Haematology (Blood borne parasites) Flashcards
What is parasitism?
A form of symbiosis where the parasite benefits form the relationship at the expense of the host
What are the main groups of endoparasites that affect humans?
Protozoa and helminth worms
What is malaria? What is it transmitted by?
- A potentially fatal infectious disease
- May be transmitted by female mosquitoes of the genus Anopheles
Other than through mosquitoes, how may malaria be passed on?
Transfusion
Transplanation of infected bone marrow
Placental transmission (congenital malaria)
Where is malaria common?
Tropical and sub-tropical areas
How many deaths are there each year from malaria?
1-3 million
mainly of yound children in sub-saharan africa
Infection with what parasite causes 80% of cases?
P. falciparum
What is the receptor for P. falciparum?
Glycophorin A/B/C
Describe the process of red cell invasion by malarial merozoite
1) Merozoite in the blood attach to receptors on RBC surface
2) Merozoite re-orientates so that the apical pole is directed towards the RBC surface
3) Tight junction forms between merozoite and RBC surface accompanied by initial deformation of RBC membrane
4) Entry of merozoite coinciding with formation of parasitophorous vacuole
5) Closure of RBC and parasitophorous vacuole membranes
6) Junction between RBC membrane and parasitophorous vacuole severed releasing merozoite into cell where it transforms into young trophozoite
Describe what happens after the merozoite becomes the trophozoite?
- ‘Feeding stage’
- Ingests 80% of haemoglobin and other contents of the RBC
Name some other forms of malaria forming parasites
P. falciparum
P. vivax
P. ovale
P. malariae
What is the incubation period between infection and onset of clinical symptoms for P. flaciparum?
7-14 days
What are the common symptoms in all species?
- Fever
- Sweating
- Headache
- Weakness
- Dizziness
- Nausea
- Anaemia
What are some symptoms unique to P. falciparum?
- Neurological imbalances
- Muscle spasms
- Pulmonary oedema
- Jaundice/liver failure
- Hypoglycemia
- Diarrhoea
- Circulatory collapse
What is a potentially life threatening consequence of malaria?
Haemolytic anaemia