Dust Mites

9048122236......Page 1
Title Page......Page 3
Copyright Page......Page 4
Table of Contents......Page 5
Acknowledgements......Page 8
Preface......Page 10
What are dust mites and why are they important?......Page 11
Allergens......Page 12
Epidemiology......Page 13
Perceptions of dust mites and allergicdiseases......Page 14
1.1 What is the use of taxonomy?......Page 15
1.2.1 Perceptions of taxonomy......Page 17
1.2.2 Names and nomenclature......Page 18
a Binomial nomenclature......Page 19
b Synonymy and the oldest name......Page 20
1.3.2 Classification of the Glycyphagoidea and Acaroidea......Page 22
1.3.3 Classification of the Pyroglyphidae......Page 25
a The identity of Blomia tropicalis, B. kulaginiand B. gracilipes......Page 26
1.4.1 Phylogeny and the value of predictive classifications......Page 27
a The Glycyphagoidea......Page 23
b The Acaroidea......Page 24
1.4.3 Biodiversity and phylogenetic relationships within the Pyroglyphidae –out of Africa in the nests of birds?......Page 28
1.4.4 Evolutionary inferences from the biology and ecology of pyroglyphids and other Astigmata......Page 30
a Free-living soil dwellers and the effects of the development of agriculture......Page 31
c The evolution of resistance to desiccation......Page 32
d Differences in fecundity and population dynamics between pyroglyphids, acaroids and glycyphagoids......Page 33
1.5.1 Divisions of the body......Page 34
1.5.2 Idiosomal chaetotaxy – the names of the hairs of the body......Page 35
1.5.4 The ventral surface of the idiosoma......Page 36
1.5.6 Legs, their setae and solenidia......Page 37
1.6.1 Notes on use of the keys......Page 39
2.1 Physiology – the functional biology of organisms......Page 59
a Anatomy of the mouthparts......Page 60
2.2.2 Digestion, egestion and the functional anatomy of the gut......Page 62
a The pharynx and oesophagus......Page 63
b The midgut and midgut caeca......Page 64
c The posterior midgut and theperitrophic envelope......Page 67
e Gut pH......Page 68
f Redox potential......Page 69
a Localisation of digestive enzyme-allergens......Page 70
b Glycosidases......Page 72
c Cysteine endopeptidases (cysteine proteinases) (EC 3.4.22)......Page 73
e Serine endopeptidases (serine proteinases) (EC 3.4.21)......Page 74
a Gut contents analysis......Page 75
b Dermatophagy – feeding on skin scales......Page 76
d Mycophagy – feeding on fungi......Page 79
f Cannibalism......Page 82
a Vitamins and minerals......Page 83
c Lipids......Page 84
a Uncompartmentalised model......Page 88
a The removal of excess nitrogen......Page 89
c Organs involved in nitrogenous excretion......Page 90
2.4 Respiration and gas exchange......Page 91
2.6 Reproduction......Page 92
2.6.1 The female reproductive system of the Pyroglyphidae......Page 93
c The receptaculum seminis......Page 94
d The ejaculatory duct and penis......Page 95
2.6.4 Copulatory behaviour in the Pyroglyphidae......Page 96
2.7.1 The brain and central nervous system......Page 97
c Chemoreceptors......Page 98
2.8.1 The cuticle......Page 99
2.8.3 Ecdysis......Page 102
2.9 Chemical communication –pheromones and behaviour......Page 103
a The chemical nature of mite pheromones......Page 106
d Sex pheromones......Page 110
f Chemical, stereochemical and isomeric requirements for biological activity......Page 111
2.10 Consequences of acarine physiology for ecological interactions......Page 112
3.2.1 Biological measures – water activity and osmolarity......Page 115
3.3 Water uptake versus loss, and the critical equilibrium activity......Page 116
3.3.2 Effects of temperature on critical equilibrium activity......Page 118
3.3.3 Body water compartmentalisation – how much and where is it?......Page 120
3.3.4 Water balance of different stages of the life cycle......Page 121
a Oviposition......Page 122
c Egestion, excretion and osmoregulation......Page 127
d Lateral opisthosomal glands......Page 128
3.4.4 Behavioural limitation of water loss......Page 129
a Active uptake – the supracoxal glands......Page 130
b Supracoxal glands, salt concentrationsand flow rates......Page 132
d Eating and drinking......Page 133
3.6 Water balance and survival at low or fluctuating humidity......Page 136
3.7 Conclusions......Page 137
4.1.1 Characteristics of ecosystems......Page 139
4.1.2 Detrital ecosystems......Page 140
4.1.3 Domestic textiles......Page 141
4.1.5 Early agriculture and the development of food storage......Page 144
4.1.6 Nests of birds and mammals – the origin of the domestic acarofauna......Page 145
4.1.7 Mites in archaeological remains......Page 146
a Papua New Guinea......Page 147
b Colombia......Page 149
4.2.1 1650–1750: Leeuwenhoek, Hooke and Baker......Page 151
4.2.2 The 19th century......Page 153
4.2.3 Twentieth century observers......Page 155
4.3 Ecological concepts – distribution, abundance, biodiversity, communities and ecosystems......Page 157
4.3.2 Populations, communities and ecosystems......Page 158
4.3.3 Spatial heterogeneity, focality and niche theory......Page 159
4.3.4 Biological diversity, species richness and heterogeneity......Page 161
a Functional groups – the components of food webs......Page 162
b Transfer of nutrients and energy – trophic interactions......Page 165
4.3.6 Colonisation and succession......Page 166
4.3.7 Behaviour and dispersal in relation to distribution and abundance......Page 168
4.4 Spatial scales in dust mite ecology......Page 169
a Water vapour pressure and vapour pressure deficit......Page 171
b Relative humidity......Page 172
d Dewpoint temperature......Page 173
4.6 The microhabitat scale......Page 174
a The nature of house dust......Page 175
b Spatial and temporal differences in composition of house dust......Page 176
4.6.3 The climate of the microhabitat......Page 178
a Microclimate of beds and carpets......Page 180
b Microclimate and the boundary layer......Page 181
a Distribution and abundance within beds......Page 182
a Outdoor and indoor climate......Page 187
c Dwelling construction and design......Page 188
4.7.2 Variation in habitat availability......Page 189
b Age of homes......Page 191
c Social and economic status and density of occupancy......Page 192
4.7.4 Habitats other than houses......Page 193
4.8 The regional scale......Page 194
a Elevation, latitude and distance from the coast......Page 195
4.8.2 Regional scale examples of effects of climate on mite distribution and abundance......Page 196
a Israel and Gaza......Page 197
b Colombia......Page 200
c California......Page 201
d Australia......Page 203
e South Africa......Page 204
4.8.3 Conclusions from regional scale examples......Page 207
4.9.1 The biogeography of dust mites......Page 212
b Dermatophagoides farinae......Page 219
c Dermatophagoides microceras......Page 222
i Blomia tropicalis......Page 223
4.9.2 Conclusions......Page 224
4.10.2 Spatial and temporal scales and dustmite ecology – some concluding remarks......Page 225
5.1 Introduction......Page 228
5.2.2 The prelarval and larval stages......Page 229
a The protonymph......Page 231
b The hypopus......Page 232
b Andropolymorphism......Page 234
5.3 Why population dynamics is of practical importance......Page 235
5.4.1 Migration......Page 236
a Mortality and the life table......Page 238
b Natality, net reproductive rateand generation time......Page 240
5.4.3 The intrinsic and finite rates of natural increase......Page 241
b The stable age distribution......Page 243
5.5.1 Age and size at maturity – effects on fecundity and mortality......Page 246
5.5.2 Differences in life history traits between dust mites......Page 248
a Effects on stages in the life cycle......Page 249
c Effects on laboratory populations......Page 252
5.6.2 Diet......Page 253
a Predation......Page 255
c Density dependent effects......Page 256
5.7.1 Mites......Page 257
5.7.2 Allergens......Page 259
5.8 Population models......Page 264
5.9 Summary......Page 266
6.1 Sampling mite populations in homes......Page 268
6.1.1 Vacuum sampling......Page 269
c Heat attractant trapping......Page 271
6.1.6 Partial and total estimatesof mite populations......Page 272
6.2 Dimensions of the samples and units of measurement......Page 273
6.3.1 Flotation......Page 274
6.3.2 Suspension......Page 276
6.4 Mounting, counting and identification of mites......Page 277
6.4.2 Counting and identification......Page 278
6.5.2 Temperature and humidity control......Page 279
a The heat escape method......Page 280
6.6.1 Basic equipment......Page 281
6.6.4 Culture vessels......Page 282
6.6.6 Subculturing......Page 283
6.6.8 Laboratory hygiene and safety......Page 284
7.1 Why do dust mites produce allergens?......Page 285
7.2 Which mites produce clinically important allergens?......Page 292
b Euroglyphus......Page 293
c Aleuroglyphus......Page 296
d Blomia......Page 297
7.2.7 Tetranychoidea......Page 298
7.3 Localisation of allergens within the mites......Page 299
7.4.2 Classification of mite allergens......Page 300
7.4.3 The peptidases......Page 304
a Group 1 allergens......Page 305
b Group 3 allergens......Page 306
d Group 9 allergens......Page 307
a Group 4 allergens......Page 309
c Group 15 allergens......Page 311
7.4.5 The transferases......Page 312
7.4.6 The small alpha-helical proteins......Page 313
c Group 21 allergens......Page 314
b Group 11 allergens......Page 315
a Group 2 allergens......Page 316
c Group 14 allergens......Page 318
c Group 19 allergens......Page 319
c Enzyme inhibitors......Page 320
g Others......Page 321
7.6 Conclusions......Page 322
Appendix – amino acid sequences......Page 324
8.1 Introduction......Page 341
a Allergic asthma......Page 342
d Anaphylaxis......Page 343
e Gastrointestinal allergy......Page 344
8.3.1 Birth cohorts......Page 345
8.3.2 The hygiene hypothesis and the microbiota hypothesis......Page 347
8.4.1 Mite allergen concentrations as risk factors for allergy and asthma......Page 348
8.4.3 Sampling and measurement of allergens in reservoir dust......Page 350
8.4.4 Monitoring airborne allergens and personal exposure......Page 351
8.6 Variability in allergen concentration between homes......Page 353
b Age of home and state of repair......Page 354
d Temperature and humidity, damp, condensation and mould......Page 359
e Heating and ventilation......Page 360
Bedding type......Page 361
b Soil type......Page 362
8.6.4 Summary – hidden sources of variation?......Page 363
8.7.2 Population densities of mites......Page 365
8.7.3 Concentrations of allergens......Page 370
8.7.4 Regional and global patterns of allergen diversity and exposure......Page 372
a Species assemblages and allergen exposure......Page 374
8.8 Epidemiological implications of variation in allergen concentrations......Page 379
8.9 Changes in exposure to mite allergens?......Page 381
9.1 Introduction......Page 384
9.2.1 Chemical acaricides......Page 386
a Benzyl benzoate and related compounds......Page 387
Disinfectants containing benzyl benzoate......Page 389
b Pyrethroids......Page 390
Dehumidifiers......Page 391
Hot washing and tumble-drying......Page 392
9.2.3 Domestic redesign......Page 394
9.3.1 Vacuum cleaning......Page 396
9.3.2 Washing......Page 398
b Physical denaturation......Page 399
9.3.4 Barrier covers for mattresses and bedding......Page 400
9.4.1 Meta-analyses......Page 401
a Introduction......Page 402
Clinical trials......Page 403
Field trials......Page 405
9.4.3 Other issues with clinical trials......Page 407
b Atopic dermatitis......Page 409
9.4.5 Primary trials – allergen control to prevent children developing asthma......Page 410
9.5 Integrated approaches to mite and allergen control......Page 411
10.1 Why are dust mites still a problem?......Page 413
10.2.1 Resolving allergen exposure patterns......Page 414
10.2.3 Extending the temporal scale –acarological archaeology......Page 415
10.5 Interactions between dust mites, fungi and bacteria – metagenomics of allergenic organisms......Page 416
10.6 Why is atopy so common?......Page 417
10.7 New ways of thinking about dust mite control......Page 418
Campephilocoptes paraguayensis Fain, Gaudand Pérez, 1982......Page 419
Gymnoglyphus longior (Trouessart, 1897)......Page 420
Genus Dermatophagoides Bogdanov, 1864......Page 421
Dermatophagoides microceras Griffithsand Cunnington, 1971......Page 422
Dermatophagoides simplex Fain and Rosa, 1982......Page 423
Hirstia chelidonis Hull, 1931......Page 424
Genus Onychalges Gaud and Mouchet, 1959......Page 425
Onychalges spinitarsis (Fain and Gaud, 1984)......Page 426
Pottocola (Capitonocoptes) ventriscutata Fainand Gaud, 1984......Page 427
Paralgopsis paradoxus (Trouessart, 1899)......Page 428
Blomia tjibodas Oudemans, 1910......Page 429
Blomia tropicalis Bronswijk, Cock and Oshima, 1973......Page 430
Distribution of species of domestic mites, based on published surveys......Page 431
Abundance and frequency of occurrence of domestic mites in house dust, based on published surveys......Page 457
Concentrations of Dermatophagoides group 1 allergens in settled house dust, based on published surveys......Page 480
References......Page 488