Parasites Chapter 10

Parasitology  Parasites that infect humans have various classifications, characteristics, and life cycles  Parasites are organisms that nourish themselves at the expense of other living things and cause them damage

PROTOZOA  Microscopic, one-celled animals  Ciliophora (Ciliates)  Mastigophora  Sarcodina

Ciliophora (Ciliates)  Protozoa that move by means of many short, hair- like projections  Balantidium coli is the only ciliate parasite harmful to humans  Causes dysentary  Transmitted by feces, fingers, food, fomites, flies

Mastigophora  Also known as flagellates  Move by one or more long, whip-like flagella  Giardia lamblia – most common intestinal parasite in the US  Traveller’s diarrhea  Transmitted by drinking contaminated water

 Trypanosoma rhodesiense  African sleeping sickness  Fever, headaches, joint pains  Most common in Uganda, and Congo  Confusion, disruption of sleep cycle  Fatal if not treated  Mother to Child  Blood transfusion  Sexual Contact  Tsetse fly (large brown biting fly) Mastigophora

 Trypanosoma cruzi  Chagas’ disease  Fever, fatigue, body aches, headache, rash, diarrhea, vomiting  Swelling of eyelids on the side of the face near the bite wound  % will never develop symptoms  20-40% will develop life-threatening heart and/or digestive disorders Mastigophora

 Trichomonas vaginalis  Most common pathogenic protozoan infection of humans in industrialized countries  Infection rates between men and women are the same with women showing symptoms while men are usually asymptomatic  WHO estimates 180 million cases annually  North America = 5-8 million infections each year

Trichomonas vaginalis  Sexually transmitted in the urogential tract  Most common site of infection is the urethra and the vagina in women  Complications include pregnancy complications (preterm delivery, low birth weight, increased mortality) cervical cancer, pneumonia, bronchitis, and increased secretions, and itching

Sarcodina  Also known as amoebas  Move by extending cytoplasmic projections  Reproduces by fission

Sarcodina  Entamoeba histolytica  Causes dysentery in humans  Can invade the liver and cause hepatitis

 Parasitic worms that include  Cestodes (flatworms)  Nematodes (roundworms)  Trematodes (flukes) Helminthes

Nematodes  Roundworms  Hookworms  Pinworms  Whipworms  Distributed worldwide, found mostly in children

Cestodes  Flatworms  Taenia saginata (beef) tapeworm  Taenia solium (pork) tapeworm  Cause intestinal disorders and severe weight loss  Can grow up to 20 meters 28 foot tapeworm taken from person (transmitted by sushi)

Trematodes  Flukes, flat leaf-shaped helminths  Can inhabit the intestine, the liver, the lung, and the blood vessels  Chronic diarrhea  Abdominal pain  Ulcers  Hemorrhage of the intestinal wall  Liver damage  Transmitted  Drinking infected water  Eating infected raw meat or shellfish

Arthropods  Insects (flies, mosquitoes, lice, fleas, arachnids)  Insects  Pediculus – head lice  Phthirus – sexually transmitted crab lice

Arachnids  Spiders, ticks, and mites  Scabies  Caused by Sarcoptes (Itch mite)  Lyme Disease  Caused by tick

Bacteria is the perhaps the most common and harmful parasite to humans because it can produce disease

Turn to page 188 in textbook  Answer questions numbered: 1-6, 8-9, 13,  Make sure name is on paper and turn into tray when complete