(LE4) Protozoan Pathogens Flashcards
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
