Number Of Mites Research Articles

Sensitivity and Specificity of Slit-Lamp Demodex Infestation Detection in Patients With Blepharitis

Purpose: To determine whether the sensitivity and specificity of detecting Demodex infestation using slit-lamp examination are comparable with those of light microscopy. Methods: We evaluated 22 eyelids of 22 patients with clinical signs and symptoms of blepharitis that suggested Demodex infestation. Two lashes with cylindrical dandruff were epilated from each lid and mounted on a glass slide. A coverslip was mounted on each slide, then placed on a strip of white paper, and examined on a slit lamp with a 90D lens attached. Number of mites per lash were documented. The slides were then examined under a light microscope. The same procedure was followed with a control group. Results were evaluated per lash and per patient. Results: Twenty-two patients were included, 11 were men, with an average age of 54.8 years. A total of 176 epilated lashes were examined. Mean total Demodex count per lash was 0.9 ± 1.3 mites by slit-lamp examination and 1.22 ± 1.73 by light microscopy. Corresponding values per patient were 7.3 ± 4.4 and 9.7 ± 7.18. Correlation between Demodex counts by slit lamp and light microscopy was mildly positive and statistically significant per patient (8 lashes, r= 0.69, P < 0.001). Analysis of positive/negative results yielded 43.2% with a positive result for slit lamp and 51.7% for light microscopy. The sensitivity of the slit-lamp examination for the presence of Demodex per patient was 96.6%, with a specificity of 90.9%; the positive predictive value was 91.6%, and the negative predictive value was 95.2%. Conclusions: Demodex infestation in patients with blepharitis and cylindrical dandruff can be confirmed using a slit lamp. This technique demonstrates diagnostic performance that is noninferior to that of light microscopy.

Efficacy of Terpinen-4-ol Combined With Eyelid Deep Cleaning for the Treatment of Demodex Blepharitis: A Randomized, Open-Label Trial.

We aimed to evaluate the clinical efficacy of a combined treatment regimen involving terpinen-4-ol (T4O) and eyelid deep cleaning for managing Demodex blepharitis. In this randomized, open-label trial, 40 patients diagnosed with Demodex blepharitis at the Cornea Specialty Clinic of Hankou Aier Eye Hospital were enrolled. Participants were randomly assigned to either a T4O or a combination treatment group. The T4O group used T4O cleaning wipes exclusively for two months. The combination group used T4O cleaning wipes and underwent deep eyelid cleaning at three scheduled visits (initial, first-, and second-month time points). A final follow-up was conducted one month after completion of treatment (three months after the beginning of treatment). At each visit, we assessed the number of Demodex mites, the ocular surface disease index (OSDI), eyelid margin sign scores, and corneal fluorescein staining scores. After two months of treatment, both the T4O and combination groups exhibited significant reductions in Demodex mite counts of 5.65 ± 6.03 and 7.75 ± 6.91, respectively. The T4O group, however, showed an increase in mite counts one month after ceasing treatment. Conversely, the combination group maintained and enhanced the reduction in mite counts post-treatment, with a significant difference at the third-month follow-up (8.70 ± 6.81 vs. 4.15 ± 6.91, P = 0.043). Although both groups demonstrated overall declines in OSDI scores post-treatment, only the combination group showed significant improvements at the second- and third-month follow-ups. No adverse events were reported in either group. Treatment with T4O wipes for two months significantly reduces Demodex mite counts, although there is a notable risk of mite rebound when treatment is ceased. Combining T4O wipes and eyelid deep cleaning offers a more effective reduction in Demodex mite counts and improvement in ocular symptoms compared to T4O treatment alone. The study finds that T4O combined with eyelid deep cleaning is more effective in treating Demodex blepharitis, highlighting the need for appropriate treatment duration and adjunctive therapies.

Species Diversity and Spatial Distribution of Some Oribatid Mites in Bory Tucholskie National Park (N Poland)

There are 23 national parks in Poland, and only a few of them have been studied thoroughly with regard to acarofauna so far. One of the least-examined areas in this regard is Bory Tucholskie National Park (BTNP), established in 1996. The aim of this research study was to explore the species diversity, community structure, and spatial distribution of mites from the order Oribatida: ptyctimous mites (Acari: Oribatida) and species from the families Nothridae and Camisiidae (Acari: Oribatida: Crotonioidea) inhabiting different forests open and unstable microhabitats in the area of Bory Tucholskie National Park (BTNP). In the case of ptyctimous mites, the communities were compared to those in other Polish national parks. Based on the analysis of 285 samples collected in BTNP between 2022 and 2024, 8 species of Crotonioidea with dominant Heminothrus peltifer (C. L. Koch, 1839) and 21 species of ptyctimous mites with the most numerous Atropacarus (Atropacarus) striculus (C. L. Koch, 1835) were identified in the analyzed material. The highest species diversity was observed in different types of pine forests (25 species) and in alder forests (24 species), while the lowest diversity occurred in areas with reeds (11 species). The comparison of the number of ptyctimous mites in Polish national parks revealed that BTNP can be ranked second in terms of species diversity among 12 national parks examined in Poland so far.

Steam Treatment Controls Cyclamen Mite (Phytonemus pallidus) Without Compromising Strawberry Plant Survival, Growth and Yield

ABSTRACT Cyclamen mite is a pest of strawberry that is difficult to control due to its small size and preference for inhabiting concealed spaces in new plant growth. Steam treatment of transplants effectively reduces some strawberry pathogens and may be a valuable tool against cyclamen mite. Strawberry transplants (“Jewel” and “Annapolis”) that were artificially infested with cyclamen mite were steam-treated at 44°C for 1 h or at 48°C for 0.5 h. Both treatments reduced cyclamen mite numbers by > 99% compared to the control, and 44°C for 1 h had no negative effects on plant survival, growth or yield. In a second, similar, field experiment, transplants (“Jewel”) were categorized by crown size as small (6–8 mm) and large (10–13 mm) and steam-treated at 44°C for 1 or 4 h. Steam treatments reduced cyclamen mite numbers by 92–93% compared to the control, but in the 4 h treatment, survival of small crowns was 40%. Steam treatment of strawberry transplants at 44°C for 1 h is an effective tool and may reduce reliance on miticides for cyclamen mite control. Additional research is needed to determine the optimal steam treatment protocols for cyclamen mite control and to understand the effect of the steam treatment on strawberry transplants with different crown sizes.

Role of eggplant trichome in whitefly oviposition and its relevance to biological control under greenhouse conditions.

The combined release of the predatory mite Amblyseius swirskii (Athias-Henriot) and the mirid Nesidiocoris tenuis (Reuter) provides effective biological control of the tobacco whitefly (Bemisia tabaci (Gennadius)) in greenhouse eggplant. However, knowing how plants' trichomes affect pest-predator interactions could improve whitefly management. Here, the effect of two varieties with either the presence or absence of trichomes was assessed on naturally occurring whitefly populations and predator abundance in a first experiment under field conditions. Predator-prey models were developed to assess the effect of trichomes on pest and predator population dynamics under field conditions. In a second semi-field experiment, the occurrence and oviposition preferences of B. tabaci and A. swirskii in the same eggplant varieties were compared. Significantly higher numbers of whitefly and mite, adults and eggs, were found on the hairy variety in both experiments. However, no differences were found in N. tenuis abundance between varieties under field conditions. Predator-prey models showed that whitefly growth rate increased in the hairy variety. N. tenuis and A. swirskii showed different fitness parameters according to the variety, with the former displaying better performance in the hairless variety and the latter in the hairy variety. Both predators effectively controlled the increase in whitefly populations in both varieties. Overall, the findings suggest that the hairless variety is more effective in deterring whiteflies. Additionally, the higher population of A. swirskii on the hairy variety indicates that this predator benefited from both the presence of trichomes and the prey.

Methicillin-Resistant Staphylococcus aureus Secondary Infection as a Comorbid in Crusted Scabies Patient

Introduction: Crusted scabies (CS) is characterized by uncontrolled proliferation of mites up to thousands. Complications include glomerulonephritis, rheumatic fever, and secondary infection which can cause bacteremia and sepsis. This case report describes a case of CS that was hospitalized with secondary complications of MRSA infection. Case Presentation: A 44-year-old woman complained of thick scales and itching all over her body for 6 months. Complaints begin with reddish bumps between the fingers, toes, body, genitals, and scalp, accompanied by itching, especially at night. The patient took self-purchased corticosteroids for this complaint for 6 months. Dermatology status all over the body showed erythematous papules plaques with greenish-yellow scales, blackish crusts, hyperkeratosis, and excoriation, also erythematous base erosions and blackish crusts in the right thoracic region. Ectoparasite scrapping examination showed large amounts of Sarcoptes scabiei, eggs, and scybala, so the patient was diagnosed with Crusted scabies. A wound culture and nasal swab showed MRSA. The patient died of septic shock on day 12 of treatment. Discussion: Crusted scabies is a highly contagious form of scabies, characterized by thickening of the skin layer and crusts. Long-term corticosteroid consumption in this case caused a compromised immune response so that the number of mites multiplied rapidly and increased the risk of MRSA infection. MRSA mortality rates range from 5-60%. Conclusion: Ignored cases of scabies can develop into crusted scabies which have a high risk of secondary infection, such as MRSA which can cause serious morbidity and even mortality.

Infectious diseases of bees and their impact on the vital activity and honey productivity of honey bee colonies in Ukraine

The article presents the results of the study of the mass mortality of honey bee colonies in different apiaries from different regions of Ukraine. The epizootic status of 102 honey bee colonies was studied and 607 samples of pathological material were analyzed in 2021–2023. According to the results of the monitoring of the epizootic situation in Ukrainian beekeeping it was found that the share of parasitic diseases (54.4%, 74.0%, 69.3%) constantly prevails over infectious diseases. It was noted that the incidence of varroosis in honey bees (34.4%, 71.4%, 41.47%) remains the highest among other diseases. Against the background of severe damage to honey bee colonies by the Varroa mite, infectious diseases began to appear in an atypical form, which significantly complicates their differential diagnosis. A probable increase in the incidence of nosemosis in adult bees and the detection of Nosema cysts in the intestines of bees, both in spring and summer, and the detection of cysts in honey indicate the spread of another pathogen, Nosema cerana, which causes nosemosis in the summer season. The reason for the periodic mass death of bees in Ukraine is the combination of a high number of parasitic Varroa mites in the honey bee colony with the presence of bee infection with microsporidia Nosema spp. These pathogens negatively affect the immunity of the honey bee colony, and cause exacerbation of latent infections in bees, which leads to a decrease in the number of honey bee colonies, weakening their viability and reducing the quality of honey products

Population Dynamics of the Mite Varroa destructor in Honey Bee (Apis mellifera) Colonies in a Temperate Semi-Arid Climate.

This study aimed to analyze the population dynamics of the mite Varroa destructor in honey bee (Apis mellifera) colonies in a temperate semi-arid climate in Mexico. Ten colonies homogeneous in population, food stores, and levels of mite infestation were used. The mite infestation rate in brood and adult bees, total number of mites, daily mite fall, brood and adult bee population, and food stores were determined periodically for 10 months. There was a significant effect (p < 0.05) of sampling period on the population of V. destructor in adult bees, brood, total mite population, and daily fallen mites. The total mite population increased by 26% on average per colony. The increase in brood amount reduced the mite infestation rate in adult bees, and the opposite occurred when the brood decreased. Monitoring V. destructor populations by recording fallen mites is more reliable than determining mite infestation rates in bees, as mite fall has a dynamic pattern similar to that of the total mite population. The best period to apply an acaricide treatment in the region of study is between November and December because most mites were in the phoretic phase, since there was less brood in the colonies compared to other times.

Tracking Varroa Parasitism Using Handheld Infrared Cameras: Is Eusocial Fever the Key?

The Varroa destructor is the most significant bee parasite and the greatest threat to bee health all around the world. Due to its hidden lifestyle, detection within the brood cell is only possible through invasive techniques. Enhancing detection methods is essential for advancing research on population dynamics, spread, selection efforts, and control methodologies against the mite. In our study, we employed infrared imaging to measure the thermal differences in parasite and intact Apis mellifera worker broods. Experiments were conducted over two years at the MATE Kaposvár Campus in Hungary involving five beehives in 2022 and five beehives in 2023. A FLIR E5-XT WIFI handheld infrared camera was used to create a heat map of capped brood frames. Our results indicate that the resolution of these cameras is sufficient to provide detailed IR images of a bee colony, making them suitable to detect temperature differences in intact and Varroa parasitized capped brood cells. Mite parasitism causes a time-dependent and sustained temperature increase in developing bee pupae, observable regardless of mite number. Our work demonstrates two different heating patterns: hotspot heating and heating cells that are responsible for the elevated temperature of the Varroa-infested cells as a social fever response by the worker bees. Based on our results, future research combined with AI-based image evaluation software could offer beekeepers and researchers practical and valuable tools for high-throughput, non-invasive Varroa detection in the field.

Species composition of phytophages on ornamental plants

Goal. Monitoring the phytosanitary status and determining the species composition of phytophages on decorative coniferous and deciduous plants. Methods. Field — determination of the species composition of pests and the dynamics of the number of main species; laboratory — determination of pests selected on experimental plots. Research was conducted in accordance with generally accepted methods in entomology and plant protection. Results. In the industrial plant nursery of open soil «Megaplant» located in the Kyiv region, Fastiv district, village The monitoring of the phytosanitary state of ornamental plant plantations was carried out in Trilys. The natural saturation of harmful organisms and the level of their harmfulness were studied. Conclusions. It has been established that plants in industrial nurseries in open ground are damaged by a large number of insects and mites. The most dangerous and widespread on conifer ornamental plants were 8 pests from the following families coccids (Coccidae), bark beetles (Scolytidae), adelgids (Adelgidae), snout beetles (Curculionidae) and spider mites (Tetranychidae); 9 most harmful species from the following families were noted on decorative leafy plants: crambid Snout Moths (Crambidae), mealybugs (Pseudococcidae) and аrmored scales or diaspidids (Diaspididae), eriophyidae mites (Eriophyidae), aphids (Aphididae), snout beetles (Curculionidae), scarab beetles (Scarabaeidae).

The mite Dentocarpus silvai (Acari, chirodiscidae) as a parasite of the bat Molossus molossus (Chiroptera, molossidae) in southeastern Brazil

ABSTRACT Factors that influence the parasite load in a host bat include sex, age, reproductive condition, health, and body condition. Among the ectoparasitic mites found on bats, species from the family Chirodiscidae are commonly observed on molossid bats. This study aimed to analyse the parasitism of Dentocarpus silvai on Molossus molossus in two roosts, discussing the ecology of the host–ectoparasite relationship. We sampled a colony of M. molossus sheltering in the roof lining of a house and in the hollow of a Mangifera indica tree located on Itacuruçá Island, Rio de Janeiro state, southeastern Brazil. A total of 495 D. silvai were collected from 176 M. molossus. Parasitological indices (mean intensity and prevalence) were higher in the tree hollow than in the roof lining, with females being more heavily parasitized than males. Among the six models evaluated, bat abundance best explained the variation in the number of mites. The dispersal success and infestation of D. silvai are associated with roost commuting by individuals (mainly females) of M. molossus that favours the infestation of new bats, which may extend the parasite occurrence. The present study is the first to analyse the infestation of D. silvai on a host species.

ЭКОЛОГО-ЭПИЗООТОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА АНОПЛОЦЕФАЛИДОЗОВ МЕЛКОГО РОГАТОГО СКОТА В ФЕРМЕРСКИХ ХОЗЯЙСТВАХ АЛТАЙСКОГО КРАЯ

The purpose of the study is to identify in the Altay Region the most pathogenic helminths among small livestock that threaten the health of farm animals, and their harmfulness and extent of spread. Using the coprooscopic method, fecal samples from sheep of 3 groups were examined: up to one year, from 1 to 2 years and over 2 years. Using the method of complete helminthological autopsies, 18 heads of sheep were opened on farms, of which 11 were aged from 1 to 2 years and 7 heads were older than 2 years. We studied the timing of infection in lambs by monthly examination of the same animals, starting from two months of age until they reach two years of age. All lambs were from the same farm; no anticestodal measures were carried out, so the natural course of the invasion was not disturbed. The survey began at the end of May 2020 with a group of lambs that reached two months of age in the amount of 26 heads. The number of oribatid mites was studied by collecting oribatid mites using a special technique. From the class of cestodes among sheep, 5 species are most often recorded with an average level of extensive infestation from 0.5 to 44.4 %. Anoplocephalid eggs were first discovered in lambs of the current year of birth in July. Moniesia were found throughout the year in young animals from one to two years of age. In March, April, and May they were recorded in single animals in this group of sheep. The seasonal dynamics of the number of oribatid ticks is directly dependent on natural and climatic conditions: significantly fewer ticks were recorded in the steppe zone than in the forest-steppe and floodplain zones. The results of the study show that monieziosis in young lambs kept on pasture is detected coprologically in the conditions of the Altai Region no earlier than July. Two peaks of activity of the intermediate hosts of moniesia, oribatid mites, have been recorded: spring and autumn.

Genetic and genomic analysis of Belgian Blue’s susceptibility for psoroptic mange

BackgroundPsoroptic mange, caused by Psoroptes ovis mites, is affecting Belgian Blue cattle’s welfare and production potential. The Belgian Blue cattle—known for its high degree of muscling, low feed conversion ratio and high beef quality—is highly susceptible for this disease.ResultsIn this study, we phenotyped 1975 Belgian Blue cattle from more than 100 different groups on commercial beef farms for their psoroptic mange susceptibility. Substantial individual differences were observed within these management groups, with lesion extent differences up to ± 15%. Animal models showed that estimated heritabilities were low for lesion extent and severe lesion extent (0.07 and 0.09, respectively) and 0.12 for the number of mites. A genome wide association study for mange susceptibility revealed signals on BTA6, BTA11, BTA15 and BTA24. In these regions, candidate genes GBA3, RAG2, and TRAF6 were identified.ConclusionsDespite the challenges in phenotyping for psoroptic mange due to the timing of screening, the continuous evolution of lesions and different management conditions, we successfully conducted a study on the genetic susceptibility to psoroptic mange in Belgian Blue cattle. Our results clearly indicate that psoroptic mange is under polygenic control and the underlying candidate genes should be studied more thoroughly. This is the first study providing candidate genes for this complex disease. These results are already valuable for Belgian Blue breeding, however, further research is needed to unravel the architecture of this disease and to identify causal mutations.

Factors affecting meibomian gland area loss in symptomatic adults.

To characterize the distribution of meibomian gland (MG) area loss (MGL) and its relationship with demographic characteristics, mites, and symptoms. This retrospective observational study included patients who visited the Dry Eye Clinic of Shenzhen Eye Hospital between June 2020 and August 2021. General patient characteristics, ocular symptoms, Demodex test results of the eyelid edges, and the results of a comprehensive ocular surface analysis were collected. MGL was analyzed using Image J software. This study enrolled 1204 outpatients aged 20-80 (40.70±13.44)y, including 357 males (29.65%) and 847 females (70.35%). The patients were classified into mild (n=155; 12.87%), moderate (n=795; 66.03%), severe (n=206; 17.11%), and extremely severe (n=48; 3.99%) MGL groups. MGL was significantly larger in female than in male (P=0.006). The degree of MGL also significantly differed in age (P<0.001) and the more numbers of mites with severity (P<0.001). Multivariate disordered multinomial logistic regression analysis identified that female sex, older age, secretory symptoms, and a large number of mites were risk factors for MGL (P<0.05). Patients with MGL are more likely to be older, female, more numbers of mites, and increased secretion.

Mite non-reproduction is not a consequence of the brood removal behavior of varroa sensitive hygiene honey bee colonies (Apis mellifera).

A sustainable solution to the global threat of the Varroa destructor mite is the selection of varroa-resistant honey bee (Apis mellifera) colonies. Both "mite non-reproduction" (MNR) and "varroa sensitive hygiene" (VSH) appear to be promising selection traits for achieving the goal of a resistant honey bee. MNR describes colonies that have a high number of non-reproductive mites (no offspring, no males, or delayed development of mite offspring). High numbers of non-reproductive mites have been observed in selected colonies, but the mechanism behind this trait has not yet been identified. The specialized hygienic behavior of selected honey bees, called VSH, is the removal of varroa-infested brood. These traits were thought to be linked by VSH bees preferentially removing reproductive varroa females leaving only non-reproductive mites behind in cells and thus creating colonies with high levels of MNR. To further investigate this link, we used an experimental setup and data sets from a four-year selection project designed to breed for MNR and VSH colonies. In addition, we sought to answer the question of whether non-reproductive mites are a direct consequence of worker removal behavior. To test this, we artificially induced removal behavior, and after providing the mite with enough time to re-enter another cell, we opened all capped cells, relocated the mites, and evaluated their reproduction. As shown in previous studies and in this study, VSH had no effect on MNR levels. Also, the induced removal behavior did not lead to non-reproduction in the subsequent reproductive cycle post interruption. We thus concluded that breeding for non-reproductive mites does not automatically breed for VSH behavior and worker removal behavior does not cause subsequent reproductive failure of the mites forced to flee and find a new cell for reproduction.

Comprehensive Approach to Phenotype Varroa destructor Reproduction in Honey Bee Drone Brood and Its Correlation with Decreased Mite Reproduction (DMR).

The mechanisms of action behind decreased mite reproduction (DMR) are still unknown, but current hypotheses state that DMR is the result of brood-intrinsic and/or external disturbances in the V. destructor-honey bee pupa signal interactions. For accurate and precise DMR phenotyping, sufficient single infested honey bee brood cells are required (e.g., 35), which requires extensive labor and time and may exclude many samples not reaching the threshold. We defined a new comprehensive trait called the 'mean V. destructor reproduction rate' (mVR), which describes the mean number of offspring mites per infested cell in the sample while compensating for the reduced number of offspring with increasing multiple infested cells. We found a significant correlation between mVR and DMR, allowing for an estimation of DMR based on the mVR only. When the mVR was calculated with 10 infested cells, we found an average variation in mVR of 16.8%. For the same variation in DMR determination, 40 single infested cells are required. This broader look at V. destructor resistance phenotyping can improve the applicability and effectiveness of traits related to V. destructor reproduction in honey bee breeding programs.

Evaluation of Demodex mite in chronic urticaria

Objective: Determining the possible role of Demodex mites in patients with chronic urticaria Methods: Demodex screening results in 49 patients with chronic urticaria were evaluated retrospectively. Results: The mean number of Demodex mites per 1 cm2 measured with standardized skin-surface biopsy (SSSB) was 0.89 which was at a similar level as control groups in the literature. Conclusion: Demodex mites seemed not to play a role in patients with chronic urticaria who had no facial eruptions. Patients with skin eruptions with the possible contribution of Demodex as rosacea could be investigated for chronic urticaria in other studies.

In vitro evaluation of the potential of mites of the family Macrochelidae (Acari: Mesostigmata) as macrobiological agents against the nematode Haemonchus contortus (Strongylida: Trichostrongylidae)

Small ruminants (sheep and goats) constantly suffer from endoparasitoses caused by gastrointestinal nematodes. Among these, the species Haemonchus contortus (Rudolphi, 1803) is considered to be the one of greatest importance within sheep farming. This nematode is difficult to control due to its resistance to most commercial anthelmintics. The aim of the present study was to assess the potential of macrochelid mites as macrobiological agents for controlling endoparasitoses of sheep caused by the nematode, H. contortus. For this, novel in vitro methodology was used, in which assessments were made not only of the predatory ability but also the population growth of mite species (Macrocheles merdarius, Macrocheles robustulus and Holostaspella bifoliata) when offered larvae of the nematode, H. contortus. The predatory ability of the mites, M. merdarius and H. bifoliata were efficient regarding their predatory ability against H. contortus nematode larvae. The mite, M. merdarius exhibited the highest predation rate with mean distribution values for the treated group of 18656 ± 10091 and for the control group of 1178 ± 712 (P < 0.0001). The species, H. bifoliata presented the highest population growth rate, with a percentage acarid recovery rate of 263% in relation to the number added initially. The data from this in vitro predation experiment suggest that, M. merdarius and H. bifoliata showed promise as macrobiological agents for controlling gastrointestinal endoparasitoses of sheep caused by the nematode, H. contortus given that both species reduced the population of this helminth by more 70% and the number of mites recovered was three times greater than the number added.

Changes in Cellular and Humoral Immunity of Children with Respiratory Diseases Living in Areas of Kyrgyzstan at Different Altitudes

Immunological aspects of respiratory diseases due to altitude can have a significant impact on the pathogenesis and clinical course of the disease. Research objectives: to study changes in cellular and humoral immunity in children with respiratory diseases living in areas of Kyrgyzstan located at different altitudes above sea level. This study used methods to assess cellular and humoral immunity in 209 children living at various altitudes above sea level in Kyrgyzstan. Research results contribute to a deeper understanding of the immunological mechanisms underlying respiratory diseases in children at high altitudes, which may be of practical importance for the development of more effective methods for diagnosis, prevention and treatment of such diseases. It is assumed that at high altitude the number of allergens in the body decreases, in particular, the number of dust mites, which often act as a provoking factor in allergic respiratory diseases.

The effects of spatially-constrained treatment regions upon a model of wombat mange

The use of therapeutic agents is a critical option to manage wildlife disease, but their implementation is usually spatially constrained. We seek to expand knowledge around the effectiveness of management of environmentally-transmitted Sarcoptes scabiei on a host population, by studying the effect of a spatially constrained treatment regime on disease dynamics in the bare-nosed wombat Vombatus ursinus. A host population of wombats is modelled using a system of non-linear partial differential equations, a spatially-varying treatment regime is applied to this population and the dynamics are studied over a period of several years. Treatment could result in mite decrease within the treatment region, extending to a lesser degree outside, with significant increases in wombat population. However, the benefits of targeted treatment regions within an environment are shown to be dependent on conditions at the start (endemic vs. disease free), as well as on the locations of these special regions (centre of the wombat population or against a geographical boundary). This research demonstrates the importance of understanding the state of the environment and populations before treatment commences, the effects of re-treatment schedules within the treatment region, and the transient large-scale changes in mite numbers that can be brought about by sudden changes to the environment. It also demonstrates that, with good knowledge of the host-pathogen dynamics and the spatial terrain, it is possible to achieve substantial reduction in mite numbers within the target region, with increases in wombat numbers throughout the environment.