Introduction to Parasitology PDF

PARASITOLOGY LECTURE LECTURE | 3RD YEAR | FIRST SEMESTER INTRODUCTION TO PARASITOLOGY PARASITOLOGY Ex. parasitic worms like Is the area of biology concerned with the...

PARASITOLOGY LECTURE LECTURE | 3RD YEAR | FIRST SEMESTER INTRODUCTION TO PARASITOLOGY PARASITOLOGY Ex. parasitic worms like Is the area of biology concerned with the Tapeworm phenomenon of dependence of one living organism ACCORDING TO HOST REQUIREMENTS Medical parasitology is concerned primarily Obligate parasites with parasites of humans and their medical ○ They need a host at some stage of significance, as well as their importance in human communities their life cycle to complete their A tropical disease is an illness, which is development and to propagate their indigenous (local) to or endemic in tropical species areas but may also occur in sporadic or Facultative parasites epidemic proportions in areas that are not ○ may exist in a free-living state or may tropical. become parasitic when the need o Like in the Philippines arises. o parasitism is under tropical disease. Accidental/incidental parasites TROPICAL MEDICINE branch of medicine ○ A parasite, which establishes itself in a that deals with tropical disease host where it does not ordinarily live BIOLOGICAL RELATIONSHIP Symbiosis (is any type of a close and ○ Accidentally nakita parasite sayo long-term biological interaction, between Erratic parasites TWO organisms of different species) ○ A permanent parasite remains on or in the body of the host for its entire life, COMMENSALISM Temporary parasites A symbiotic relationship in which two species ○ lives on the host only for a short period live together and one species benefits from of time. the relationship without harming or Spurious parasites benefiting the other ○ is a free-living organism that passes Host is not affected while the other benefits through the digestive tract without o Ex. gut flora infecting the host. MUTUALISM CLASSIFICATION OF HOST An ecological interaction between 2 or more DEFINITIVE/FINAL HOST spp. Where each species has a net benefit is one in which the parasite attains sexual Mutual benefits. BOTH BENEFITS maturity. ○ Ex. Gut microbiota and us both Parasite is sexually mature meaning it is benefits ready for infection inside the host PARASITISM INTERMEDIATE HOST Is a close relationship between spp. where harbors the asexual or larval stage of the one organism, the parasite, lives on or inside parasite. another organisms, the host, causing it some Asexual or sexually immature parasite harm, and is adapted structurally to this way PARENTIC HOST of life. is one in which the parasite does not develop All of these benefits from their host and the or mature further to later stages host is compromise However, the parasite remains alive and is ○ Ex of parasites: tick, lice, fleas, able to infect another susceptible host. roundworm, whipworm, hookworm, tapeworm RESERVOIR HOST CLASSIFICATION OF PARASITES There are also other animals that harbor the ACCORDING TO HOST HABITAT parasite other than definitive, intermediate, and paratenic hosts. Ectoparasite -> infection ○ e.g.: Balantidium coli, Toxoplasma ○ Ecto, live outside the body gondii ○ Infested since outside VECTORS ex. Lice are responsible for transmitting the parasite Endoparasite -> infestation from one host to another. ○ Endo, live inside the body BIOLOGIC VECTORS 2. Consumption of raw or undercooked food transmits the parasite only after the latter has a. Pork – Taenia solium completed its development within the host. b. Beef – Taenia saginata A biologic vector is therefore an essential part c. Fish – diphyllobothrium latum of the parasite’s life cycle. 3. Arthropod-borne ○ e.g: Malaria a. serve as vectors and transmit parasites through their bites MECHANICAL OR PHORETIC VECTORS b. Ex. malaria, filariasis, leishmaniasis, only transports the parasite. trypanosomiasis, and babesiosis ○ Flies and cockroaches that feed on c. Mosquito – Plasmodium and filarial fecal material may carry enteric worms organisms and transfer these to food d. Triatoma bugs – Trypanosoma cruzi EXPOSURE VS INFECTION e. Sand flies – leishmania spp. EXPOSURE 4. Direct contact with wild or domesticated is the process of inoculating an infective agent. animals Introduction to the host a. Cat – Toxoplasma spp. b. Rats – Hymenolepsis nana INFECTION c. Pigs – Balantidum coli connotes the establishment of the infective d. Get from sa tae nila then if kinakain agent in the host nila tae nila then your pet will kiss you full blown proliferation to the host kaya ma expose ka na sa parasite INCUBATION PERIOD/CLINICAL INCUBATION 5. Fomites, asymptomatic carriers, PERIOD autoinfection is the period between infection and evidence MODES OF TRANSMISSION 1. Ingestion / drinking contaminated water of symptoms. a. Taenia solium, PREPATENT PERIOD/BIOLOGICAL PERIOD b. Taenia saginata, is the period between infection or acquisition c. Diphyllobothrium latum of the parasite and evidence or demonstration 2. Skin penetration of infection a. Hookworm spp. b. Strongyloides stercoralis AUTOINFECTION 3. Arthropod vector Results when an infected individual becomes a. agents of malaria, filariasis, his own direct source of infection. leishmaniasis, trypanosomiasis, and He/she infect themselves babesiosis. SUPERINFECTION/HYPERINFECTION 4. Vertical and transmammary happens when the already infected individual a. Toxoplasma gondii (can transfer to is further infected with the same species pregnant women) trophozoites can leading to massive infection with the parasite. cross the placental barrier during pregnancy. CO-INFECTION b. Ancylostoma complicated severe infection where two c. Strongyloides different infections are present in the body with 5. Inhalation different types of causative agent. 6. Sexual intercourse SOURCES OF INFECTION a. Trichomonas vaginalis. 1. Lack of Sanitation — soil and water b. Entamoeba histolytica contaminants NOMENCLATURE a. Improper segregation classified according to the International Code b. Dirty toilets of Zoological Nomenclature. c. Ex. Soil transmitted helminth Each phylum is divided into classes, which are infection: Ascaris lumbricoides, further subdivided into orders, families, Trichuris trichiura, Strongyloides genera, and species stercoralis, hookworm spp., First letter of genus name is capitalized other d. Water borne: Schistosoma spp. lower e. Kids playing at the soil and ○ Ex. contaminated ito possible na mag Class: Chromadorea infect siya ng parasite Phylum: Nematoda 2 | LAGARTEJA,Y  Scientific: Ascaris lumbricoides Domain: Eukaryota Family: Ascarididae Genus: Ascaris Kingdom: Animalia EPIDEMIOLOGICAL MEASURES EPIDEMIOLOGY study of patterns, distribution, and occurrence of disease. INCIDENCE is the number of new cases of infection appearing in a population in a given period of time. PREVALENCE is the number (usually expressed as percentage) of individuals in a population estimated to be infected with a particular parasite species at a given time. Total number of either old or new case Cumulative prevalence is the percentage of individuals in a population infected with at least one parasite INTENSITY OF INFECTION refers to burden of infection which is related to the number of worms per infected person Morbidity (harmed) vs mortality (Death) ERADICATION AND ELIMINATION Eradication ○ Disease eradication is defined as a permanent reduction to zero of the worldwide incidence of infection caused by a specific agent, as a result of deliberate efforts. Elimination ○ n is a reduction to zero of the incidence of a specified disease in a defined geographic area as a result of deliberate efforts. Continued intervention or surveillance measures are still required 3 | LAGARTEJA,Y