Parasitology — General Considerations (S01T01)

Vocabulary flashcards covering key terms and definitions from the parasitology notes, including branches of parasitology, host roles, vectors, transmission modes, epidemiologic measures, and diagnostic concepts.

Parasitology

The area of biology concerned with the dependence of one living organism on another.

Clinical Parasitology (Medical Parasitology)

Concerned primarily with the animal parasites of humans and their medical significance, and their importance in human communities.

Tropical Medicine

A branch of medicine dealing with tropical diseases and other medical problems of tropical regions.

Tropical Diseases

Diseases indigenous to tropical areas that may also occur sporadically or epidemic-ally in non-tropical areas.

Neglected Tropical Diseases (NTDs)

Infectious diseases, many parasitic, that remain important causes of morbidity and are often linked to poverty.

Prevalence

The proportion of a population that is infected at a given time; specifically, the proportion of infected people among those examined.

Kato-Katz Technique

A quantitative stool examination method that measures infection intensity by counting eggs per gram of stool; uses about 42 mg of stool placed on a slide with a fixed template.

Cure Rate

The proportion of previously egg-positive individuals who become egg-negative after deworming.

Egg Reduction Rate (ERR)

Percentage fall in egg counts after deworming, used to measure reduction in infection intensity.

Deworming

Administration of anthelmintic drugs to an individual or a public health program.

Morbidity

Negative health effects or symptoms caused by infection or disease.

Information-Education-Communication (IEC)

A strategy to teach and encourage healthy behaviors to improve public health.

Environmental Management

Actions to change the environment to stop disease spread, reducing human contact with disease agents.

Environmental Sanitation

Efforts to lower environmental health risks via proper waste disposal, clean water, hygiene, and safe housing.

Eradication

Permanent reduction to zero worldwide incidence of infection; no further intervention is needed.

Elimination

Reduction to zero incidence of a disease in a defined geographic area; ongoing surveillance is often required.

Incidence

The number of new infection cases in a population within a specific time frame.

Prevalence (epidemiology)

The percentage of people currently infected with a parasite at a given time.

Cumulative Prevalence

The proportion of people in a population who have ever been infected by a parasite at least once.

Intensity of Infection (Burden of Infection)

Measures how many worms are present in an infected person; can be counted directly or inferred from eggs per gram.

Definitive Host

The host in which the parasite reaches sexual maturity and reproduces (adult stage).

Intermediate Host

The host in which the parasite undergoes development; often where larval or asexual stages occur.

Paratenic Host

Transport host that carries the parasite without development; enhances distribution.

Reservoir Host

An animal host that maintains the parasite in the environment and serves as a ready, constant source of infection.

Zoonosis / Zoonotic Parasite

An animal disease or parasite that can be transmitted to humans.

Endoparasite

Lives inside the host and causes infection.

Ectoparasite

Lives on the outside of the host and causes infestation.

Facultative Parasite

Can be free-living or parasitic; an opportunist.

Obligate Parasite

Cannot survive outside the host; dependent on the host for survival and reproduction.

Vector

An organism that transmits a parasite from one host to another; essential part of the parasite’s life cycle.

Biologic Vector

A vector in which the parasite develops or multiplies inside (e.g., mosquitoes and malaria).

Mechanical (Phoretic) Vector

A vector that carries the parasite without enabling development inside; not essential to the parasite’s life cycle.

Accidental Parasite

Not normally a human parasite; acquired accidentally.

Erratic Parasite

Parasite found in an unusual place due to migration; not normally in that organ.

Spurious Parasite

Not a true parasite; a free-living organism or parasite of animals passing through the human digestive tract.

Temporary Parasite

Short-term parasite (e.g., some ticks).

Permanent Parasite

Long-term parasite (e.g., many endoparasites that reside in the host).

Horizontal Transmission

Person-to-person transfer of a parasite.

Portal of Entry (Mouth)

The entry site; mouth is a common portal for parasites entering by ingestion.

Foodborne Transmission

Ingestion of infective larvae or eggs in contaminated food; examples include Taenia, Diphyllobothrium, Clonorchis, Haplorchis, Capillaria philippinensis, and intestinal protozoa.

Waterborne Transmission

Ingestion of cysts or other forms in contaminated water (e.g., Entamoeba histolytica, Giardia lamblia).

Skin Penetration

Infection acquired through contact with contaminated soil or water; e.g., hookworms and Schistosoma japonicum.

Congenital/Vertical Transmission

Transmission of parasites from mother to fetus or via breast milk (e.g., Toxoplasma gondii).

Inhalation Transmission

Inhalation of airborne parasite stages (e.g., Enterobius vermicularis eggs).

Sexual Transmission

Transmission of parasites through sexual intercourse (e.g., Trichomonas vaginalis).

Incubation Period

Period between exposure to a parasite and the onset of clinical signs or symptoms.

Prepatent Period

Period between infection and demonstration of infection (laboratory evidence) without clinical symptoms.

Patent Period

Time during which the infection can be demonstrated (clinical evidence).