MEDICAL PARASITOLOGY & ENTOMOLOGY Prepared by: Sr. norazsida

CLASSIFICATION OF PARASITES Phylum Sarcomastigophora Phylum Ciliophora Phylum Apicomplexa Phylum Microspora Phylum Aschelminthes Phylum Platyhelminthes

Phylum Sarcomastigophora Subphylum Sarcodina (amebae) Subphylum Mastighopora (flagellates) Characteristics: Amebae move by means of cytoplasmic protrusions called pseudopods (false feet). Flagellates move by means of whiplike appendages known as flagella. Asexual

PHYLUM CILIOPHORA Move by means of cilia, threadlike extensions which are shorter and more numerous than flagella- arise from small basal granules. Most are free-living and nonpathogenic. The sole human pathogen: Balantidium coli, the largest intestinal protozoan known to infect man.

PHYLUM APICOMPLEXA Class Sporozoa. Having complex life cycles with alternating sexual and asexual generations. Pathogens include the Coccidia: parasites found in the intestinal mucosa. Found in blood and tissues.

PHYLUM MICROSPORA Tiny intracellular parasites. Cause infections in vertebrate and invertebrate. In human- Immunocompetent individuals are rarely infected.

PHYLUM ASCHELMINTHES Roundworms (nematodes). round, elongated bodies with coiled tails. Sexes separated. Male usually being smaller than the female. Most are free living. Life cycle involve intermediate as well as definitive hosts. Class Nematoda

PHYLUM PLATYHELMINTHESE Flatworms with flattened shape of the adult worm. Hermaphroditic : having male and female reproductive structures Found in class: 1)Trematoda (flukes) 2) Cestoda (tapeworms). Complex life cycle. Tapeworms: elongated, ribbonlike bodies, consisting of a scolex, an organelle of attachment, anteriorly, a neck region and segmented called proglottids.

Protozoa Are unicellular animals that occur singly or in colony formation. A complete unit capable of performing the physiologic functions that in higher organisms are carried out on by specialized cells. For the most part they are free-living, but some are parasitic, having adapted themselves to an altered existence inside the host.

Amoeba parasite in human Entamoeba histolytica (pathogenic) E. hartmanni (commensal) E. coli (commensal) E. gingivalis (commensal) Iodomoeoba buetschili (commensal) Endolimax nana ( commensal)

Entamoeba histolytica Diseases: amebiasis, amebic dysentery, amebic hepatitis. Also known as E. dispar (non pathogenic strain) Life cycle consist of: 1) trophozoite 2) Cyst (infective stage) -wide geographical distribution.

Mode of transmission -usually acquired by ingestion of contaminated water or food containing amebic cyst (oral), -male homosexual.

Symptoms Abdominal pain Diarrhea or bloody diarrhea Ulcers in appendix, cecum and other parts of colon. Flask-shaped ulcer- with a small mucosal opening and an eroded area beneath the surface.

Laboratory diagnosis Concentration technique – permenant smears stained by trichrome method Serological procedures: -Indirect hemagglutination assay (IHA) -enzyme linked immunosorbent assay (ELISA) -Indirect immunofluorescent (IFA)

Treatment Using amebicidial agents: Luminal amebicides: iodoquinol, diloxanide furoate Tissue amebicides: metronidazole, chloroquine, dehydroemetine

Prevention Filtration and chemical treatment – bcoz- resistant to chlorination Avoidance of contaminated water