Protozoa and helminths

• What are protozoa?

  Eukaryotes
• What is the size range of protozoa?

  2-100 micrometres
• What is a characteristic of most protozoa?

  Most are free-living
• Where are protozoa prevalent?

  In subtropical regions
• How do protozoa infect tissues or organs?

  As intracellular parasites
• Where can protozoa act as extracellular parasites?

  In blood, intestines, urogenital system
• How are protozoa transmitted?

  By a vector or contaminated resources
• What causes malaria?

  Protozoa like Plasmodium
• What is a common vector for malaria transmission?

  Mosquitos
• What are some sources of contamination for protozoa?

  Water, soil, and food
• What are characteristic features of a protozoal (amoeba) cell?

  Eukaryotic with a nucleus and organelles
• What is the function of food vacuoles in protozoa?

  Nutrient storage
• What do contractile vacuoles do in protozoa?

  Osmoregulation
• What are pseudopodia used for in protozoa?

  Locomotion and feeding
• How can protozoa be classified?

  Amoebas, flagellates, ciliates, apicomplexa
• What is the most dangerous species of malaria-causing protozoa?

  Plasmodium falciparum
• Where is malaria found at risk?

  In tropical areas of Africa, Asia, South America
• What percentage of the world population is at risk for malaria?

  40%
• What percentage of malaria deaths occur in Africa?

  90%
• What has contributed to the decrease in malaria deaths over time?

  Better prevention strategies and new drugs
• What is chemoprophylaxis?

  Medications taken before exposure
• What are helminths?

  Worms that can be parasitic
• What are the features of helminths?

  Multicellular with differentiated organs
• What are the three main classes of helminths?

  Nematodes, cestodes, trematodes
• How are intestinal nematodes transmitted?

  Fecal-oral and skin penetration
• What is the life cycle of intestinal nematode: Ascariasis?

  Infectious eggs contaminate soil/water/food
• What happens after ingestion of Ascaris eggs?

  Eggs hatch in the small intestine
• Where do larvae migrate after hatching in Ascariasis?

  To the liver, heart, and lungs
• What happens to larvae in the lungs during Ascariasis?

  They cause inflammation and irritation
• What is the maximum intensity of infection in children?

  0-5 years
• What can heavy infection of Ascaris cause?

  Abdominal pain and malnutrition
• What is the life cycle of blood and tissue nematodes: Filariae?

  Infectious larvae enter blood from arthropod feeds
• Where are adult filariae found?

  In tissues or lymphatic system
• What happens to microfilariae after entering the bloodstream?

  They are ingested by arthropods
• What are features of cestodes?

  Infect humans, over 10m in length
• How do humans become primary hosts for cestodes?

  By ingesting a cyst from undercooked meat
• What are features of trematodes?

  Live in tissues for decades, cause damage
• What are the symptoms of snail fever?

  Rash, fever, chills, cough, muscle aches
• How is schistosomiasis primarily transmitted?

  Through infected water
• How are helminths diagnosed?

  By finding larvae or eggs in samples