[DISCUSSION] MODULE 3 UNIT 2 AND UNIT 3 Flashcards
The phylum Nematoda is divided into classes based on the presence or absence of “(?)’, which are caudal chemoreceptors.
phasmids
The two (2) classes were earlier called Aphasmidia and Phasmidia, but now have been renamed as (?), respectively.
Adenophorea and Secernentea
The origin of the name (Gr. trichos = hair + oura = the tail), is not quite correct because it is the (?) of the worm that is hair-like and not the tail.
anterior end
Whipworm
A. Trichuris trichiura
Infection is caused by ingestion of embryonated eggs.
A. Trichuris trichiura
Eggs – hatch in the small intestine.
A. Trichuris trichiura
larvae (L1) – released and penetrate the intestinal villi and undergo 4 molts in 3-10 days.
A. Trichuris trichiura
young adult – passively migrate to the cecum (also in the ascending colon) and mature in about 2-3 months
A. Trichuris trichiura
usually asymptomatic, except in heavy infection
Trichuriasis
Heavily infected individuals - those with a high worm burden (greater than 200 worms, >5,000 EPG)- are most likely to
develop clinical disease.
Trichuriasis
hypochromic, microcytic type
Iron-deficiency anemia
results from chronic blood loss at the attachment site coupled with the long life span of the worms
Iron-deficiency anemia
Small amounts of blood (0.005 ml per worm) are lost each day at the ulceration in the intestinal mucosa
Iron-deficiency anemia
worm may be found even up to the rectum in heavy infection
Rectal prolapse
mucosa of the rectum protrudes through the anal opening associated with the loss of muscle tone of the anus
Rectal prolapse
Children with severe trichuriasis have:
o growth retardation
o impaired mental development
o cognitive function
Sever Trichuriasis
Pudoc worm
B. Capillaria philippinensis
In 1967, an epidemic of Capillariasis took place in
Pudoc West, Tagudin, Ilocos Sur
B. Capillaria philippinensis
Infection is caused by ingestion of larvae in raw or
undercooked infected fish
B. Capillaria philippinensis
larvae - develop into adults in the small intestine
(jejenum) where they burrow into the mucosa
B. Capillaria philippinensis
Female worms - may produce two types of eggs:
o Unembryonated shelled eggs –
passed in the feces
o Embryonated eggs – hatches
within human host
B. Capillaria philippinensis
larvae - will re-invade and cause autoinfection.
B. Capillaria philippinensis
unembryonated eggs - ingested by fish when
passed into water.
B. Capillaria philippinensis
malabsorption syndrome with severe diarrhea
Intestinal capillariasis