Hymenolepis diminuta
Anticipatory
Do you know that man can be infected by a rat
tape worm?
Objectives
- To identify parasite shape.
- To describe the path of the parasite in human
body and identify the diagnostic and infective stages.
- To know the pathognomonic symptoms and
signs.
- To diagnose, treat and control this infection.
Habitat
Adult lives in the small intestine of rat, mice and occasionally man (definitive hosts).
Development H. diminuta
- Gravid segments detach and disintegrate liberating eggs that pass with faeces.
- Eggs of the parasite are swallowed by flea larva or grain beetles (intermediate hosts) in which egg hatches, liberating onchosphere which passes to the body cavity where it develops into cysticercoid. Cysticercoid remains alive until the larva metamorphoses into adult flea.
- When man gets infected, the cysticercoids are set free in his small intestine and develop into adult.
Eggs are the diagnostic stage.
Cysticercoid diminuta is the infective stage.
Mode of Infection
Man and other definitive hosts are infected by
ingestion of these infected insect vectors.
Clinical Picture
- Usually asymptomatic.
- Occasionally mild gastrointestinal tract disturbances occur.
Diagnosis
Detection of eggs in faeces.
Treatment
Praziquantel is the drug of choice.
Epidemiology
It is a true zoonosis (an animal disease which transmitted to man), since the source of infection is mainly infected rats.
Prevention and Control
Rodent control.
True-False QuestionState true or false
Man is the main host in Hymenolepis diminuta infection.
True False
Transition
What is the dog tape worm which can affect man?