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.

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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.

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• It has been estimated that more than 50% of all living plants and animals are parasitic at some stage during their life cycle.

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Introduction to Parasitology

• In this course we will concentrate on 3 major groups of parasites:

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1. Protozoa- flagellates, amebas, malarial organisms

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

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3. Arthropods - insects and arachnids that are ectoparasites and carriers (vectors) of diseases

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Protozoa!

Helminths!

Arthropods!

Why do we study parasites?

• Parasites provide unique examples of biological phenomena not found in free-living organisms.

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Why do we study parasites?

• Parasites provide unique examples of biological phenomena not found in free-living organisms.
• Medical Importance

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Why do we study parasites?

• Parasites provide unique examples of biological phenomena not found in free-living organisms.
• Medical Importance
• Veterinary Importance

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Why do we study parasites?

• Parasites provide unique examples of biological phenomena not found in free-living organisms.
• Medical Importance
• Veterinary Importance
• Economic Importance

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Medical Importance of Parasites

• Humans are hosts to many species of parasites.

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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.

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Recent estimates of the number of people infected with parasites in the world are:

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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.

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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.

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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.

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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.

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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.

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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.

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• 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.

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• 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.

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• 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.

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• Cats are infected by many species of protozoans and helminths.