1、Medical arthropodaVery small(1.3-3.5 mm)Hairy bodyWings held in a“V”above the bodyWeak flying insects Sand flies(白蛉白蛉)Act as vector of LeishmaniasisLife cycle:6-8 weeksSeasonal existence:Jun-SeptActivity area and distributionSensitive to insecticidev3mm and brownvLaterally compressed and winglessvWi
2、th 3 pairs of powerful legs adapted for jumping,adults can jump about 70 cm vertically,30 cm horizontally Fleas(蚤蚤)Life cycle and habits Complete metamorphosis Both sexes can take a blood meal Excreting while feeding Sensitive to body temperature of hostvGeneral nuisance:biting humans on exposed sur
3、faces resulting in discomfort.Flea-bites induce pruritic（痒的痒的）urticaria（风疹风疹）;vParasitism:Females of Tunga penetrans,Tungiasis（潜蚤潜蚤病病）Direct harmsTungiasis（潜蚤病）（潜蚤病）鼠疫鼠疫(plague)(Yersinia pestis)Vectors:致痒蚤致痒蚤(Pulex irritans);印鼠客蚤印鼠客蚤(Xenopsylla cheopis)Mechanism:When takes a blood meal,the plague or
4、ganism rapidly multiplies and blocks the fleas proventriculus(前胃).While the fleas feeds again,it is unable to engorge and is forced to regurgitate blood and the bacteria from the proventriculus into the host.Clinical manifestation:bubonic plague,pneumonic plague,septicemic plague鼠型斑疹伤寒鼠型斑疹伤寒 Rickett
5、sia mooseri transmitted by Xenopsylla cheopis intermediate hosts of Hymenolepis Disease transmissionDisease transmissionMouse flea humanproventriculus Enlarged and inflamed lymph nodes around arm pits,neck and groin(腹股沟腹股沟).The term bubonic refers to the characteristic bubo or enlarged lymphatic gla
6、nd.Victims were subject to headaches,nausea,aching joints,fever,vomiting,and a general feeling of illness.Symptoms took from 1-7 days to appear.Bubonic plaguebubonic Plague（鼠疫（鼠疫,黑死病）黑死病）The picture above demonstrates what DIC(disseminated intravascular coagulation)can look like.Symptoms were a high
7、 fever and skin turning deep shades of purple due to DIC.Victims usually died the same day symptoms appeared.Louse(Pediculus)2.54.2mm,dorsoventrally flattenedProminent tarsal clawProtuberance of tibia（胫突）（胫突）and claws form gripping organ（攫握器）v All stages and both sexes feed solely on bloodv Inject s
8、aliva into the wound;meanwhile feces are continually passed onto the skinv Live in 29-32,RH 70%(on skin of host)Pediculus humanus corporis(人体人体虱虱)and Pediculus humanus capitis(人人头头虱虱)are the two species that cause human infestations.They are transmitted from human to human by direct contact or via c
9、ontaminated clothing,bedding and personal hygiene items(combs,brushes,etc.).人体虱Pediculosis capitisPththirus pubis(耻阴虱),the crab louse,is more difficult to transmit and less common.It is associated almost exclusively with sexual transmission,and is rarely found outside the genital region.Louse-borne
10、diseases Louse-borne diseases q 流行性斑疹伤寒流行性斑疹伤寒（Epidemic typhus）普氏立克次体普氏立克次体（Rickettsia prowazekii）q战壕热战壕热(Trench fever)五日立克次体五日立克次体（Rochalimaea quintana）q虱媒回归热虱媒回归热（Louse-borne relapsing fever）包柔疏螺旋体包柔疏螺旋体（Borrelia recurrentis）Bed bug(臭虫臭虫)Cimex hemipterus,热带臭虫Cimex lectularis,温带臭虫 不完全变态不完全变态栖息在木质床榻
11、的缝隙中，夜间吸血，群居栖息在木质床榻的缝隙中，夜间吸血，群居Cockroach(蜚蠊蜚蠊)德国小蠊德国小蠊美洲大蠊美洲大蠊黑胸大蠊黑胸大蠊生活习性：生活习性：栖息于温暖及与食物、水近的场所，昼伏夜栖息于温暖及与食物、水近的场所，昼伏夜出，分泌出，分泌“信息素信息素”，杂食性，杂食性，“电脑害虫电脑害虫”卵荚（鞘）卵荚（鞘）Harms to humans Mechanical vectors of a number of bacterial agents Causing asthma in children by secretion and feces犀牛蟑螂Class Class Arach
12、nidaArachnida 蛛形纲蛛形纲蜱螨亚纲蜱螨亚纲蜘蛛亚纲蜘蛛亚纲蝎亚纲蝎亚纲Gnathosoma(颚体颚体)Idiosoma（躯体）（躯体）Two parts:idiosoma(躯体)and gnathosoma(颚体);Adults have 4 pires of legs,without antenna and wingsGnathosoma(颚体颚体)Hard Ticks and Soft Ticks颚体颚体gnathosoma盾板盾板(Scute)躯体躯体IdiosomaLife cycle Change host frequently:one host,two host,th
13、ree host Hard ticks:3 host tick;Soft ticks:multi-host tick Life habit:all stages take blood,including larva,nymph and adults adults larva,female maleSucking blood by tick-tick paralysis Vector Pathogen DiseaseIxodes persulcatusEncephalophilus silvestris森林森林脑脑炎炎Tick-borne encephalitisHyalomma,Asiatic
14、um kozloniRNA virus新疆出血热新疆出血热Xinjiang hemorrhagic feverOrnithodoros popillipesBorrelia persica andB.latyschevi蜱媒回归热蜱媒回归热 Tick-borne relapsing feverIxodes persulcatusB.burgdorferi莱姆病莱姆病Lyme diseaseOrnithodoros papillipes Coxiella burnetii Q热热Q feverTick-borne diseases人兽共患病；传播方式多样：粪便、唾液、分泌物、卵；经卵传递经卵传递
15、Itch mite(Scab mite)Female dorsal sideMale ventral side永久性寄生螨，寄生在人和哺乳动物的皮肤表皮内，引起永久性寄生螨，寄生在人和哺乳动物的皮肤表皮内，引起有剧烈瘙痒的皮肤病，疥疮（有剧烈瘙痒的皮肤病，疥疮（scabies）。）。Living habitat and Life cycle Mate in skin,females dig burrows,and deposit egg in the upper layers of the epidermis,eggs hatch into larvae and then excavate n
16、ew burrows and mature in 4 days.Preferred sites of infestation Skin between fingers,the shoulders blades,around the penis,in the creases of the knees and elbows.Scabies Scabies itch resulted from the sensitization to the tunneling,the secretory and excretory products and eggs,severe at night.Rash,se
17、ptic pustules（脓疱）（脓疱）may develop after scratching.Diagnosis and treatment finding the mites by scrape the skin under microscope using 10%Brimstone ointment after a hot,soapy bath,all clothing and bedding should be launderedDemodicid mite蠕形螨蠕形螨Ferocious appearance,0.1 to 0.4 mm,4 pairs of stubby legs
18、Two species D.folliculorum(hair follicles)毛囊蠕形螨毛囊蠕形螨 D.brevis(sebaceous glands)皮脂腺蠕形螨皮脂腺蠕形螨D.folliculorum(hair follicles)毛囊蠕形螨毛囊蠕形螨D.brevis(sebaceous glands)皮脂腺蠕形螨皮脂腺蠕形螨Most commonly occur on the forehead,malar areas of the cheeks,nose,or anywhere on the face.Most people acquire follicle mites early
19、 in life from household contacts-primarily maternal.痤疮痤疮酒糟鼻酒糟鼻 蠕形螨吞食毛囊上皮细胞，引起毛囊扩张肿胀（毛囊粗毛囊粗大大，皮肤粗燥皮肤粗燥）皮肤角化过度或不全，真皮层血管扩张（痤疮痤疮、酒糟鼻酒糟鼻）皮脂腺分泌异常（脂溢性皮脂溢性皮炎炎）继发感染（毛囊炎毛囊炎）Diagnosis and treatment透明胶纸法挤刮涂片法挤粘结合法拔毛法Dust mite（尘螨）（尘螨）q Elongate elliptic body,commonly inhabit mattresses,carpets and house dust.q L
20、ive in 20-30,humidity 80%Anaphylaxis:allergic rhinitis（鼻炎）（鼻炎）Asthma dermatitisHow to control?Kill but do not destroy mite allergensReduction of allergen burdenLarva of Leptotrombidium deliensis (地里纤恙螨地里纤恙螨)Chigger mite(恙螨恙螨)Only larval stage takes blood and transmits scrub typhus(恙虫病恙虫病)by eggsq Ge
21、neral review General reviewPacking up the parasites:The morphology,life cycle,pathogenesis&symptomology,pathogenic diagnosis,factors of prevalence and strategy of control(treatment),of which life cycle is the key link.Systemic summary:of the intestinal system(tract and associated organs)of the brain of the eyes of the lung of the skin or subcutaneous tissues of the blood&lymph
