PARASITIC PROTOZOA

Biology of the protozoa: Protozoa are unicellular animals that occur singly or in colony formation.

MORPHOLOGY: The vital functions of the protozoa are carried out by the protoplasm. The vital functions of the protozoa are carried out by the protoplasm. Protoplasm is differentiated into nucleoplasm and cytoplasm. Protoplasm is differentiated into nucleoplasm and cytoplasm.

Physiology: All essential metabolic, reproductive, and protective functions are carried on by either specialized properties of the protoplasm or by structural and functional adaptations known as the organelles. All essential metabolic, reproductive, and protective functions are carried on by either specialized properties of the protoplasm or by structural and functional adaptations known as the organelles. Pseudopodia produce amoeboid movements in sarcodina, cilia rhythmically propel the infusoria, and flagella the mastigophora Pseudopodia produce amoeboid movements in sarcodina, cilia rhythmically propel the infusoria, and flagella the mastigophora

Transmission: The parasites pass from host directly or through food and water after an extracorporeal existence. The parasites pass from host directly or through food and water after an extracorporeal existence.

Pathology and Symptomatology: Protozoa, in contrast to worms, multiply in their hosts, so disease can result from infection initiated by only a few organisms. Protozoa, in contrast to worms, multiply in their hosts, so disease can result from infection initiated by only a few organisms.

Diagnosis: Clinical impressions should always be confirmed by laboratory diagnosis that identifies the parasite in intestinal contents or in blood and tissues. Clinical impressions should always be confirmed by laboratory diagnosis that identifies the parasite in intestinal contents or in blood and tissues.

Immunity: Natural resistance may be lowered by malnutrition, concurrent disease, or immunosuppressive drugs. Natural resistance may be lowered by malnutrition, concurrent disease, or immunosuppressive drugs. Protective immunity often develops to protozoan infections involving the blood and tissues. Protective immunity often develops to protozoan infections involving the blood and tissues.

Prevention: The usual methods of reducing the sources of infection, blocking the channels of transmission, and protecting the susceptible host are employed. The usual methods of reducing the sources of infection, blocking the channels of transmission, and protecting the susceptible host are employed.

INTESTINAL AND LUMINAL PROTOZOA

AMEBAS: Members of this group of protozoa, which includes many free-living and parasitic amebas, are probably the most primitive of animal forms. Members of this group of protozoa, which includes many free-living and parasitic amebas, are probably the most primitive of animal forms. 6 species of Amebas in Man 6 species of Amebas in Man :1.Entamoeba histolytica, 2.Entamoeba coli, 3.Entamoeba gingivalis, 4.Dientamoeba fragilis, 5.Endolimax nana, 6.Iodamoeba butschilii. :1.Entamoeba histolytica, 2.Entamoeba coli, 3.Entamoeba gingivalis, 4.Dientamoeba fragilis, 5.Endolimax nana, 6.Iodamoeba butschilii.

Entamoeba gingivalis trophozoites

Life Cycle: The resistant infective cysts, formed in the lumen of the large intestine, pass out in the feces, and are immediately infective. The resistant infective cysts, formed in the lumen of the large intestine, pass out in the feces, and are immediately infective. Human beings are the principal host and source of infection. Human beings are the principal host and source of infection.

Entamoeba histolytica Life Cycle

Pathology: The pathogenic activities of E. histolytica depend upon 1.the resistance of the host, 2.the virulence and invasiveness of the amebic strain, and the 3.conditions in the intestinal tract. The pathogenic activities of E. histolytica depend upon 1.the resistance of the host, 2.the virulence and invasiveness of the amebic strain, and the 3.conditions in the intestinal tract.

Symptomatology: The clinical response is exceedingly variable, depending upon the location and intensity of the infection. The clinical response is exceedingly variable, depending upon the location and intensity of the infection. Asymptomatic infections are the most common, especially in temperate zones. Asymptomatic infections are the most common, especially in temperate zones.

Diagnosis: The final diagnosis of amebiasis rests upon the identification of the parasite an the feces or tissues, and serologic studies. All available methods should be exhausted before accepting a clinical diagnosis. On the other hand, diagnosis by therapy must be resorted to occasionally. The final diagnosis of amebiasis rests upon the identification of the parasite an the feces or tissues, and serologic studies. All available methods should be exhausted before accepting a clinical diagnosis. On the other hand, diagnosis by therapy must be resorted to occasionally.

Prevention: Carriers should be removed from the food- handling occupations, instructed in personal hygiene and, treated. Carriers should be removed from the food- handling occupations, instructed in personal hygiene and, treated. Effective environmental sanitation Effective environmental sanitation Boiling water Boiling water