(LE4) Protozoan Pathogens Flashcards
(10 cards)
What kingdom are protozoans in?
Protista
Describe the lifecycle of protozoans
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Pathogen: Amoebic dysentery
Pathogen: Entamoeba histolytica (sarcodina)
MOT: Oral-fecal transmission (Cyst ingested)
S/S: Diarrhea (often bloody) with mucus due to SI lining damage
Tx: Flagyl
ETC: - outbreaks in wars or natural disasters
- Dx: fecal sample required
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Giardiasis, “Backpackers disease”
Pathogen: Giardia lamblia (flagellate)
MOT: fecal-oral transmission (fresh water), People, Cow, beavers
S/S: Watery-diarrhea (no blood)
Tx: Flagyl
ETC: Cyst survives boiling and chlorination. Requires filter
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Balantidiasis (rare form of dysentery)
Pathogen: Balantidium coli (ciliaphora)
MOT: Fecal-oral transmission
S/S: bloody diarrhea (not as severe as Entamoeba)
Tx: Flagyl
ETC: Only ciliated human pathogen
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Toxoplasmosis
Pathogen: Toxoplasma gondii (apicomplexa; gliding motion)
MOT: Direct contact (improper handling of cat feces), contaminated undercooked beef
S/S: Asymptomatic unless immunocompromised
Tx: Flagyl in combination with other drugs
ETC: can cross placenta and cause infant mortality
- Definite host: cat (sexual reproduction)
- Intermediate host: mouse
- accidental host: humans and cows (no reproduction, end point)
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: African sleeping sickness
Pathogen: Trypanosoma brucei (hemoflagellate; moves with undulating membrane)
- Subspecies: gambiense - W. Africa ( chronic form 1-5 yrs, rare fatality)
rhodiense - E. Africa (acute form 1-3 mo, higher severity and fatality)
MOT: vector-borne( Tsetse fly)
S/S: can cross BBB, confusion, fatigue, coma, death
Tx: no effective treatment. Highly toxic, cross BBB. given last resort
ETC: - Reservoir: large mammals
- lives and divides in blood
- epimastigote: multiplies asexually in intermediate host
- trypomastigote: multiplies sexually in definite host (humans)
- Antigenic variation: change protein (antigen) expression on cell surface allows it to survive in blood
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Chagas disease, “South American sleeping sickness”
Pathogen: Trypanosoma cruzi (hemoflagellate)
MOT: Vectorborne (Reduviid bug; found in thatch rooftops and adobe houses)
S/S: - chagoma: swollen eye at bite site
- chronic digestive and heart symptoms.
- mega-disease
- ineffective cardiac muscle cells and smooth cells
Tx: none. Preventative: vector control
ETC: Dx: - antibody tests (previously xenodiagnosis)
- trypomastigote is infective stage
- no replication in blood
- no antigenic variation
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Malaria
Pathogen: Plasmodium (apicomplexa; gliding motion): 1. P. vivax (milder, chronic)
2. P. falciparum (acute, fatal)
MOT: vectorborne (female anopheles mosquito in tropical areas)
S/S: Cyclical. Anemia, chills, nausea, vomiting, headaches, spiking fever, diaphoresis. High fever can cause seizures. 2-3 days
Tx: - chloroquine.
- Prevention: vector control. Malaria vaccine for children
Describe the Plasmodium lifecycle
Life cycle: Mosquito saliva infective stage delivers sporozite->enters liver, asexual reproduction-> released as merozites -> enters RBC -> ring stage-> asexual reproduction becomes schizont -> RBC ruptures and release gametes
