What are roundworms?
- Roundworms are parasites; they use the human body to stay alive, feed and reproduce.
- Ascariasis is the name of an infection caused by the roundworm Ascaris lumbricoides; when a worm lives inside the human body, the condition is called a parasitic infection.
- While the vast majority of these cases are asymptomatic, infected persons may present with pulmonary or potentially severe gastrointestinal complaints.
Ascaris lumbricoides is the largest of the intestinal nematodes affecting humans, measuring 15-35 cm in length in adulthood.
- Infection begins with the ingestion of embryonated (infective) eggs in feces-contaminated soil or foodstuffs.
- Once ingested, eggs hatch, usually in the small intestine, releasing small larvae that penetrate the intestinal wall.
- Larvae migrate to the pulmonary vascular beds and then to the alveoli via the portal veins usually 1-2 weeks after infection, during which time they may cause pulmonary symptoms (e.g., cough, wheezing).
- After migrating up the respiratory tract and being swallowed, they mature, copulate, and lay eggs in the intestines.
- Adult worms may live in the gut for 6-24 months, where they can cause partial or complete bowel obstruction in large numbers, or they can migrate into the appendix, hepatobiliary system, or pancreatic ducts and rarely other organs such as kidneys or brain.
- From egg ingestion to new egg passage takes approximately nine weeks, with an additional three weeks needed for egg molting before they are capable of infecting a new host.
Statistics and Incidences
Intestinal nematode infections affect one fourth to one-third of the world’s population; of these, the intestinal roundworm Ascaris lumbricoides is the most common.
- In the United States, approximately 4 million people are believed to be infected.
- High-risk groups include international travelers, recent immigrants (especially from Latin America and Asia), refugees, and international adoptees.
- Ascariasis is indigenous to the rural southeast, where cross-infection by pigs with the nematode Ascaris suum is thought to occur. (Children aged 2-10 years are thought to be more heavily infected in this and all other regions.)
- Worldwide, 1.4 billion people are infected with Ascaris lumbricoides, with prevalence among developing countries as low as 4% in Mafia Island, Zanzibar, to as high as 90% in some areas of Indonesia.
- The rate of complications secondary to ascariasis ranges from 11-67%, with intestinal and biliary tract obstruction representing the most common serious sequelae.
- Although infection with A. lumbricoides is often asymptomatic, it is responsible for an estimated 730,000 cases of bowel obstruction annually, 11,000 of which are fatal.
- In one series of pregnant patients in Bangladesh, biliary ascariasis was responsible for a plurality (28%) of nonobstetric etiologies of acute abdomen.
- No racial predilection is known; a genetic predisposition has been described in a study of families from Nepal.
- Male children are thought to be infected more frequently, owing to a greater propensity to eat soil.
Most patients are asymptomatic. When symptoms occur, they are divided into two categories: early (larval migration) and late (mechanical effects).
- Respiratory symptoms. In the early phase (4-16 d after egg ingestion), respiratory symptoms result from the migration of larvae through the lungs; classically, these symptoms occur in the setting of eosinophilic pneumonia (Löffler syndrome): fever, nonproductive cough, dyspnea, wheezing.
- Gastrointestinal symptoms. In the late phase (6-8 wk after egg ingestion), gastrointestinal symptoms may occur and are more typically related to the mechanical effects of high parasite loads; passage of worms (from mouth, nares, anus), diffuse or epigastric abdominal pain, nausea, vomiting, pharyngeal globus, “tingling throat”, frequent throat clearing, and dry cough are some of the GI symptoms.
Assessment and Diagnostic Findings
Diagnosis of roundworms is confirmed through the following:
- CBC count. Complete blood count (CBC) may show eosinophilia.
- Sputum analysis. Sputum analysis may reveal larvae or Charcot-Leyden crystals (collections of crystalloid composed of eosinophilic proteins).
- Stool exam. Stool examination findings are typically normal in the absence of previous infection (during the first 40 d); in the adult phase, stool examination findings include characteristic eggs; adult females lay about 200,000 eggs per day, aiding microscopic identification of characteristic eggs.
- Chest radiography. Chest radiography may reveal patchy infiltrates of eosinophilic pneumonia.
- Abdominal radiography. Abdominal radiography may reveal signs of bowel obstruction (e.g., air-fluid levels) or the “cigar bundle” appearance of a worm bolus.
- CT scan. On computed tomography (CT) scanning, Ascaris worms may be visualized as linear or cylindrical filling defects in the presence of contrast or may be identifiable in groups or masses (sometimes having a whirled appearance).
- Ultrasonography. Some authors have recommended ultrasonography as the initial imaging study of choice, especially when pretest suspicion of pancreatobiliary involvement is high; diagnosis of Ascaris infection has been described using point-of-care emergency department ultrasonography (POCUS).
Treatment is divided according to the phases of infection: early infection (larval migration) and established infection (adult phase).
- Benzimidazoles. Benzimidazoles are the mainstay of treatment of symptomatic and asymptomatic infections; they are poorly systemically absorbed and thus have low human toxicity and exert their action directly on worms; the most common members of this family are albendazole and mebendazole.
- Bowel obstruction. Treatment of bowel obstruction includes intravenous hydration, nasogastric suctioning, electrolyte monitoring, and laparotomy if conservative measures fail; colonoscopy and esophagogastroduodenoscopy (EGD) may be useful in removing obstructing masses of worms.
Medications used to treat roundworms include:
- Albendazole. Decreases ATP production in worm, causing energy depletion, immobilization, and finally death.
- Mebendazole. Causes worm death by selectively and irreversibly blocking uptake of glucose and other nutrients in the susceptible adult intestine where helminths dwell.
- Piperazine citrate. Recommend for GI or biliary obstruction secondary to ascariasis; causes flaccid paralysis of the helminth by blocking the response to worm muscle to acetylcholine.
- Pyrantel pamoate. Depolarizing neuromuscular blocking agent; inhibits cholinesterases, resulting in spastic paralysis of the worm.
- Ivermectin. Binds selectively with glutamate-gated chloride ion channels in invertebrate nerve and muscle cells, causing cell death.
- Levamisole. May inhibit worm copulation via agonism of L-subtype nicotinic acetylcholine receptors in male nematode muscles.
Nursing care of a child with roundworms may include the following:
Assessment of the child include:
- History. Soil-transmitted worm infections, including roundworm, are among the most common infections worldwide; they affect poor and deprived communities, where there is overcrowding and poor sanitation; most recorded cases of roundworm are contracted abroad, either by travelers or migrants who come from parts of the world where roundworm is present.
- Physical exam. General symptoms include fever, jaundice, cachexia, pallor, and urticaria; pulmonary symptoms include wheezing, rales, and diminished breath sounds; GI symptoms include abdominal tenderness, distention, nausea, and vomiting.
Based on the assessment data, the major nursing diagnoses are:
- Fluid volume deficit related to fluid loss secondary to diarrhea.
- Impaired sense of comfort: pain related to smooth muscle spasm secondary to migration of parasites in the stomach.
- Imbalanced Nutrition: less than body requirements related to anorexia and vomiting.
- Hyperthermia related to decrease in circulation secondary to dehydration.
Nursing Care Planning and Goals
The major nursing care planning goals for patients with roundworm are:
- Maintain fluid and electrolyte balance.
- Pain will be lost or diminished.
- Improve nutritional requirements.
- Maintain normothermia indicated by the absence of signs and symptoms of hyperthermia, such as tachycardia, skin redness, temperature and blood pressure normal.
Nursing interventions for a child with roundworm include the following:
- Improve fluid and electrolyte balance. Monitor intake and output of fluids; observe signs of dehydration; give oral rehydration solution to assist in adequate hydration; observe accurate intravenous fluid administration.
- Reduce pain and discomfort. Assess the extent and characteristics of pain; give a warm compress on the abdomen; teach a method of distraction to reduce pain; set a comfortable position that can reduce pain.
- Improve nutrition. Give adequate and nutritious food; measure body weight every day; explain the importance of adequate nutrition, and maintain good oral hygiene.
- Maintain normothermia. Teach the client and family the importance of adequate feedback; monitor fluid intake and output; monitor the temperature and vital signs; provide tepid sponge baths, and administer analgesics as indicated.
Goals are met as evidenced by:
- Maintained fluid and electrolyte balance.
- Pain was lost or diminished.
- Improved nutritional requirements.
- Maintained normothermia as indicated by the absence of signs and symptoms of hyperthermia, such as tachycardia, skin redness, temperature and blood pressure normal.
Documentation in a child with roundworms include the following:
- Individual findings, including factors affecting, interactions, nature of social exchanges, specifics of individual behavior.
- Cultural and religious beliefs, and expectations.
- Plan of care.
- Teaching plan.
- Responses to interventions, teaching, and actions performed.
- Attainment or progress toward the desired outcome.
Practice Quiz: Roundworms
1. Roundworm is a helminthic infection that is caused by which of the following?
D. Nectator americanus
1. Answer: C. Nematodes
- Option C: Roundworms is caused by nematodes.
- Option A: Tapeworm is caused by cestodes.
- Option B: Flukes are caused by trematodes.
- Option D: Hookworm is caused by nectator americanus.
2. Ascaris lumbricoides infections are more likely occur in:
A. Western countries
B. Developing countries
C. Pork eating countries
D. Tropical countries
2. Answer: B. Developing countries
- Option B: Worldwide, 1.4 billion people are infected with A lumbricoides, with prevalence among developing countries as low as 4% in Mafia Island, Zanzibar, to as high as 90% in some areas of Indonesia.
- Options A, C, D: There are low incidences of ascariasis among western, tropical and pork eating countries.
3. What is the infective form of Ascaris lumbricoides?
B. Unembryonated ova
C. Embryonated eggs
D. All of the above
3. Answer: C. Embryonated eggs
- Option C: Infection begins with the ingestion of embryonated (infective) eggs in feces-contaminated soil or foodstuffs.
- Options A, B, D: These options are incorrect.
4. What is the common specimen source required to detect Ascaris lumbricoides?
A. Food sample
D. Both b and c are correct
4. Answer: D. Both b and c are correct.
- Option D: Sputum analysis may reveal larvae or Charcot-Leyden crystals; while stool examination findings include characteristic eggs.
- Option A: Food samples are not used to diagnose ascariasis.
5. The main feature that distinguishes fertilized egg from unfertilized eggs of Ascaris lumbricoides?
D. All of the above
5. Answer: B. Size
- Option B: Fertilized eggs are larger than unfertilized eggs.
- Options A, C, D: These options are incorrect.
Related topics to this study guide:
- Pediatric Nursing Study Guides
- Nursing Notes: Study Guides for Various Topics
- Pediatric Nursing NCLEX Practice Questions
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