Practical Parasitology Lecture (1)

Practical Parasitology Lecture (1) 23/2/2019
Parasitology: is the science that’s study of morphology, taxonomy, life-cycles, pathogenesis, epidemiology, ecology, physiology, biochemistry, genetics and molecular biology, diagnosis, immunology and treatment of parasites infections.
Parasite : is the organism that lives on host with benefits food , habitat and protection.
Host : is the organisms that harmed from the presences of parasite . Relation ships among the organisms are :
1-Parasitism : is the relationship between two organisms one of the organism benefits food and protection(parasite) and the other is harmed (the host) . 2-Commensalism : One organism benefits and the other is unharmed
3- Mutualism: is the relationship between two organisms and both of them are useful .
Types of Parasites:
A-1)Types of Parasites according to the specialization :
1-Obligate Parasite is completely dependent on its host
2-Facultative parasite can exist free living or parasitism.
3- Incidental Parasite is parasite that enter the wrong host .
A-2)Types of Parasites according to the presence period of parasite on a host :
1-Temporary parasite that s only visits host for meals e.g. Ticks 2-Permenet parasite that s completely lives on its host. e g lice 3-Opportunistic parasite that can exists in immunodeficient patient e. g Toxoplasma
A-3)Types of Parasites according to the habitat : 1-Ectoparasite is attached to skin e.g. mites , lice 2-Endoparasite lives inside body of host e.g. worms and protozoa
A-4)Types of Parasites according to the number of hosts which parasite required :
1-Monoxenous parasite : which has one a host )
2-Heteroxenous parasite : which have more than one a host )
B-Types of Hosts: 1-Definitve Host that harbors adult sexually mature stage of the parasites( human , animal) . 2- Intermediate Host: that harbors immature larvae (unsexual). 3-Reservoir Host : that harbors all stages of parasites . 4-Vector host : is the host that transmits parasite from one host to another.
Taxonomy : Parasites of humans are classified in six major divisions. These include the :
1-Protozoa (amebae, flagellates, ciliates, protozoans, coccidian, microsporidia),
2-Nematoda or roundworms.
3-Platyhelminthes or flatworms (Cestodes, Trematodes).
4-Pentastomids or tongue worms (may be grouped with the arthropods), the
5-Acanthocephala or thorny-headed worms.
6-Arthropoda (e.g., insects, spiders, mites, ticks).