PARASITIC Diseases Lecture(zoonosis) .pptx

**Parasitic Diseases in Community Medicine:** Parasitic diseases significantly impact public health, especially in low-income areas. Community medicine focuses on understanding the epidemiology, prevention, and control of these diseases. Parasitic infections like malaria, schistosomiasis, and intestinal worms thrive in environments with poor sanitation, inadequate water supply, and limited healthcare access. Effective community-based measures include health education, vector control, improving sanitation, and mass drug administration. Emphasizing these approaches helps reduce morbidity, prevent transmission, and improve overall community health.**Diagnosis of Parasitic Diseases:** Diagnosis often involves detecting parasites or their eggs in body samples like blood, stool, or urine. Techniques include microscopy, serological tests, PCR, and imaging.

**Prevention of Parasitic Diseases:** Prevention includes maintaining good hygiene, using insect repellents, drinking safe water, cooking food properly, and using prophylactic medications in high-risk areas. Vaccination is limited but under development for some parasitic infections.

**Control of Parasitic Diseases:** Control efforts focus on reducing vector populations, improving sanitation, promoting health education, and mass drug administration programs to treat and reduce transmission in endemic areas.

1. DR HALA BASHIR HASHMI COMMUNITY MEDICINE

2. PARASITIC ZOONOSIS

3. parasitology It is branch of biology concerned with the phenomenon of dependence of one living organism on another. It’s study of parasites, their hosts, and the relationship between them.

4. parasite lives on or in its host, which is usually a larger organism, that provides physical protection and nourishment. An organism that has sustained contact with another organism to the detriment to the host organism.

5. host An organism from which a parasite obtains its nutrition and/or shelter. Intermediate host- is used normally by a parasite in the course of its life cycle and it which it may multiply asexually and but not sexually Definitive host- is the host in which the sexual reproduction of parasite takes place. Reservoir host- is an organism in which a parasite that is pathogenic for some other species, lives and multiplies usually without damaging its host.

6. vectors Hosts that transmits parasites to man. BIOLOGIC VECTORS -- those that are essential in the life cycle. PHORETIC OR MECHNICAL VECTORS --Those that are not essential in the life cycle.

7. Taeniasis I mportant zoonotic disease caused by Taenia saginata and Taenia solium . They are found in intestine of human host. They pass through two distinct phases in two different hosts to complete their development cycles. Eggs passed in the feces of the human carriers can cause further disease if ingested by cattle, pigs, or human and develop.

8. epidemiology  1. Taenia  Saginata :- This parasite is found all over the world, where beaf is eaten. In European countries, it is found in 0.3 to 0.4 percent of slaughtered animals. • 2. Taenia solium :- T. solium infection is reported to be endemic in many countries of the latin America, Africa and Asia as well as in some parts of Europe and It is endemic in india .

9. host   T.Saginata and T.solium pass through two distinct phases in two different hosts known as definite host which is man and intermediate hosts. • Cattle is the intermediate host for the larval stage of T.Saginata where as pig is the main host(intermediate host) for the larval stage of T.solium • The Adult T.saginata measues 5-12 metres in length and T.solium measures 2-6 metres . • The adult stages of T. saginata and T.solium may persists for several years in infected humans.

10. Mode of transmission  Through ingestion of infective cysticerci in undercooked beef ( T.saginata ) or pork ( T.Solium ). • Through ingestion of food, water or vegetables contaminated with eggs of the worm. Infection can also occur between individuals through contaminated hands.

11. Life cycle

12. Incubation period • 8-14 weeks Clinical Features: • In the vast majority of cases, no symptoms are seen. • Abdominal discomfort, anorexia, vomiting and chronic indigestion occur occasionally. • Appendicitis or cholangitis due to straying proglottids. • Cysticercosis may occur due to T.solium infection. In this case, brain may be involved causing cerebral damage and epilepsy.

13. complications Human cysticercosis Human infection occurs due to ingestion of eggs of T. solium in contaminated water or food or regurgitation of eggs from the small intestine. . The eggs disintegrate and the infective stage leave the intestine via the hepatic portal system and reach the different parts of the body where there develop to form cysticerci . Cysticerci which develop in the brain is a serious threat to the individual and the community health. As a result of mechanical pressure, obstruction or inflammation, they produce the following conditions: 1. Epilepsy 2. Intracranial hypertensive syndrome 3. Hydrocephalus 4.Psychiatric diseases or death.

14. Preventive measures • Thorough inspection of meat and pork in the slaughter houses by the veterinary surgeon. proper housing and feeding of pigs also help to control T.solium . • Adequate sewage treatment and safe disposal of excreta. • Thorough cooking of meat( beaf ) and pork is the most effective method of prevention of food- brone diseases.

15. Health education • regarding strict personal hygiene, thorough hand washing before eating and after using toilet. • regarding prevention of soil, water and food pollution with human feces. Nails must be cut short and kept clean. • Educating the public regarding improving their general living conditios , using sanitary latrines and safe drinking water. • regarding safe treatment of sewage which is used for farming.

16. Control measures • Early detection and treatment of infected person should be carried out with praziquantel and niclosamide . They are safe and effective In more than 90% of patients. • Praziquantel 10mg/kg body weight, a single dose is 99% effective. side effective are minimal at this dose. • Niclosamide 4 tablets(2 grams) single dose is effective in over 90% of cases. • No pre and post purges are used for either drug to tret T.saginata . For T.solium , moderate purgative 2-3 hours after the drug is given to rapidly eliminate the segments and eggs from the bowels. • Surgical removal of symptom-producing cysts are removed.

17. Treatment • It depends upon the number and location of cysts and their viability. • Albendazole and praziquantel are both effective in the treatment. • Albendazole is the drug of choice and if co- administered with a steroid, it results in increased absorption of albendazole. • These drugs are given with fatty meals to increase their absorption.

18. ascaris

19. ASCARIASIS

20. Ascaris Geographic Distribution The most common human helminthic infection. Worldwide distribution. Highest prevalence in tropical and subtropical regions, and areas with inadequate sanitation.

21. INFECTION TO MAN It occurs when the man swallows the infective eggs of Ascaris with contaminated food or water. Symptoms of Ascariasis No symptoms Stage 1: worm larvae in the bowels attach to bowel walls Stage 2: worm larvae migrate into the lungs: Fever and breathing difficulty Coughing and pneumonia Stage 3: worms enter the small intestine and mature into worms and remain there to feed Abdominal symptoms , Abdominal discomfort , Intestinal blockage - may be partial or complete , Partial intestinal blockage ,Total intestinal blockage ,Severe abdominal pain , Vomiting , Restlessness , Disturbed sleep , Worm in stool ,Worm in vomit

22. Treatment Infections with A.lumbricoides are easily treated with a number of anthelmintic drugs: pyrantel pamoate given as a single dose of 10 mg/kg. levamisole given as a single dose of 2.5 mg/kg. mebendazole given as a single dose of 500 mg. albendazole given as a single dose of 400 mg.

23. prevention Keeping good sanitation conditions is the only way to prevent the infection of Ascaris. Pollution of soil with human faeces should be avoided. Vegetable should be thoroughly washed in a mild solution of Pottasium permanganate and properly cooked before use. Finger nails should be regularly cut to avoid the collection of dirt and eggs below them. Hands should be properly washed with some antiseptic soap before touching edibles or eating.

24. HOOKWORM ETIOLOGY • Hookworms are intestinal ,blood feeding, parasitic roundworms that cause infections known as Helminthiases • In humans hook worm infection caused by two main species of round worm belonging to Ancylostoma duodenale and Necator americanus • In other animals the main parasites are species of ancylostoma brazilience and ancylostoma tubaeforme • Wild cats are infected by ancylostoma pluridentatum • Dogs are commlonly infected by ancylostoma caninum

25. EPIDEMIOLOGY • Three conditions are important for transmission: 1) Human fecal contamination of soil 2) Favorable soil conditions for larva survival( moisture, warmth, shade) 3) Contact of human skin with contaminated soil

26. lifecycle • The host is infected by larva not by eggs and usual route is skin • Hookworm need moist soil, above 18c ,in order to hatch, they die if exposed to direct sunlight or if they become dry • First stage larva [L1]are noninfective ,feed on soil microorganism until they moult into second stage larva[L2] • First and second stage larva are in rhabditiform stage • After feeding for seven days they moult into Third stage larva[L3]known as filariform stage .This is nonfeeding ,infective stage`

27. Common route of passage of larva is skin of bare foot walkers • Once larva entered the host they travel in circulatory system to lungs , where they leave venules and enter alveoli • Then they travel up trachea where they are coughed up, swallowed and end up in small intestine • In small intestine, larva moult into stage 4 adult worm • It takes from 5-9 weeks from penetration to maturity in intestine • Worms need 5-7 weeks to reach maturity and symptoms of infection

28. Clinical features • They lead to combination of intestinal inflammation and progressive iron deficiency anemia and protein deficiency • Pulmonary manifestations: Cough, chest pain, pharyngeal irriation , wheezing, fever result from severe infection • GIT manifestations: Epigastric pain, indigestion, nausea, vomiting, constipation, diarrhea, flatulence can occur in later stages • Signs if advanced severe infection are protein deficiency anemia, cardiac failure, abdominal distension with ascites

29. diagnosis Microscopic examination of stools with standard technique called KATO KATZ technique • Classification can be performed based on buccal cavity, space between oral opening and esophagus: Hookworm rhabditiform larvae have long buccal cavities • Whereas strongyloides rhabditiform larvae have short buccal cavities • Blood analysis shows eosinophilia(1350-3828 cells/ microL ) • Recent research has focused on development of DNA based tools for diagnosis of infection • PCR assays could serve as a molecular approach for accurate diagnosis of hookworm in the feces

30. TREATMENT • Anthelminthic drugs: benzimidazoles ( albendazole 400mg once on empty stomach, mebendazole 100mg 2 times for 3 days) • In some cases, levamisole and pyrantel pamoate(11mg/kg/day for 3 days) may be used • Efficacy of single dose treatment for hookworm infections is 72% for albendazole, 15% for mebendazole, 31% for pyrantel pamoate • World Health Organization does recommend anthelmintic treatment in pregnant women after the first trimester. • It is also recommended that if the patient also suffers from anemia that ferrous sulfate (200 mg) be administered three times daily at the same time as anthelmintic treatment; this should be continued until hemoglobin values return to normal which could take up to 3 months. • Hookworm infection can be treated with local cryotherapy when the hookworm is still in the skin. • Triple therapy with albendazole 400mg, pyrantel pamoate 200mg/kg and oxantel pamoate 20mg/kg showed cure rate of 84% when compared with other combinations

31. prevention • Do not walk barefoot in known infected areas • Do not use raw sewage as fertilizer in agriculture • Do not defecate in open but rather in toilets • School-based mass deworming • Public health education • Sanitation

32. HYDATED DISEASE

33. “drop of water” Echinococcus: “hedgehog” . Hydated disease (one of the oldest disease) know to mainkind , is a parasitic infestation caused by tapeworm of genus Echinococcus. It was first described in th talmud as a “Bladder full of water”. Hippocrates described the hydated disease more then two thousand years ago with a very intresting expression “Liver filled with water”

34. EPIDEMIOLOGY Genus Echinococcus 4 species : E.granulosus -The most commonest cuases “cystic” hydated diseaase . E.multilocularis -most virulant causes alveolar disease. E.vogeli & oligarthus -the polycystic echinococcosis. E.granulosa is present worldwide (more common in sheep and cattle raising countries) including Pakistan and India. E.multilocularis the alveolar form common in central and northern Europe, north America and Asia E.vogeli and oligarthus in central and south America.  Approximately 1.4 million are affected annually.  In 1990 ,2000 deaths were reported  2010, 1200 deaths reported.

35. Organs affected Liver:52-75% Lungs:10-30% Abd cavity:8% Kidneys:7% CNS: less then 2% , Bones:1-2%

36. hosts Definitive host : dogs Intermediate host : Seep, cattle. Human is accidental and dead end host E.Granulosus Dogs and other Canidae Sheep, goat, cattle, camel, buffalos, kangaroos and other wild herbivores E.Multilocularis (Small fox echinococcosis) Foxes, dogs and cats Small rodents (Mice, rats , squirrals , rabbits.) E.Vogeli and oligarthus Bush Dogs and dogs Small rodents

37. Life cycle Adult warm resides in the small intestine of definitive host, eggs are produced by the gravid proglottids which are released in feces, being ingested by intermediate host or incidental host like human. The egg hatches in small intestine and releases oncosphere (embryo with 6 suckers) which penetrate intestinal wall and reach diff organs like liver through blood stream and develops into cyst.  The cyst enlarges creating many protocolizes and daughter cyst within cyst. The cyst containing organs are then ingested by the definitive host and and the cycle restarts.  In case of human the eggs are ingested accidently in vegetables berries and soil.

38. Clinical features In case of liver hydated cyst it can be asymptomatic or patient can present with abdominal pain, dyspepsia, vomiting, fever and jaundice.  Frequent sign is hepatomegaly/palpable mass.  Bacterial superinfection can cause pyogenic abscess.  Rupture can occur into biliary tree.  Free rupture into body either spontaneously or during surgery can cause fatal anaphylactic reaction, fever, pruritis , oedema, dyspnea and stridor.  Incase of lung it can cause cough, SOB and chest pain and mass effect.

39. TREATMENT Albendazole 10-15mg/kg/day or 400mg twise daily for adults given in cycles of 28 days with 2 weeks treatment free period. Schedules 1. Inoperable cases- 3 cycles 2. Pre operative cases- 6 weeks continues to reduce risk of recurrence 3. Post operative cases- 3 cycles to reduce recurrence incase of intra operative spillage of cyst contents.

40. Preventions.  Keep dogs away from eating infected feces and contaminated meat.  Keep yourself away from eating raw offal and food or substances infected with dogs feces.