2/23/99

Public Health

 

Worms

Handout PH17

Table in book, p638

 

Filiaria

·         Wuchereria bancrofti

·         Burgia malayi

·         Blockage of the lymphatic system

·         Enlargement of organs and limbs

·         Transmitted by insects like aides, culex, anophlene (mosquito, blood sucking)

·         Ch 12 in book, life cycle Wuchereria bancrofti p 302

 

Old World Hook Worm

·         Anclostoma duodenale

·         Necator americanus—New World Hook Worm—rhobditiform

·         ground itch found where worm enters, allergic reaction

·         Can penetrate the skin of the feet to become blood borne

·         P 635 in text

·         Carried to heart and lung

·         Swallowed and get to GI tract

·         Leave the body

·         Problem w/blood vasculature

 

Ascaris lumbricoides

·         GI nematode

·         Grows abundantly in GI tract

·         Responsible for physical blockage of GI tract lumen,

·         Persistent constipation

·         Can be removed by surgical means

·         P 635 figure

 

Anisakis species

·         Raw fish

·         Public health block on p635

·         Have pulled out large worm from the esophagus

 

Enterobius vermicularis

·         Pinworm

·         Commonly seen in children

·         Known for conditions known as oxuriases or pinworm infestations or seatworm infestation

·         Ingestion of contaminate food and soil

·         Gives the feeling that someone is sticking you w/a pin

·         Lower GI tract

·         Adult worm gets out at night to lay eggs and then returns to system

·         Eggs released into fecal material

·         Retrofection—adult female getting out and coming back

·         Dx:  scotch tape or swab who have intense itching in perianal area

 

 

Trichinella spiralis

·         Hog feeding on garbage

·         Trichinosis

·         Transmission:  Ingestion of contaminate pork that was not properly cooked

·         Goes to GI tract

·         In GI tract can penetrate gut wall and become blood borne

·         P 634; description and picture of

·         Cyst embedded in muscle

·         Clinically:  depends upon where in the body the cyst develops

·         Can be in heart, kidney, lung

·         Can produce toxin which can be hazardous

·         Freezing of food does not necessarily kill larvae

·         Microwave cooking is safe only if internal temp of meat reaches 77`C

 

Strongyloides stercoralis

·         Thread worm

·         P 637

 

Trichuris trichiura

·         Whip worm

·         Found in cecum

 

Flukes

·         Involve many host

·         Trematodes

·         Snails, human, crab, fish

·         Schistomsoma—blood fluke, most common, several different species

·         Transmitted to humans by penetration of skin by head portion of cercaria (larvae)

·         Life cycle from the book—p 647-8

·         Maturation in lever blood vessels

·         Carried by urine and fecal material

·         Maracidum found in snail, ciliated

·         Oriental countries where they grow rice, it is found where it can penetrate the skin

·         Major disease in the world

·         No hermaphroditic

·         Swimmer’s itch is S. mansoni—allergic reaction at the site where it enters the human system, can be released in bird feces