UNIT 1 (part two) Flashcards
is the study of a disease in relation to the population, aspects of disease such as incidence, prevalence and transmission in a population
epidemiology
disease refers to a disease that occurs with a predictable frequency with minor fluctuations in a population
endemic
disease refers to diseases that occur at a higher level in a place at a time than expected for the disease in the place at that particular time
epidemic
are those diseases that occurs irregularly with widely dispersed incidence or a disease that occurs infrequently
sporadic
is an epidemic occurring in a wide/larger area.
pandemic
is the time lapse between the entry of the parasite and the first appearance or onset of clinical signs
incubation period
is the period in which the form of the parasite is demonstrated in the clinical materialof the host.
prepatent period
refers to temporary cessation in the development of immature stages of some nematode parasites in the host due to adverse environmental conditions
hypobiosis
refers to low activity of parasites in winter.
hibernation/winter sleep
is the period of low activity in summer
aestivation
is aperiod of low activity in arthropods.
diapause
hypobiosis classifications:
- hybernation
- aestivation
- diapause
is a (Virgin birth) refers to formation of progeny without fertilization
parthenogenesis
example or parthenogenesis
haemaphysalis ticks and strongyloids, specifically of nematodes
(Juvenile multiplication) refers to multiplication of juvenile/immature stages of parasite in intermediate hosts.
paedogenesis
example of paedogenesis
multiplication of immature snail eggs
(Alternation of generation) refers to sexual multiplication alterating with asexual multiplication
metagenesis
example of metagenesis
trematodes, Sexual multiplication in definitive host alternating with paedogenesis in intermediate hosts
is a type of asexual division/ multiplication in protozoa where a parasite multiplies into numerous individuals by multiple fission. The nucleus of the parasites undergoes repeated division without cytokinesis
schizogony
is the differentiation of gamonts in to male and female gametes
gametogony
is the union of the male and female gametes to form the zygote
syngamy
is the differentiation of zygote to cocyst, sporecyst and sporozoites
sporogony
schizogony classifications:
- gametogony
- syngamy
- sporogony
modes of transmission:
- ingestion
- skin penetration
- contact
- predation
- coitus
- transplacental/transmammary transmission
classification of parasites:
- phylum protozoa
- phylum platyhelminthes/nemathelminthes
- phylum arthropoda
single-celled organism, multiply in human host, Medical Protozoology
phylum protozoa
multicellular worms, do not normally multiply in human host, medical Helminthology.
phylum platyhelminthes and phylum nemathelminthes
medical entomology
phylum arthropoda
effect of parasites on the host:
- direct effects
- indirect effects
may be inflicted by a parasite by means of pressure as it grows larger
mechanical injury
in Plasmodium falciparum production of toxic Substonces may cause nigors and other symptoms.
deleterious effect of toxic substances
parasite may produce disease by competing with the host for nutrients.
deprivation of nutrients, fluids, and metabolites
direct effects:
- mechanical injury
- deleterious effect to toxic substances
- deprivation of nutrients, fluids, and metabolites
indirect effects:
immunological reaction
“Excessive proliferation of certain tissues due to invasion by some parasites can also cause tissue damage in man” is an example of?
immunological reaction
the route followed by a parasite from the time of entry to the host to exit
life cycle of parasites
infection is the result of entry and development within the body of any injurious organism regardless of its size.
host parasite relationship
Once the infecting organism is introduced into the body of the host, it reacts in different ways and this could result in a
carrier state
this is due to an imperfect host parasite relationship where the porasite dominates the upper hand.
disease state
occurs when the host takes the upper hand.
parasite destruction
in those parasitic infections where the parasite itself in any stage of its development circulates in the ______ stream, examination of _____ film forms one of the main procedures for specific diagnosis.
blood
examination of the ______ forms an important part in the diagnosis of intestinal parasific infections and also for those helminthic parasites that localize in the biliary tract and discharge their eggs into the intestine.
stool
when the parasite localizes in the urinary tract, examination of the ______ will be of help in establishing the parasitological diagnosis.
urine
examination of _______ is useful in the following:
1. In cases where the habitat of the parasite is in the respiratory tract, as in Paragonimiasis. the eggs of Paragonimus westermani are found.
2. In amoebic abscess of lung or in the case of amoebic liver abscess bursting into the lungs. the trophozoites of E. histolytica are detected in the _______.
sputum
varies with different parasitic infections. For example spleen punctures in cases of kala-azar, muscle biopsy in cases of Cysticerosis, Trichinelliasis, and Chagas disease, Skin snip for Onchocerciasis.
biopsy material
for Trichomonas vaginalis Indirect evidences - changes indicative of intestinal parasitic infections
urethral or vaginal discharge
eosinophilia often gives an indication of tissue invasion by helminthes, a reduction in white blood cell count is an indication of kala-azar, and anemia is a feature of hookworm infestation and malaria.
cytological changes in the blood
are carried out only in laboratories where special antigens are available.
serological tests
many parasitic infections can be cured by specific chemotherapy. The greatest advances have been made in the treatment of protozoal diseases.
treatment
measures may be taken against every parasite infecting humans. Preventive measures designed to break the transmission cycle are crucial to successful parasitic eradication.
prevention and control
classification of medical parasitology:
- medical protozoology
- medical helminthology
- medical entomology
Deal with the study of medically important protozoa.
medical protozology
Deals with the study of helminthes (worms) that affect man.
medical helminthology
Deals with the study of arthropods which cause or transmit disease to man
medical entomology
asexual multiplication classifications:
- simple binary fission
- multiple fission or schizogony
in this process, after division of all the structures, the individual parasite divides either longitudinally or transversely into two more or less equal parts.
simple binary fission
in these process more than two individuals is produced, e.g. asexual reproduction in Plasmodia.
multiple fission or schizogony
sexual reproduction classifications:
- conjugation
- syngamy
in this process, a temporary union of two individuals occurs during which time interchange of nuclear material takes place. Later on, the two individuals separate.
conjugation
in this process, sexually differentiated cells, called gametes, unite permanently and o complete fusion of the nuclear material takes place. The resulting product is then known as a zygote.
syngamy
protozoa classifications:
- ameobas
- ciliates
- flagellates
- sporozoans
parasite that consists of a single “cell-like-unit” which is morphologically and functionally complete and can perform all functions of life.
protozoa
