[PL2.1] Group of Parasites with Medical and Public Health Importance

Kingdom to which protozoa belong

Protista

Phylum that includes Sarcomastigophora, Ciliophora, Apicomplexa, and Microspora

Protozoa

Phylum with subgroups Mastigophora and Sarcodina

Sarcomastigophora

Subgroup under Sarcomastigophora characterized by flagella

Mastigophora

Examples of protozoa with flagella

Giardia, Chilomastix, Trichomonas, Dientamoeba, Trypanosoma, Leishmania

Subgroup under Sarcomastigophora characterized by pseudopodia

Sarcodina

Examples of protozoa with pseudopodia (Amebae)

Entamoeba, Iodamoeba, Acanthamoeba, Naegleria

Subgroup of protozoa that move using cilia

Ciliophora

Example of a ciliated protozoan

Balantidium coli

Phylum of protozoa characterized by an apical complex

Apicomplexa

Group of protozoa under Apicomplexa known as sporozoa

Plasmodia, Babesia, Toxoplasma, Isospora, Cryptosporidium, Cyclospora

Phylum of protozoa that are spore-forming

Microspora

Examples of protozoa under Microspora

Enterocytozoon, Encephalitozoon

Type of cellular organization of protozoa

Unicellular or Multicellular

Main components of protozoa structure

Nucleus/nuclei, cytoplasm, outer limiting membrane, and organelles

Environmental requirement of protozoa for locomotion, osmoregulation, and reproduction

Wet environment

Infective stage of protozoa

Cysts

Vegetative stage of protozoa

Trophozoites

Classification where nematodes belong

Metazoan (Helminths or Arthropods)

Subgroups under helminths

Annelids, Nematodes & Flatworms

Common name for nematodes

Roundworms

Sexual characteristics of nematodes

Have separate sexes (some are parthenogenetic)

Sensory organs found in nematodes

Amphids & Phasmids

Group of nematodes without phasmids

Aphasmid

Examples of aphasmid nematodes

Trichuris, Trichinella & Capillaria

Group of nematodes with phasmids

Phasmid

Examples of phasmid nematodes

Ascaridida, Strongylida, Rhabditida, Oxyurida & Spirurida

Basis for grouping nematodes

Habitat of the adult worms

Nematodes found in the small intestine

Ascaris, Hookworms, Strongyloides & Capillaria

Nematodes found in the colon

Trichuris & Enterobius

Nematodes that affect the lymphatic system

Wuchereria & Brugia

Nematode that affects the eyes and meninges

Angiostrongylus

Nematode that affects the muscles

Trichinella

Mode of Infection

Ingestion of embryonated egg

Skin penetration

Mosquito bite

Ingestion of Infective larva

Autoinfection

Inhalation

Phylum of flatworms including tapeworms

Platyhelminthes

Body structure of cestodes

Segmented with ribbon-like appearance

Digestive and circulatory system of cestodes

Absent

Where the adult tapeworm is found

Intestines of the definitive host

Where the larval stage of tapeworms is found

Encysted in the tissues of the intermediate host

Organ of attachment in tapeworms

Scolex

Orders of cestodes

Pseudophyllidea & Cyclophyllidea

Characteristic of pseudophyllidean worms

Require two intermediate hosts in their life cycle

Examples of pseudophyllidean worms

Diphyllobothrium, Spirometra

First intermediate host stage of pseudophyllidean worms

Procercoid larva

Second intermediate host stage of pseudophyllidean worms

Plerocercoid larva

Order of cestodes that requires only one intermediate host

Cyclophyllidea

Characteristic of larval development in different cyclophyllidean species

Produces different types of encysted larvae in the intermediate host

Encysted larval form of Taenia spp.

Cysticercus

Encysted larval form of Hymenolepis, Dipylidium, and Raillietina

Cysticercoid

Encysted larval form of Echinococcus spp.

Hydatid

Common name for trematodes

Flukes

Body shape and segmentation of trematodes

Leaf-like and unsegmented

Do trematodes have a complete digestive tract?

No, they have an incomplete digestive tract

Do trematodes have a circulatory system?

No

Main organs for attachment in adult trematodes

Oral and ventral suckers (acetabulum)

Additional sucker found in some trematodes

Genital sucker / gonotyl

Sexual characteristic of most trematodes

They are all hermaphroditic

Number of intermediate hosts required in trematode life cycle

Two

Characteristic of trematode eggs

Operculated

Infective stage of most trematodes

Metacercaria

Infective stage of schistosomes

Cercaria

First intermediate host of trematodes

Snails

Possible second intermediate hosts of trematodes

Fish, crustacean, another snail, or freshwater plants

Trematodes grouped by adult habitat

Habitat-based classification

Trematodes that live in blood vessels

Blood flukes (Schistosomes)

Trematodes that inhabit the lungs

Paragonimus (Lung fluke)

Trematodes that inhabit the liver and bile ducts

Fasciola, Clonorchis, and Opisthorchis

Trematodes that inhabit the intestines

Fasciolopsis, Echinostoma, and Heterophyids

Body symmetry of arthropods

Bilaterally symmetrical

Distinctive body structure of arthropods

Segmented body with jointed appendages

Main outer covering of arthropods

Chitinous exoskeleton

Examples of arthropods

Insects, mites, ticks, fleas, spiders, scorpions, centipedes, millipedes, crustaceans

Ways arthropods affect human health

Envenomization through bites

Role of arthropods in disease transmission

They act as biological or mechanical vectors