1 / 72

FILARIASIS

FILARIASIS. Species. Geographic distribution. Pathogenicity. Adults (site of infection). Microfilariae (characteristics. Vector. Wuchereria bancrofti. Asia, Pacific, Tropical Africa, Americas. Lymphagitis, fever, elephantiasis hydrocoele, chyluria. Lymphatics.

deo
Download Presentation

FILARIASIS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. FILARIASIS para-lab by l. wafa menawi

  2. Species Geographic distribution Pathogenicity Adults (site of infection) Microfilariae (characteristics Vector Wuchereria bancrofti Asia, Pacific, Tropical Africa, Americas Lymphagitis, fever, elephantiasis hydrocoele, chyluria Lymphatics Found in blood, sheathed, periodicity variable Culicidae (mosquitoes) Brugia malayi South and East Asia Lymphagitis, fever. Elephantiasis Lymphatics Found in blood, sheathed, nocturnally periodic or subperiodic Culicidae (mosquitoes) Dipetalonema perstans Africa and South America No definite pathogenicity Peritoneal & pleural cavity Found in blood, unsheathed, nocturnally subperiodic Culicoides (biting midges) Dipetalonema streptocerca Africa (Ghana and Congo) Cutaneous oedema, elephantiasis Subcutaneous tissues Found in skin, unsheathed, nonperiodic Culicoides (biting midges) Mansonella ozzardi Central and South America No definite pathogenitis Peritoneal cavity Found in blood, unsheathed, nonperiodic Culicoides (biting midges) Loa loa Tropical Africa Skin swellings, allergic reactions Subcutaneous tissues Found in blood, sheathed, diurnally periodic Chrysops (Tabanidae or Horse fly) Onchocerca volvulus Africa, Central and South America Skin nodules, occular complications (blindness) Subcutaneous tissues Found in skin, unsheathed, nonperiodic Simulium (Black fly)

  3. Lymphatic filariasis • Wuchereriabancrofti and Brugiamalayi are filarial nematodes • Spread by several species of night - feeding mosquitoes • Causes lymphatic filariasis, also known as Elephantiasis • Commonly and incorrectly referred to as “Elephantitis” para-lab by l. wafa menawi

  4. Definitive host • Humans are the definitive host for the worms that cause lymphatic filariasis • There are no known reservoirs for W.bancrofti. • B.malayi has been found in macaques, leaf monkeys, cats and civet cats para-lab by l. wafa menawi

  5. Anopheles Intermediate host • W.bancroftiis transmitted by Culex, Aedes, and Anopheles species • B.malayi is transmitted by Anopheles and Mansonia species. Aedes Culex Mansonia para-lab by l. wafa menawi

  6. Epidemeology • Endemic in 83 countries • 1.2 billion at risk • More than 120 million people infected • More than 25 million men suffer from genital symptoms • More than 15 million people suffer from lymphoedema or elephantiasis of the leg para-lab by l. wafa menawi

  7. Morphology • Adult: White and thread-like. Two rings of small papillae on the head. • Female:5~10cm in length • Male: 2.5~4cm and a curved tail with two copulatory spicules. para-lab by l. wafa menawi

  8. Adult worm of filaria

  9. Microfilaria: 177~296 µm in length, a sheath with free endings. Bluntly rounded anteriorly and tapers to a point posteriorly. A nerve ring with no nuclei at anterior 1/5 of the body. para-lab by l. wafa menawi Wuchereria bancrofti Brugia malayi

  10. B.malayi microfilariae are slightly smaller than those of W.bancrofti. • Microfilariae are sheathed, and about 200 to 275 µm. • Not much is known about the adult worms, as they are not often recovered • One distinctive feature of B.malayi is that the microfilarial nuclei extends to the tip of the tail para-lab by l. wafa menawi

  11. Microfilaria of W. bancrofti and B. malayi

  12. Microfilaria of W. bancrofti

  13. Anterior part and posterior part of bancroftian microfilaria

  14. Microfilaria of W. bancrofti showing it’s appearance

  15. Bancroftianmicrofilaria:body nuclei equal sized, clearly, defined, countable without caudal nucleus

  16. Microfilaria of W. bancrofti

  17. Microfilaria of B. malayi: the body nuclei is unequal sized, coalescing,uncountable. The cephalic space is longer with two caudal nuclei.

  18. Microfilaria of B. malayi

  19. Species Size of Microfilariae Morphology of microfilariae Wuchereria bancrofti 210 – 320m by 8 - 10m Sheathed. Tail pointed and clear Brugia malayi 170 – 260m by 5 - 6m Sheathed. Tail pointed with 2 nuclei Loa loa 230 – 300m by 6 - 8m Sheathed. Tail blunt with nuclei Mansonella perstans 200m by 6m Unsheathed. Tail blunt with nuclei Mansonella ozzardi 250m by 6 - 7m Unsheathed. Tail pointed and clear

  20. Differences between microfilaria

  21. Life cycle • Host: Mosqutoes (intermediate host) Human (final host) • Location: Lymphatics and lymph nodes • Infective stage: Infective larvae • Transmission stage: Microfilariae • Diagnostic stage: Microfilariae para-lab by l. wafa menawi

  22. Life cycle para-lab by l. wafa menawi

  23. Wuchereria Life Cycle para-lab by l. wafa menawi

  24. Proboscis of a mosquito containing filariform larvae

  25. A large number of 3rd stage larvae of a filarial sp emerging from the proboscis of a mosquito.

  26. Nocturnal periodicity • Phenomen which the number of microfilariae in peripherial blood is very low density during daytime, but increase from evening to midnight and reach the greatest density at 10p.m to 2 a.m. • May be related to cerebral activity and vasoactivity of pulmonary vessels. para-lab by l. wafa menawi

  27. Larva deposited by mosquito bite • Travel through dermis to lymphatic vessels • Growth (approx 9 months) to mature worms(20-100mm long) • Worms live 5-7 years (occasionally up to15 years) • Mate->Microfilariae (1st stage larva) • Females->release up to 10,000 microfilariae/day into bloodstream • Microfilarie taken up by mosquito bite • Develop into 2nd and 3rd stage larva over 10-14 days inside mosquito vector para-lab by l. wafa menawi

  28. para-lab by l. wafa menawi

  29. Clinical features • Initially asymptomatic • Symptoms develop with increasing numbers of worms • Less than 1/3 of infected individuals have acute symptoms • Clinical Course is 3 phases: • Asymptomatic Microfilaremia • Acute Adenolymphangitis (ADL) • Chronic/Irreversible lymphedema • Superimposed upon repeated episodes of ADL para-lab by l. wafa menawi

  30. Presents with sudden onset of fever and painful lymphadenopathy • Retrograde Lymphangitis • Inflammation spreads distally away from lymph node group • Immune mediated response to dying worms • Most common areas: Inguinal nodes and Lower extremities para-lab by l. wafa menawi

  31. Inflammation spontaneously resolve after 4-7 days but can recur frequently • Recurrences usually 1-4 times/year with increasing severity of lymphedema • Secondary bacterial infections in edematous(elephantatic) areas • Filarial fever (fever w/o lymphangitis) • Tropical Pulmonary Eosinophilia • Hyperresponsiveness to microfilariae trapped in lungs • Nocturnal Wheezing para-lab by l. wafa menawi

  32. Lymphedema Mostly LE and inguinal, but can affect UE and breast Initially pitting edema, with gradual hardening of tissues hyperpigmentation & hyperkeratosis GenitaliaHydroceles Chronic filariasis para-lab by l. wafa menawi

  33. Renal involvement • Chylurialymph discharge into urine • Loss of fat and protein hypoproteinemia & anemia • Hematuria, proteinuria from ?immune complex nephritis • Secondary bacterial/fungal infections para-lab by l. wafa menawi

  34. Elephantiasis: accumulation of lymph in extremeties, fibrosis, and thickening of skin. para-lab by l. wafa menawi

  35. A patient of elephantiasis

  36. Elephantiasis of leg due to filariasis

  37. Elephantiasis due to Brugia malayi. Pitting does not occur in this stage (solid edema)

  38. Elephantiasis due to Brugia malayi, complicated by severe dermatitis and secondary bacterial infection

  39. This lady has elephantiasis of the right leg and edema in the left

  40. Hydrocele is only found in infection of W. bancrofti.

  41. elephantiasis of the left leg and scrotum

  42. The standard method for diagnosing active infection is the identification of microfilariae by microscopic examination However, microfilariae circulate nocturnally, making blood collection an issue Lab diagnosis para-lab by l. wafa menawi

  43. A “card test” for parasite antigens requring only a small amount of blood has been developed • Does not require laboratory equipment • Blood drawn by finger stick • Urinalysis, CBC and Comprehensive Chemistries • Foot Biopsy: Normal Skin with areas of chronic inflammation para-lab by l. wafa menawi

  44. Species Geographic location Periodicity Collection time Wuchereria bancrofti Tropics / Subtropics Nocturnal 12.midnight. Wuchereria bancrofti Pacific Diurnal subperiodic 16.00 hours Brugia malayi SE Asia and SW India Nocturnal 12.midnight. Brugia malayi Indonesia Nocturnal subperiodic 21.00 hours Brugia timori Indonesia Nocturnal 12.midnight Loa loa West / Central Africa Diurnal 13.00 hours Mansonella perstans Africa / S. America Non periodic Any time Mansonella ozzardi Central & S America Non periodic Any time

  45. Microfilariae are seen in blood smears and are DIAGNOSTIC para-lab by l. wafa menawi

  46. Blood Smear - Microfilaria • Note wavy microfilarial worm in the thick part of blood film. • Dark blue structures are nuclei • Tail end tapering (no nuclei) • Sheath covering worm. para-lab by l. wafa menawi

More Related