Test 1 Notes Flashcards
1
Q
Factors Influencing Distribution of Parasitic Disease
A
- Rapid Travel
- Immigration
- Increased number of immunocompromised patients
2
Q
Amebia of duck, geese and swan. Its accidental parasite of humans causing meningitis
A
Naeglaria Fowleri
3
Q
Intestinal flagella without flagellum or pseudopodia that causes diarrhea in humans
A
Dientamoeba Fragilis
4
Q
Infestation
A
Parasitic Organism or arthropod that live on surface of a host without multiplication
5
Q
Infection
A
Invasion and multiplication of a pathogenic parasite in the body with accompanying reaction by the host
6
Q
Disease
A
any damage of hot tissue or organs that leads to malfunction of an organ caused by a parasite
7
Q
Protozoa
A
Unicellular microscopic eukaryoticorganism
8
Q
Helminths
A
worms, muticellular, often visible to the naked eye
9
Q
arthropoda
A
insects lice etc.
hard exoskeletons, jointed appendages
10
Q
Most Prevalent Tropical Diseases
A
7 out of 8 are parasites
11
Q
Most harmfull infective diseases afflicting humans
A
5 out of are parasites
12
Q
More than 1,000,000 people are
A
afflicted by parasites
13
Q
Humans play host to
A
dozens of parasites
14
Q
Parasites can also infect
A
animals and plants
15
Q
Vector
A
Any arthropod or other living organism that transports a pathogenic microorganism form an infected to a non-infected host
Usually an intermediate Host
ex. malaria
16
Q
Final Host
A
the host organism in which a parasite passes its adult and or sexual reproduction phase (trophozoite)
17
Q
Intermediate Host
A
The host organism in which a parasite passes its larval stage or asexual reproduction phase
Vector is usually an intermediate host
18
Q
Mosquitos in Malaria
A
Anopheles mosquitos carry plasmodium and transmit malaria from host to host. The mosquito is the Final host.
Humans are intermediate hosts.
19
Q
Reservoir Host
A
An animal that harbors a species of parasite and can serve as a source of parasitic infection for human
Can also be the intermediate host
20
Q
Vector
A
usually an intermediate Host, an invertebrate (insect) that transmits the larval or juvenile parasite by its bite. It is a vehicle by which some parasites are transmitted from host to host
21
Q
Premunition
A
Immunity, generally of a low level, resulting from the continued presence of the parasite (chronic). It does not eliminate the original infective parasite but is prevents hyper infection
22
Q
Premunition
A
A poorest who has been infected is producing immunity but is not strong enough to wipe out he parasite
23
Q
Disease
A
interruption of the normal function of an organ and or a morbid change in a tissue
24
Q
Infection
A
acquisition of a microorganism that may establish itself (grow and reproduce) in/on a host or may be transient in a host
25
Infestation
microorganism living on the surface of a host. Pets with Flees
26
All parasites elicite immune responses including the formation of
IgM, IgG, and IgA antibodies
27
Host's immune response to parasitic infection is complex and time consuming and sometimes ineffective. Why?
1. Rapid rate of reproduction
2. Large size
3. Production of slime layer
4. Complex life-cycle (various morphological forms and antigen conversions)
5. Masking of there surface antigens withe n host cell maker (HLA= Human leukocyte Antigen)
6. By=production can prevent the function of antibodies macrophages lymphocytes and cause immunosuppression
7. Production of high level of IgE Antibody (Helminth Worm)
8. Induce T-Cell delayed hypersensitivity response (protozoa)
9. Concominant
10. Parasitic organism that had a long coevolution with their host
28
Concominant
Parasites larval form can be destroyed by host antibodies, and the presence of these antibodies provide resistance to reinfestation by new larvae
29
Protozoa
Single Celled organism, animal like, microbes usually having motility
30
Classification of Protozoa
1. style of movement
2. Mode of reproduction
3. Stages in life Cycle
31
Sarcodina
Ameba
32
Sarcodina/Ameba
Pseudopdia (false feet)
some flagella during reproduction
most are not infectious
Reprodution Binary Fission
Usual form cyst
33
Enamoeba histoytica
only human pathogen ameba
34
Mastogophora
Glagellata
35
Mastogophora/Flagellata
flagella with some ameboid species
sexual and asexual reproduction
most free living
some parasite
36
Trypanosoma and Leishmania
Flagellata parasites with one flagellum
37
Giardia
Flagellata parasite with 4 flagellum
| Intestinal
38
Trichomonas
Flagellata parasite with 6 flagellum
| reproductive tract
39
Ciliphora
Ciliata
40
Ciliphora/Ciliata
Moved by Cilia
also used for attachment and feeding
Transverse fission = asexual
majority free living
41
Balantidium coli
only pathogenic Ciliate
| lives in animals intestines may infect humans
42
Sporozoa
```
Movement not characteristic
soe flagella or pseupoda preset
well developed asexual and sexual stages
most form cyst
ALL ARE PARASITIC
```
43
Plasmodium
causes Malaria
| 100-300 million cases/year in world
44
Transition of protozoa
ingestion infected stage or protozoa
| arthropod vector
45
Sacodina/Ameba
General Characteristics
1. Motile and parasite to human intestine
2. Reproduce by simple asexual division
3. Most common in the lower GI tract
4. Some form of non-feeding, non-motile cyst stage
which is infective to humans
5. Transmission by ingestion of cyst in fecaffy contaminated food or water
46
Morphological Life Cycle of Amebea:
Trophozoite---Active feeding cell
This stage is metabolizing stage and sensitive to environmental change.
Cyst---A dormant form that can survive for periods outside the host.
47
Morphological Life Cycle of Amebea:
It is surrounded by mineral wall, mostly calcium, and is resistant to environmental changes ( e.g....heat, cold ...etc.).
May have 1-8 nuclei depending to species Each nucleus can produce one adult trophozoite during excyst stage
Infection usually acquired by ingestion of food or drink contaminated with cyst
48
Excystation--Amebea
Cyst survive the oral and gastric secretions but alkaline pH and digestive juice stimulate excystation within 24 hours.
49
Cyst to Trophozoites
One nucleus = one Trophozoite
50
Encystation - Amebea
As trophozoites moves along with bowel
| movement, the environemnt becomes drier and the trophozoites start to undergo encystation
51
Cyst formation
cannot occur in active dysentery because the feces are so rapidly flushed from body.
52
Transmitionof Protozoa
1. Ingestion of the cyst stage in food/water and hand to mouth.
2. Via arthropod vector - such as the mosquito. Usually, these infect
subcutaneous tissues, deep organs etc.
3. Intimate contact - such as trichomonas found in the oral passage, urethra
of males, vaginal tract of females. We transmit the adult organism from person to person or host to host (sorry - the picture was cut out to avoid X-rating).
4. Penetration of the skin - usually these would be things like hookworms. The parasite is out in the environment and penetrates into the skin to the
circulatory system which takes it to the intestinal tract. Anther example is swimmer's itch.
53
Trophozoite
requires ample food and moisture to remain active.
54
Cyst stage
dormant, resting stage
| when conditions in the environment become unfavorable for growth and feeding.
55
Encystment
he trophozoite cell fOlmds up into a sphere, and its ectoplasm secretes a tough, thick cuticle around the cell membrane.
56
Excystment
If provided with moisture and nutrients, a cyst break open and releases the active trophozoite.
57
Trophozoite
adult stage of protozoa. There is lots of cytoplasm surrounding the nucleus. Trophozoites are produced by binary fission (asexual). The trophozoite has mobility. In humans, they are usually found in the small intestines which is very wet and highly acidic. As it passes to the rectum the pH rises and the oxygen content decreases so that by the rectum the stool is well formed. These changes are bad for the protozoa and since there is no more moisture and nutrient it undergoes excystment to cyst stage by the rectum.
58
Cyst
dormant stage. Just a nucleus with very little cytoplasm. The cyst forms when the organism sense the pH, moisture and oxygen change and decides to condense its nucleus and squeeze out all of the free water. The only water left is bound water - water bound to the chromosomes. The DNA is double stranded and hydrogen bonding holds the strands together. That hydrogen bonding comes from water that is bound to the DNA Bound
water does not freeze nor does it become steam if you heat up that organism. As a result, the cyst can be out in the environment for long periods of time through freezing and ultra hot temperatures and survive. The cyst may contain 1-8 nuclei depending on the species. One cyst that contains 8 nuclei will give rise to four adult forms. (We said the cycle is both protective and reproductive ).
59
trophozoite vs cyst
The trophozoite usually produces the symptoms but we usually consume and excrete the cyst. cyst tends to be the infective stage
60
Host-Parasite Relationship: Depends on various factors:
I. Number of parasites: pathogenicity is usually proportional to the number of adults that are present.
2. Different people have different tolerance levels.
3. Toxic secretions - are what actually cause diarrhea to occur. 4. Host Response: Natural and acquired resistance.
61
Entamoeba Histolytica
amebic dysentery
62
Entamoeba Histolytica
| Epidemiology
Worldwide
63
Entamoeba Histolytica
| Forms
Trophozoites in large intestinal
| mucosa, liver, or other tissues
64
Entamoeba Histolytica
| Infection
Ingestion of cyst in
| fecally contaminated food or water
65
Entamoeba Histolytica
| Disease
Amebiasis, amebic dysentery, amebic hepatitis (if the liver is involved)
Enteritis with
abdominal pain
and bloody dysentery Diagnosis: cysts and trophozoites in feces
66
Entamoeba Histolytica
| Symptoms
abdominal pain, fever" diarrhea, fatigue, bloody dysentery and weight loss.
67
Entamoeba Histolytica
| extraintestinal
a. amebic hepatitis-necrotized
and fluid develop at the site of invasion of trophozoites Symptoms: Enlarged liver, fever, chills, and leukocytosis.
b. pulmonary amebiasis-by direct penetration of the diaphragm get to the lung.
c. Less frequently invade spleen, kidney, skin, and brain.
Chronic infection may last for years, and
amebiasis is often spread by chronic healthy carriers.
68
Entamoeba Histolytica
| Primary infectionsite
Cecum
69
Dysentery
Dysentery is diarrhea with blood and mucous in it
70
Naegleria Fowleri-
Free living ameba---
Normally found among water fowls, ducks, geese
and swans. They are abundant in standing fresh
water, lake, ponds, and even swimming pools and hot tubs.
In animals it causes an intestinal infection with diarrhea or dysentery.
Accidental parasites of human, and may cause primary acute meningeoencephalitis.
71
trophozoite of Naegleria
small, flask- shaped that moves by a single broad pseudopod.
72
Naegleria fowleri
| Disease
```
Primary acute meningoencephalitis
Infection begins through nasal passage as a result
of swimming or diving.
Amebic form=>
l nasal mucosa=>
2 multiplication =>
3 migration=>
4 cross the
cribiform plate=>
5 enters the brain and meninges
6 rapid destruction brain and spinal tissues
7 hemorrhage and coma
8 death within a week
```
73
Naegleria fowleri
(primary amebic (acute) meningoencephalit is (PAM)
74
Naegleria fowleri
| Epidemoilogy
Worldwide
75
Naegleria fowleri
| How Disease Occurs
Accidental entrance of free living water-borne trophozoites through nasopharynx mucosa
Water up nose forcefully
76
MASTIGOPHORANS (THE FLAGELLATES)
| General characteristics:
1. Free living to parasitic
2. Inhabit the gastrointestinal tract, atria (an opening, in humans refers to the mouth, vagina, and urethra), bloodstream and tissues of human
3. Extensive role in human disease
77
Trichomonas Vaginalis:
| Reservoir--
human urogenital tract
78
Trichomonas Vaginalis
| Signs/Symptoms
Pathogen of the reproductive tract that causes
SID caned trichomonoiasis (Trichomonad vaginitis in females and urethritis in males).
Symptoms and sign:
female--
creamy, odorous, green to yellowish vaginal discharge, vulvitis, cervicitis and urinary
frequency and pain.
persistant vaginal inflammation causes tenderness edema, and itching
male--
asymptomatic infection- (for years that can lead to proctitis)
symptomatic infection- recurring urethritis with a milky discharge and prostate infection
majority of infected male are asymptomatic carriers
79
Trichomonas Vaginalis
trich
80
Trichomonas vaginalis
| Disease Producing Form
Trophozoites in urethra or vagina
81
Trichomonas vaginalis
| Infection
Sexual Contact
82
Trichomonas vaginalis
| Disease
Trichomonad vaginitis, urethritis, trich
Irritating, frothy vaginal discharge in women; men usually asymptomatic Diagnosis: trophozoites in urine or vaginal smear (no cysts formed)
83
Trichomonas vaginalis
venereal disease
84
Trichomonas tenax
Is a normal organism of the human body commonly found in the oral passage. It is NOT a pathogen, but rather it is beneficial to us serving as a scavenger along the gingiva.
