Lymphatic filariasis

Background

• Also known as elephantiasis
• Causative agents (transmitted by mosquito):
  • Wuchereria bancrofti
  • Brugia malayi
  • Brugia timori
• No known natural animal reservoir
• Larvae migrate to lymphatic vessels and mature into adults (can take 6-12 months)
  • These worms block lymphatic vessels, which causes the clinical presentation of the disease
• Coinfection is common (filiariae cause immunosuppression and allows for malaria and/or TB to thrive)

Clinical Features

• 2/3 will be asymptomatic
• Chronic infection leads to massive peripheral edema with thickening of overlying skin particularly in lower extremities and genitalia
• Recurrent cellulitis is common

Diagnostic Evaluation

• Establish possible exposure in endemic areas
• Serology (peripheral blood) - draw at night due to periodicity of filiariae
• Tests for W. bancrofti
  • PCR
  • Antigen detection
  • Ultrasound may occasionally show movement of adult filiariae

Management

• Diethylcarbamazine (DEC):
  • Day 1: 50mg PO
  • Day 2: 50mg TID
  • Day 3: 100mg TID
  • Days 4-21: 6 mg/kg/day divided TID
• Ivermectin + Albendazole
• Combined treatment with diethylcarbamazine/albendazole may be more effective than single drug treatment
• Meticulous skin care to prevent superinfection/cellulitis
• Surgical management of scrotal elephantiasis and chronic lymphatic obstruction

Disposition

• Generally may be discharged unless complicated by other factors.

See Also

• Parasitic Diseases
• Travel Medicine
• Worm Infections