Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HSS1100 > 7 > Flashcards

7 Flashcards

1
Q

What is a parasitism

A

Intimate and obligatory and symbiotic relationship between two organisms of different species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In what way is the parasite dependent on a host

A

Metabolically and physiologically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Example of a short term and a permanent parasite

A

Mosquito and tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How common is parasite

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are true parasite

A

Protozoans (single celled )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Success of parasite dined in terms of:

A

Prevalence in host
Number of host species available
Geographic range
Number of offspring
Available routes of transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is giardia lamblia history

A

Documented as first true pathogen in 1900
Leeuwenhoek 1681
Most frequently identified intestinal parasite worldwide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Symptoms of g. Lamblia

A

Asymptomatic (carriers)
Acute guardian: diarrhea, WL, abdominal discomfort, nausea, vomiting
Retardation of growth and development in young children (failure to thrive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the prevalence of giardia lamblia

A

Most common infection of intestinal tract
-2-5 in industrialized world 20-30% in developing world
-prevelnace rises in infancy and childhood and declines in adolescence
-travellers and immunocporised
-water/outdoor activities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Life cycle of gardia lamblia

A

Excystation
Trophozoites in small intestines
Longitudinal binary fission
Encystation
Cysts shed with faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how is g.lamblia diagnosed

A

MICROSCOPY (stool exam)
* cysts concentrated by flotation and
identified using bright-field
microscopy

immunofluorecence microscopy
using fluorochrome-conjugated
mAb’s that bind to cyst wall

Immunological Testing
* detection of Giardia-specific antigens in
faeces (eg. ELISA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

treatment of Glamblia

A

Nitroimidazole derivatives
- metronidazole and tinidazole are the
drugs of choice; 2 g (single dose) daily
for 3 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how to control g.lamblia out break with water treatemtn

A

Nitroimidazole derivatives
- metronidazole and tinidazole are the
drugs of choice; 2 g (single dose) daily
for 3 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

PUBLIC HEALTH EDUCATION of g.lamnlia

A

increase awareness of person-to-person transmission;
improve hygienic practices (e.g., daycares)
* food-borne infections (food handlers, wash produce)
* backpackers drinking raw surface water are at risk
(portable filters, boil water)
* Advice to travelers (avoid tap water, peeled fruits)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Trichomonas vaginalis

A

most common sexually transmitted disease worldwide (200 million cases)
Transmitted through mucous membrane contact
(no resistant cyst stage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Trichomonas vaginalis - Symptoms

A

40-50% asymptomatic carriage
* Vaginitis (trichomoniasis) with itching, foul-smelling,
sometimes frothy discharge
* May increase susceptibility to cervical cancer and HIV infection
* Infection during pregnancy may result in premature delivery and
low birth weight
* Males usually asymptomatic; occasionally urethritis, prostatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Trichomonas vaginalis - Diagnosis

A

Microscopy (wet mounts) to identify trichomonads in vaginal or urethral discharge

Vary greatly in size
(10-30µm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Trichomonas vaginalis - Treatment

A

metronidazole and tinidazole are drugs of
choice
* To avoid re-infection, testing and treatment
of partners is important

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Toxoplasma gondii

A

Recognized as a human pathogen in early 1900’s
* Very high seroprevalence in humans worldwide
* Large number of mammals and birds act as
intermediate hosts
* cats are the only definitive hosts (shed oocysts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Toxoplasma gondii- Transmission

A
  1. Ingestion of sporulated oocysts (10-12 µm)
    - contaminated soil/sand
    - contaminated fruits and vegetables
    - waterborne outbreaks (Victoria, B.C., 1995)
  2. Ingestion of tissue cysts
    - raw or poorly cooked meat
  3. Congenital infection of fetus
    - infection acquired during pregnancy (most severe if
    acquired in first trimester)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Symptoms of toxoplasmosis

A
  1. Immunocompetent host
    90% asymptomatic, lymphadenopathy, headaches,
    muscle aches, fever, malaise
  2. Immunocompromised host
    encephalitis, myocarditis, pneumonia
    (AIDS-defining disease)
  3. Congenital infection
    hepatosplenomegaly, mental retardation,
    retinochoroiditis, hydrocephalus
22
Q

Treatment of toxoplasmosis

A

Diagnosis based on serological assays
* Immunocompetent patients normally don’t require
treatment unless symptoms become severe or
chronic
* Immunocompromised patients require prompt
treatment with a combination of pyrimethamine and
sulfadiazine
* Congenital infections:
– Mother/fetus can be treated to reduce incidence and
severity of fetal infection
– Infected newborns can also be treated to minimize
sequelae

23
Q

Malaria -Transmission

A

Anopheline mosquitoes (vectors)
* Blood transfusion / shared needles
* Congenital infection
* “Airport malaria

24
Q

Symptoms of Malari

A
  • Spiking fever and chills
  • Flu-like symptoms (myalgias, headaches,
    abdominal pain, malaise)
  • Severe symptoms (P. falciparum)
    seizures, coma, renal failure, respiratory
    failure
25
Q

Malaria prophylaxis and treatment

A
  • Chloroquine and mefloquine are drugs of
    choice for prevention and treatment
  • drug resistance is a serious problem
26
Q

Control of Malaria

A

Largely a man-made disease (clearing of
forests, building of irrigation canals)
* Eradication or control of mosquitoes
(resistance to insecticides)
* Protection against mosquito bites
– Avoid rural areas at night
– Long-sleeved shirts/long pants
– Insect repellent
– Bed netting

27
Q

Cryptosporidium spp

A

recognized as human pathogen (1976)
* reported in humans worldwide
* The most common symptom of cryptosporidiosis is
watery diarrhea; other symptoms include dehydration,
weight loss, abdominal pain, fever, nausea, vomiting
* chronic, debilitating, and potentially life-threatening
symptoms in immunocompromised

28
Q

Life cycle – Cryptosporidium

A

complex life cycle including both sexual and asexual phases (oocysts 4-6 µ)

obligate intracellular protozoan which infects the intestinal epithelial cells of the host (typically in small intestine)

29
Q

Transmission - Cryptosporidium

A

WATER
* numerically the most important mode of
transmission (contaminated drinking water)
* recently numerous outbreaks associated with
water parks/pools

30
Q

Transmission - C. parvum

A

PERSON-TO-PERSON
* ingestion of oocysts due to poor hygiene
(e.g., day cares, institutionalized patients)

AUTOINFECTION
* thin-walled oocysts are released into the lumen
and cause autoinfection
* responsible for chronic and life-threatening
disease in immunocompromised

ZOONOTIC
* cattle serve as important
reservoir hosts
* calves with diarrhea can excrete up to 1010
oocysts/day
* environmental contamination; veterinary
personnel and animal handlers at increased risk
(petting zoo visitors)

31
Q

Diagnosis - C. parvum

A

MICROSCOPY
* oocyst shedding intermittent;
multiple stools examined
* concentration methods can be used
when low oocyst shedding
* wet-mounts or permanent stains are
used (acid-fast)
* Fluorescein-labelled IgG mAb is
used in immunofluorescence
microscopy

32
Q

Control - C. parvum

A

PUBLIC HEALTH EDUCATION
* in endemic areas, avoid drinking tap water/ice cubes,
raw fruits and vegetables unless you can peel them
* immunocompromised patients should consider
bottled water
* exposure to temperatures above 60°C and below
-20°C will kill oocysts

because crypto is spread person-to-person,
handwashing helps prevent infection

  • precautions are required when caring for
    patients with crypto diarrhea; lack of
    effective disinfectants against oocysts
    (nosocomial infections)
33
Q

Cyclospora cayetanensis

A

Identified as a coccidian protozoan parasite and
named in 1993
* Cases reported in North, Central, South America,
Caribbean, S.E. Asia, Europe, UK, India, Africa
* Endemic countries include Nepal, Haiti, Peru,
and Guatemala

34
Q

Cyclosporiasis - Symptoms

A

Low infectious dose
* Incubation period approximately 1 week
* Profuse and prolonged diarrhea
* Abdominal pain, nausea, vomiting, fatigue,
fever, loss of appetite
* Effectively treated with bactrim
(trimethoprim-sulfamethoxazole)

35
Q

Cyclosporiasis - Diagnosis

A

microscopic examination of wet mount
stool for oocysts (brightfield, differential
interference contrast, autofluorescence)
* staining methods (e.g. acid-fast)

36
Q

Cyclosporiasis - Transmission

A

Person-to-person transmission unlikely
* Zoonotic transmission unlikely
* Most earlier outbreaks were waterborne
* 90-99% of cases in U.S. are foodborne
* Numerous foodborne outbreaks in recent years

37
Q

Enterobius vermicularis

A

Prevalent world wide
* Highest incidence in school-age children
* Up to 50% of children in North America
* More of a nuisance than a health problem
* Eggs ingested (faecal-oral route)

38
Q

Pinworm - Symptoms

A

Mild infection of caecum/colon
* May cause itching (pruritus ani) leading to
disturbed sleep, irritability
* Scratching may cause secondary infections

39
Q

Pinworm – Diagnosis/Treatment

A

Scotch-tape test of perianal area
* Microscopic identification of
eggs; adult female worms may
also be present (8-13mm)
* Drug of choice is pyrantel pamoate

40
Q

Pinworm - Control

A

Personal hygiene education for children
(wash hands)
* Discourage scratching, nail biting
* Frequent bathing; regular change of
underclothing, pajamas, and bedding

41
Q

Trichinella spp.

A

Small roundworm found worldwide in many
carnivorous and omnivorous animals, including
humans
* Transmitted through ingestion of larvae in raw or
poorly cooked meat
* Survives as adult in small intestine; as larvae
encysted in striated muscle

42
Q

Trichinella spiralis vs Trichinella nativa

A

Trichinella spiralis (domestic form)
- humans, swine, rats (responsible for endemicity)
- horses! (probably fed animal products as supplement)

Trichinella nativa (sylvatic or wild form)
- humans, bears, wild boar, wolf, fox, walrus, etc

43
Q

Trichinellosis - Symptoms

A

Symptoms dependent upon phase of life cycle
* When larvae excyst in small intestine - diarrhea,
abdominal pain, vomiting
* When next generation of larvae migrate into muscle tissues
- facial edema, conjunctivitis, fever, myalgias
* Occasional life-threatening manifestations include
myocarditis, central nervous system involvement, and
pneumonitis

44
Q

Trichinellosis - Treatment

A

Thiabendazole effective against intestinal phase
* Mebendazole and albendazole have some effect
on tissue phases
* Steroids may be used to reduce inflammation

45
Q

Trichinellosis - Control

A

Rodent control
* Avoid garbage feeding to livestock
* Inspection programs (trichinoscopy, digestion, ELISA)
* Cooking /freezing (T. nativa very resistent to freezing

46
Q

Diphyllobothrium spp.
(Broad fish tapeworm

A

large tapeworm (10 m long)
* Adult tapeworm inhabits the small intestine
of humans and other fish-eating mammals
* Larval stages in freshwater fishes (e.g. pike,
trout, perch, whitefish, salmon) which act as
intermediate hosts

47
Q

Diphyllobothrium spp.

A

Transmitted through the consumption of raw or
poorly cooked freshwater fish containing
infective larvae

48
Q

Diphyllobothrium spp. - Symptoms

A
  • Most cases are asymptomatic
  • Abdominal pain, dizziness, fatigue, vomiting,
    diarrhea/constipation
  • Vitamin B12 deficiency with
    pernicious anemia
49
Q

Diphyllobothrium spp. – Diagnosis
and Treatment

A
  • Stool examination for eggs (microscopy) or
    proglottids (segments)
    Anthelmintic drugs effective (Praziquantel)
50
Q

Taenia spp

A

Large tapeworms (up to 20 m in length)
* Adult stage only found in humans
* Transmitted through ingestion of larvae in
raw or poorly cooked meat

51
Q

Taenia spp. (symptom diagnosos trestment)

A

Symptoms (adult tapeworm)
-mild abdominal complaints
Diagnosis
-Eggs or proglottids in stool
-Serological techniques
Treatment
-Anthelmintic drugs (Praziquantel)
-surgery

HSS1100 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions