CHAPTER 1: Introduction to Parasitology Flashcards
Living 2 organisms of different species in which both members are so dependent upon each other that life apart is impossible
Symbiosis
LIving 2 organisms of different species in which both members benefit from each other life w/out each other is still possible
Mutualism
Two living organisms of different species in which one member benefits but the other one is not affected
Commensalism
One of the members lives at the expense of the others
Parasitism
An organism that lives in the body of the host
Endoparasite (infection)
An organism that lives outside the body of the host or the exterior surface of the host
Ectoparasite (infestation)
An organism that lives in an organ different from the one it usually parasitizes or not its usual habit
give example
Erratic parasite
Ascaris lumbricoides
A parasite that causes injury to the host by its mechanical, traumatic and toxic activities
Pathogenic parasite
A parasite that does not cause injury to the host
Non-pathogenic parasite
An organism that is completely dependent on its host or cannot survive outside the host
*Example
Obligate parasite
*Leishmania, Tapeworms
Able to live as an independent organism or as a parasite at its own. FREE-LIVING STATE
*Example
Facultative parasite
*Strongyloides stercoralis
A parasite that visits and leaves the host at intervals
*Example
Intermittent parasite
*Mosquito
A parasite in which its larval stage develops in a host different from that adult
Periodic parasite
A parasite which occasionally occurs in an unusual host
*Example
Accidental/ Incidental parasite
*Echinococcus granulosus (dog), Ancylostoma caninum (dog)
A parasite living inside the cells of the tissue
*Example
Cytozoic parasite
*Isospora belli, I. nominus
A parasite living inside the lumen of the intestine
Enterozoic parasite
An organism that passes the alimentary tract w/o infecting the host
*Example
Spurious parasite
*Eimeria sardinae
Artifacts mistaken as parasites
Pseudoparasite
Neutrophils are mistaken as
Entamoeba histolytica cyst
Macrophages are mistaken as
Entamoeba histolytica trophozoite
A parasite that lives its entire life in the body of the host
Permanent parasite
A parasite which passes its larval period of development within the body of the host while the adult is free-living
Transitory parasite
A parasite living inside the RBC
*Example
Hematozoic parasite
*Plasmodium falciparum, Babesia
A parasite living inside the body cavities
*Example
Coezolic parasite
*Mansonella ozzardi
A parasite that lives on the host only for a short period of time
Temporary parasite
A parasite which infects a host where they cannot develop further
*Example
Aberrant parasite
*Toxoplasma gondii (cats)
Harbors the adult or sexual stage of the parasite where the parasite attains it’s sexual maturity
Definitive/Final host
Humans are the definitive host EXCEPT what disease?
Malaria
1st and 2nd intermediate host harbors the larva or asexual stage of the parasite. Host that harbors the asexual stage of parasite development.
Intermediate host
Parasite that humans is both definitive and intermediate host.
Trichinella spiralis
Host not necessary in the arrested stage of development or host other the normal one that is harboring the parasite.
Accidental/Incidental host
Harbors the parasite in an arrested stage of development. The parasite do not develop into the further or later stages. However, the parasite is still alive enabling it to infect a susceptible host.
Paratenic host
Host in w/c parasite can not be transmitted further
Dead end host
Animal host that harbors the same parasite as man or parasitic to man. They harbor the definitive, intermediate and paratenic host.
Reservoir host
Ex. Pigs: Bacantidium coli
Carabaos: Schistosoma japonicum
Host that carries the parasite inside but shows no signs and symptoms of infection
Carrier host
Host responsible for transferring a parasite from one location to another
Transfer host
TYPES OF HOST
Definitive host Intermediate host Accidental/incidental host Paratenic host Dead end host Reservoir host Carrier host Transport host
Responsible for transmitting the parasite from one host to another
Vector
Transmit the parasite only after the latter has completed it’s development within the host
Biologic vector
Vector of Malaria
Anopheles spp.
The sole purpose is only to transmit the parasite regardless of it’s stage
Mechanical vector or Phoretic vector
TYPES OF VECTOR
Biologic and Mechanical vector
Harbors a particular pathogen without manifesting any signs and symptoms
Carrier
Process of inoculating an infective agent
Exposure
establishment of the infective agent in the host that leads to the manifestation of signs and symptoms or invasion of the body
Infection
invasion of the body
Infestation
period between infection or acquisition of the parasite and evidence or demonstration of infection
Pre-patent period or
Biologic Incubation Period
period between infection and manifestation of signs and symptoms.
ex. diarrhea, fever, chills, abdominal pain and cramping
Patent period or
Clinical Incubation Period
results when an individual becomes his own direct source of infection
Autoinfection
happens when an infected individual is further infected with the same species leading to massive infection with the parasite or increase the worm burden
Superinfection or Hyperinfection
parasite examples of autoinfection
CCHETS Capillaria philipinensis Cryptosporidium parvum Hymenolepis nana Enterobius vermicularis (romeo&juliet) Taenia solium Strongyloides stercolons
parasite that usually has no eggs in stool until it becomes superinfection
Strongyloides stercolons
stage that is infective to host (human)
Infective stage
stage that can be identified, detected, or measured by different laboratory procedures
Diagnostic stage
when parasite that requires only single host to complete it’s development
Direct Life cycle
when parasite requires 2 or more species of host to complete it’s cycle
Indirect Life cycle
when a disease in human pop. maintains a relatively steady, moderate level
Endemic
there is a sharp rise in the incidence or an outbreak of disease
Epidemic
if the prevalence of a disease in a community is high
Hyper endemic
if the disease appears only occasionally in one or few members of the society
Sporadic
when the disease covers extensive area of infection
Pandemic
parasites using transmission thru skin by direct penetration
Strongyloides stercoralis: hookworm in soil
Schistosoma: water
examples of anthropod vectors
Mosquitoes Flies Fleas Tick Bugs
examples of mosquito anthropod vectors
Culex
Anopheles/Aedes
Mansonia
what does Culex transmit?
Wuchereria bancrofti
what does Anoheles/Aedes transmit?
Plasmodium
what does Mansonia transmit?
Wuchereria bancrofti and
Brugia malayi
examples of flies anthropod vectors
Simulium Blackfly
Chrysops Fly
Sand Fly
Tsetse Fly
What does Simulium Blackfly transmit?
Onchocerca vulvulus
What does Chrysops Fly transmit?
Loa loa
What does Sand Fly transmit?
Leismania
What does Tsetse Fly transmit?
Trypanosoma rhodiense and
Trypanosoma gambiense
Examples of flea anthropod vectors
Dog flea
Rat flea
Water flea
What does dog flea transmit?
Dipylidium caninum
What does rat flea transmit?
Hymenolepsis diminuta
What does water flea transmit?
Diphylobothrium latum
What does deer tick transmit?
Babesia spp.
What does Reduviid bug (kissing bug) transmit?
Trypanosoma cruzi
parasites transmitted from CATS
Toxoplasma gondii Dipylidium caninum (and from dogs)
parasites transmitted from DOGS
Toxocara canis
Echinococcus granolus
parasites transmitted from RATS
Hymenolepsis nana
examples of parasites transmitted thru ingestion of contaminated food, water, and milk
Helminths (Ascaris)
- ingestion of embryonated eggs
Drancunculus medinesis
- ingestion of embryo in infected flesh
Trichinella spiralis and Taenia solium/saginata
- ingestion of encysted larvae in infected flesh
examples of parasite transmitted thru sexual activity
Giargia lamblia Entamoeba histolytica Trichomonas vaginalis (ping pong disease) *from oral sex: Entamoeba gingivalis Trichomonas tenax
examples of parasite transmitted thru respiratory tract
Enterobius vermicularis
Acantamoeba (can cause granulomatous amebic encephalitis)
Naegleria fowleri (can cause Primary amoebic meningoencephalitis PAM )
examples of parasite transmitted thru placenta or congenital
Plasmodium
Toxoplasma gondi
Trypanosoma
parasite transmitted thru mother’s milk
Strongyloides stercolaris and
Ancyclostoma stercoralis
examples of parasite transmitted thru eye contact with infected swimming water
Acanthamoeba
study of patterns, distribution and occurrence of disease
Epidemiology
number of new cases of infection appearing in a population in a given period of time
Incidence
number in a population estimated to be infected with a particular parasite species at a given time expressed as percentage
Prevalence
percentage of individuals in a population infected with at least one parasite
Cumulative prevalence
measured directly by counting expelled worms or indirectly by counting the eggs in the feces. Expressed as eggs per gram
Intensity of Infection or
Worm burden
disease
Morbidity
Death
Mortality
involves individual-level deworming with selection for treatment on a diagnosis of infections or an assessment of the intensity of infection or based on presumptive grounds
Selective Treatment
group-level deworming where the (risk) group to the treated (without prior diagnosis) may be defined by age, sex, or otehr social characteristics irrespective of infection status.
Targeted Treatment
population-level deworming in which the community is treated irrespective of age, sex, infection status or other social characteristics
Universal Treatment
use of anti-helmintnic drugs in an individual or public health program
Deworming
refers to the number (expressed as percentage) 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
Cure rate
percentage fall or decrease in egg counts after deworming based on examination of a stool or urine sample using a standard procedure at a set time after the treatment
Egg reduction rate
proportion of the target population reached by an intervention
Coverage
genetically transmitted loss of susceptibility to a drug in a worm population that was previously sensitive to the appropriate therapeutic dose
Drug resistance
effect of drug against an infective agent in ideal experiment conditions and isolated from any context
Efficacy
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
Effectiveness
a reduction in zero of the incidence of a specified disease in a defined geographic area as a result of deliberate efforts. continued intervention or surveillance measures still required
Elimination
defined as a permanent reduction to zero of the worldwide incidence of infection caused by specific agent as a result of deliberate efforts. Surveillance and measures are no longer needed.
Eradication
