Filarial worm丝虫)
Filarial worm(丝虫)
General Introduction Wuchereria bancrofti Brugia malayi Brugia timori Onchocerca volvulus(river blindness -black fly Loa loa(eye worm -deer fly Dipetalonema streptocerca Dipetalonema perstans Mansonella ozzardi
Wuchereia bancrofti Brugia malayi Brugia timori Onchocerca volvulus (river blindness - black fly) Loa loa (eye worm - deer fly) Dipetalonema streptocerca Dipetalonema perstans Mansonella ozzardi General Introduction
General Introduction ☆ Roundworm Adult filaria live in body cavities lymphatics, and subcutaneous tissues %s Embryos(microfilaria) live in blood or dermis 8 All require an insect vector
❖ Roundworm ❖ Adult filaria live in body cavities, lymphatics, and subcutaneous tissues ❖ Embryos (microfilaria) live in blood or dermis ❖ All require an insect vector General Introduction
Wuchereja bancrofti(班氏吴策线虫) & Brugia ma|ay(马来布鲁线虫)
Wuchereia bancrofti (班氏吴策线虫) & Brugia malayi (马来布鲁线虫)
Morphology o ADULTS: 2 cm-120 cm(4-10um wide) oRWB Female -105mm: Male -42mm cRB. M. Female 58.5mm; Male -23mm
❖ ADULTS: 2 cm – 120 cm (4 – 10µ m wide) W. B. Female ~105mm; Male ~42mm B. M. Female ~58.5mm; Male ~23mm Morphology
Morphology 令 Microfilaria 150350mong 63 8 将 a282 头部 尾部 head tail
❖ Microfilaria: 150-350 µm long Morphology head tail
Morphological differences between W bancrofti &B. malayi microfilariae E w bancrofti B malayi Wbancrofti B. malayi Size(um) Larger 244-296x7 Smaller 177-230x5-6 Body Graceful, gently curved Irregular, kinky curves curvature Cephalic Shorter longer space Somatic Equal sized, visualized Unequal sized, tightly nuclei individually packed terminal Two nucler
W. bancrofti B. malayi Size (µm) Larger 244-296x7 Smaller 177-230x5-6 Body curvature Graceful, gently curved Irregular, kinky curves Cephalic space Shorter longer Somatic nuclei Equal sized, visualized individually Unequal sized, tightly packed terminal nuclei No Two Morphological differences between W. bancrofti & B. malayi microfilariae w.bancrofti B.malayi
Life Cycle Wuchereria bancrofti Mosquito Stages Mosquito takes Human Stages a blood meal (L3 larvae enter skn Migrate to an mosquito's proboscis )0约 L3 larva Adults in lymphatics L1 larvae Adults produce sheathed microfilariae that migrate 4 Mosquito takes into lymph and blood channels (ingests mctohtanae) Microfilariae shed sheaths pentrate mosquitos midgut, and migrate to thoracic muscles s Infective Stage ADiagnostic Stage
Life Cycle
Life Cycle ☆Host ca W, bancrofti; human c B, malayi: human and reservior host &o Residing place(adult worm): lymphatics c& W bancrofti: lymphatics of limbs and genital system c& B. malayi: lymphatics of limbs ,o Infective stage: Third-stage filariform larvae( L3) .o Intermediate host: mosquito c& W bancrofti: culex(Culex pipiens pallens, C fatigans) CR B. malayi: anopheles(A sinensis) cR The larvae only undergo growth but no propagation there %o Diagnostic stages: microfilariae
❖ Host: W. bancrofti : human B. malayi : human and reservior host ❖ Residing place (adult worm): lymphatics W. bancrofti: lymphatics of limbs and genital system B. malayi: lymphatics of limbs ❖ Infective stage：Third-stage filariform larvae (L3) ❖ Intermediate host：mosquito W. bancrofti: culex (Culex pipiens pallens, C. fatigans) B. malayi: anopheles ( A. sinensis) The larvae only undergo growth but no propagation there ❖ Diagnostic stages: microfilariae Life Cycle
nocturnal periodicity .o The phenomena that the presenting of microfilariae in the peripheral blood is very low in density at daytime but the number of microfilariae gradually increase from evening to early next morning. This periodic pattern was called nocturnal periodicity. The microfilariae mostly stay in the pulmonary capillary vessels during the day .o The peak time of microfilariae in the peripheral blood is cR W. bancroft: 10pm-2am CR B. malayi: 8pm-4am
nocturnal periodicity ❖ The phenomena that the presenting of microfilariae in the peripheral blood is very low in density at daytime but the number of microfilariae gradually increase from evening to early next morning. This periodic pattern was called nocturnal periodicity. The microfilariae mostly stay in the pulmonary capillary vessels during the day. ❖ The peak time of microfilariae in the peripheral blood is: W. bancrofti: 10pm – 2am B. malayi: 8pm –4am