Dirofilariasis Treatment & Management

Updated: Oct 05, 2015
  • Author: Alena Klochko, MD; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Treatment

Approach Considerations

The use of anthelmintic chemotherapy is not routinely recommended after the removal of nodules. If secondary lesions are suspected or confirmed in deep body sites (ie, chest, abdomen), a course of ivermectin and diethylcarbamazine (DEC) may be advisable to prevent further invasive surgery. A course of chemotherapy may also be warranted after heavy exposure to mosquitoes in an area known to be endemic for dirofilariasis.

A novel approach for the treatment of cardiopulmonary dirofilariosis is targeting the Wolbachia rickettsial endosymbionts. Treatment with tetracyclines has been reported to damage D immitis, even causing death of adult worms. [78]

Long-lasting administration of both doxycycline and ivermectin before or in the place of melarsomine injections can eliminate adult worms and reduce the risk of thromboembolism. Therefore, it has been suggested that a combination of doxycycline for 30 days and ivermectin for 6 months has a potential efficacy, as high as 73%, in the adulticide therapy in dogs infested with D immitis. [79, 80]

Inappropriate treatment

Although this scenario is much less likely than incorrect diagnosis, inappropriate treatment of dirofilariasis is a potential issue, even if the diagnosis is made correctly.

One case has been reported in which a mastectomy was mistakenly performed because of a presumptive diagnosis of carcinoma when in fact the patient had breast dirofilariasis.

To prevent inappropriate treatment, consult an infectious disease specialist in all cases of suspected dirofilariasis.

Reaction to treatment

Care must be taken to ascertain whether a patient with dirofilariasis has ever had any antiparasitic drugs and if the drugs were ever noted to cause problems.

Monitoring

Patients with dirofilariasis who undergo surgical removal of lesions usually receive follow-up care at least once in the postoperative period for the removal of sutures and to monitor wound healing.

Patients with dirofilariasis may be at risk for other parasites. After treatment, patients should be monitored for other symptomology characteristic of parasitic infections.

Deterrence/prevention

Avoidance of mosquito bites during peak biting times of the day in areas known to be endemic for D immitis or D repens is the best method of preventing dirofilariasis.

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Antifilarial Medications

Parasite biochemical pathways are sufficiently different from the human host to allow selective interference by chemotherapeutic agents in relatively small doses.

In many cases, antifilarial medications are not administered prior to surgical resection of dirofilarial lesions. One group of authors, however, has recommended a single dose of ivermectin followed by 3 doses of diethylcarbamazine (DEC) if the syndrome is strongly suspected prior to surgery. However, almost all cases are diagnosed only when histopathologic sections of biopsy or excised material are viewed.

Surgical Excision

Surgical excision of lesions and affected areas is the treatment of choice for patients with dirofilariasis. [7] Some authors have recommended a period of observing chest coin lesions for several months if dirofilariasis is suspected and no other features in the history or examination suggesting malignancy or other infection are present.

Patients with human pulmonary dirofilariasis (HPD) who have undergone wedge resection of a lung lesion require routine postoperative care for thoracic surgery (eg, intercostal drainage, monitoring of blood loss, chest wound care).

Patients with subcutaneous dirofilarial lesions can usually be treated as outpatients or undergo day-case surgical procedures.

Transfer

Transfer to an institution performing thoracic surgery may be required in patients with HPD in whom a fine-needle aspiration lung biopsy, wedge resection, or both is thought necessary for diagnosis.

Consultations

The following specialists may be involved in the treatment of dirofilariasis:

  • Infectious diseases specialist
  • Travel medicine clinician
  • General surgeon
  • Cardiothoracic surgeon
  • Ophthalmologist
  • Otorhinolaryngologist
  • Plastic surgeon
  • Urologist
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