Bancroftian Filariasis

 
Bancroftian filariasis is an infection with the parasite Wuchereria bancrofti. 

Pathophysiology

The parasite worm begins its life cycle as a first-stage larva, also called a microfilaria, that is ingested by an insect and are called vectors, which could be mosquitoes and flies.  The microfilaria undergoes developmental changes within the insect twice before transferring to a vertebral host when the insect feeds, where it completes its development. 

Epidemiology

Lymphatic filariasis is more commonly seen in the tropical and subtropical countries.  People of all ages and both sexes are susceptible to infection.

Clinical Features

Bancroftian filariasis may be acute or chronic.  When the adult worms reside in the lymphatic system, they cause the condition called Lymphatic filariasis.  The most common complaints are fever, pain and enlarged lymph nodes at the groin and axillary regions, testicular pain, and swelling of the limb or genitals.  There are cases where there is passage of cloudy milklike urine called chyluria.  Acute attacks are referred to as adenolymphangitis, characterized by fever, swelling of the lymph nodes in the groin, and swelling of the testes and lower extremities.  Repeated episodes of swelling leads to damage of the lymphatic system, prolonged swelling, and elephantiasis of the arms, legs, scrotum, vulva, and breasts.

Another form of Bancroftian filariasis is Tropical Pulmonary Eosinophilia.  Symptoms include dry cough, difficulty breathing, wheezing, and weight loss.

Diagnosis

Bancrofti filariasis can be diagnosed by detecting the presence of microfilariae in the blood.  The urine can also be examined for chyluria and microfilariae.  Imaging studies like a chest x-ray and ultrasound of the groin and scrotum can also be performed.

Treatment

If the patient has no presenting symptoms, oral diethylcarbamazine therapy is given on an outpatient basis.  Hospital admission may be necessary for those with adenolymphangitis and chronic infection. 

Medications usually given are Ivermectib, Diethylcarbamazine, Albendazole, and Doxycycline.  Corticosteroids can help reduce the swelling.

Elevation of the affected limb, bed rest, and compression bandages alleviate chronic swelling of the limb. 

Surgery may be an option in cases of enlarged scrotum. 

Prognosis/ Complications

There is good prognosis especially if treatment is initiated early.  A common complication is a secondary bacterial infection.