Working towards healthy air in dwellings in Europe.

Poor indoor air quality has been implicated in the increase in allergic and respiratory diseases seen in industrialized countries in recent decades. Although air pollution in the workplace is well studied, much less is known about the consequences of poor air quality in homes. In an attempt to halt or slow down the increase in allergic and respiratory diseases, the European Federation of Allergy and Airways Diseases Patients Associations (EFA) carried out the EU-funded project entitled 'Towards Healthy Air in Dwellings in Europe' (THADE). The aims were to: compile an overview of evidence-based data about exposure to indoor air pollution and its health effects, particularly in relation to allergies, asthma and other respiratory diseases such as chronic obstructive pulmonary disease; review cost-effective measures and technology to improve indoor air quality; review legislation and guidelines on indoor air pollution; produce maps of pollutants in dwellings; and recommend an integrated strategy that defines appropriate indoor air quality policies for implementation in Europe. This paper summarizes the information about air quality in dwellings and indoor environment-related diseases collected by expert consultants within the framework of THADE and terminates with recommendations for actions aimed at improving air quality in homes. The results of this project confirmed that air pollution in dwellings is a relevant health problem. It is a complex problem that must be addressed at European and international levels, and it involves the medical profession, scientific societies, patients' organizations, lawmakers, architects and the building industry. The complete THADE report is available at http://www.efanet.org/activities/documents/THADEReport.pdf.

Delusions of parasitosis. A psychiatric disorder to be treated by dermatologists? An analysis of 33 patients.

Delusions of parasitosis is a rare disorder in which patients have the false and fixed belief that they are infested by parasites. It is a psychiatric disorder, but patients usually present to a dermatologist and referral to a psychiatrist is almost always rejected. Treating a patient with delusions of parasitosis requires patience and tact. The neuroleptic pimozide is the treatment of choice, but a significant problem is convincing the patient to take the drug. We report a study of 33 patients (13 men and 20 women) with delusions of parasitosis. The mean age at onset was 56.9 years and the mean duration of symptoms before attending the department of dermatology was 1.3 years. Pimozide (Orap) was prescribed for 24 patients, but only 18 patients took it. Follow-up information was available for 18 patients: five had full remission, four were less symptomatic, five were unchanged and four had died of unrelated causes.

Quantifying the potential for independent living in COPD-patients.

In patients with Chronic Obstructive Pulmonary Disease (COPD), daily physical functioning as quantified by energy expenditure, is limited by decreased ventilatory capacity and increased basal metabolic rate in relation to their physical capacity. Starting from the Dutch Health-Care situation, a measurement interpretation model is presented to quantify individual potential for independent living from energy expenditure, aerobic capacity and lung function. The interpretation model concerns only simple routine measurements. After further validation, this model will be used in predicting the clinical effects of environmental improvements.

Clinical improvement after unusual avoidance measures in the home of an atopic dermatitis patient.

A 27-year-old female office clerk with widespread atopic dermatitis (AD) since infancy appeared to be highly sensitized and exposed to molds, storage mites, and chicken feathers and moderately sensitized to house-dust mites and grass and birch pollens. Hardly any textiles were present in her home; that is, only 28 m2, which is less than 25% of the Dutch national average. The causal relationship between eczema and molds plus storage mites in this case of AD was strengthened by the positive effect of an unusual, multidisciplinary home-sanitation program involving cleaning of mineral surfaces and ventilation improvement. This home-sanitation program led to a gradual drop of total IgE and clinical symptom scores to 21% and 13%, respectively, of the original values.

Mechanisms and patient compliance of dust-mite avoidance regimens in dwellings of mite-allergic rhinitic patients.

We report on the mechanisms, the environmental changes and patient compliance with regard to conventional and new dust and mite avoidance measures to prevent allergic symptoms caused by mite allergens, taking into account both allergen contamination and the developmental success of pyroglyphid Acari. Twenty patients with persisting rhinitic complaints were selected and matched. Although the patients had performed some conventional dust and mite avoidance measures (patient compliance was 90%), the dwellings proved to be a stimulus for mite development. Moisture problems due to faulty construction and excessive moisture production were common. Since humidity conditions could not be changed at short notice, the 20 homes were subjected to the new variants of mite allergen avoidance based on intensive cleaning without (control) and with an acaricide incorporated (acaricidal cleaner [Acarosan]). After the carrying out of conventional avoidance measures, these patients still had allergic symptoms, and dust from only 23 to 52% of their textile objects was under the proposed guanine (mite faeces indicator) risk level. Only the acaricidal cleaner was able to decrease the allergenic mite load (and the burden of the patients) significantly in this 12 month period. With respect to mite-extermination, acaricidal cleaning was 88% better than intensive cleaning. Reduction of guanine was 38% better in the Acarosan treatment group. Clinical results have been reported elsewhere. A significant difference in favour of the acaricidal cleaning was seen in both subjective (as regards symptoms) and in objective data (total IgE). Another 50 patients were questioned.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative efficacy of house dust mite extermination products.

The acaricidal efficacy of nine marketed products, i.e. Acardust, Acarosan (foam and powder), Actelic 50, Artilin 3A (spirit and water base), liquid nitrogen, Paragerm AK, and Tymasil, and of intensive vacuum-cleaning have been compared on four different test surfaces: mattress, tufted carpet, gypsum board and rough wooden board, all covered with artificial house dust. They were inoculated with the house dust mite, Dermatophagoides pteronyssinus or the house-dust fungus Aspergillus repens for evaluation of the fungistatic claims of some products. The acaricidal activity of Tymasil did not surpass that of vacuuming; its fungistatic effect was not apparent. The other products showed complete to almost complete eradication on at least one of the substrates tested. Taking into account the results of acaricidal efficacy as well as the data on safety and practicality acquired earlier, Acarosan powder was considered first choice for carpet treatment. Acarosan and liquid nitrogen, were found to be effective in the treatment of mattress, pillow, upholstered furniture and heavy curtains. On wooden surfaces Acarosan was found to be both effective and safe, while Acardust, Actelic 50, Artilin 3A (both fungistatic as well as acaricidal), liquid nitrogen and Paragerm also passed the efficiency test.

Clinical evaluation of a double-blind dust-mite avoidance trial with mite-allergic rhinitic patients.

Inheritance and allergen exposure are key factors in the development and the course of atopic allergy, expressed as conjunctivitis, rhinitis, asthma or dermatitis. This study concerns the clinical significance of mite and mite-allergen avoidance measures based on intensive cleaning with acaricide (solidified benzylbenzoate) added (10 dwellings), and without biocidal activity (10 other homes) as a control in a double-blind trial with matched pairs. Twenty subjects with persisting rhinitic complaints were selected. They lived in 20 different dwellings and were all sensitized to pyroglyphid mites; 12 of them were also sensitized to stored product mites (Acari). Daily symptoms and medication score, guanine and dust exposure, total and mite-specific IgE in serum, eosinophilia in the blood and in the nasal smear, intracutaneous tests with house dust mite and storage mite extracts were compared in both pairs and groups. Acarological data, physiochemical aspects and exposure assessment are discussed in detail elsewhere. Symptom scores dropped significantly, as did the total IgE and exposure to dust and mite products in the acaricidal cleaner treatment group. After 1 year, the daily symptoms median was 47% (P = 0.025), total IgE was 38% (P = 0.0049), and exposure to dust and mite products (guanine exposure) was 53% (P = 0.0449) better or lower than in the controls. Intensive cleaning, without acaricidal treatment performed twice a year, resulted in clinical improvement in four out of 10 subjects, of whom none became free of complaints. In the Acarosan treatment group (cleaning + benzylbenzoate) eight out of 10 subjects improved, in three cases subjective symptoms disappeared.(ABSTRACT TRUNCATED AT 250 WORDS)

The management of house dust mite allergies.

A safe and practical home sanitation procedure for the removal of house dust mites (Dermatophagoides pteronyssinus) and their allergens is described. The severity of mite infestation was assessed with the use of the Acarex test, which measures the concentration of guanine in house dust, and all affected house textiles were then treated with an Acarosan product. The active ingredient of Acarosan is benzyl benzoate, which has been used as a scabicide for over 100 years. The results of several studies of Acarosan treatment were reviewed and it was concluded that use of the guanine test and Acarosan products allows many sensitized persons to control the concentration of house dust mite allergens in their homes.

Evaluating mite (Acari) allergenicity of house dust by guanine quantification.

The development of a quick color reaction for guanine in house dust has made it possible to screen many homes for mite products of allergenic consequence. The azo dye methods are specific enough to be useful for the development of a sanitary standard. Comparing the guanine quantification results with mite counts and determinations of the mite antigen P1 (Der p I) leads to the conclusion that the provisional standard for mattress dust of 0.6 mg guanine/g dust can be extended to dust from floor coverings and padded furniture, at least in western Europe. Below this level, the sensitization risk to patients allergic to house dust mites seems to be minimal.

Effects of fungicide treatment and vacuuming on pyroglyphid mites and their allergens in mattress dust.

House-dust mites (Pyroglyphidae) are an important source of indoor airborne allergens. Several methods may be applied to reduce the population growth of these mites and thus the quantity of allergen formed. One such method is to interfere with the mites' food chain. Fungi are a key factor in this food chain: they serve as an indirect food source. In this study we investigated the results of the repeated application of a fungicide (natamycin) on mattresses. As controls we treated some mattresses with a placebo, while others were left untreated. The application of natamycin appeared to hamper mite development. Additional vacuuming reduced the quantity of mite allergens present. In the usual household situation repeated treatment will be necessary to obtain a long-term reduction.

Control of house-dust mites (Pyroglyphidae) with home disinfectants.

Chemical disinfectants and biocidal preparations used in households were tested in the laboratory for their ability to kill the house-dust mite Dermatophagoides farinae. Batches of ten specimens were soaked in aqueous solutions or suspensions containing 0.0, 0.1, 0.3, 1.0, 3.0 and 10.0% (by volume) of the test preparations. Direct effect was tested without food. Population effect was tested with food added. The results showed a high mortality with all preparations except for a regular carpet cleaner (containing detergents) and natamycin (a fungicide). Nevertheless, not all tested preparations are practical in the home environment. Best results in homes were obtained with a carpet cleaning solution which incorporates an acaricide (benzylbenzoate). This particular preparation has an outstanding acaricidal efficacy and can easily and routinely be used by the householder. The degree of cleanliness in the household is a measure of the number of house-dust mites and their allergens.

Guanine as a hygienic index for allergologically relevant mite infestations in mattress dust.

Since guanine is not only an essential constituent of vital nucleic acids, but also the main end product of nitrogenous waste excretion in arachnids, it is a potential candidate for a hygienic index for mite activity in house dust. The public health significance of these mites is based on their production of allergen in the home environment. In 101 mattress-dust samples, total number of mites and guanine content were positively correlated. The hygienic standard of 10 mites per 0.1 g dust (as derived from Danish investigations) was met in all samples with less than 0.06% guanine in the dry dust. Where the guanine content was more than or equal to 0.25% in the dry dust, mite numbers were higher than 10 mites per 0.1 g dust in 43 of the 44 samples. The three different groups (negligible mite content, possibly allergologically relevant mite concentration and allergologically unhygienic mite situation) could be easily discriminated on the color scale. The guanine-AZO-dye reaction in vacuum cleaner dust is a strong and promising candidate for an allergologically relevant hygienic index in the home.

House-dust community (Fungi, mites) in different climatic regions.

House-dust flora and fauna were compared in the maritime cool temperate climate (in three degrees of continentality), the mediterranean warm temperate climate, the arctic climate and the tropical climate.An inverse relationship exists between continentality of the temperate climate and the numbers of arthropods and fungi (mesophilic as well as xerophilic) in the dust of the houses.The numbers of arthropods and fungi were lowest in mediterranean and arctic climates, most likely because of the limiting effect of the drier indoor climate. Fungi are more tolerant of dry conditions than house-dust inhabiting mites. Generally the highest numbers of fungal diaspores and arthropods were found in the tropics, where, however, the lowest number of positive samples was also found, especially for the species of the Aspergillus glaucus group and for Wallemia sebi. Maritime cool temperate climate showed the highest numbers of positive samples for fungi and mites.In general, a relationship exists between relative humidity and the density of fungal diaspores and arthropods.

A bibliography on ticks and tick-borne diseases in the countries of the Benelux (1567-1978).

Information published between 1567 and 1978 on this subject contains at least 223 titles. They cover medical and veterinary as well as biological aspects. Full bibliographical details of the publication are given. A subject index (to tick species, host species, and diseases transmitted) increases the availability of the data included. Some of the more interesting results of the study are discussed in a short introduction.

[The brown dog tick Rhipicephalus sanguineus Latreille 1806 in the Netherlands, an analysis of imported cases, including their veterinary and medical significance (author's transl)]. / De hondeteek Rhipicephalus sanguineus Latreille 1806 in Nederland, een analyse van de tot nu toe bekende 'importgevallen' en het veterinaire en medische belang.

Eighteen cases of infestation with Rhipicephalus sanguineus were reported during the past five years. Of the cases, six were observed during the first seven months of 1979. Of all infestations, four originated from sources within the territory of the Netherlands. Several cases of infestation with canine babesiosis were reported. There could have been a relationship between some of these cases and infestation with R. sanguineus. Populations of this tick can survive and develop in Dutch homes. Forming reservoirs of boutonneuse fever and canine babesiosis would appear to be possible.

A bibliography on ticks and tick-borne diseases in the countries of the Benelux (1567-1978).

Summary Information published between 1567 and 1978 on this subject contains at least 223 titles. They cover medical and veterinary as well as biological aspects. Full bibliographical details of the publications are given. A subject index (to tick species, host species, and diseases transmitted) increases the availability of the data included. Some of the more interesting results of the study are discussed in a short introduction.

An evaluation of biological methods in house-dust allergen research.

Methods in house dust analysis pertaining to particle identification, to extraction and identification of mites, other arthropods, fungi, bacteria and algae are evaluated. As far as possible, quantitative data are given to compare the extractive efficiency of the different methods.