Library Lecture author Onlineby © ESCMID Dr. Annie Sulahian St Louis Hospital Paris Domain Eukaryota Library Kingdom Animalia Phylum NematodaLecture Class Chromoderea Order Spiruridaauthor SuperfamilyOnline Filarioideaby Family Onchocercidae© ESCMID Filarial worms occupy a numerically minute place in the immense phylum of nematodes.Library Origin thought to be remote, in the Secondary era, with lst representatives in crocodiles and transmit- ted by culicids (150 M years).Lecture Main expansion during theauthor tertiary, synchronously with bird and mammalOnlineby diversification. © The constraint of being restricted to the host’s tissues without any direct communication with the exteriorESCMID has resulted in an original adaptation: a mobile embryo (the microfilaria). Adults or Macrofilariae Lymphatic system: Wuchereria bancrofti,Library Brugia malayi, Brugia timori. Subcutaneous, deep connective tissues: Loa loa, Onchocerca volvulus, Mansonella streptocerca. Body cavities: MansonellaLecture perstans , Mansonella ozzardi author Microfilariae Onlineby Blood © Skin ESCMIDUrine PERIODICITY Mf may exhibit periodicity in the circulation: - nocturnal periodicity: largest n° of mf in the peripheral circulation occurs at night betweenLibrary 9 p.m. and 2 a.m. (W. bancrofti). - diurnal periodicity: largest n° of mf found during daytime (Loa loa). Lecture - aperiodic: (Mansonella perstans ). - subperiodic or nocturnally subperiodic: mf can be detected during the day butauthor at higher levels during the late afternoonOnline or byat night (W. bancrofti, pacific region) . © The basis of periodicity is unknown and when they areESCMID not in the peripheral blood, they are primarily in capillaries and blood vessels of the lungs. - Ranked as one of the leading causes of Library permanent disability worldwide by WHO. - Prevalent in many tropical and subtropi- Lecture cal countries where the vector mosquitoes are common: ~120 million infectedauthor worldwide. Onlineby As of 31 December 2006,© the total population at risk for ly mphatic filariasis was estimated to be 1.254 million peopl eESCMID in 83 endemic countries. - Mf in blood Library Lecture author Onlineby © ESCMID Geographical map of Wuchereria bancrofti Library Lecture author Onlineby © ESCMID Geographical map of Brugia malayi Library Lecture author Onlineby © ESCMID Mosquito vectors: Culex , Mansonia , Aedes Disease manifestations are due toLibrary lymphatic dysunction resulting from: - the presence of livingLecture and dead worms, - lymph thrombi, author Onlineby - inflammation, © - immune reactions to worms and worm ESCMID products - Symptomless mf+ carriers Library - Amicrofilaremic patients - Lymphangitis Lecture - Lymphadenopathy - Lymphadenitis author Onlineby - Chronic Manifestations© in endemic areas : Hydrocoele ESCMIDOrchi-epididymitis Elephantiasis Two major groups are observed in lymphatic filariasis: - Microfilaremic individuals who have no discernibleLibrary symptoms of infection: majority of infected cases . Their immunity is strongly associated with down-regulated cell-mediated respon- ses, a Th2-type response with high immunoglobulin response (IgE) and IgG4 levels and eosinophilia.Lecture - Amicrofilaremic patients with chronicauthor disease and vigorous specific immune responsesOnlineby (Th1 type ). © It is becoming clear that filarial nematode development in the context of a Th2 immune response conveys an advantage for parasiteESCMID survival in the human host. Heterogeneity in infection and disease attributed to: - differences in immune mediated inflammatoryLibrary processes, - secondary bacterial infectionsLecture superimposed on the lymphatic dysfunction, author - immunogeneticsOnline of theby host: key role for genetic factors in determining© host response to filarial in- fections in humans shown in various studies within populationsESCMID and families Library Lecture author Onlineby © ESCMID Elephantiasis of the leg produces gross deformity and requires surgery 15 million suffer from this condition Library Lecture author Onlineby © ESCMID Orchi-epidymitis in the acute stage associated with hydrocele and mf in the h. fluid Hydrocele is observed in 25 million probably genetically predisposed persons Library Lecture author Onlineby © ESCMID Elephantiasis of the scrotum; scrotum; W. bancrofti B. timori rarely canaffects affect the legs, genitals arms, vulva, breasts and Library - 1. LOASIS Loa loa : Chrysops sp.Lecture Only in Central and Westauthor African rain forests.Onlineby © Blood Mf ESCMID Asymptomatic mf+ carriers Library Transient Calabar swellings Almost constant pruritisLecture Migration of the worm underauthor the skin and the conjonctivaOnlineby © Neurological , cardiac and renal complications ESCMIDVery rarely hydrocele and orchitis Library Lecture author Onlineby © ESCMID Geographical map of Loa loa Endemic in 11 countries: 12-13 million have loiaisis from the Gulf of Guinea in the west of the Great Lakes east Library Lecture author Onlineby © ESCMID Tabanid or deerfly or mango fly: Blood-sucking and day-biting, live in forested, muddy habitats and rotting vegetation Chrysops sp. in rain forests in west and central Africa Library Lecture author Onlineby © ESCMID Chrysops feeding: very painful bite due to the laceration stylet Library Lecture author Onlineby © ESCMID Calabar swelling of the cheek lasts about 3 days; larvae mature to adult worms in ~ 1-4 yrs Adult worms can live up to 17 years Library Lecture author Onlineby © ESCMID Calabar swelling of the hands; marked associated Eo (60-90%) Library Lecture � 2. Onchocerciasisauthor Online Onchocercaby volvulus: Simulium © Tropical Africa, South America, Yemen ESCMIDMf in the dermis Library - Asymptomatic but mf+ - Cutaneous lesions: nodules or onchocercoma, due to loss of skin elasticityLecture as a rx to worms and mf . - Pruritis, dermatitis with lichenification,author lizard or elephant skin Onlineby © - Ocular lesions: living and dead mf in the eye cause trauma and reactions that can result in blindness ESCMID Library Lecture author Onlineby © ESCMID Geographical map of Onchocerca volvulus mainly a disease of riverine countries Library Lecture author Onlineby © ESCMID Simulium or buffalo-fly with a humped back (larval stages in fast runnig water) Library Lecture author Onlineby © ESCMID Onchocercal scabies Library Lecture author Onlineby © ESCMID Subcutaneous nodule predominantely in the lower part of the body in Africa Library 3- Mansonella streptocerca : Culicoides Lecture Africa : Ghana, Zaïre, Congo, Uganda, often co- endemic with O. volvulusauthor - In many casesOnline no clinicalby symptoms or © - Acute and more often chronic papular dermatitis mainly on the upper part of the body ESCMID Mansonella perstans: Africa, Latin LibraryAmerica. Mansonella ozzardi: Latin America Blood Mf: Culicoides (biting gnat) Most infections are asymptomaticLecture but can be sometimes associated with eosinophilia, pruritis, fever, headaches and arthralgiaauthor (M. perstans). M. ozzardi can causeOnline arthralgias,by fever, pulmonary symptoms. © Association between M. perstans and other filarial speciesESCMID is frequent in Africa. 4- Superfamily: Dracunculoidea Library Dracunculiasis or Guinea Worm disease, Known since antiquity: fiery serpent of the exodus, cal- Lecture cified male found in an Egyptian mummy. In 1950’s, 50 million cases inauthor Africa and Asia Onlineby and by 1999: 66000 cases© (2/3 in Sudan) thanks to multiple eradication programs done by ESCMID various agencies (Carter Foundation, UNICEF, WHO, etc) Library Lecture author Onlineby © ESCMID Intermediate host: Cyclops copepods); prepatent period: 10-14 months (transmission by drinking water containing infected Symptomatology - Urticaria, Library - The gravid female induces the formation of an ulcer like sore through which it can Lecture protrude its anterior end with water contact. (blisters reported on the ankles,author knee joints, hands, Onlineby buttocks, scrotum)© - Encystment, abcess, calcifications, radiologicalESCMID images, artritis Library Lecture author Onlineby © ESCMID Guinea worm: radiological appearance showing calcification:1% of infected persons suffer permanent damage from synovial ankylosis Library Lecture author Onlineby © ESCMID Guinea worm: adult under the skin Since Dracunculus transmission dependsLibrary almost entirely on water for its transmission eradication programs have focused on: - Provision of safe water,Lecture including use of filte- ring devices and chemicalauthor treatment of water sources. Onlineby - Health education© - Case containment -ESCMID Community-based surveillance systems Of orientation: eosinophilia high duringLibrary invasi- on, low or absent during the adult stage. Not specific Of confirmation: mf, adultsLecture Immunological: antibodies and antigen Molecular biology: PCRauthor Onlineby Imaging like CT, ©MRI may reveal « Filarial Dance Sign » in Chylus fluid; X-Ray can show calcifiedESCMID adult worms in lymphatics Blood Library - Diurnal or nocturnal periodicity: finger prick - Venous blood Microscopic detection ofLecture mf - Direct wet smears - Thin and thick blood smearsauthor (numeration of mf in loiasis); mf oftenOnline at outer edges of film. - Concentration techniques:by Knott, leucoconcentration© - Membrane filtration technique - QBCESCMID method (fluorescent microscope) Urine: W. bancrofti (chyle), O. volvulus (after Tt), - Mf normally in blood (hematuria dueLibrary to bilharziases) : L. loa, M. perstans, O. volvulus. Hydrocoele fluid Lymphatic filariasis, Loa, LectureOnchocerca