Parasites Protista Kingdom

							                                                                                                  Parasites

                                         Protista Kingdom                                                                                                     Animal Kingdom


                                  Protozoa group-microscopic                                                                                              Helminth parasites
                                  singled-celled, Eukaryotic                                                                                              macroscopic, multicellular
                                  organisms                                                                                                               Eukaryotic organisms



   Sarcodina group      Flagellate group       Cilliate group                   Sporozoan group                                    Cestodes                Trematodes                      Nematodes
     Movement:             Movement:              Movement:                       Movement:                                      Tapeworms              Flukes (flat, leaf-                Roundworms
    Pseudo-podia            Flagella                  cilia                      Intracellular                                    (long, flat,               shaped,                (long, thin, unsegmented
                                                                                                                                 segmented)               unsegmented)                      cylindrical)
Entamoeba               Trichomonas              No human       Toxoplasma gondii          Plasmodium falciparum
hystolytica             vaginalis                pathogens      Zoonotic parasite          Disease: Malaria
                                                                                                                             Taenia solium            Schistosoma mansoni         Ascaris lumbricoldes
Protozoan -             Disease: Vaginitis                      Primary reservoir/         Life cycle - 2 hosts needed
                                                                                                                             (pork) & Taenia          Disease: Blood Flukes       Most common world-wide (1
Trophozoites (active    Infects the vaginal                     host - feline family       for survival: mosquitoes
                                                                                                                             saginate (beef)          Obtains nutrients from      billion) Larvae develop in the
feeding stage found     canal                                   (domestic/wild)            (definite host)-animal/host
                                                                                                                             Intestinal parasites -   host through                egg. If swallowed →
in host) alternate      Burning & intense                       Crosses the placenta       that harbors the sexual
                                                                                                                             contain a Scolex -       oral/ventral sucker         (contaminated food/ water)
between trophozoite     itching                                 Disease:                   reproducing stage
                                                                                                                             small organ suckers      Stages: (1) Eggs            → will be released into
& cyst (dormant,        Frothy, foul                            Toxoplasmosis              humans (intermediate host)-
                                                                                                                             or hooks to tissue.      deposited in freshwater     intestine →invade intestine
resistant survival      smelling, greenish                      Contact w/cats,            host that harbors larval or
                                                                                                                             - Proglottids - Body     - hatch, release larvae     wall→enter circ/lymp
body outside the        discharge - also                        infective feces, or        asexual stage.
                                                                                                                             segement grow            (miracidia). (2) Within     systems →goes to lungs →
host)                   infects the urethra                     ingestion of cysts in      All s/sx associated w/parasite
                                                                                                                             continuously behind      24 hours- burrow into       coughed up into trachea/
Disease: Amebic         Primarily - STD,                        animal flesh (cattle/      intracellular stage in the RBC.
                                                                                                                             neck area -remains       snail (3) After 2-3         pharynx and swallowed
Dysentery               survives on fomites                     sheep) AIDS pts can        Massive hemolysis, fever, &
                                                                                                                             attached to the host.    cycles of asexual           →adult in intestines
Bloody and mucus-       (bedding, toilet                        produce extensive          chills. Main sx = paroxysms of
                                                                                                                             Mature producing         reproduction - larvae       Ancylostoma duodenale
filled stools           seats, clothes, etc)                    brain lesions (altered     chills/fever- result of RBC
                                                                                                                             male/female organs.      called Cercariae are        & Necator amercanus
Extraintestinal         Wet mount-live                          mental state/coma),        lysis caused by release of
                                                                                                                             Segments near the        produced (4) Cercariae      Hookworm - Eggs → stool
amebiasis-amebas        flagellate                              heart & lungs.             merozoites when all the
                                                                                                                             end are gravid or full   leave snail - free-         (humans) →soil → hatch.
invade viscera of the   Metronidazole                           Tx: Good hygiene           infected RBC rupture at the
                                                                                                                             or fertilized eggs.      swimming (5) Seek out       Live over 5 wks. Burrows
peritoneal cavity       (Flagyl)                                No vaccine                 same time.
                                                                                                                             Each proglottid is       humans and penetrate        thru skin → circ. sys
                        No immunity                                                        Anopheles (female) mosquito
                                                                                                                             monoecious.              skin (6) Once in definite   →heart/lungs → burrow
                                                                                           bite transmits infective
                                                                                                                             Beef/Swine               host, parasite migrates     thru pulmonary mucosa ↑
                                                                                           sporozoite into human blood.
                                                                                                                             intermediate hosts       to appropriate site &       trachea then swallowed
                                                                                           Dx: Stained Blood smears
                                                                                                                             Some cases may           develop as adults (7)       Enterobius vermicularis
                                                                                           (Giemsa stain)
                                                                                                                             cause nausea,            Adult worms form eggs       Pinworm - human only host -
                                                                                           Tx: Chloroquine for RBC;
                                                                                                                             abdominal pain, wt       that pass into              usually children. Scratching
                                                                                           Primaquine to eliminate
                                                                                                                             loss and diarrhea        environment thru feces      dislodges eggs from anal
                                                                                           parasite
                                                                                                                                                      & urine                     area
                                                                                           Mosquito control