Lymphatic Filariasis

Lymphatic filariasis, commonly known as elephantiasis, is a parasitic infection caused by filarial worms transmitted through mosquito bites. Chronic infection can damage the lymphatic system, causing marked swelling, most often of the legs or genitals.

• Many infections cause no early symptoms despite ongoing infection
• Recurrent episodes of fever with painful swelling and redness along the affected limb (acute inflammatory episodes)
• Progressive, painless swelling of the leg, arm, or genitals over months to years in chronic disease
• Thickened, hardened skin over the swollen area in advanced disease
• Genital swelling, including of the scrotum, can occur in men with chronic infection

• Caused by filarial worms, transmitted through the bite of infected mosquitoes.
• Repeated mosquito bites over time in an endemic area are usually needed to establish infection.
• Damage to the lymphatic vessels from the parasites leads to the characteristic chronic swelling.

• Diagnosed through blood testing for filarial parasites or antigens, ideally collected at night when the parasites are most detectable in the blood in many settings.
• Chronic swelling in a person from an endemic area is often managed based on the clinical picture even without laboratory confirmation, particularly where testing is not readily available.
• Ultrasound of the affected area, where available, can sometimes show the adult worms moving within lymphatic vessels.

A combination of antifilarial medicines (such as diethylcarbamazine and albendazole, or other combinations depending on the region) is used to treat active infection and is also the basis for community mass drug administration in endemic areas.

Chronic limb swelling (lymphoedema) is managed with careful daily hygiene, skin care, gentle exercise, and elevation of the limb to reduce swelling and prevent episodes of acute inflammation and secondary bacterial infection.

Acute inflammatory episodes with fever are treated with rest, elevation of the limb, pain relief, and an antibiotic if there is evidence of secondary bacterial skin infection.

Significant genital swelling (hydrocele) may be treated with a minor surgical procedure at a facility with the appropriate capability.

• Sleep under an insecticide-treated mosquito net to reduce mosquito bites.
• Support community mass drug administration campaigns in known endemic areas.
• Practise regular limb hygiene and skin care for anyone with existing lymphoedema to prevent complications.
• Support vector-control measures aimed at reducing mosquito populations in endemic communities.