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common nematode pathogens.pptx
- 1. Common nematode pathogens of humans M. HEMA I-MSC ZOOLOGY GOVT ARTS AND SCIENCE COLLEGE
- 2. Nematodes Nematodes also known as roundworms are Among the most numerous of all animals. A cubic metre of soil contains about millions of round worms. Simplest animals Linear digestive system Most primitive animals to show cephalization.
- 3. Nematodes Characteristics: Slender, unsegmented with tapered ends. Range from microscopic to 1 meter long. Most are free living and some are parasitic. Develop from three germ layers. Have a digestive tract with two openings.
- 4. Form and function Feeding Free living worms are predators with grasping mouth parts Soil dwelling and aquatic forms eat algae, fungi or decaying organic matter Respiration, Circulation and Excretion These processes take place by diffusion
- 5. Form and function Response Simple nervous system with several ganglia Numerous sense organs Movement Nematodes have muscles that extend the length of the body Use the pseudocoelom and a hydrostatic skeleton
- 6. Reproduction Separate male and female organisms Reproduce sexually using internal fertilization Parasitic roundworms have life cycles that involve two or three host or multiple organs in one host
- 7. Some Important Nematode Parasites of Humans Ascaris lumbricoides Enterobius vermicularis Necator americanus Trichinella spiralis Wuchereria bancrofti
- 8. Ascaris lumbricoides The Giant Intestinal Roundworm- The adult female worm can be over 30 cm long and 2-6 mm wide 800 million infected- most common parasitic worm disease in the world the largest of the human intestinal nematodes. This is the most common parasitic worm disease in the world, very prevalent in tropical regions but rarely found also in our country. In the United States about 4 million people are infected. The adult female worm can be over 30 cm long and 2-6 mm wide. The female worm produces 200.000 eggs per day.
- 9. Ascaris lumbricoides Adults live in small intestines of humans Eggs exit with through feces Once the eggs are ingested, they hatch in intestine and travel to the lungs Larvae molt twice, they travel to the trachea where they are swallowed
- 10. Life cycle
- 11. Also
- 12. Ascaris lumbricoides Mass of Ascariasis lumbricoides worms passed rectally by a child in Africa; SOURCE: James Gathany/CDC Ascariasis lumbricoides nematode worms (male on left, female on right); females can reach lengths of over 12 inches (26.4 cm); SOURCE: CDC
- 13. Fertilized egg Microscopic appearance of a fertilized egg from Ascaris lumbricoides;
- 14. Signs and symptoms The signs and symptoms of the nematode infection by Ascaris lumbricoides may include the following: Abdominal discomfort Abdominal cramping Abdominal swelling(especially in children) Fever Coughing and/or wheezing Nausea Vomiting Passing roundworms and their eggs in the stool
- 15. Treatments Fortunately, there are effective anthelmintic treatments available for ascariasis. Medications such as single-dose albendazole (Albenza) or mebendazole (Vermox) are drugs of choice for ascariasis.Health care providers administer drugs for only about one to three days. Other drugs such as ivermectin (Stromectol), levamisole (Ergamisol), pyrantel pamoate (Pin Rid, Pin X), nitazoxanide, and piperazine citrate have also been used effectively. Pyrantel pamoate treats pregnant women; other drugs like mebendazole and albendazole may cause teratogenic effects in the fetus. There are a number of home remedies for ascariasis. Garlic, wormwood, pumpkin seeds, and many other herbs have been used to treat ascariasis.
- 16. Prevention and control Before handling or eating any food, wash hands with soap and water. Avoid drinking any local water sources when traveling. Use only boiled water or bottled water avoid raw vegetables .
- 17. Ascaris lumbricoides When ascaris becomes a big problem….
- 18. Enterobius vermicularis Pinworm Most common parasite in US Adults live in large intestine At night females migrate out of the anus and lay eggs on skin
- 19. Enterobius vermicularis Human ingest eggs, hatch and molt 4 times in small intestine & migrate to large
- 21. Symptoms Enterobiasis is frequently asymptomatic. The most typical symptom is perianal pruritus, especially at night, which may lead to excoriations and bacterial superinfection. Occasionally, invasion of the female genital tract with vulvovaginitis and pelvic or peritoneal granulomas can occur. Other symptoms include, teeth grinding, enuresia, insomnia, anorexia, irritability, and abdominal pain, which can mimic appendicitis. E. vermicularis larvae are often found within the appendix on appendectomy, but the role of this appendectomy, but the role of this nematode in appendicitis remains controversial.
- 22. TREATMENT The medications used for the treatment of pinworm are either mebendazole, pyrantel pamoate, or albendazole. Any of these drugs are given in one dose initially, and then another single dose of the same drug two weeks later. Pyrantel Health practitioner and parents should weigh the health risks and benefits of these drugs for patients under 2 years of age. Repeated infections should be treated by the same method as the first infection. In households where more than one member is infected or where repeated, symptomatic infections occur, it is recommended that all household members be treated at the same time. In institutions, mass and simultaneous treatment, repeated in 2 weeks, can be effective.
- 23. Prevention and control with good hygiene practices such as washing their hands with soap and warm water after using the toilet changing diapers, and before handling food. They should also cut fingernails regularly, and avoid biting the nails and scratching around the anus. Frequent changing of underclothes and bed linens first thing in the morning is a great way to prevent possible transmission of eggs in the environment and risk of reinfection. These items should not be shaken and carefully placed into a washer and laundered in hot water followed by a hot dryer to kill any eggs that may be there In institutions, day care centers, and schools, control of pinworm can be difficult, but mass drug administration during an outbreak can be successful. Teach children the importance of washing hands to prevent infection.
- 24. Necator americanus Hookworm Found in Southern US Adults live in small intestine with teeth and feed on blood & tissue fluid Females 10,000 eggs daily & pass out of body in feces Hookworm
- 25. Necator americanus Eggs hatch in warm moist soil and releases a small larva, the larva molts and becomes the infective filariform larva.
- 26. Necator americanus Humans become infected when filariform penetrates the skin (usually b/w toes) to reach our circulatory system
- 28. Life cycle
- 29. Symptoms High-intensity infections with these worms are less common among adults. The most serious effects of hookworm infection are the development of anemia and protein deficiency caused by blood loss at the site of the intestinal attachment of the adult worms. When children are continuously infected by many worms, the loss of iron and protein can retard growth and mental development.
- 30. Treatment Anthelminthic medications (drugs that rid the body of parasitic worms), such as albendazole and mebendazole, are the drugs of choice for treatment of hookworm infections. Infections are generally treated for 1-3 days. The recommended medications are effective and appear to have few side effects. Iron supplements may also be prescribed if the infected person has anemia.
- 31. Prevention and control The best way to avoid hookworm infection is not to walk barefoot in areas where hookworm is common and where there may be human fecal contamination of the soil. Also, avoid other skin contact with such soil and avoid ingesting it. Infection can also be prevented by not defecating outdoors and by effective sewage disposal systems.
- 32. Trichinella spiralis The Porkworm Adults live in mucus of small intestine of humans and other mammals
- 33. Trichinella spiralis Females birth young, larvae enter circulatory system and are carried to Skeletal (striated) Muscles
- 34. Trichinella spiralis Larvae encyst in muscles & remains infective for many years
- 35. Trichinella spiralis Another host must ingest infective meat to continue the life cycle
- 36. Trichinella spiralis Humans become infected by eating improperly cooked pork products Larvae encyst in stomach move to small intestine molt 4 times, turn into Adults
- 37. Symptoms The first symptoms of trichinellosis are gastrointestinal, usually occurring 1–2 days after a person consumes raw or undercooked meat from a trichinella infected animal. Nausea Diarrhea Vomiting Abdominal pain
- 38. Symptoms The following classic symptoms of trichinellosis often occur within 2 weeks after eating contaminated meat, and can last up to 8 weeks Muscle pain Fever Swelling of the face, particularly the eyes Weakness or fatigue Headache Chills Itchy skin or rash Cough Diarrhea Constipation
- 39. • Control and prevention The best way to prevent trichinellosis is to cook meat to safe temperaturesexternal icon. A food thermometer should be used to measure the internal temperature of cooked meat. Do not sample meat until it is cooked. In addition: Wash your hands with warm water and soap after handling raw meat. Curing (salting), drying, smoking, or microwaving meat alone does not consistently kill infective worms; homemade jerky and sausage were the cause of many cases of trichinellosis reported to CDC in recent years. Freeze pork less than 6 inches thick for 20 days at 5°F (-15°C) to kill any worms. Freezing wild game meats, unlike freezing pork products, may not effectively kill all worms because some worm species that infect wild game animals are freeze-resistant. Clean meat grinders thoroughly after each use.
- 40. Wuchereria bancrofti The Filarial worms In tropical countries over 250 million human infected
- 41. Wuchereria bancrofti Thread-like worms that live in the Lymphatic System, block the vessels This causes enlargement of various appendages: Elephantiasis An Adult female Wuchereria bancrofti is about 80-100 mm long and 0.24-0.30 mm in diameter, whereas a male is about 40 mm long and 0.1 mm in diameter.
- 42. Elephantiasis
- 43. Wuchereria bancrofti Adults copulate produce microfilariae. The microfilariae released into the blood stream A microfilaria is about 240-300 µm (micrometers) long and 7.5-10 µm thick
- 44. Wuchereria bancrofti Mosquito (intermediate host) feeds on human (definitive host) ingest microfilariae and larvae molts 2 times Mosquito bites another human it injects 3rd stage larvae into human blood, molts, enters lymphatic system Wuchereria bancrofti
- 45. Life cycle
- 46. SYMPTOMS Although the parasite damages the lymph system , most infected people have no symptoms and will never develop clinical symptoms. These people do not know they have lymphatic filariasis unless tested. A small percentage of persons will develop lymphedema. This is caused by fluid collection because of improper functioning of the lymph system resulting in swelling. This mostly affects the legs, but can also occur in the arms, breasts, and genitalia. Most people develop these symptoms years after being infected. The swelling and the decreased function of the lymph system make it difficult for the body to fight germs and infections. These people will have more bacterial infections in the skin and lymph system. This causes hardening and thickening of the skin, which is called elephantiasis. Many of these bacterial infections can be prevented with appropriate skin hygiene as well as skin and wound care . Men can develop hydrocele or swelling of the scrotum due to infection with one of the parasites that causes LF specifically W. bancrofti. Filarial infection can also cause tropical pulmonary eosinophilia syndrome, although this syndrome is typically found in persons living with the disease in Asia. Eosinophilia is the presence of higher than normal disease-fighting white blood cells in the body. Symptoms of tropical pulmonary eosinophilia syndrome include cough, shortness of breath, and wheezing. The eosinophilia is often accompanied by high levels of Immunoglobulin E ( IgE) and antifilarial antibodies.
- 47. Prevention and control The best way to prevent lymphatic filariasis is to avoid mosquito bites. The mosquitoes that carry the microscopic worms usually bite between the hours of dusk and dawn . If you live in an area with lymphatic filariasis: Sleep in an air-conditioned room or Sleep under a mosquito net Wear long sleeves and trousers and Use mosquito repellent on exposed skin.
- 48. THANK YOU