Parasitology Exam 2

In people, most species of trematodes occur in habitats other than the intestine. Name three of these other habitats and (1) list a trematode species that lives there. For each of the species named, (2) explain how their eggs escape from the human host, and (3) describe the consequences to the host of the escape.

In people, most species of trematodes occur in habitats other than the intestine. Name three of these other habitats and (1) list a trematode species that lives there. For each of the species named, (2) explain how their eggs escape from the human host, and (3) describe the consequences to the host of the escape.

Liver: Fasciola hepatica; eggs are released in feces; no consequence of eggs escaping Blood vessels: Schistosoma mansoni; eggs burrow their way through tissue to the s. intestine to then be released in feces; granuloma forms around eggs and general tissue damage Lungs: Paragonimus westermani; eggs are coughed up and either spit out or swallowed; fibrosis around egg (damage to lung tissues)

The photograph below shows two males one 13 and one 24 years old. One of them is infected with a species of parasite and the other is not. The caption below (not shown) refers to stunting of growth due to a parasitic disease.

caused by Schistosoma japonicum anterior mesentenic veins of small intestine interfere with absorption

The cartoon below is amusing but biologically it is inaccurate in several regards. From a parasitological point of view what are at least three flaws?

1. tapeworms are segmented

2. tapeworms generally stay in the small intestine

3. tapeworm offspring do not stay in the same individual, they are released as eggs in either proglottids or in the feces

The photograph below represents a woman from Kenya infected with a parasite. Based on her condition in the photograph, what are (1) two likely species of parasites and (2) their ontogenetic stages that she may be infected with? Second how would you (3) diagnose her infection for each of these parasites? Knowing that she is a Turkana woman from a dry part of Kenya (4) which species of the two parasites might you assume she is infected with?

1. Schistosoma mansoni and Echinococcus granulosus

2. infected with adults laying eggs; hydatid cyst continuous growth

3. look for eggs in feces; physical imaging or serodiagonosis

4. Schistosoma mansoni

An ontogenetic stage of a cyclophyllidean tapeworm that would be found in an intermediate host

ooncosphere or hydatid cyst

An ontogenetic stage of a cyclophyllidean tapeworm that would be infective to a definitive host

hydatid cyst

A genus of the intermediate host for Schistosoma mansoni

Biomphalaria

An ontogenetic stage of a pseudophyllidean tapeworm that hatches from an egg

coracidium

An organism from which people could acquire the infective stage of Fasciola heatica

aquatic grasses (uncooked infected watercrest)

The ontogenetic stage of Paragonimus westermani infective to people

metacercaria

what is the larval stage and potential species?

Spirometra mansonoides, plerocercoid

what is the larval stage and potential species?

Taenia solium, cysticercus

what is the larval stage and potential species?

Echinococcus granulosus, hydatid cyst

what is the larval stage and potential species?

Echinococcus multiocularis, alveolar hydatid cyst