Umm AlQura University Health Sciences College at AlLeith

Objectives 1/ Know of Enterobius vermicularis classification and Geographical distribution. 2/ Study of Enterobius

Morphology • The female worm measures 8 mm x 0. 5 mm; the male

Life cycle 1 - Infection occurs when embryonated eggs are ingested from the environment,

Life cycle • 4 - The gravid females, containing more than 10, 000 eggs

Epidemiology 1 -Enterobiasis is by far the commonest helminthic infection in the US (18

Diagnosis is made by finding the adult worm or eggs in the perianal area,

Treatment and Prevention 1 - Two doses (10 mg/kg; maximum of 1 g each)

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�� Umm Al-Qura University Health Sciences College at Al-Leith Department of Public Health Lecture (7) 1

Enterobius vermicularis (pinworm) 2

Objectives 1/ Know of Enterobius vermicularis classification and Geographical distribution. 2/ Study of Enterobius vermicularis External Morphology , Habitat, Life cycle, Mode of Transmission, Pathogenicity. 3/ Show Symptoms of Enterobiasis disease. 4/ Show Laboratory diagnosis of Enterobius vermicularis. 5/ Know Treatment and prevention. 3

Morphology • The female worm measures 8 mm x 0. 5 mm; the male is smaller. Eggs (60 micrometers x 27 micrometers) are ovoid but asymmetrically flat on one side. • 5

Life cycle 1 - Infection occurs when embryonated eggs are ingested from the environment, with food or by hand to mouth contact. 2 -. The embryonic larvae hatch in the duodenum. 3 - worms descend into lower cecum and colon and live there for 7 to 8 weeks. 9

Life cycle • 4 - The gravid females, containing more than 10, 000 eggs migrate, at night, to the perianal region and deposit their eggs there. • 5 - Eggs mature in an oxygenated and are infectious 3 to 4 hours later. • 6 -. Man-to-man and auto infection are common Man is the only host. 13

Mode of transmition

Epidemiology 1 -Enterobiasis is by far the commonest helminthic infection in the US (18 million cases at any given time). 2 - The worldwide infection is about 210 million. 3 - It is an urban disease of children in crowded environment (schools, day care centers, etc. ). Adults may get it from their children. 21

Diagnosis is made by finding the adult worm or eggs in the perianal area, particularly at night. Scotch tape or a pinworm paddle is used to obtain eggs. 23

Treatment and Prevention 1 - Two doses (10 mg/kg; maximum of 1 g each) of Pyrental Pamoate two weeks apart gives a very high cure rate. 2 - Mebendazole is an alternative. 3 - The whole family should be treated, to avoid reinfection. Bedding and underclothing must be sanitized between the two treatment doses. 4 - Personal cleanliness provides the most effective in prevention. • 27

prevention 28