Introduction to Parasitology

							    General Parasitology
       Zoology 4104




Matthew Bolek, LSW 415 bolek@okstate.edu
    Introduction to Parasitology
• Each animal is a host of many parasites; thus,
  there are far more parasitic organisms on earth
  than there are nonparasitic organisms.
     Introduction to Parasitology
• Each animal is a host of many parasites; thus, there are
  far more parasitic organisms on earth than there are
  nonparasitic organisms.


• It has been estimated that more than 50% of all
  living plants and animals are parasitic at some
  stage during their life cycle.
    Introduction to Parasitology
• In this course we will concentrate on 3 major
  groups of parasites:

      1. Protozoa- flagellates, amebas, malarial
      organisms

      2. Helminths - parasitic worms such as the flukes,
      tapeworms, and roundworms

      3. Arthropods - insects and arachnids that are
      ectoparasites and carriers (vectors) of diseases
Protozoa!
Helminths!
Arthropods!
 Why do we study parasites?
• Parasites provide unique examples of
  biological phenomena not found in free-
  living organisms.
 Why do we study parasites?
• Parasites provide unique examples of
  biological phenomena not found in free-
  living organisms.
  • Medical Importance
 Why do we study parasites?
• Parasites provide unique examples of
  biological phenomena not found in free-
  living organisms.
  • Medical Importance
  • Veterinary Importance
 Why do we study parasites?
• Parasites provide unique examples of
  biological phenomena not found in free-
  living organisms.
  • Medical Importance
  • Veterinary Importance
  • Economic Importance
Medical Importance of Parasites
• Humans are hosts to many species of
  parasites.
Medical Importance of Parasites
• Humans are hosts to many species of parasites.

• Many of these parasites are causative agents
  of major public health problems of the
  world.
Recent estimates of the number of people
infected with parasites in the world are:
     Ascaris                 1.3 billion
     Hookworms               1.3 billion
     Whipworms               1 billion
     Filarial worms          657 million
     Malaria                 500 million
     Schistosomes            270 million
     Amebiasis               50 million
     Taeniad tapeworms       50 million
     Clonorchis              20 million
     Chagas’ Disease         15 million

These parasites cause untold suffering and death
in the world today.
Examples of Medical Importance
         in the World
 Examples of Medical Importance
          in the World
• The life expectancy of an Egyptian is in the
  mid-40's due to Schistosomes.
 Examples of Medical Importance
          in the World
• The life expectancy of an Egyptian is in the mid-40's
  due to Schistosomes.
• 15 million children in the world will die this
  year from a combination of malnutrition and
  parasites.
 Examples of Medical Importance
          in the World
• The life expectancy of an Egyptian is in the mid-40's
  due to Schistosomes.
• 15 million children in the world will die this year from
  a combination of malnutrition and parasites.
• Over 1 million African children will die this
  year from the effects of malaria.
 Examples of Medical Importance
          in the World
• The life expectancy of an Egyptian is in the mid-40's
  due to Schistosomes.
• 15 million children in the world will die this year from
  a combination of malnutrition and parasites.
• Over 1 million African children will die this year from
  the effects of malaria.
• Many cases of plague, transmitted by
  fleas, still occur throughout the world.
 Examples of Medical Importance
           in the U.S.
• We in the comfort of the U.S. are not
  immune from parasites.
  Common parasitic diseases in the
         U.S. include:




Pinworms   Giardiasis   Dog roundworms   Ticks
  Importation of Parasites from
      Tropics to the U.S.
• Movement of persons from all areas of
  the world have introduced parasitic
  diseases into the U.S.
  Importation of Parasites from
      Tropics to the U.S.
• Movement of persons from all areas of
  the world have introduced parasitic
  diseases into the U.S.
  – Numerous cases of malaria are brought back
    by vacationers from the tropics.
  Importation of Parasites from
      Tropics to the U.S.
• Movement of persons from all areas of
  the world have introduced parasitic
  diseases into the U.S.
  – Numerous cases of malaria are brought back by
    vacationers from the tropics.
  – Service personnel are often employed in
    areas endemic with many parasites.
  Importation of Parasites from
      Tropics to the U.S.
• Movement of persons from all areas of
  the world have introduced parasitic
  diseases into the U.S.
  – Numerous cases of malaria are brought back by
    vacationers from the tropics.
  – Service personnel are often employed in areas
    endemic with many parasites.
  – Many immigrants have brought their
    parasites with them.
Veterinary Importance of
        Parasites
      Veterinary Importance of
              Parasites
• In Africa, cattle cannot be raised in an area
  equal to that of the U.S. due to trypanosoms.
       Veterinary Importance of
               Parasites
• In Africa, cattle cannot be raised in an area equal to
  that of the U.S. due to trypanosoms.


• A poultry farmer can be wiped out by coccidia.
       Veterinary Importance of
               Parasites
• In Africa, cattle cannot be raised in an area equal to
  that of the U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.

• Cattle, pigs, and sheep infected with parasites
  fail to gain weight and may not reproduce.
        Veterinary Importance of
                Parasites
• In Africa, cattle cannot be raised in an area equal to
  that of the U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.
• Cattle, pigs, and sheep infected with parasites fail to
  gain weight and may not reproduce.


• Dogs may become infected with heartworm and
  die if untreated.
         Veterinary Importance of
                 Parasites
• In Africa, cattle cannot be raised in an area equal to that of the
  U.S. due to trypanosoms.
• A poultry farmer can be wiped out by coccidia.
• Cattle, pigs, and sheep infected with parasites fail to gain weight
  and may not reproduce.
• Dogs may become infected with heartworm and die if
  untreated.


• Cats are infected by many species of
  protozoans and helminths.
  Some Veterinary Parasites may
         infect Humans
• Several dog parasites are transmissible to
  humans:
Intestinal roundworm can infect humans
   causing the disease Visceral Larval
                Migrants
  Some Veterinary Parasites may
         infect Humans
• Many species of dog and cat tapeworms can
  infect humans.
  Some Veterinary Parasites may
         infect Humans
• Many species of dog and cat tapeworms can infect
  humans.


• Cattle are infected with Cryptosporidium that
  can contaminate drinking water and infect
  humans.
  Some Veterinary Parasites may
         infect Humans
• Many species of dog and cat tapeworms can infect
  humans.
• Cattle are infected with Cryptosporidium that can
  contaminate drinking water and infect humans.

• Toxoplasma gondii occurs in cats and can cause
  serious congenital infections in humans.