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• Parasitology studies organisms' dependence on one another.
• Medical parasitology focuses on human parasites, their significance, and importance.
• Tropical medicine addresses tropical diseases and health problems specific to tropical regions.
• Tropical diseases are endemic to tropical areas and may occur sporadically in non-tropical regions.
• Anthroponotic infections affect humans exclusively.
• Zoo-anthroponotic infections primarily affect humans, involving animals in the parasite's lifecycle.
• Anthropozoonosis refers to parasitic infections mainly in animals, with humans as accidental hosts.
• Medical parasitology is a branch of science that deals with organisms living temporarily or permanently in/on the human body

Classes of Medical Parasitology

• Medical protozoology is focused on the study of medically important protozoa.
• Medical helminthology deals with the study of worms affecting humans.
• Medical entomology studies arthropods that cause or transmit diseases to humans.

Biological Relationships

• Symbiosis involves different organisms living together.
• Commensalism: one species gains benefits without affecting the other.
• Entamoeba coli in the intestinal lumen represents an example of commensalism.
• Mutualism is a symbiotic relationship where both organisms mutually benefit.
• Termites and flagellates in their digestive system exemplify mutualism.
• Parasitism involves one organism benefiting at the expense of the other.
• Entamoeba histolytica causing amebic dysentery is an example of parasitism.
• Parasites live in/on another organism, deriving nutrients at the host's expense.

Classification of Parasites

• Endoparasites live inside the host's body, and their presence indicates infection.
• Obligate parasites require a host to complete their lifecycle, such as tapeworms.
• Facultative parasites can exist freely but may become parasitic when necessary.
• Accidental parasites establish themselves in hosts where they don't typically live.
• Aberrant parasites infect a host where they cannot develop further, also known as wandering parasites.
• Ectoparasites live outside the host's body.
• Infestation indicates the presence of an ectoparasite on a host.
• Examples of ectoparasites: lice, ticks, and mites.
• Permanent parasites remain in/on the host's body for their entire life.
• Temporary parasites live on the host for a limited time.
• Free-living parasites exist independently and are non-pathogenic.
• Spurious parasites pass through the digestive tract without infecting the host.
• An example of a spurious parasite is the cystic stage of Naegleria fowleri.
• Hosts harbor parasites providing nourishment or shelter.
• The definitive host is where parasites attain sexual maturity.
• Humans are definitive hosts in taeniasis.
• The intermediate host harbors the asexual or larval stage of the parasite.
• Pigs or cattle serve as intermediate hosts for Taenia spp.
• Paratenic hosts do not support further parasite development.
• Reservoir hosts allow parasite life cycles to persist and augment human infection sources.
• The life cycle encompasses development from the definitive host and back.
• The direct life cycle relies on a single host to complete its development.
• The parasite is transmitted directly between hosts without an intermediate stage.
• The indirect life cycle involves two or more hosts for parasite development.
• Malarial parasites need both human and mosquito hosts for the completion of their life cycle.
• In self-infection, the infected individual is the source of their own source of infection
• Oral transmission commonly involves ingesting contaminated food, water, etc.
• Skin transmission involves parasites entering through the skin, e.g., hookworms.
• Vector transmission: parasites transmitted by insect bites, e.g., Anopheles mosquito.
• Direct transmission occurs through contact, e.g., kissing or sexual intercourse.
• Vertical transmission refers to mother-to-fetus transmission
• Iatrogenic transmission can happen via transfusion malaria and toxoplasmosis.
• Inhalation is another route of parasite transmission.

Effects of Parasites on the Host

• Lytic necrosis happens because of enzymes from some parasites.
• Trauma from parasite attachment causes physical damage.
• Allergic manifestations can be host immune responses to parasitic infection.
• Roundworm masses can cause physical obstructions.
• Inflammatory reactions can cause filariasis or urinary granuloma.
• Neoplasia is associated with liver flukes and urinary bladder cancer.
• Space-occupying lesions can compress surrounding tissue (e.g., hydatid cysts).
• Genetics. sickle-cell trait protecting against falciparum malaria is one example of host genetics affecting the parasite.
• Nutritional status alters the susceptibility to parasitic infection.
• Immune processes can either increase or decrease infectivity by protozoa.
• Exposure initiates inoculation of an infective agent.
• Infection connotes the establishment of an infective agent in the host.
• The incubation period is the time between infection and symptom appearance.
• Superinfection or hyper-infection occurs when an already infected individual contracts the parasite.
• Epidemiology studies disease patterns, distribution, and occurrence.
• Incidence is the number of new infections in a stated time frame.
• Prevalence is the estimated percentage of infected individuals.
• The intensity of infection is the burden that is related to number of pathogens per infected individual.
• Morbidity refers clinical consequences of infections.
• Deworming uses anti-helminth products.
• Efficacy defines the effect of a anti-helminth drug on an infectious agent.
• Medication resistance, and tolerance is a genetic factor.
• IEC - Information education strategy to maintain and promote health life practices.
• Eradication is defined as the permanent reduction to zero of the infectious disease.
• Elimination in medicine is defined as a reduction to zero of an infection in an area.

Classification of Medically Important Parasites

• Protozoa: Sarcodina (Amoebae), Mastigophora (Flagellates), Sporozoa, Ciliates.
• Metazoa (Helminths): Platyhelminthes, Trematodea.

Basic Concepts in Medical Parasitology

• Morphology involves the structure and forms of parasites.
• Geographical distributions relates to where the parasites are located
• Mode of infection refers to how the parasite infected the host
• Pathology and clinical manifestations include symptoms and diagnoses.
• Laboratory diagnosis is the use of available tools and techniques to identify the species
• Preventative and control measures aim to halt the spread of the species

Laboratory Diagnosis

• Examination of various body fluids and materials like blood, stool, urine, or biopsy samples is key.
• Malaria, and filariasis can be diagnosed in the lab.

Protozoa

• Protozoa translates to "first animal"
• They contain eukaryotic single-celled protists
• Key elements include the ability to move during a cycle and the presence of a nucleus.
• Multiplication done by asexual reproduction
• Transmission routes include fecal-oral, insect bites, sexual intercourse.
• Pathogenesis factors include the toxic products and immune interference.
• Based on morphology (shape and structure) they can locomotive system.

Intestinal Amoebae

• Intestinal amoebae includes histolytica, coli, gingivitis, and nana, ect.
• Can be transmitted via fecal contamination.
• Morphology: pseudopodia for locomotion and engulfs food for phagocytosis.
• Endolimax Nanae is irregular in shape to some extent.
• Motility done from the help of pseudopodia
• Encystation is another means of transportation for amoeba.
• Dysentery is commonly caused by it.

NAEGLERIA FOWLERI

• Only type of species to infect humans in fowleri genues
• There are three known forms of morphology.
• Stages include the cyst, trophozite and flaggable.
• Occurs when people go swimming in lakes or poorly ventilated swimming pools.