Filariasis Treatment & Management

Updated: Dec 10, 2015
  • Author: Siddharth Wayangankar, MD, MPH; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Treatment

Approach Considerations

The medical management of a filarial infection should be specific and based on the microfilariae isolated or antigenemia detected.

Mass drug administration reduces the transmission of filarial infection and disease morbidity by decreasing the burden of microfilaremia, resulting in suboptimal levels for transmission by disease vectors. [44, 45, 46, 47, 48, 49]

For example, annual mass treatment with albendazole and ivermectin is employed to interrupt the transmission of W bancrofti. Since this species has no alternative hosts, this approach could theoretically result in eventual eradication of bancroftian filariasis.

One study evaluated the effect of higher dose and increased frequency (twice yearly) of albendazole-ivermectin therapy for W bancrofti and found that it resulted in complete microfilarial clearance, as well as a more sustained clearance than that resulting from standard-dose albendazole-ivermectin treatment. [50]

The effects of mass treatment on filariasis have reportedly been sustained for up to 6 years. [51, 52, 53, 54] No filariasis vaccine is currently available, but efforts to develop an effective one are under way. [55]

Surgery

Lymphatic filariasis

Large hydroceles and scrotal elephantiasis can be managed with surgical excision. Correcting gross limb elephantiasis with surgery is less successful and may necessitate multiple procedures and skin grafting.

Onchocerciasis

Nodulectomy with local anesthetic is a common treatment to reduce skin and eye complications.

Diet and activity

Fatty foods are restricted in individuals with proven chyluria that is associated with lymphatic filariasis.

Individuals with chronic lymphatic filariasis are encouraged to mobilize (with compression bandage support) the affected limb.

Prevention

Avoidance of bites from insect vectors is usually not feasible for residents of endemic areas, but visitors to these regions should use insect repellent and mosquito nets.

Consultations

To prevent inappropriate treatment, consult an infectious disease specialist in all cases of suspected filariasis outside of endemic nations. Other possible consultations include:

  • Urologist
  • Ophthalmologist
  • General surgeon
  • Plastic surgeon
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Pharmacologic Therapy

Lymphatic filariasis

Patients with asymptomatic microfilaremia can be treated on an outpatient basis. Supervision of oral DEC therapy and provocation with postadministration observation is recommended for patient compliance with therapy and for the management of febrile reactions in heavily infected patients. [31]

Inpatient care may initially be required for adenolymphangitis (ADL) and chronic filariasis. Such care includes the use of antihistamines, steroids, pain relief, and intravenous antibiotics for secondary infections.

Lymphedema

Steroids can be used to soften and reduce the swelling of lymphedematous tissues. Mild to moderate filarial lymphedema has been shown to improve with a 6-week course of doxycycline, independent of ongoing infection. [56]

Bed rest, limb elevation, and compression bandages traditionally have been used for the management of chronic lymphedema.

Chronic filariasis

Treatment of chronic filariasis does not change the prognosis, as irreversible fibrosis usually destroys lymphatic tissue. However, asymptomatic patients, hoping to diminish progression of the disease, still typically undergo treatment, although the benefit of this is unclear. [57]

Chyluria

In the treatment of chyluria, a special low-fat, high-protein diet supplemented with medium-chain triglycerides may prove beneficial. In addition, the sclerosing action conferred by diagnostic lymphangiography may plug the leak.

Secondary infection

Supportive care should include the prevention of secondary infection, especially in patients with advanced disease. Individuals with chronic infections should wash the affected area frequently, apply antiseptic creams to abrasions, keep their nails clean, wear comfortable footwear, and exercise the affected limb to aid lymphatic flow.

Onchocerciasis

If DEC and suramin (currently the only drug in clinical use for onchocerciasis that is effective against adult worms) are used, inpatient care is recommended to monitor for reactions and complications of therapy. [28]

Moxidectin is being investigated as an alternative to ivermectin for the treatment of river blindness. This agent may shorten the number of annual treatments to 6.

Bancroftian filariasis

Ivermectin is now considered the drug of choice for the treatment of bancroftian filariasis. In the United States, it can be obtained from the Centers for Disease Control and Prevention (CDC); in endemic areas of the world, it is provided free by the Mectizan Donation Program. The addition of albendazole seems to improve response. [58, 59, 60, 61]

Six-week and 8-week courses of doxycycline have compared favorably with ivermectin plus albendazole. [62] Doxycycline therapy may be more readily available and may be better tolerated by some patients. It may also be capable of preventing or reversing lymphatic pathology. [63]

In one study, a 3-week course of doxycycline followed by a single dose of DEC was shown to be microfilaricidal. [63]

Findings have validated the use of single-dose regimens of ivermectin and DEC or albendazole for large-scale control and eradication programs aimed at reducing Wuchereria bancrofti microfilaremia, antigenemia, and clinical manifestations. [50, 64, 65, 66, 67]

M perstans infection

Because M perstans is resistant to standard antiparasitic treatment, doxycycline is sometimes used to eradicate Wolbachia, an endosymbiont found in most filarial species. [26, 68]

Doxycycline treatment typically kills or sterilizes the filarial nematode. In an open-label, randomized trial, Coulibaly et al recruited patients with M perstans infection from 4 African villages in Mali. Patients were randomly assigned to receive 200 mg of doxycycline orally every day for 6 weeks or no treatment. [69]

At 12 months, 97% of patients who received doxycycline had no detectable blood levels of M perstans, compared with 16% of patients in the group that did not receive treatment. At 36 months, M perstans remained suppressed in 75% of patients who had received doxycycline. [69]

Long-Term Monitoring

Patient monitoring includes posttreatment follow-up for 12 months, with examination of peripheral blood and skin snips for microfilariae.

Observe and monitor oral therapeutic plans with DEC because compliance with therapy is poor and usually incomplete.

Patients with filariasis are, by default, at risk for other parasitic infections because areas endemic for bancroftian filariasis are also endemic for other parasites. After treatment, patients should be monitored for symptoms that are characteristic of parasitic infections.

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