Nematoda

discussion about nematode,
their form, general characteristics, life cycle, discussion about their host.
diseases caused by nematodes
and discussion about different class of nematodes.

1. NEMATODA VIVEK DEV

2. FORM, FUNCTION SHAPE AND BODY STRUCTURE 1. SYMMETRY: BILATERAL 2. BODY CAVITY: PSEUDOCOEL 3. BODY SHAPE: THREAD LIKE, NON SEGMENTED, CYLINDRICAL BODY 4.SIMPLE DIGESTIVE SYSTEM 5. PROTECTIVE CUTICLE 6. PARASITISM 7. NERVOUS SYSTEM CONSISTS OF NERVE RING 8. NO CIRCULATORY SYSTEM 9. REPRODUCTION GENERALLY SEXUAL AND GONOCHORISTIC

3. Morphology of Roundworms

4. Morphology

5. LIFE CYCLE IN GENERAL

6. CLASSIFICATION They are divided into two classes distinguished by differences in sensory and excretory system. 1. Class Enoplea -Subclass Dorylaimia Amphids are well developed .Excretory system are found in single,ventral,glandular cells or entirely absent. Mostly free-living and some are parasiitic on plants and animals. Orders – Trichurida,Dioctophymatida,Muspiceida,Mermithida

7. Trichuris trichiura -”Whipworm” -Most common gastrointestinal parasites of human -Eggs posses plugs -Have stichosome esophagus -Male have coiled posterior ends. -Pathogenesis- Trichuriasis

8. Kingdom-Animalia Phylum- Nematoda Class- Enoplea Order- Trichurida Family- Trichuridae Genus- Trichuris Species- trichiura

9. Class Rhabditea Subclass Rhabditia Amphids are generally poorly developed. Phasmids are present . Excretory system with one or two lateral canals,with or without associated glandular cells .Both free living and parasitic. Orders- Rhabditida,Strongylida,Ascaridida,Oxyurida,Spirurida .

10. Kingdom Phylum Class Order Family Genus Species Animalia Nematoda Rhabditea Ascaridida Ascarididae Ascaris l umbricoides Ascaris lumbricoides

11. MORPHOLOGY Because of their great size, abundance, and cosmopolitan distribution, these nematodes may well have been the first parasites known to humans. These species are characterized by, in addition to their great size, having three prominent lips, each with a dentigerous ridge, and no interlabia or alae . Male ( 15 cms to 31 cms ) and females (20 cms to 49 cms ) are of different size.

12. Fertilized egg of Ascaris

13. Biology of Ascaris Ascaris lumbricoides , a roundworm, infects humans when an ingested fertilised egg becomes a larval worm (called  rhabditiform larva) that penetrates the wall of the duodenum and enters the blood stream. From there, it is carried to the liver and heart, and enters pulmonary circulation to break free in the alveoli, where it grows and molts. In three weeks, the larva passes from the respiratory system to be coughed up, swallowed, and thus returned to the small intestine, where it matures to an adult male or female worm

14. Pathogenesis Little damage is caused by penetration of intestinal mucosa by newly hatched worms. Infection with  Ascaris lumbricoides   often causes no symptoms .   Infections with a large number of worms may cause abdominal pain or intestinal obstruction.  Adults feed on the contents of the small intestine and in heavy infections this may compound problems in malnourished individuals (especially children).

15. Life cycle of Ascaris lumbricoides

16. Diagnosis and Treatment DIAGNOSIS —  The diagnosis of ascariasis is usually made via stool microscopy. Other forms of diagnosis are through eosinophilia, imaging, ultrasound, or serology examination. TREATMENT —  Treatment consists of choosing the right drugs, therapy, follow-up, and supportive care for each patient. PREVENTION —  Prevention of reinfection poses a substantial problem since Ascaris parasites are abundant in soil. Good sanitation to prevent fecal contamination of soil is required. An education program advising against the use of human feces as a fertilizer is also needed in some areas. Soil treatments have been attempted but are generally not practical.

17. HOOKWORM FAMILY ANCYLOSTOMIDAE Kingdom Animalia Phylum Nematoda Class Secernentea Order Strongylida Family Ancylostomatidae Genus Ancylostoma Species duodenale C. Name Hookworm

18. MORPHOLOGY MOST SPECIES ARE RATHER STOUT, AND THE ANTERIOR END IS CURVED DORSALLY, GIVING THE WORM A HOOKLIKE APPEARANCE THE BUCCAL CAPSULE IS LARGE AND HEAVILY SCLEROTIZED AND USUALLY IS ARMED WITH CUTTING PLATES, TEETH, LANCETS, OR A DORSAL CONE. LIPS ARE REDUCED OR ABSENT. THE ESOPHAGUS IS STOUT, WITH A SWOLLEN POSTERIOR END, GIVING IT A CLUB SHAPE

19. MORPHOLOGY MALES HAVE A CONSPICUOUS COPULATORY BURSA, CONSISTING OF TWO BROAD LATERAL LOBES AND A SMALLER DORSAL LOBE, ALL SUPPORTED BY FLESHY RAYS FEMALES HAVE A SIMPLE, CONICAL TAIL. THE VULVA IS POSTEQUATORIAL, AND TWO OVARIES ARE PRESENT. ABOUT 5% OF THE DAILY OUTPUT OF EGGS IS FOUND IN THE UTERI AT ANY ONE TIME; THE TOTAL PRODUCTION IS SEVERAL THOUSAND PER DAY FOR AS LONG AS NINE YEARS.

20. BIOLOGY OF HOOKWORM HOOKWORMS MATURE AND MATE IN THE SMALL INTESTINE OF THEIR HOST SPECIES INFECTING HUMANS CANNOT BE DIAGNOSED RELIABLY BY THEIR EGGS ALONE EGGS REQUIRE WARMTH, SHADE, AND MOISTURE FOR CONTINUED DEVELOPMENT JUVENILES LIVE IN THE FECES, FEEDING ON FECAL MATTER, AND MOLT THEIR CUTICLE IN TWO TO THREE DAYS

21. BIOLOGY OF HOOKWORM WHEN THE GROUND SURFACE IS DRY, THEY MIGRATE A SHORT DISTANCE INTO THE SOIL, FOLLOWING THE RETREATING WATER. UNDER IDEAL CONDITIONS, THEY CAN LIVE FOR SEVERAL WEEKS. INFECTION OCCURS WHEN WORM CONTACT A HOST’S SKIN AND BURROW INTO IT, AND THEY RESUME FEEDING AT ABOUT THIS TIME. SECOND STAGE JUVENILES, WHICH ALSO HAVE A RHABDITIFORM ESOPHAGUS, CONTINUE TO FEED AND GROW AND, AFTER ABOUT FIVE DAYS, MOLT TO THE THIRD STAGE, WHICH IS INFECTIVE TO A HOST. SECOND-STAGE CUTICLE MAY BE RETAINED AS A LOOSEFITTING SHEATH UNTIL PENETRATION OF A NEW HOST, OR IT MAY BE LOST EARLIER

22. Diagnosis, Symptoms and Treatment Symptoms abdominal pain colic, or cramping and excessive crying in infants intestinal cramps nausea fever blood in stool a loss of appetite Treatment & Prevention Albendazole , Mebendazole wearing shoes when you walk outdoors, especially in areas that might have feces in the soil drinking safe water properly cleaning and cooking food practicing proper handwashing Diagnosis : The standard method for diagnosing the presence of hookworm is by identifying hookworm eggs in a stool sample using a microscope

23. Wuchereria bancrofti Scientific Classification Kingdom : Animalia Phylum : Nematoda Class : Secernentea Order : Spirurida Family : Filariidae Genus : Wuchereria Species : bancrofti

24. Wuchereria bancrofti Definitive Host: Humans Intermediate Host: Mosquitoes (especially night-feeding mosquitoes) Species: Anopheles, Aedes , Culex , Mansonia Morphology: Males: 40 mm long & 100 μm wide Fingerlike tail Females: 6-10 cm long & 300 μm wide They are viviparous Their vulva is near the level of the middle of their esophagus

25. Geographic Distribution Its infection is mainly found in the tropical region, pacific islands and sometimes in the Caribbean. West and south parts of Africa Egypt Southern Asia Western Pacific islands Northeastern coast of Brazil Guyana Caribbean island of Hispaniola

26. Life Cycle

27. The mosquito takes a blood meal, transferring the L3 larva into the skin. The L3 larva grow into adults in the lymph ducts. The adults reproduce, producing sheathed microfilariae ; the microfilariae migrate into the blood and lymph channels A mosquito takes a blood meal, ingesting the microfilariae . Once in the mosquito, the sheath of the microfilariae is sloughed off. The microfilariae then penetrates the midgut of the mosquito, making its way into the thoracic muscles. L1 larvae form L3 larvae form The L3 larvae are the infective stage, traveling to the mosquito’s head and proboscis.

28. Asymptomatic Phase: High levels of microfilaria in the blood No symptoms present Inflammatory (Acute) Phase: Inflammatory responses happen in response to antigens from adult worms Lymphedema —swelling due to blockage of lymph vessels Orchitis —inflammation of the testes Epididymitis —inflammation of the spermatic cord Obstructive Phase: Lymph varices —enlarged lymph vessels (synonymous with varicose veins) Lymph scrotum — enlarged lymph vessels in the scrotum Chyluria —lymph in urine (milky and sometimes bloody urine) Elephantiasis —enlargement of limbs and thickening of the skin due to repeated inflammatory episodes

29. Elephantiasis Elephantiasis Lymphedema Orchitis

30. Pathogenesis 6-12 months must pass before the microfilariae mature and reproduce Once a person is infected, microfilariae can be produced for up to ten years. There are 3 phases of infections: asymptomatic, inflammatory (acute), and obstructive.

31. Diagnosis Thick blood smear Juveniles must be present in peripheral blood Polymerase chain reaction (PCR) Distinguishes between other similar species Ultrasonography Detects vigorous movement of adults known as “ filaria dance sign” X-rays Detects dead, calcified worms

32. Treatment Primary drug of choice: diethylcarbamazine (DEC) Eliminates microfilaria from the blood and (if administered correctly) kills adult worms Ivermectin Albendazole & Mectizan Application of pressure bandages

33. Control Administration of Albendazole & Mectizan to control the spread of the disease. There are currently no vaccines Elimination of common mosquito breeding grounds Fallen coconuts containers filled with stagnant water Marshy and swampy areas. They hope to eradicate it by year 2020; so far, the diseased population has declined significantly

34. THANK YOU