Flashcards in Lecture 18 Deck (95)
What type of organism are parasites?
eukaryotic organisms- animal cells
WHat is medical parasitology?
deals with eukaryotic organisms that cause disease among humans
Define protozoa and metazoa
What are multicellular parasites known as
What are the types of protozoa?
intestinal, urogenital, blood and tissue
What is Entamoeba Histolytica
Type of intestinal protozoa- known as ameba. Causes amoebic dysentry and liver abscess in humans
Who is the reservoir in Entamoeba Histolytica?
2 forms of Entamoeba Histolytica
vegetative form and durable form
What is the vegetative form?
active and motile- known as trophozoit- multiplies inside host
What is the durable form?
cyst- non motile and survive in environment for a few months
Where is vegetative form seen?
in intestinal, extra intestinal lesions and in diarrheal stool
Where is cystic form seen?
in non-diarrheal stool
Pathogenesis of Entamoeba Histolytica?
disease acquired by ingestion of cyst- oral/fecal route- contaminated food and water
Pathology of cyst
differentiate in ileum and tend to colonize in caecum and colon
Pathology of trophozoite?
invade colonic epithelium- secrete proteolytic enzyme that cause localized necrosis- little inflammation occurs
Is Entamoeba Histolytica world wide in distribution?
Clinical manifestations of Entamoeba Histolytica
acute infection- dysentery, low abdominal discomfort, flatulence, tenesmus
chronic- occasional diarrhea, weight loss and fatigue
Define Amoebic liver abscess
Rt upper quadrant pain, weight loss, fever and tender enlarged liver
What happens if right lobe liver abscess bursts?
invade lung through diaphragm, causing lung abscess, anchovy sauce like pus
Diagnosis of Entamoeba Histolytica
stool examination may show cyst and vegetative forms- trophozoit contains ingested RBCs
Treatment for Entamoeba Histolytica
intestinal amoebiasis and liver abscess- Metronidazol/Tinidazol
Prevention of Entamoeba Histolytica
proper disposal of night soil/sanitation
Define Giardia lamblia
pear shaped trophozoit with 2 nuclei and 4 pairs of flagellum- suction disc which attaches to cell wall- cyst has 4 nuclei
Transmission of Giardia lamblia
ingestions- oral fecal route
What does Giardia lamblia cause?
excystation in duodenum, inflammation and mal absorption of protein + fat
What are the reservoirs for Giardia lamblia
human and animal - pass cyst in stool
Clinical features of Giardia lamblia
non bloody, foul smelling, diarrhea, nausea, anorexia, abdominal cramps, persists for week/months, no fever
Treatment for Giardia lamblia
Define Trichomonas vaginalis
Pear shaped trophozoit with single nuclei, 4 flagellum + undulating membrane