ASCARIS (ROUNDWORM) Flashcards
What kind of pathogen is Ascaris?
Parasite (roundworm/nematode), largest of all intestinal nematodes
What is the most common type of Ascaris?
A. lumbricoides
How are roundworms (Ascaris) transmitted?
Spread by feces (contaminated soil)
-poor sanitation
Roundworms (Ascaris) are predominant in areas with higher incidences in ___?
Those with:
-poor sanitation
-malnutrition
-iron deficiency anemia
-growth and cognitive impairment
Who is at high risk of infection by roundworms (Ascaris)?
-International travelers/adoptees
-Immigrants
What is the pathogenesis of A. lumbricoides?
-Ingestion of eggs
-Hatch in small intestine and larvae penetrate intestinal wall
-Can migrate to alveoli through portal veins 1-2 weeks after infection and can cause pulmonary issues
-The larvae are then coughed into the mouth and swallowed (ew)
-larvae will mature in the GI tract and shed eggs in the intestines (up to 200,00 eggs per worm, the worms are going crazy just like us studying for this exam)
What are the symptoms of an infection by A. lumbricoides?
-Most are asymptomatic (can have pulmonary or GI complaints)
Symptomatic:
Early (14-16 days after ingestion)- fever, non-productive cough, dyspnea, wheezing
Late (6-8 wks after ingestion)- GI symptoms, possible bowel obstruction, appendicitis, pancreatitis, can travel to kidneys and brain (RARE)
How long can A. lumbricoides live in a person?
6-24 months
How can you diagnose A. lumbricoides?
Early:
-Complete blood count (eosino-philia, increased # of eosinophils)
-increased IgE and IgG
-Sputum can reveal live larvae or crystals produced by white blood cells
Established infection:
-Stool shows eggs and parasites 40 days after ingestion
How can you treat A. lumbricoides?
Early phase: symptomatic treatment
Established infection: Albendazole/Mebendazole
If pregnant: pyrantel
Bowel Obstruction: IV hydration, NG suctioning, Electrolyte monitoring, Laparotomy/Colonoscopy/Endoscopy to remove obstructing mass of worms
