapra pyrenaica) and three groups of Spanish ibex (Capra pyrenaica) were established to study the effects of sarcoptic mange on serum proteins and immunoglobulin G (IgG) levels. The first group of chamois consisted of 22 healthy Pyrenean chamois (R. pyrenaica pyrenaica) from a non-infested area, the second group consisted of 20 healthy Cantabrian chamois (R. p. parva) from an area where sarcoptic mange has been reported since 1994 and the third group consisted of 16 Cantabrian chamois from the same area but naturally infested by Sarcoptes scabiei. The first group of Spanish ibex was 39 healthy animals from a sarcoptic mange non-infested area, the second group was 23 healthy animals from a sarcoptic mange infested area and the third group consisted of 20 animals from the same area but naturally infested with the parasite. Blood samples were taken after killing the animals as part of hunting programmes. Values for total proteins, gamma-globulin and IgG were higher in infested and healthy chamois from the infested area compared to healthy chamois from the non-infested area, and IgG levels were higher in infested chamois compared to healthy-exposed chamois. Values for alpha2-globulin were higher in healthy Cantabrian chamois. In Spanish ibex, albumin, alpha2-globulin and IgG levels were lower in the healthy Spanish ibex from the non-infested area than in healthy animals from an infested area. The differences found in the chamois were indicative of the establishment of a humoral antibody response in the animals in contact with the disease. As the IgG levels were not significantly different between healthy and infested Spanish ibex from the same area, a different pattern of chronic infection with humoral response to the disease was suggested.

Immunologic cross-reactivity among various strains of Sarcoptes scabiei.

Varieties of Sarcoptes scabiei from different hosts are highly host specific but they are morphologically indistinguishable. The purpose of this study was to investigate the immunologic cross-reactivity among several varieties of scabies mites using serum from a human scabies patient and from several other species of infested hosts. Homologous and heterologous crossed-immunoelectrophoretic (CIE) analysis of extracts prepared from var. canis (dog) and var. suis (pig) mites yielded very similar antigen profiles. Serum from a human patient infested with var. hominis had circulating IgE that bound to antigens present in extracts prepared from each animal mite variety. Antigen homology was further confirmed by fused peaks on tandem CIE. Additionally, sodium dodecyl sulfate polyacrylamide gel electrophoresis/immunoblot analysis showed that the 2 extracts contained proteins that bound antibody in serum from a var. suis-infested pig, a var. canis-infested dog, var. canis-infested rabbits, and a var. hominis-infested human. The results of this study clearly indicate that different varieties of scabies mites, though host specific, introduce some immunologically cross-reactive molecules into the host. However, each serum from the 4 scabies-infested hosts also contained antibody that was specific for proteins in extract from only 1 variety of mite. These data indicated that each variety of scabies introduced some unique molecules into the host, each strain produced some similar molecules, or both, but different hosts responded immunologically to different sets of these.