Test 5 Intestinal Nematodes Flashcards
What is the common name of the Intestinal Nematodes?
Roundworms
What is the shape of the Intestinal Nematode (Roundworm)?
Cylindrical
Tapering at both ends
Unsegmented
What portion of the Intestinal Nematode is the outer covering, relatively impermeable, protective, and is shed during molting?
Cuticle
Describe the Nervous system of the Intestinal Nematode?
Nerve Rings: Anterior or Posterior.
Receptors (Sense Organs): Photo, Mechanical and Chemical
-Two lateral longitudinal nerves
The intestinal nematode has what specialized structure for attachment?
Buccal Structures
What are the Copulatory organs of the intestinal nematode?
- Bursa: Grasping the female
- Spicules: Injection of spermatozoa
Name the different Intestinal Nematodes?
- Ascaris lumbricoides
- Enterobius vermicularis
- Hookworm
- Strongyloides stercoralis
- Trichuris trichiura
What is the common name of the Ascaris lumbricoides?
Giant intestinal roundworm
How many Giant intestinal roundworm (Ascaris lumbricoides) can be found in a host?
Up to 1,500 worms/host
General Characteristics of Ascaris LUmbricoides (Giant Intestinal roundworm) symptoms?
- Blockage intestinal lumen
- Localized hemorrhage
- Localized Edema
- Appendicitis
- Ascarid Pneumonitis
- Visceral larval migrans (Ectopic foci are sites other than the usual habitat in the body)
What is the life cycle of the Ascaris Lymbricoides (Giant Intestinal Roundworm)?
1) Eggs passed in feces
2) Mature egg ingested
3) Larva hatch in GI
4) Enters Venules via intestinal wall
5) Travel to Heart and Lungs
6) Travel into Alveoli
7) Molt
8) Coughed up and Swallowed
9) Mature and mate in intestine
10) Female lays eggs
What is the habitat of the Giant Intestinal Roundworm (Ascaris lumbricoides)?
Small Intestines
What are the intermediate and Reservoir host of the Ascaris lumbricoides (Giant Intestinal Roundworm)?
Intermediate: NONE
Reservoir: SWINE
What is the infective form and mode of infection of the Giant Intestinal Roundworm (Ascaris lumbricoides)?
- Infective form: Mature Embryonated egg
- Mode: Ingestion
Infection with Ascaris lymbricoides cause (pathology) what symptoms?
- Most asymptomatic
- Some pulmonary symptoms during lung migration phase
- Mild abd discomfort
- Dyspepsia
- Loss of appetite
- Nausea
How does Ascaris lymbricoides infection affect children?
- Affects intellectual development, cognitive performance, and growth
- Secrete molecules that modulate lymphocyte proliferation and cytokine production
- Depresses appetite and food intake by children: (interferes w/absorption of proteins, fats, lactose, Vit. A, and Iodine)
How is diagnosis made for Ascaris lumbricoides infection?
Id of passed adult worms
Stool for eggs
What is the specimen of choice for lab Id of an Ascaris lumbricoides (Giant Intestinal Roundworm) infection?
Feces
Lab Id of the Decorticated ova of Ascaris lumbricoides eggs what is the size, color, and shape?
- Size: Small-Medium
- Shape: Oval to round
- Color: Hyaline to Light Brown
What is the Content of the Ascaris lumbricoides egg and what appearance does it have fertilized and unfertilized?
Yolk Mass
- Fertilized: Organized, pulled away from wall
- Unfertilized: Disorganized, Fills the shell
Lab Id of the Corticated ova of Ascaris lumbricoides eggs what is the size, shape, color, and content?
- Size: Medium
- Shape: Oval, Elongated, somewhat rectangular
- Color: Brown cortication, hyaline shell wall
- Content: Yolk mass
Lab Id of Adult form? (Size)
Male: 15-30cm
Female: 20-35cm
Lab Id of Adult form, Shape, Color, and Buccal structures?
- Shape: Round and slender, male curved tail
- Color: Creamy-white w/pinkish cast
- Buccal: Three lips
What is the Geographical Distribution of the Ascaris lumbricoides (Giant Intestinal Roundworm)?
-Worldwide
-Most prevalent helminth
(25%)
What is the common name of the Enterobius vermicularis?
Pinworm or seatworm
What is the pathogenesis of the Pinworm (AKA: Seatworm, Enterobius vermicularis)?
- Asymptomatic
- Mild to severe itching of perianal and vaginal region
- Occasional appendicitis
- Anxiety, insomnia, and irritability
What is the habitat of the Enterobius vermicularis (Pinworm, Seatworm)?
Large Intestine, Cecum
Name the intermediate host and Reservoir host of the Enterobius Vermicularis (Pinworm, Seatworm)?
Intermediate: None
Reservoir: None Known
What is the Infective form and Mode of infection of the Enterobius Vermicularis (Pinworm, Seatworm)?
- Infective: Embryonated egg (Rhabditiform larva)
- Mode: Ingestion
What is the life cycle of the Pinworm (Enterobius Vermicularis, Seatworm)?
1) Gravid Female migrates to perianal region
2) Eggs oviposited along perianal folds
3) Eggs fully Embryonated and infective in 4-6hrs
4) Eggs spread from host to host easily
5) Eggs spread anus to mouth
6) Eggs ingested
7) Eggs hatch, infective 3rd stage larvae in small intestine
8) Molt
9) Travel to lg. intestine
10) Male and female mate
11) Female gravid
What population groups are commonly affected with Enterobius vermicularis (Pinworm, Seatworm) infections?
Pathogenesis
- Easily spread
- Household
- Children 5-14
In the pathogenesis of Enterobius vermicularis, when do the eggs become infective and for how long are they infective?
Infective within 6hrs and last up to 20 days
Common transmission sources of Enterobius Vermicularis (Pinworm, Seatworm)?
- Hand-to-mouth
- Anal pruritus encourages scratching
- Secondary infection
- Worms migrate to ectopic locations
What is the specimen of choice for Lab Id of Enterobius Vermicularis (Pinworm, Seatworm) infection?
Pinworm Paddle or “Scotch-tape prep” (Transparent adhesive tape specimen)
What is the lab Id characteristics for the Ova form of Enterobius vermicularis (pinworm, Seatworm)? Shape, Color, Content, Shell Wall
-Shape: “D” Shape (Oval); Usually flattened on one side
-Color: Hyaline
-Content: 1st stage- “Vermiform” larva
or undeveloped larva “tadpole” larva
-Shell Wall: Triple Layer
What is the lab Id characteristics for the Adult form of Enterobius vermicularis (pinworm, Seatworm)? Size, Shape, Color, Cephalic alae, Esophageal bulb
- Size: Male smaller than Female
- Shape: Sharply pointed tail in female
- Color: White
- Cephalic alae: Wing-like Structure
- Esophageal Bulb: Prominent
What is the Geographical distribution of Enterobius Vermicularis (Pinworms, Seatworms)?
Worldwide
What are the scientific names for the Hookworms?
- Ancylostoma Duodenale
- Nector Americanus
Which Hookworm is commonly known as the Old World Hookworm?
Ancylostoma Duodenale
In the Pathogenesis of the Hookworm (Ancylostoma Duodenale and Nector Americanus) name the different periods and phases of infection?
- Invasion Period
- Pulmonary Phase
- Intestinal Phase
- Sequelae
What pathogenesis period consist of Ground itch and larval penetration?
Invasion Period
What phase in the pathogenesis of the hookworm consists of Pneumonitis; due to larval irritation?
Pulmonary Phase
What is the Geographical distribution of the hookworm (Ancylostoma Duodenale)?
Europe and Asia
Becoming Worldwide due to migration
What is the infective stage of the Hookworm?
Filariform larva penetrates skin
Where are the adult forms of the Hookworm (Ancylostoma Duodenale and Nector Americanus) found in the human body?
Small Intestine
What is the diagnostic stage of a hookworm infection?
Eggs in feces
Describe the Intestinal Phase of Ancylostoma Duodenale (Hookworm) infection?
- Anemia: Blood Loss- .67ml blood worm/day
- Desquamation
- Malnutrition
What is the Secondary bacterial infection; TOXEMIA of the hookworm infection?
Sequelae
What are Characteristic signs of hookworm infection?
- Creeping Eruption
- Pruritus
- Iron Deficiency Anemia
- Bleeding at site
- Light infection- asymptomatic
What does the bite wound continue to bleed after the hookworm is no longer at the site?
Anticoagulants from the worm
What signs will Children infected with hookworm show?
Diminished:
- Physical Growth
- Cognitive Growth
- Intellectual Growth
If an individual is previously sensitized to a hookworm infection what sign may be seen?
Pruritis maculopapular rash (ground itch)
During migration of a hookworm infection an infected individual may have transient what?
Transient Pneumonitis
What signs may appear 30-45 days post infection?
- Epigastric Pain
- Diarrhea
- Anorexia
- Eosinophilia
What is the specimen of choice for lab Id of a hookworm infection?
Feces
In the Lab Id of the Hookworm Ova what characteristics will be seen?
- Shape: Oval w/bluntly rounded ends
- Color: Hyaline
- Content: Yolk Mass usually in cleavage
- Shell Wall: Thin, Single
In what environment are Roundworms found?
Free Living
Plant Parasites
Animal Parasites
What parasite has a complete digestive tract w/specialized esophageal area, intestines, rectum, Ammonia waste system and may have excretory pore and renette gland?
Roundworm
What is Monoecious?
Reproductive organs of male and female in one organism or segment
What is Dioecious?
Separate male and female organisms
What are the stages of development for the roundworm?
Ova: Nonoperculated
- Rhabditiform larva
- Filariform larva
- Molts
- Several between stages
- Intermediate forms
What is the common name of Strongyloides Stercoralis?
Threadworm
What is the diagnostic stage of a Strongyloides Stercoralis (Threadworm) infection?
Rhabditiform larvae excreted in stool
What are the infective stages of the Strongyloides Stercoralis (Threadworm) infection?
Filariform larvae penetrate human skin
-Autoinfect
What are the ways in which Strongyloides Stercoralis (Threadworm) will autoinfect?
Internal Autoinfection:
-Rhabditiform larvae become filariform larvae and penetrate intestinal mucosa
External Autoinfection:
-Rhabditiform larvae become filariform larvae and penetrate the skin of the perianal area
What parasite resembles that of the hookworm, males are eliminated early in parasitic cycle or gravid females enter mucosa and deposit eggs through parthenogenesis?
Streongyloides Stercoralis (Threadworm)
When the Strongyloides Stercoralis eggs hatch what typically occurs next?
Rhabditiform larvae burrow into lumen of intestine and pass out w/feces
What parasite may develop into infective filariform larvae penetrate the skin and follow a lung migration (Blood-Lung-Intestinal Route)?
Strongyloides Stercoralis
What parasite may develop into adults and exist for several generations as free-living nematodes, producing filariform later?
Strongyloides Stercoralis (Threadworm)
What is the Habitat of the Strongyloides Stercoralis (Threadworm)?
Small Intestine
What are the Intermediate Host and Reservoir host of the Strongyloides Stercoralis parasite?
Intermediate: None
Reservoir: Dogs and APES
What is the infective form of the Strongyloides Stercoralis and mode of infection?
Filariform Larva
Mode: Active Penetration
A Strongyloides Stercoralis infection may cause what pathogenesis reactions?
Skin: Portal of Entry -Petechial Hemorrhage -Pruritis Larval Migration: -High Eosinophilia -Sensitization Reaction Intestinal Infection: -Desquamation -Severe diarrhea and gastroenteritis -Anemia -Wt. Loss -Hyperinfection may be fatal in immunosuppressed pt
What is significant of the pathology of a Strongyloides Stercoralis infection?
- Autoinfective: can build large numbers in victim
- Infection can last long time (60years)
- Epigastric Pain
- Fluctuating Eosinophilia
- Recurrent Maculopapular rash of buttocks, perineum, and thighs
What is the Specimen of choice for Strongyloides Stercoralis infection?
Feces
Describe the Strongyloides Stercoralis ova and Rhabditiform Larva?
Ova: rarely seen -Similar to hookworm -Frequently Embryonated Rhabditiform Larva: -Buccal Cavity: Short -Genital Primordium: Large and Conspicuous -Tail: Short and Stubby
Describe the Lab Id of the adult form of Strongyloides Stercoralis?
Male: Only in free living cycle (>1mm) Female: free living (1mm), parasitic (2mm) Shape: Very slender, thread-like Color: Colorless; semitransparent Buccal: Short buccal cavity Copulatory bursa: Absent Spicules: Two
After treatment of Strongyloides stercoralis w/either, Ivermectin, Thiabendazole, or Albendazole, should fecal examination occur and when will IgG decline?
1 month after therapy
IgG declines 6-12 months after therapy
What is the common name of Trichuris Trichiura parasite?
Whipworm
What parasitic infection has a pathogenesis of Asymptomatic to severe disease, localized inflammation and bleeding, with anemia in severe infection and secondary bacterial infection?
Trichuris Trichiura (Whipworm)
What is the Diagnostic Stage of a Trichuris Trichiura (Whipworm) infection?
Unembryonated eggs in feces
What is the infective stage of a Trichuris Trichiura (Whipworm) infection?
Embryonated eggs ingested
What is the habitat of the Trichuris Trichiura (Whipworm) parasite?
Large Intestine, Cecum
What is the Intermediate and Reservoir Host of the Trichuris Trichiura (Whipworm) parasite?
Intermediate: NONE
Reservoir: NONE
What is the infective form and mode of infection of Trichuris Trichiura (Whipworm)?
Mature Embryonated Egg
Mode: Ingestion
What Parasite secretes proteins that forms pores in the lipid bilayers allowing the anterior end to embed in the epithelium?
Trichuris Trichiura (Whipworm)
What may be seen in severe infections of Whipworm (Trichuris Trichiura), especially in children?
- Chronic abdominal pain
- Diarrhea
- Iron Deficiency Anemia
- Growth Retardation and impaired cognitive function
- Clubbing of Fingers
- Bloody Stools, recurrent rectal Prolapse and Peritonitis due to perforation of intestinal wall
What is the specimen of choice for Lab Id of Trichuris Trichiura (Whipworm)?
Feces
What are the significant identifying indicators for the Ova of Trichuris Trichiura (Whipworm)?
- Size: Small to medium
- SHAPE: FOOTBALL, BARREL-SHAPE w/BIPOLAR PLUGS
- Color: Golden Brown
- Content: Yolk Mass
What parasite on Lab Id of Adult form has a female larger than male, shape Thick posterior and whip-like anterior, and flesh-coloration?
Whipworm (Trichuris Trichiura)
What is the Geographical distribution of the Whipworm?
Worldwide
How long after treatment w/Mebendazole, Albendazole, or Ivermectin should fecal examination occur to ensure cure?
2-4 weeks after therapy
What parasite on Lab Id is found to have a Cylindrical shape, head curved dorsally, Grayish-white coloration, and Two fused “teeth” on ea. side of ventral surface?
Ancylostoma Duodenale (Old World Hookworm)
The Male Ancylostoma Duodenale (Old World Hookworm) Has what kind of paired copulatory spicules and small paired dorsal rays?
Spicules: Separated
Dorsal Rays: Tripartite
Describe the Buccal Cavity, Genital Primordium, and Tail of the Rhabditiform Larvae of the Ancylostoma Duodenale Parasite?
Buccal Cavity: Large (Longitudinal Parallel Lines)
Genital Primordium: Small (Inconspicuous)
Tail: Slender, Long, and tapering
What is the common name of the Necator Americanus Parasite?
New World Hookworm
What is the Geographical Distribution of the New World Hookworm (Necator Americanus)?
Western Hemistphere
- Central and S. Africa
- Southern Asia
- Pacific Islands
- Becoming worldwide due to migration
What is the habitat for the New World Hookworm (Necator Americanus)?
Small Intestines
What are the Intermediate and Reservoir Host for the New World Hookworm (Necator Americanus)?
Intermediate: None
Reservoir: None
What is the infective form of the New World Hookworm (Necator Americanus) and mode of infection?
Filariform Larva
Mode: Active Penetration
What is the specimen of choice for the Lab Id of the New World Hookworm?
Feces
Describe the adult form of the New World Hookworm (Necator Americanus) that would be seen on Laboratory Identification?
- Size: smaller than Ancylostoma Duodenale (Old World)
- Shape: Cylindrical; Head sharply dorsally curved
- Color: Grayish-white
- Bucccal structures: Prominent Ventral and Dorsal Semilunar cutting plates
- Copulatory Bursa: Male
- Paired copulatory spicules: fused w/barb
- Small paired dorsal rays: bipartite
How long after treatment w/ Albendazole, Medbendazole, or Pyrantel Pamoate (Severe infection) should examination of the feces occur for hookworm infections?
2-4 weeks post therapy
What should be supplemented in a hookworm infection?
Iron
What are some Prevention technique to prevent Hookworm infection?
- Drink safe water
- Proper cooking and Cleaning food
- Handwashing
- Wear shoes
- Don’t sleep on exposed ground