Introduction to Parasitology PDF

INTRODUCTION TO PARASITOLOGY DIFFERENT FORM OF SYMBIOSIS PARASITOLOGY - means eating at the same table Parasitology the branch of biology - association that is beneficial to one partner concer...

INTRODUCTION TO PARASITOLOGY DIFFERENT FORM OF SYMBIOSIS PARASITOLOGY - means eating at the same table Parasitology the branch of biology - association that is beneficial to one partner concerned with the phenomenon of and at least not disadvantageous to the other. dependence of one living organism on another. - a relation between two kinds of organisms in It's study of parasites, their hosts, and the which one obtains food or other benefits relationship between them. from the other without damaging it. PARASITE SPECIALIZED TYPE OF COMMENSALISM An organism that lives on or in its host, Mutualism which is usually a larger organism, that provides - association is beneficial to booth. physical protection and nourishment. Parasitism An organism that has sustained contact - symbiotic relationship in which one with another organism to the detriment to the organism, the host is to some degree injured host organism. thru the activities of the other. FIELDS /BRANCHES OF PARASITOLOGY VECTORS Medical parasitology Hosts that transmit parasites to man. Veterinary parasitology Structural parasitology BIOLOGIC VECTORS Quantitative parasitology those that are essential in the life cycle. Parasite ecology PHORETIC OR MECHNICAL VECTORS Conservation biology of parasite Those that are not essential in the life Taxonomy and phylogenetics cycle. PREDATOR ZOONOSIS Organism that attack another living - Disease of animals (literally) animal, not necessarily killing them. ( attacker) - Disease of animals that are transmissible to man PREY They are the victim. CLASSIFICATION OF ZOONOSIS Euzoonosis- Common to man and reservoir HOST host. The organism from which a parasite Parazoonosis- man is infrequent host and obtains its nutrition and/ or shelter. incidental Anthropozoonosis- infection acquired by man Intermediate host- is used normally by a from other vertebrates. parasite in the course of its life cycle Zooanthroponosis- human infection that maybe and it which it may multiply asexually acquired by other vertebrates and but not sexually. Obligate parasite- cannot exist without the host Definitive host- is the host in which the Facultative parasite- can be free living or sexual reproduction of parasite takes Amphizoic- free living amoeba that may invade place. and colonize the brain and other sites Reservoir host- is an organism in which (Naegleria and Acanthomoeba) a parasite that is pathogenic for some Spurious- Free living parasites or organisms that other species, lives and multiplies parasitize other hosts, usually without damaging its host. - they merely passedthe intestine, - recovered in living or dead state from the SCAVENGERS human feces. Devouring those dead of natural causes or taking the leavings of the predator. PROTOZOA SYMBIOSIS Living together in more or less intimate association or close union of two dissimilar organisms From the Greek symbiosis which means the state of living together. HELMINTHS ARTHROPODS on, particularly to another species of host, is also a Biological Vector However, fi the parasite does not undergo some aspect of its life cycle as it is transported by one organisms to a second, then the first organism is described as a Mechanical Vector E.g., flies can be mechanical vectos of feces- born pathogens such as Salmonella FRANCESCO REDI Types of Hosts Definitive Host: The host in which the parasite goes through its sexual cycle (I.e., fertilization & meiosis) E.g., mosquitoes serve as definitive hosts of the malaria parasite (Plasmodium spp.) E.g., snakes (~30 species) serve as definitive hosts of Sarcocystis singaporensis, a disease of mammals The Italian Francesco Redi, considered to be Intermediate Host: Host in which the the father of modern parasitology, was the first parasite replicates but does not go through its to recognize and correctly describe details of sexual cycle many important parasites. E.g., mammals, including humans, serve as intermediate hosts of the malaria parasite Parasitology (Plasmodium spp.) Parasites include things that live internal E.g., mammals (~30 species, including (endoparasites) or external (ectoparasites) to humans) serve as intermediate hosts of the infected (or infested) host Sarcocystis singaporensis Broadly speaking, all pathogens may be classified as parasites S. singaporensis has been proposed as Narrowly speaking, Parasitology is the science biological control of rodents pests apparently it that studies the relatively large parasites can selectively killt h e m ! including parasitic Protists, Worms, and, to a lesser degree, pathogenic Fungi and Arthropod Reservior Hosts: The reservoir host is the ectoparasites population in which a parasite resides when it Today we'll consider Protists, Helminths isn't affecting a population that we care more (worms), Fungi, and the Arthropod Vectors of about infectious disease E.g., the rabies virus normally is passed back and forth among wild mammals (these serve as Vectors and Hosts the reservoir hosts-t h e populations that we A Vector is a living organism that carries a don't much disease- causing organism to new Hosts care about) This distinction can be arbitrary, however, Occasionally, however, rabies can infect pets, depending on which organism's infection we and thereby us (the population we do care are most concerned with about) Thus, the Anopheles mosquito is a vector for To prevent the latter (i) we vaccinate pets, (ii) the parasitic disease malaria because we care avoid handling wild animals, and (iii) otherwise more about the health of the human host than attempt to reduced the incidence of rabies in that of the mosquito reservoir pops. However, in addition, the malaria parasite has a much greater impact on the health of the human host than it does on the health of the Parasitic protitis mosquito vector Biological vs. Mechanical Vector The real confusion between host and vector comes from the concept of Biological Vector Within (or upon) both a host and a Biological Vector the parasite undergoes some aspect of its life cycle Thus, in one sense, all hosts that can pass a parasite MEDICAL PARASITOLOGY One of the largest fields in parasitology, medical parasitology is the subject that deals with the parasites that infect humans, the diseases caused by them, clinical picture and the response generated by humans against them. It is also concerned with the various methods of their diagnosis, treatment and finally their prevention & control. A parasite is an organism that live on or within another organism called the host. These include organisms such as: Plasmodium spp., the protozoan parasite which causes malaria. The four species infective to humans are P. falciparum, P. malariae, P. vivax and P. ovale. Leishmania, unicellular organisms which cause leishmaniasis Entamoeba and Giardia, which cause intestinal infections (dysentery and diarrhoea) Multicellular organisms and intestinal worms (helminths) such as Schistosoma spp., Wuchereria bancrofti, Necator americanus (hookworm) and Taenia spp. (tapeworm) Ectoparasites such as ticks, scabies and lice