Waterborne protozoa Flashcards
Giardia lamblia/intestinalis/duodenalis is most common where?
poorer countries
name 2 features of Giardia lamblia
Giardins
Contractile proteins
what is the pathogenesis of Giardia lamblia?
- cause apoptosis
- activate lymphocytes
- cause malabsorption and increased transit in intestine
what type of symptoms does Giardia lamblia cause?
chronic/ persistent symptoms
what was Metronidazole developed as a treatment foir?
treatment of protozoan disease
what can Metronidazole also treat?
bacterial gingivitis ( and now G+ve or G-ve anaerobic)
describe luminal protozoan parasites1
- anaerobic
- no mitochondria
- lack fermentation enzymes
- acquired BACTERIAL GENES for fermentation enzymes
how does Metronidazole work?
- is activated in the presence of POR protein
- antimicrobial effect—> breaks strands of DNA
where is Cryptosporidium commonly found (env)?
lakes, rivers contaminated with sewage and animal faeces
where do Cryptosporium mature?
exocytoplasmic vacuoles
what are 3 possibilities for the pathogenicity mechanism for Cryptosporidosis?
- impaired Na+ and H2O abs?
- inc Cl- secretion
- induction of host cell apoptosis
who does Cryptosporidosis mainly affect?
what does it cause?
associated with what?
- children (1st year of life) in developing countries
- causes diarrhoea
- associated with malnutrition
if the host is immunocompromised, what can it Cryptosporidosis cause?
SEVERE diarrhoea—> severe dehydration and weigh loss
what are the 4 variants of Cryptosporidosis disease?
1 acute
2 chronic
3 intermittent
4 transient
if the host is immunocompetent in Cryptosporidosis, what is the treatment?
how long does illness last?
fluid and electrolyte replacement
illness lasts 1-2 weeks (self lim)
if the host is immunocompromised, what is the treatment?
- no targeted treatment
- VIGOROUS rehydration
- anti-diarrhoeal drugs
Hygiene: handwashing
Cyclospora cayetanesis causes what? what are the differences comp[ared to Cryptosporidosis?
‘big Cryptosporidium’
- 40 day duration w/ relapses
- TROPICS (but becoming more prevalent worldwide)
- seasonal occurrence (esp summer months)
Acanthamoeba Keratitis is caused by?
A.polyphaga and A.castellanii
what does Acanthamoeba Keratitis cause?
Keratisis- inflammation of the cornea
who does Acanthamoeba Keratitis affect? who is at risk?
contact lens wearers
Risk factors: swimming in pools/lakes/sea while wearing contact lenses
- storage of contact lenses in home made solutions
- poor contact lens hygiene
what are the symptoms of Acanthamoeba Keratitis infection?
- severe pain
- redness
- scant discharge
OF EYE
severe: severe loss of vision
more severely, what can Acanthamoeba Keratitis cause?
granulomatous encephalitis
due to proximity of brain to the eyes
how is Acanthamoeba Keratitis treated?
how long for?
- multiple antimicrobials
- req hospitalisation
if SEVERE corneal scarring—> CORNEAL transplantation - treatment can last more than a year
