BELIZARIO_CHAPTER 1 - INTRODUCTION TO MEDICAL PARASITOLOGY

Question 1

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

Answer 1

Parasitology

Question 2

Branch of parasitology concerned primarily with parasites that affect humans and their medical significance, as well as their importance in human communities.

Answer 2

Medical Parasitology

Question 3

A branch of medicine that deals with tropical diseases and other special medical problems of tropical regions.

Answer 3

Tropical Medicine

Question 4

An illness that is indigenous to or endemic in a tropical area but may also occur in sporadic or epidemic proportions in areas that are not tropical.

Answer 4

Tropical disease

Question 5

TRUE or FALSE:

Many tropical diseases are parasitic diseases.

Answer 5

TRUE

Question 6

A relationship (“living together”) between two unlike organisms

Answer 6

Symbiosis

Question 7

A symbiotic relationship in which two species live together and one species benefits from the relationship without harming or benefiting the other.

Answer 7

Commensalism

Question 8

A symbiotic relationship where two organisms benefit from each other.

Answer 8

Mutualism

Question 9

A symbiotic relationship where one organism lives in or on another for its survival and usually at the expense of the host.

Answer 9

Parasitism

Question 10

Identify the symbiotic relationship involved:

Entamoeba coli living in the intestinal lumen of the host.

Answer 10

Commensalism

NOTE:
E. coli is nourished and protected from harm but does not cause damage to the tissue of its host.

Question 11

Identify the symbiotic relationship involved:

Entamoeba histolytica living in the intestinal lumen of its host.

Answer 11

Parasitism

NOTE:
E. histolytica deprives the host from nutrition and causes amebic dysentery.

Question 12

Identify the symbiotic relationship involved:

Flagellates and termites

Answer 12

Mutualism

NOTE:
Flagellates are protected inside the termites’ guts and the termites benefit from the flagellates by synthesizing cellulase to aid in the breakdown of ingested wood (Termites cannot digest cellulose by themselves)

Question 13

A parasite living inside the body of a host is termed as ______________.

Answer 13

Endoparasite

Question 14

A parasite living outside the body of a host is termed as _____________.

Answer 14

Ectoparasite

Question 15

When an endoparasite is present in a host, the harm caused is called ___________.

Answer 15

Infection

Question 16

When an ectoparasite is present on a host, the harm caused is called ____________.

Answer 16

Infestation

Question 16

When an ectoparasite is present on a host, the harm caused is called ____________.

Answer 16

Infestation

Question 17

The term used for parasites who are found in an organ that is not its usual habitat.

Answer 17

Erratic

Question 18

Parasites who need a host at some stage of the life cycle to complete their development and to propagate their species are called _________.

Answer 18

Obligate parasites

Question 19

A type of parasite who may exist in a free-living state or become parasitic when the need arises.

Answer 19

Facultative

Question 20

A parasite who establishes itself in a host where it does not ordinarily live.

Answer 20

Accidental/Incidental parasite

Question 21

A parasite is said to be ___________ when it remains on or in the body of the host for its entire life.

Answer 21

Permanent

Question 22

A parasite is __________ when it lives on or in the body of the host for a short period of time.

Answer 22

Temporary

Question 23

A __________ parasite is a free-living organism that passes through the digestive tract without infecting the host.

Answer 23

Spurious

Question 24

A ________ host is a host in which the parasite attains sexual maturity.

Answer 24

Definitive/Final

Question 25

A type of host which harbors the asexual or larval stage of the parasite.

Answer 25

Intermediate

Question 26

TRUE or FALSE: There can be more than one intermediate host.

Answer 26

TRUE Some organisms have first and second intermediate hosts.

Question 27

A type of host in which the parasite does not develop further to later stages but is able to remain alive and infect another susceptible host.

Answer 27

Paratenic

Question 28

These types of hosts are capable of widening the parasite distribution and bridging the ecological gap between the definitive and intermediate hosts.

Answer 28

Paratenic

Question 29

Type of hosts who harbor and allow the parasite’s life cycle to continue and become additional sources of human infection.

Answer 29

Reservoir

Question 30

TRUE or FALSE: Humans are always the final hosts.

Answer 30

FALSE Humans may be considered the most important host in the spread of disease or an incidental host of parasites prevalent in other animals but they are not always the final hosts.

Question 31

These are responsible for transmitting the parasite from one host to another.

Answer 31

Vectors

Question 32

Two types of vectors

Answer 32

* Biological * Mechanical/Phoretic

Question 33

This vector transmits the parasite only after the latter has complete its development within the host and is therefore an essential part of a parasite’s life cycle.

Answer 33

Biological

Question 34

This vector is responsible only for the transportation of the parasite.

Answer 34

Phoretic/Mechanical

Question 35

TRUE or FALSE: Majority of parasites are pathogens.

Answer 35

TRUE NOTE: Parasites often cause harm to their hosts.

Question 36

One who harbors a particular pathogen without manifesting signs and symptoms is termed as _________.

Answer 36

Carrier

Question 37

The process of inoculating an infective agent

Answer 37

Exposure

Question 38

This connotes the establishment of the infective agent in the host.

Answer 38

Infection

Question 39

This is the period between infection and evidence of symptoms.

Answer 39

Incubation period (or Clinical incubation period)

Question 40

This is the period between infection or acquisition of the parasite and evidence or demonstration of an infection.

Answer 40

Pre-patent period (or Biologic incubation period)

Question 41

This happens when an infected individual becomes his own direct source of infection

Answer 41

Autoinfection

Question 42

This happens when the already infected individual is further infected with the same species leading to massive infection with the parasite.

Answer 42

Superinfection or hyperinfection

Question 43

Most common sources of parasitic infection

Answer 43

Contaminated soil and water

Question 44

These are vectors of malaria and filarial parasites

Answer 44

Mosquitoes

Question 45

These are carriers of Trypanosoma cruzi causing Chagas disease.

Answer 45

Triatoma bugs

Question 46

Natural vectors of all types of Leishmania

Answer 46

Sand flies

Question 47

Parasites capable of autoinfection

Answer 47

* Capillaria philippinensis * Enterobius vermicularis * Hymenolepis nana * Strongyloides stercoralis

Question 48

The most common portal of entry which causes infection

Answer 48

Mouth

Question 49

Parasites who have skin penetration as route of transmission

Answer 49

* Strongyloides (exposure of skin to soil) * Hookworms (exposure of skin to soil) * Schistosoma spp. (enters skin via water)

Question 50

TRUE or FALSE: Arthropods are capable of being vectors by transmitting parasites through their bites.

Answer 50

TRUE

Question 51

TRUE or FALSE: Congenital transmission and transmammary infection may be modes of acquiring infection.

Answer 51

TRUE NOTE: * Congenital transmission (Toxoplasma gondii can cross placental barrier during pregnancy) * Transmammary infection (Ancylostoma and Strongyloides can be transmitted through mother’s milk)

Question 52

TRUE or FALSE: Animals parasites are classified according to the International Code of Zoological Nomenclature.

Answer 52

TRUE

Question 53

Complete the Hierarchy of Nomenclature: * Domain * Kingdom * A * B * C * D * E * F * G * H

Answer 53

A: Phylum B: Class C: Order D: Suborder E: Family F: Genus G: Species H: Subspecies

Question 54

TRUE or FALSE: Generic names consist of a single word written in initial capital letter

Answer 54

TRUE Example: Trichomonas

Question 55

TRUE or FALSE: Specific names must begin in capital letter.

Answer 55

FALSE: Names of species always begin in small letter. Example: Genus – Trichomonas Species – vaginalis Trichomonas vaginalis (must be italicized)

Question 56

TRUE or FALSE: The more complicated the life cycle of a parasite, the lesser chances are for them to survive.

Answer 56

TRUE

Question 57

This is the study of patterns, distribution, and occurrence of disease.

Answer 57

Epidemiology

Question 58

The number of new cases of infection appearing in a population in a given period of time is termed as _________.

Answer 58

Incidence

Question 59

The number of individuals in a population estimated to be infected with a particular parasite species at a given time is termed as ___________.

Answer 59

Prevalence NOTE: Prevalence is usually expressed as percentage.

Question 60

This is the percentage of individuals in a population infected with at least one parasite.

Answer 60

Cumulative prevalence

Question 61

This refers to burden of infection that is related to the number of worms per infected person.

Answer 61

Intensity of infection NOTE: This may be measured directly or indirectly and can be referred to as worm burden.

Question 62

Clinical consequences of infections or diseases that affect an individual’s well-being refer to __________.

Answer 62

Morbidity

Question 63

The use of antihelminthic drugs in an individual or a public health program.

Answer 63

Deworming

Question 64

This refers to the number of previously positive subjects found to be egg negative on examination of a stool or urine sample using a standard procedure at a set time after deworming.

Answer 64

Cure rate NOTE: This is often expressed as percentage

Question 65

The percentage fall in egg counts after deworming based on examination of a stool or urine sample using a standard procedure at a same time after the treatment is termed as _________.

Answer 65

Egg reduction rate (ERR)

Question 66

This involves individual-level deworming with selection for treatment based on a diagnosis of infection or assessment of intensity of infection.

Answer 66

Selective treatment NOTE: This can be used in whole populations or in defined risk groups.

Question 67

This is a group-level deworming where the risk group to be treated (without prior diagnosis) may be defined by age, sex, or other social characteristics irrespective of infection status.

Answer 67

Targeted treatment

Question 68

A population-level deworming in which the community is treated irrespective of age, sex, infection status, or other social characteristics.

Answer 68

Universal treatment

Question 69

The regular, systematic, large-scale intervention involving the administration of one or more drugs to selected population groups with the aim of reducing morbidity and transmission of selected helminth infections.

Answer 69

Preventive chemotherapy

Question 70

This refers to the proportion of the target population reached by an intervention.

Answer 70

Coverage

Question 71

The effect of a drug against an infective agent is termed as __________.

Answer 71

Efficacy

Question 72

The measure of the effect of a drug against an infective agent in a particular host, living in a particular environment with specific ecological, immunological, and epidemiological determinants.

Answer 72

Effectiveness

Question 73

TRUE or FALSE: Measurement of effectiveness may be qualitative or quantitative.

Answer 73

TRUE

Question 74

This is the indicator to measure reduction in prevalence.

Answer 74

Cure rate

Question 75

This is the indicator to measure reduction in intensity of infection.

Answer 75

Egg reduction rate

Question 76

The genetically transmitted loss of susceptibility to a drug in a parasite population that was previously sensitive to the appropriate therapeutic dose.

Answer 76

Drug resistance

Question 77

The avoidance of illness caused by infections

Answer 77

Morbidity control

Question 78

A health education strategy that aims to encourage people to adapt and maintain healthy life practices.

Answer 78

Information-education-communication (IEC)

Question 79

This refers to the planning, organization, performance, and monitoring of activities for the modification and/or manipulation of environmental factors or their interaction with human beings with a view to preventing or minimizing vector or intermediate host propagation and reducing contact between humans and the infective agent.

Answer 79

Environmental management

Question 80

This involves the interventions to reduce environmental health risks including the safe disposal and hygienic management of human and animal excreta, refuse, and waste water.

Answer 80

Environmental sanitation

Question 81

This involves the control of vectors, intermediate hosts, and reservoirs of disease as well as the provision of safe drinking water and food safety, shelter quality, and safe and healthy working conditions.

Answer 81

Environmental sanitation

Question 82

The provision of access to adequate facilities for the safe disposal of human excreta, usually combined with safe access to safe drinking water.

Answer 82

Sanitation

Question 83

This 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.

Answer 83

Disease eradication

Question 84

This is the reduction to zero of the incidences of a specified disease in a defined geographic area as a result of deliberate efforts.

Answer 84

Disease elimination

Question 85

ERADICATION or ELIMINATION? Continued interventions or surveillance measures are still required.

Answer 85

Elimination NOTE: Once disease eradication is achieved, continued measures are no longer required/necessary.