Parasitic Infections PDF

PARASITISM IT IS A SYMBIOTIC RELATIONSHIP THAT IS OF BENEFIT TO ONE PARTY OR SYMBIONT (THE PARASITE) AT THE EXPENSE OF THE OTHER PARTY (THE HOST). PARASITES These are organisms that live on or in other living organisms, at whose expense they gain some advantage. ECTOPARAS...

PARASITISM IT IS A SYMBIOTIC RELATIONSHIP THAT IS OF BENEFIT TO ONE PARTY OR SYMBIONT (THE PARASITE) AT THE EXPENSE OF THE OTHER PARTY (THE HOST). PARASITES These are organisms that live on or in other living organisms, at whose expense they gain some advantage. ECTOPARASITES These are the parasites that live outside the host’s body. Examples are Arthropods such as mites, ticks, and lice. ENDOPARASITES These are the parasites that live inside the host. Examples are parasitic protozoa and helminths.  TYPES OF PARASITES: FACULTATIVE PARASITE It is an organism that can be parasitic but does not have to live as a parasite. It is capable of living an independent life, apart from a host. TYPES OF PARASITES: OBLIGATE PARASITE It has no choice; to survive, it must be a parasite. Most parasites that infect humans are obligate parasites.  PARASITIC PROTOZOA Protozoa are classified taxonomically by their mode of locomotion. AMEBAS FLAGELLATES CILIATES move SPOROZOA (amebae) move move by means by means of (sporozoans) have by means of of whiplike hairlike cilia. no pseudopodia, pseudopodia flagella. flagella, or cilia, (literally, “false and therefore exhibit no motility. feet”).  S IS SKIN M A N IA ISH LE It is transmitted to humans through the bites of infected female phlebotomine sandflies. PARASITE: Flagellated protozoa in the genus Leishmania MOT: bite of an infected sand fly blood transfusion person-to-person contact Patient Care: Use Standard Precautions  FORMS OF LEISHMANIASIS Cutaneous Mucocutaneous Visceral Leishmaniasis Leishmaniasis Leishmaniasis a.k.a. Kala-azar (or mucosal) It starts with a papule Characterized by fever, enlarged that enlarges into a Individual ulcers may liver and spleen, lymphadenopathy, anemia, crater-like ulcer coalesce, causing severe leukopenia, and progressive tissue destruction and emaciation and weakness. Death disfigurement may result in untreated cases. EYES PARASITE: Amebas in the genus Acanthamoeba MOT: Wearing soft contact lenses Using nonsterile, homemade cleaning or wetting solutions CONJUNCTIVITIS AND Have become infected in ameba- KERATOCONJUNCTIVITIS contaminated spas or hot tubs. Inflammation of the cornea and Patient Care: Use Standard conjunctiva. Precautions EYES PARASITE: Sporozoan, Toxoplasma gondii MOT: Eating infected raw or undercooked meat (usually pork or mutton) containing the cyst form of the parasite TOXOPLASMOSIS Ingesting oocysts that have been shed Systemic sporozoan infection that, in the feces of infected cats. in immunocompetent persons, may Transplacentally be asymptomatic or resemble Blood transfusion infectious mononucleosis. However, Organ transplantation serious disease, even death, may occur in immunodeficient persons. Patient Care: Use Standard Precautions  GASTROINTESTINAL TRACT PARASITE: Entamoeba histolytica MOT: ingestion of fecally contaminated food or water containing cysts by flies transporting cysts from feces to food AMEBIASIS fecally soiled hands of infected Amebiasis or amebic dysentery is a food handlers protozoal gastrointestinal infection oral–anal sexual contact that may be asymptomatic, mild, or anal intercourse involving multiple severe and is often accompanied by sex partners. dysentery, fever, chills, bloody or mucoid diarrhea or constipation, and Patient Care: Use Standard colitis. Precautions  GASTROINTESTINAL TRACT PARASITE: Balantidium coli, a ciliated protozoan MOT: Ingestion of pig feces with B. coli cysts in fecally contaminated BALANTIDIASIS food or water A protozoal gastrointestinal infection of the colon causing Patient Care: Use Standard diarrhea or dysentery, colic, nausea, Precautions and vomiting. GENITOURINARY TRACT PARASITE: Trichomonas vaginalis, a flagellate MOT: Direct contact with vaginal and TRICHOMONIASIS urethral discharges of infected people It is a sexually transmitted protozoal during sexual intercourse disease affecting both men and women. The disease is usually Patient Care: Use Standard Precautions symptomatic in women, causing vaginitis with a profuse, thin, foamy, malodorous, greenish-yellowish discharge.  MALARIA It is a systemic sporozoan infection with malaise, fever, chills, sweating, CIRCULATORY SYSTEM headache, and nausea. The intermittent bouts of chills and fever MOT: referred to as paroxysms. Injection of sporozoites into the It may be accompanied by cough, bloodstream by an infected female diarrhea, respiratory distress, shock, Anopheles mosquito while taking a renal and liver failure, pulmonary blood meal. and cerebral edema, coma, and Infection may also occur as a death. result of blood transfusion Use of blood-contaminated PARASITE: Plasmodium: Plasmodium needles and syringes. vivax (most common), P. falciparum (most deadly), Plasmodium malariae, and Patient Care: Use Standard Plasmodium ovale. These are Precautions intraerythrocytic sporozoan parasites. HELMINTH The word helminth means parasitic worm. The helminths that infect humans are always endoparasites. Helminths are multicellular, eucaryotic organisms in the Kingdom Animalia.  MAJOR DIVISIONS OF HELMINTHS NEMATODES are FLATWORMS are bilaterally also known as symmetrical and Platyhelminthes, are elongated, usually a group of simple, tapered at both soft-bodied ends. invertebrates.