Ascariasis Treatment & Management

Updated: Jul 30, 2018
  • Author: David R Haburchak, MD, FACP; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Treatment

Approach Considerations

Specific patient and community-wide public health approaches to ascariasis should be coordinated. Individual patient deworming can prevent surgical and nutritional complications and can serve as an opportunity to investigate, educate, and treat other family members and neighbors. Community- and school-based epidemiological deworming programs should be administered under WHO guidelines and would be subject to diagnostic methods used to determine pretherapy and posttherapy prevalence. Newer highly sensitive diagnostic methods instead of classic stool sampling would be most useful for communities with moderate (30%-70%) prevalence, rather than very high or low prevalence, [27] while they may be more useful for screening in adults, who have lower worm burden and lower prevalence than children. [4]

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Medical Care

Because of the risk of complications, patients with ascariasis who have other concomitant helminthic infections should always undergo treatment for ascariasis first. Medical therapy is usually not indicated during active pulmonary infection because dying larvae are considered a higher risk for significant pneumonitis. Pulmonary symptoms may be ameliorated with inhaled bronchodilator therapy or corticosteroids, if necessary.

Albendazole 400 mg one dose orally is the drug of choice for ascariasis in stable patients older than 12 months with uncomplicated infection. [2] A 2012 study from Indonesia showed that albendazole provided statistically significant better sterilization of Ascaris eggs than mebendazole but equivalent cure rates and egg reduction rates. [28] A 2017 systemic review and meta-analysis of 34 studies demonstrated a 95.7% cure rate with single-dose albendazole. [29] Ascariasis commonly coexists with whipworm infection, which appears to be most susceptible to triple-dose mebendazole. [30] Albendazole is not recommended during pregnancy; pyrantel pamoate is the drug of choice in these cases.

Alternative therapy is mebendazole (100 mg bid for 3 days). Mebendazole is not recommended during pregnancy; pyrantel pamoate is the drug of choice in these cases.

As an alternative to albendazole and mebendazole, ivermectin can be given in a dose of 150-200 micrograms/kg bodyweight. [2]

Paralyzing vermifuges (eg, pyrantel pamoate, piperazine, ivermectin) should be avoided in patients with complete or partial intestinal obstruction since the paralyzed worms may necessitate or further complicate surgery.

Vitamin A supplementation improved growth development of children in Zaire; deworming did not improve growth development in this study. [31]

Drug therapy affects only adult worms. If the patient lives in an endemic area or has recently relocated, he or she may still be carrying larvae that are not yet susceptible. Such patients should be re-evaluated in 3 months and retreated if stool ova persist. In endemic areas, reinfection rates approach 80% within 6 months.

Nitazoxanide, a drug used primarily for protozoal infection, was shown to have 89% clinical efficacy for the treatment of ascariasis in rural Mexico and may offer a future alternative to other medications. [32]

Compliance with antiparasitic drugs, especially at the community level, has recently emerged as a concern, particularly for the effectiveness of community-wide therapy. [17, 33]

Newer agents are being developed because of concern for emergence of resistance potentially associated with mass deworming campaigns. [34]

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Surgical Care

Conservative (nothing by mouth) management of partial intestinal obstruction and biliary ascariasis is usually effective but might be more quickly accomplished with orally administered contrast medium. [2] A controlled trial from Pakistan found that, in patients without peritonitis, hypertonic saline enemas relieved obstruction more quickly (1.6 d vs 3.4 d) and resulted in shorter hospital stays (4 d vs 6 d) than intravenous fluids alone. A recent study from India demonstrated that conservative therapy was successful in 19 of 22 (89%) children with intestinal obstruction. The regimen used consisted of no oral intake, intravenous fluids, antibiotics, piperazine salt per nasogastric tube, and glycerine plus liquid paraffin emulsion enemas. [19]

Recommended criteria for surgical exploration include the following:

  • Passage of blood per rectum

  • Multiple air fluid levels on abdominal radiographs

  • An ill child with abdominal distension and rebound tenderness

  • Unsatisfactory response to conservative therapy

  • Appendicitis and primary peritonitis

  • Hepatobiliary disease

  • Pancreatic pseudocyst

Most (49-90%) worms eventually migrate from the biliary system spontaneously. Drug therapy should be delayed in patients with right upper quadrant or pancreatic pain, as no evidence has shown that drugs are active against worms located in the biliary tree. Regardless, death of the worm in the duct may provoke both inflammation and obstruction. Patients with ascariasis who have only minor symptoms can undergo observation for 3 days. If the minor symptoms persist after 3 days or the patient develops frank cholangitis or pancreatitis, removal of the worms with ERCP should be attempted, if available. Although technically challenging at times, ERCP extraction rates have exceeded 90%. [22]

Intestinal or biliary surgery may be necessary for complications of ascariasis.

Intestinal gangrene usually occurs at the terminal ileum, more often after the use of pyrantel pamoate, which tetanically paralyzes worms and thereby enhances the risk of obstruction. Recently, 2 cases of delayed distal intestinal disease have been reported, which were thought to be secondary to toxins from the worms. Therefore, patients should probably be monitored for some time after the surgical removal of worms.

Milking of worms to the large bowel, resection of gangrenous bowel, ileostomy, and enterotomy are the most common surgical procedures used to manage bowel obstruction.

Invasion of the gall bladder necessitates cholecystectomy, common duct exploration, and T-tube drainage until the patient is stabilized and dewormed.

Any patients from highly endemic areas should be screened, and if positive, treated for ascariasis and malnutrion prior to elective surgery because of possible provocation of worm migration with anesthesia agents. [35] In particular, patients who live in endemic areas should be dewormed before and after elective cholecystectomy.

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Prevention

Community control of ascariasis has been difficult to achieve. The most successful control programs, such as those in Japan, have consisted of combined approaches, including improved sanitation, night soil disposal, and mass community treatment. Concern has increased for the emergence of drug resistance among heavily retreated populations.

The prevalence of ascariasis in Japan in 1949 was 63%; the disease was essentially eliminated by 1973. Hand washing may be a neglected means of prevention, even in endemic areas, as shown by a recent study from Sri Lanka.

A program of latrine construction, health education, and twice-annual anthelmintics decreased the prevalence of ascariasis in Korea from 80% in 1949 to 55% by 1971. After a 4-year educational campaign and latrine construction program in northern Bangladesh, 36% of children aged 5-13 remained infected. Rates of infection were lower among children who used latrines and who had been educated concerning the risks of ascariasis. [36]  As rates of ascariasis lessen, specific infected families should be targeted. A recent systematic review and meta-analysis of preventive water and sanitation measures concluded that the risk of ascariasis was lowered 60% by piped water, 38% by access to sanitarian latrines, and 62% by handwashing before eating and 55% after defecating. [37]  Each, in combination with the use of soap, has the potential for significant control, especially if applied in schools together with thrice yearly deworming. [38]

Current ascariasis treatment strategies recommend repeated mass treatment of communities to reduce intensity of worm burden until socioeconomic progress allows improved sanitation. Although such targeted therapy programs may control the morbidity of ascariasis by decreasing the number of worms per patient, they do not seem to decrease transmission rates. The ascariasis reinfection rate after a single community campaign in South Africa was 40% at 29 weeks. Children have been targeted in school campaigns, but continued worm burden and shedding by adults have blunted impact, especially if campaigns are less than thrice yearly. A 6-month educational program directed at behavioral remediation of school children and their parents in Java has shown promise when combined with a deworming campaign.

A 2012 Cochrane review [39]  was rather discouraging in its assessment of the benefit of community deworming programs, suggesting only the possibility of slight benefit in weight gain and hemoglobin, but not cognitive improvement as measured by school attendance and performance.

Avoiding pigs and pig manure prevents A suum infection in developed countries.

Work continues on a vaccine. A recombinant, nasally administered 16-kd secretory protein, As16, was shown to result in a 56% decrease in worm burden in mice challenged with A suum larvae. [40]  The Sabin Vaccine Institute is developing a "Pan-anthelmintic" vaccine against hookworm, trichuriasis, and ascariasis using at least 2 of 6 candidate A suum antigens. It appears that at least 5 years will be required to field such a candidate vaccine. [41]

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Transfer

Patients with ascariasis who have partial or complete obstruction should be treated at facilities with surgical support.

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