Mite Contamination Research Articles

Control of Varroa Destructor in Kazakhstan.

Varroa mite is one of the most dangerous bee parasites and causes a lot of damage to the beekeeping industry. Several chemical and herbal medicines have been used to control this mite so far. In this study, the effects of Artemisia absinthium and Hypericum perforatum prescription to control Varroa mite were investigated. To this end, a total of 380 bee colonies in 5 areas in Kazakhstan were considered. The bitter wormwood herbs and Hypericum extracts were mixed in a ratio of 1:1, and then, prepared in a ratio of 1:10 with sugar syrup (100 ml infusion per 1 liter of sugar syrup). An amount of 200 ml of the prepared solution was used for 5-7 days per colony after medical collection and honey pumping. The percentage of mite infestation at the beginning and end of the experimental period, which was spring, summer, and autumn, and the number of worker mites and worker bees were determined daily. At the beginning of the experiment, the percentage of mite infestation in the experimental hives was not significantly different; however, at the end of the experiment, there was a significant difference between the experimental treatments. The use of a mixture of A. absinthium and H. perforatum extract significantly reduced the abundance index of Varroa mite to 0. Due to the adverse effects of chemical drugs and their high cost, it is recommended to use this extract to control Varroa mite contamination.

Cheyletiella Dermatitis: A Case Report

Şeyletiella dermatiti (şeyletielloz); ana rezervuarı kedi, köpek ve tavşanlar olan Cheyletiella cinsi parazitlerin rastlantısal olarak insana bulaşması sonucu oluşan bir dermatit tablosudur. Hayvanların birbirleriyle ve dış ortamla temasının arttığı bahar aylarında sık görülür. Şeyletiella dermatiti hayvanla temastan ortalama 1-2 gün sonra ortaya çıkan sıklıkla eritemli ödemli papüllerle karakterizedir. Nadiren vezikülobüllöz ve nekrotizan lezyonlar da oluşabilir. Evcil hayvan taşıyıcı olduğu için insanla her temasdan sonra lezyonlar tekrarlayabilir. Lezyonlar dışında deride parazitin kendisi de nadiren görülebilmektedir. Ancak klinik olarak şüphelenilmediği takdirde tanı konulması zordur. Burada elli sekiz yaşında şeyletiella dermatiti tanısı konulan bir kadın hasta sunulmaktadır. Tekrarlayan kaşıntılı döküntü şikayeti ve özellikle kedi olmak üzere evcil hayvan yetiştirme öyküsü olan kişilerde ayırıcı tanıda şeyletiella dermatitinin de düşünülmesi gerektiğini vurgulamak için olgumuz sunulmuştur.

Storage Mite Infestation of Dry-Stored Food Products and Its Relation to Human Intestinal Acariasis in the City of Minia, Egypt.

Initial data on the prevalence of storage mites in dry-stored food products and estimates of the presence of mites in human stool in the city of Minia, Egypt are provided. In total, 847 samples were collected randomly from houses and retail stores between March 2017 and February 2018. In addition, 1,000 human stool samples were collected for the detection of the presence of mites. Mites were extracted from 285 of 840 (33.9%) samples, and mite contamination was found to be most prevalent in wheat flour (73.3%). In total, 11 mite species belonging to six families were identified, with the pest species Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) (TP) being the most prevalent (91.2% of samples). The seasonal density distribution showed the highest storage mite density in March-April, followed by October, and the lowest in January. In addition, mites were detected in 87 (8.7%) human stool samples, with significant associations between certain occupations and some personal characteristics. Therefore, more attention needs to be paid to intestinal acariasis arising from mite infestation of dry-stored food products.

Critically Appraised Topic on Adverse Food Reactions of Companion Animals (8): Storage Mites in Commercial Pet foods

BackgroundDogs with year-round atopic dermatitis are often sensitized to Dermatophagoides house dust mites (HDM). Storage mites (SM) are known to grow on cereal-rich foods. Tyrophagus SM can exacerbate clinical signs of allergy in laboratory dogs sensitized to HDM. Consequently, atopic dogs with high-levels of HDM-specific IgE are likely to have a flare of signs after eating a food contaminated with SM; the development of such flares would lead to a false positive diagnosis of food allergy. Herein, we reviewed the published evidence about the growth of SM on commercial dry pet foods.ResultsWe searched two databases on January 25, 2019 for articles providing original information on the growth of SM on commercial dog foods. We found ten articles, five reporting results of laboratory experiments and five from field studies. Storage mites, especially Tyrophagus putrescentiae, can multiply on protein- and fat-rich dog foods. The population growth is higher when the initial mite density is high and when kibbles are crushed. When storage conditions lead to the overgrowth of molds on the kibbles, the mite proliferation is higher. Storage mites do not bore holes in food packages but invade bags via defective seals. In the field, SM contamination usually is undetectable in newly-opened commercial dog foods, and, if present, their number is low. When newly-purchased bags are stored in temperate conditions indoors, little overgrowth—if any—of SM occurs. However, when kept in environmental conditions with higher temperature and humidity, Tyrophagus mites will enter and proliferate in sealed food packages.ConclusionsCommercial dry pet foods should be kept indoors and sealed to decrease the risk of contamination with SM. When performing dietary restriction (elimination) and provocation trials for the diagnosis of food allergies in dogs, it seems preferable to choose newly-purchased bags—of both original and testing diets—to reduce the probability of their contamination with SM, especially Tyrophagus putrescentiae. In case of doubt about the presence of SM in any of these foods, one should perform food challenges with single home-cooked ingredients. Storage mite contamination might lead to an erroneous diagnosis of food allergy in HDM-sensitized dogs.

Occupational asthma due to tampico fiber bystander exposure in a brush production company—case report and literature review

A female machine operator in a brush factory presented for an expert medical examination due to suspected occupational obstructive pulmonary disease. She reported the occurrence of severe respiratory distress whenever colleagues in the same working area processed tampico fibers or a mixture of tampico fibers and bassine. The challenge posed in terms of the expert appraisal was to either prove or rule out occupational causality and IgE-mediated (IgE, immunglobulin E) sensitization in relation to the reported workplace-related symptoms. As part of the further diagnostic work-up, tampico fibers were isolated from the workplace and the proteins biotinylated and coupled to a streptavidin ImmunoCAP for specific IgE testing. The material taken from the workplace was checked for mite allergen contamination. In addition, a systematic literature search was conducted in PubMed on “agave-/tampico fibers and diseases.” Tampico-specific IgE antibodies (10.5 kU/l and immunoblot labeling of protein bands in the 25-kDa range) were detected in the patient’s serum. The inhibition assay showed that mite-allergen contamination of the tampico materials was not responsible for the IgE reactivity. Tampico fibers are robust fibers obtained from the leaves of the Mexican Agave lechugilla. The literature describes several cases of skin reactions in the form of irritant contact dermatitis due to occupational exposure to agave leaves or contact with agave sap. In the present case, the asthma symptoms of a female worker in a brush factory were attributed to inhalant bystander exposure to tampico fibers in the workplace. The unequivocal evidence of sensitization to tampico fibers met the medical requirements for the recognition of an occupational disease (BK 4301).

Should oral exposure in Hypoaspis aculeifer tests be considered in order to keep them in Tier I test battery for ecological risk assessment of PPPs?

The laboratory reproduction test with the predatory mite Hypoaspis aculeifer is currently a mandatory test in the new EU data requirements for prospective environmental risk assessment of Plant Protection Products (PPPs). However, the low sensitivity often shown by this mite towards PPPs, when compared to other invertebrates (namely Folsomia candida and Eisenia fetida), makes the test with this species not very useful in the lower tier test battery. However, the current test protocol only considers exposure to contaminants via contaminated soil, disregarding exposure via contaminated food and does not take into account the fact that H. aculeifer is a predatory species. Therefore, through this protocol, the toxicity of contaminants to soil mites might be underestimated and, thus, an adaptation of the test performance, by including exposure via contaminated food, may be necessary. With this aim, two reproduction tests with H. aculeifer were performed using copper chloride as model substance, artificial soil as test substrate and cheese mites as food. The OECD guideline was followed but, while in one test cheese mites from normal laboratory breeding cultures (clean prey mites) were provided, in the other test, cheese mites previously exposed to copper (Cu pre-exposed prey mites) were provided. Predatory mites were affected at lower concentrations in tests using Cu pre-exposed prey compared to test with clean-prey (NOEC = 1225 and 1508 mg kg−1 and EC10 = 1204 and 1903 mg kg−1 using Cu pre-exposed and clean prey, respectively). However, this higher sensitivity was not detected by EC50 values (EC50 = 2634 and 2814 mg kg−1 using Cu pre-exposed and clean prey, respectively). Further tests are needed in order to (i) investigate the relevance of oral exposure to different PPPs, (ii) optimize the contamination of prey mites according to the chemical properties of each substance and (iii) substantiate a proposal to adapt the standard protocol.

Preliminary investigation of Suidasia nesbitti breeding status in ground dust flour in Qiqihaer City

To investigate the Suidasia nesbitti breeding status in the ground dust flour collected in Qiqihaer City. Totally, 16 aliquots of ground dust flour were respectively collected from a college canteen and 15 households in Qiqihaer City. Then 10 g dust flour was taken from individual sample for isolation of the mites that were made of slide specimen, and the mites were identified and classified under a microscope. Acaroid mites were found in 15 of the 16 aliquots of samples (detection rate being 93.8％), and 7 species, belonging to 6 genera under 3 families, were identified. A total of 561 heads of mites were isolated from 160 g samples, with an average breeding density of 3.51 heads/g. The most breeding mite was associated with S. nesbitti. Various species of mites are breeding in the ground dust flour in Qiqihaer City, and S. nesbitti occurs the most. These findings indicate that effective measures should be taken to prevent and control the harm associated with acaroid mite contamination.

Storage mite contamination of commercial dry dog food in south-eastern Australia.

To evaluate contamination of unopened and opened stored sources of commercial dry dog food by viable storage mites. Prospective laboratory and field study. Samples were collected from nine brands of previously unopened bags (new bags) of dry food and 20 field sources of stored dry food in homes in Sydney and Canberra, Australia. All samples were initially examined for the presence of mites using a stereo-binocular microscope and then placed in separate filter-paper-sealed containers. Field samples were incubated at an average temperature of 29°C and 78% relative humidity (RH) for 5 weeks and then at average 26°C/83% RH for 8 weeks. Paired new-bag samples were stored under room conditions (average 23°C/47% RH) and controlled incubator conditions (average 26°C/80% RH) for 6 weeks. All samples were thoroughly examined for mites, mite eggs and visible mould once weekly using a stereo-binocular microscope. Storage mites were not visualised in any of the field samples or in new-bag samples stored at room temperature. Storage mites, identified as Tyrophagus putrescentiae, were visualised in increasing numbers in seven of nine new-bag samples after incubation, with first mites and then eggs evident after 3 weeks of incubation. We confirmed the presence of viable storage mites in a range of previously unopened commercial dry dog foods in Australia and confirmed the possibility of heavy storage mite contamination for dry food stored under conditions of moderate temperature and high humidity. These findings have relevance to storage mite and/or dust mite sensitivity in canine atopic dermatitis.

Can Volatile Organic Metabolites Be Used to Simultaneously Assess Microbial and Mite Contamination Level in Cereal Grains and Coffee Beans?

A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC–ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC–ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans.

Advanced Grain Storage Methods for Quality Preservation and Insect Control Based on Aerated or Hermetic Storage and IPM

The grain industry is facing serious problems of insect and mite contamination due to restrictions placed on the use of chemical pesticides because of adverse effects of pesticide residues in grain and environment, resulting in strict limitations on pesticide registration by regulatory agencies. Consumer demand for chemical-free and insect contamination-free products is a general tendency, with which the grain industry finds it difficult to conform. In addition, in many countries, insects in particular have been developing resistance to contact insecticides and to the conventionally used phosphine gas. In temperate and cold climates, the most common non-chemical alternative to pesticides for cereal grain stored in bulk is the use of aeration systems during the winter that can effectively reduce grain temperature. In summer, refrigeration provides an excellent solution for quality maintenance of grain. In warm climates, for cereal grain stored in bags or in bulk, a new gaseous application technology that has successfully replaced fumigants is the manipulation of modified atmospheres (MAs) using biogenerated MAs, for insect control and for quality preservation of dry cereal grains and high moisture corn. Freshly harvested high moisture corn was successfully stored under hermetic conditions, thereby maintaining its quality prior to subsequent drying or processing into feeds or ethanol. These niche applications of MAs have resulted in very promising treatments with market acceptability. A new approach to the use of pheromones is the monitoring of insects based on remote sensing electronic transmitters that are progressively integrated into control programs. An IPM program that might integrate insect monitoring, aeration in winter, chilling with refrigerated air in summer in grain silos, biogenerated MAs, for insect control and for quality preservation of grain, and assisted MAs during storage of grain and at the final stages of the processed grain before packaging is proposed.

Exposure to Grain Dust in Great Britain

Airborne grain dust is a complex mixture of fragments of organic material from grain, plus mineral matter from soil, and possible insect, fungal, or bacterial contamination or their toxic products, such as endotoxin. In the 1990s, grain workers in Britain were frequently exposed to inhalable dust >10 mg.m(-3) (8 h), with particularly high exposures being found at terminals where grain was imported or exported and in drying operations (personal exposure typically approximately 20 mg.m(-3)). Since then, the industry has made substantial progress in improving the control of airborne dust through better-designed processes, increased automation, and an improved focus on product quality. We have used information from the published scientific literature and a small survey of industry representatives to estimate current exposure levels. These data suggest that current long-term exposure to inhalable dust for most workers is on average less than approximately 3 mg.m(-3), with perhaps 15-20% of individual personal exposures being >10 mg.m(-3). There are no published data from Britain on short-term exposure during cleaning and other tasks. We have estimated average levels for a range of tasks and judge that the highest levels, for example during some cleaning activities and certain process tasks such as loading and packing, are probably approximately10 mg.m(-3). Endotoxin levels were judged likely to be <10⁴ EU m(-3) throughout the industry provided inhalable dust levels are <10 mg.m(-3). There are no published exposure data on mycotoxin, respirable crystalline silica, and mite contamination but these are not considered to present widespread problems in the British industry. Further research should be carried out to confirm these findings.

House dust and storage mite contamination of dry dog food stored in open bags and sealed boxes in 10 domestic households

Dry pet food is a potential source of exposure to house dust and storage mite allergens in canine atopic dermatitis. This study evaluated contamination of house dust and dry dog food stored in paper bags, sealable plastic bags and sealable plastic boxes in 10 households for 90 days using Acarex(®) tests for guanine, a Der p 1 ELISA and mite flotation. Acarex(®) tests were negative in all the food samples but positive in all the house dust samples. The Der p 1 levels and mite numbers significantly increased in food from paper bags (P = 0.0073 and P = 0.02, respectively), but not plastic bags or boxes. Mite numbers and Der p 1 levels were 10-1000 times higher in house dust than the corresponding food samples (P < 0.0001). There were significant correlations between Der p 1 in house dust and food from the paper (P < 0.0001) and plastic bags (P = 0.003), and mite numbers in house dust and food from the paper bags (P = 0.0007). Bedding and carpets were significantly associated with Der p 1 levels in house dust (P = 0.015 and P = 0.01, respectively), and food from the paper (both P = 0.02) and plastic bags (P = 0.03 and P = 0.04, respectively). Mites were identified in six of 10 paper bag, three of 10 plastic bag, one of 10 plastic box and nine of 10 house dust samples. These comprised Dermatophagoides (54%), Tyrophagus (10%; all from food) and unidentified mites (36%). Storage of food in sealable plastic boxes largely prevented contamination for 3 months. Exposure to mites and mite proteins in all the stored food, however, appeared to be trivial compared with house dust.

Evaluation of storage mite contamination of commercial dry dog food

Storage mites may be considered important allergens in dogs with atopic dermatitis. High sensitization rates to Tyrophagus, Acarus, and Lepidoglyphus species have been reported in atopic dogs, and dry pet food has been suggested as a potential source of storage mite exposure. The aim of the present study was to evaluate commercial dry dog food for contamination with storage mites, and how storage time and conditions could influence the risk of contamination. Ten different premium commercial dry dog foods formulated for skin disorders were selected. Food bags were opened and stored for 6 weeks under two different environmental conditions. At different time points, samples from each bag were collected and analysed by microscopy, guanine test, storage mite-specific traps, and a modified flotation technique. On opening, two storage mites identified as Acarus siro were isolated from one of the 10 bags by flotation technique, indicating that storage mites can be present in packaged dry dog food bags. After 5 weeks of storage under environmental conditions optimal for mite growth (23.2 +/- 2.1 degrees C and 71 +/- 5.6% of relative humidity), mites were detected by microscopic observation in nine of the 10 diets. When mites were identified by the flotation technique, Tyrophagus spp. were found to be the most common contaminating species. These results show that dry dog food can be a suitable substrate for storage mite reproduction, and that environmental and storage conditions may influence food contamination and mite development.

Colonization and organ invasion in chicks experimentally infected with Dermanyssus gallinae contaminated by Salmonella Enteritidis

The poultry red mite (Dermanyssus gallinae) is the most important and common ectoparasite of laying hens in Europe. This haematophagous mite has been experimentally demonstrated to be a vector of Salmonella Enteritidis by acquiring bacteria through the blood meal or cuticular contact. We have evaluated another route of infection by orally inoculating chicks with mites previously infected by S. Enteritidis. Two methods of infecting the mites were tested: mites contaminated by cuticular contact or during the blood meal. After the washing of mites with paraformaldehyde, groups of 10 Salmonella-contaminated mites were inoculated individually into 1-day-old chicks. The titre of the inoculum suspension was evaluated by crushing mites and followed by bacteriological counting. It was 3×104 colony-forming units/chick and 2.7×106 colony-forming units/chick, respectively, for cuticular contact and orally mediated contamination of mites. Each bird was found to be positive 12 days post-inoculation. Salmonella colonized the intestinal tracts and invaded the livers and spleens. The caecal content concentration reached a mean level of S. Enteritidis of 8.5×104 most probable number (MPN) Salmonella/g. This experiment demonstrated the ability of mites to orally infect 1-day-old chicks with subsequent colonization and multiplication of Salmonella. Consequently, mites infected by S. Enteritidis constitute potential reservoir hosts of this bacterium, allowing it to persist in the poultry house as a source of infection for newly introduced animals. If contaminated mites are found in poultry facilities, effective red mite control should be performed before new batches are introduced into the facility.

Housing and health counselling: Preliminary results of a new medical referral system in France

Study objectives Since 2002, a new unique service is available to physicians in southeast France. They may ask for a housing environmental inspection for their patients when they feel that the indoor environment has a negative influence on health status. This telephone survey was designed to evaluate the efficacy of this service. Design During this time period, 328 such housing environmental inspections have been performed. The protocol of these inspections included a detailed questionnaire and environmental sampling for mold identification, mite-allergen evaluation and, in selected cases, measurement of volatile organic compounds (VOC). Inspections were performed by trained technicians. From April to September 2005, we performed a telephone interview survey, using a structured questionnaire, to evaluate the reported outcome. Results Main defects identified in houses were mold infestation (44%), mite contamination (32%), and VOC exposure (9%) from new furniture, repairs performed and hobbies. Substantial repairs, including carpentry, wall floors and ceilings repairs, mold decontamination, and plumbing, had been performed in 59.4% of those houses. Full compliance, partial compliance, and no compliance by the occupant with the recommendations provided by the housing environmental inspectors were 50%, 20%, and 30%, respectively. Reasons for non-compliance included moving, time, and money constraints. When rating the efficacy of the service, total, almost total, and partial effectiveness was reported by the families to be 3%, 31%, and 56%, respectively. Conclusion This type of service holds great promise for patients as well as for physicians and should be investigated further by measuring physician-diagnosed health outcome and using cost–benefit analysis.

Monitoring and controlling mould mites in tissue culture facilities

Mould mite numbers were successfully monitored in tissue culture laboratories using black tape where numbers of mites were high Natural diamite and Parafilm M were the best barriers for preventing mould mite contamination Treating surfaces with a miticidecontaining paint (Artilin 3A) or bendiocarp prevented mites from entering containers holding food suitable for mould mites Mites were not killed when sprayed with aerosols and 70 ethanol

Mites in the mix: Dust mite contamination of a flour product

Rationale There have been at least three reported cases of anaphylaxis after ingestion of a commercial beignet (flour based fried donut) mixture containing dust mites (DM) or DM antigen. All of the patients were skin test positive to DM and negative to foods. Our objective was to determine the frequency of DM contamination in packages from local stores before and after opening. Methods Twenty unopened packages of beignet mix with different expiration dates were collected. A sample from each package was examined by light microscopy and by rapid DM antigen kits using monoclonal antibodies against group II DM antigens. Results In six of the 8 unexpired boxes, DM were seen and the mixtures tested positive to DM antigen. Two of the 12 unexpired boxes contained DM and were antigen positive despite being well sealed. The DM positive packages contained visible brown areas within the mixture that represented contamination with DM. Packages were then closed with twist ties, stored at room temperature and re-examined at 2 weeks. DM were seen in 2 additional boxes and there was a marked increase in the number of DM seen in the previously contaminated boxes. Conclusions Most (75%) of the expired boxes and 17% of the unexpired boxes contained DM prior to being opened. Exposure to air caused rapid mite proliferation once the packages were unsealed. In temperate climates, storage of this mix at room temerature may increase the risk of allergic reactions, including anaphylaxis, in those who are sensitized to DM.

The occurrence of mites in cereal-based foods destined for human consumption and possible consequences of infestation.

Seven categories of cereal-based food products purchased at food retail outlets in UK were examined for the presence of mites by analysing 20 g samples using a flotation method. Mites were found in 21% of 571 samples, which were examined soon after purchase, and in 38% of 421 samples, derived from the 571 samples which were examined after 6 weeks of storage in volunteers' homes. Most of the samples where mites were detected had fewer than five mites. However, a few samples contained more than 20 mites with a maximum of 428 mites detected in a single sample. Sixteen families, genera or species of mites were recovered. The most common species were Acarus siro. Tyrophagus putrescentiae, Lepidoglyphus destructor and Glycyphagus domesticus. The level of contamination was broadly similar for each of the seven categories of products examined. It is likely that infestation occurs at every stage of food processing and storage. This is the first study of its kind and there is no reason to believe that results from similar studies carried out in other temperate countries would be markedly different. Increase in the percentage of contaminated samples following storage in a domestic situation suggests that the domestic environment is an important factor in developing infestation. The implications of mite contamination on food quality and on human health are briefly discussed.

Contamination of public facilities with Dermatophagoides mites (Acari: Phyroglyphidae) in Japan

The distribution of allergenic mites, Dermatophagoides farinae and Dermatophagoides pteronyssinus, was surveyed among public facilities in Japan, in order to assess the risk of people, including allergic patients, being exposed to mite allergens outside homes. Dust samples were collected using a vacuum cleaner from bedclothes, floors and other materials in four hospitals, two hotels, two ryokans, one film theatre and four office buildings. Fine dust fractions of these samples were examined for mite antigens by enzyme-linked immunosorbent assay. Overall, clinically important antigen levels of 50 μg m−2 (corresponding to approximately 500 mites m−2) or more were detected in 71% of samples from chairs in a film theatre and 42% of samples from tatami and carpet floors of ryokans, whereas such serious mite contamination was not observed in samples from hospitals, hotels and offices. High mean antigen levels were observed in chairs in a film theatre (98.2 μg m−2) and floors of ryokans (81.4 μg m−2), whereas samples from other facilities showed mean antigen levels of <11 μg m−2. Hospitals had individual antigen levels of ≥50 μg m−2 in 2% of mattresses and 5% of painted and tiled floors but not in comforters, futons and pillows. No samples obtained from bedclothes in hotels and ryokans had antigen levels of ≥50 μg m−2. In office buildings where the air was fully controlled by a central air-conditioning system all the year round, 99% of samples showed low antigen levels of <10 μg m−2. © Rapid Science Ltd. 1998

Rearing and colonization of Lutzomyia evansi (Diptera: Psychodidae), a vector of visceral leishmaniasis in Colombia.

The sandfly Lutzomyia evansi from a focus of visceral leishmaniasis in northern Columbia was reared and maintained under laboratory conditions for five generations. The average time for total development was 41.9 days (range = 35.1-49.6) at 25 degrees C and 89-95% of relative humidity. The mean number of eggs laid was lower in laboratory bred females either in pots (13.2 eggs/female) or vials (29.9 eggs/female) than in wild caught females (33.4 eggs/female). Immature mortality, mainly due to fungal and mite contamination, was higher during the first two instars than in the remaining immature stages. Adults were robust and healthy although difficult to feed on hamster or chick skin membrane. In summary, Lu. evansi is a colonizable species but requires specific conditions.