Trichocephalus and Enterobius PDF

# Enterobius and Trichocephalus ## Enterobius vermicularis (PIN WORM) (الدوده الدبوسيه) - Enterobius vermicularis is a small white worm. - The worm causes enterobiasis. - Infection is common in children. ### Morphology - Small thread-like worm, whitish in color - 2 alae at the anterior end...

# Enterobius and Trichocephalus ## Enterobius vermicularis (PIN WORM) (الدوده الدبوسيه) - Enterobius vermicularis is a small white worm. - The worm causes enterobiasis. - Infection is common in children. ### Morphology - Small thread-like worm, whitish in color - 2 alae at the anterior end - Double bulbed esophagus - **Male** 2-5mm - Curved posterior end - With one spicule - **Female** 10mm - Pointed tail, 2 uteri full with eggs. ### Life Cycle - The adult worm lives in the large intestine. - After fertilization, the male dies and the female moves out through the anus to glue its eggs on the peri-anal skin. - This takes place by night. - The egg is 50x25 microns, plano-convex and contains larva. - Eggs become mature and infective in few hours. - When the eggs are swallowed, they hatch in the small intestine and the larvae migrate to the large intestine to become adult. ### Mode of Infection in Enterobiasis - Ingestion of eggs by: - Autoinfection (hand to mouth) - Contaminated food or drink - Handling contaminated linen, clothing and articles - Air-born in dust - Retro-infection ### Infective Stage - Infection is by ingestion of eggs containing larvae with contaminated raw vegetables. - **Mode of Infection:** Ingestion of eggs by: - Autoinfection (hand to mouth) - Contaminated food or drink - Handling contaminated linen, الملايات clothing and articles. - Air-born in dust ### Enterobius vermicularis → Enterobiasis - **Geographical Distribution:** cosmopolitan - **Definitive Host:** man only - **Habitat:** caecum and adjacent parts - **Diagnostic Stage:** egg - S: 50 Χ 20 μ - S: plano-convex, has 2 layers, covered with outer sticky albuminous layer - C: translucent - C: rhabditiform larva - Eggs are found mainly on perianal skin. ### Pathogenesis and Clinical Picture - **Sticky egg laid in the perianal region at night causes:** - Pruritis ani (Perianal itching). - **Pruritis ani leads to:** - Nervous irritability, Hyperactivity - Insomnia (أرق بالليل) ### Diagnosis - **Clinically:** pruritus ani at night - **Laboratory:** - Swabbing of perianal area to detect the eggs by - NIH swab - Scotch adhesive tape - Adults may be seen in stool or anal area. - Eggs are rarely found in stool ### N.I.H. swab - The perianal area is swabbed in the morning before defecation with a cellophane paper tied to the tip of glass rod and inserted in a test tube. - The cellophane is stretched on the slide and examined for eggs. ### Eggs in stool - Examination of the stool to detect the egg (positive in about 5% of cases because the eggs are glued to the peri-anal skin). - Adults may be seen in stool. ### Treatment - **Albendazole** - It should be repeated after 2 weeks. - **All members of the family should be simultaneously treated (في نفس الوقت)**. - **Application of white mercury oxide (white precipitate ointment) around the anus at night.** - Relieves itching, kills female worms coming out of the anus and prevents dispersal تبعثر of eggs. ### Prevention and Control - Mass treatment - Personal hygiene and food protection - Infected children should use tightly fitting trousers at night. ## Trichocephalus trichiuris (WHIP WORM) (الدوده الكرباجيه) - The worm is divided into a thin whip-like anterior part measuring 3/5 of the worm and a thick posterior part of 2/5 the length. ### Morphology - **Male** 3-4.5 cm in length. Its posterior end is coil. - **Female** 4-5 cm in length. Its posterior end is straight. ### Life Cycle - Ingested eggs hatch in the small intestine and the larvae migrate to the large intestine to become adult. - After mating, the female lays immature eggs, which pass with the stool to the soil and mature in 2 weeks. ### Infective Stage and Mode of Infection - Infection is by ingestion of eggs containing larvae with contaminated raw vegetables. ### Symptoms - The patient complains of dysentery (blood and mucus in stool together with tenesmus). - Rectal prolapse is also possible. ### Diagnosis - Finding of characteristic eggs: - The egg of trichuris is barrel-shaped - 50x25 microns. - The shell is thick with a one mucoid plug at each pole. - Treatment: Mebendazole. # Thank You