Infectious Disease Book



Aka: Ascaris, Ascariasis
  1. Classification
    1. Nematode: Roundworm
  2. Pathophysiology
    1. Infected patient with Ascariasis secretes eggs in stool
      1. Stool contaminates soil with Ascariasis eggs (and eggs may persist for up to 10 years in soil)
      2. Ascariasis eggs hatch into worms within 2-4 weeks at which point they are infective
    2. Ascariasis eggs are ingested by exposed persons
      1. Especially communities with open Defecation in fields or where animal feces are used to fertilize crops
      2. Ascariasis eggs that hatch after ingestion (typically by day 4) pass through the cecal mucosa
      3. Ascariasis worms enter lungs via circulatory system or Lymphatic System
    3. Ascariasis matures in lungs for 10-14 days
      1. Once mature, Ascariasis induces cough, and patient swallows coughed secretions, re-entering intestinal tract
    4. Ascariasis worms mature further in intestinal tract
      1. After 9-11 weeks from time of initial ingestion, Ascariasis starts to lay eggs
      2. Infected patients shed up to 200,000 Ascariasis eggs per day
      3. Worms live for 10 months to 2 years and do not reproduce within host patient
  3. Epidemiology
    1. Prevalence
      1. Asia (75%)
      2. Africa (10%)
      3. Latin America (10%)
    2. Transmission
      1. Human feces contaminated fruits and vegetables
      2. Fomites
        1. Flies can deposit eggs on food
  4. Symptoms
    1. Often asymptomatic
    2. Intense lower Abdominal Pain for days
  5. Signs
    1. Distinctive Ascariasis eggs in stool
    2. Roundworm passed in stool
      1. Length: 15-30 cm (6 to 12 inches)
      2. Color: creamy white
  6. Labs
    1. Stool Ova and Parasites
    2. Stool microscopy
    3. Worm if available
  7. Complications
    1. Bowel Obstruction
    2. Urticaria
    3. Asthma
  8. Management
    1. May start empiric treatment with anti-Helminth agent if classic roundworm identified
      1. However, still send stool samples as above
      2. Concurrent infection with other Helminth (e.g. Strongyloides) requires additional management
    2. Anti-Helminth agents
      1. Albendazole 400 mg orally for one dose (pregnancy category C)
      2. Mebendazole (not available in U.S. as of 2012) 500 mg daily for one dose (or up to three days)
      3. Pyrantel pamoate
        1. Indicated in pregnancy
    3. Patient Education
      1. Medication will result in passing very large numbers of worms in stool
      2. Close contacts are not empirically treated in most cases (unless unreliable for follow-up)
        1. Test suspected cases
  9. References
    1. Mason, Grock and Tenner in Herbert (2017) EM:Rap 17(11): 6

Ascariasis (C0003950)

Definition (MSH) Infection by nematodes of the genus ASCARIS. Ingestion of infective eggs causes diarrhea and pneumonitis. Its distribution is more prevalent in areas of poor sanitation and where human feces are used for fertilizer.
Concepts Disease or Syndrome (T047)
MSH D001196
ICD9 127.0
ICD10 B77, B77.9
SnomedCT 187536006, 154411000, 271435007, 187172007, 2435008
English Ascariases, Ascariasis, unspecified, [X]Ascariasis, unspecified, ascariasis (diagnosis), ascariasis, Ascariasis [Disease/Finding], ascariosis, ascaridiasis, Ascariasis - roundworm, Roundworm (& ascariasis), Roundworm (& ascariasis) (organism), [X]Ascariasis, unspecified (disorder), Roundworm (& ascariasis) (disorder), Ascariosis, Ascariasis - roundworms, Ascariasis (disorder), Ascariasis, Ascaris lumbricoides; infestation, Ascaris; infection, infestation; Ascaris lumbricoides
Japanese 回虫症, カイチュウショウ
Swedish Spolmaskinfektion
Czech askariáza, ascariasis, Askarióza
Finnish Askariaasi
German Askaridose, nicht naeher bezeichnet, Askaridose, Askariasis
Korean 상세불명의 회충증, 회충증
Polish Askarioza, Glistnica
Hungarian ascariasis
Norwegian Spolorminfeksjoner
Spanish [X]ascariasis, no especificada (trastorno), [X]ascariasis, no especificada, ascariasis (trastorno), ascariasis, infección por áscaris, Ascariasis
Dutch Ascaris lumbricoides; infestatie, Ascaris; infectie, infestatie; Ascaris lumbricoides, Ascariasis, niet gespecificeerd, ascariasis, Ascariasis
French Ascaridiase, Ascaridiose
Italian Ascariasi
Portuguese Ascaríase
Derived from the NIH UMLS (Unified Medical Language System)

Ascaris (C0003954)

Definition (CSP) genus of nematodes of the superfamily Ascaridoidea whose species usually inhabit the intestine.
Definition (MSH) A genus of nematodes of the superfamily ASCARIDOIDEA whose species usually inhabit the intestine.
Concepts Eukaryote (T204)
MSH D001200
SnomedCT 66953006
English Ascaris, Ascari, ascaris, Eelworm, Genus: Ascaris, Ascaris (organism), Ascaris, NOS
Swedish Spolmask
Czech Ascaris, škrkavka
Finnish Ascaris
Croatian ASCARIS
Polish Glista
Norwegian Ascaris
Spanish Ascaris (organismo), anguilula, ascáride, Ascaris
French Ascaris
German Ascaris
Italian Ascaris
Dutch Ascaris, Spoelwormen
Portuguese Ascaris
Derived from the NIH UMLS (Unified Medical Language System)

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