Medical parasitology is the relationship between humans and the organisms that live in them.


Parasitic diesease:

  • Unlike many bacterial and viral infections, parastic information are often chronic and could last till several years. repeated exposures would result in ever-increasing parasite burden.
  • Many infectious diseases can cause by endogenous organsims which are transmitted through oral ingestion, direct penetration through skin or other surfaces and bites of arthropod vectors.



  • Arthropoda comprises invertebrate animals.
  • Metamorphosis is a process whereby arthropods deveop from an egg to an adult.
  • Arthropods are divded into 2 catogeories; Chilopoda, Pentastomida, Crustacea, Arachnida and Insecta.
  • Two examples of arachnida are Scorpions and Ticks.
  • Another two examples of insecta (hecapods; which constitute the largest and most important of all the classes of arthro) are stinging insects and bugs.



  • Are known as roundworms and are members of the phylum Aschelminthes and the class Nematoda.
  • Cylindrical in shape and covered by a tough outer covering (cuticle).
  • Most of the time, the ova and larvae would be found in feces.
  • Embryos of nematode eggs would be developed if left in room temperature.
  • Intestinal nematodes which infect humans usually have direct lifecycles.
  • Most of the time transferred from person-to-person with no intermediate host needed.
  • Lifecycles comprises of 4 larval stages with 1 adult stage.


  • Members of the phylum Platyhelminthes.
  • Humans can be infected by either the larvae of the adult forms.