Filariasis
Not yet clinically reviewed
This protocol was migrated from the earlier Pharmapedia and Ward Guide apps for educational use. Follow your hospital's own policies and consult seniors when in doubt.
Introduction
Filariasis results from infection with vector-borne tissue dwelling nematode called filariae. Depending upon the species, adult filariae may live in the lymphatics, blood vessels, skin, connective tissue or serous membrane. Female produce microfilariae which live in bloodstream or skin
Clinical Presentation
Filariasis leads to a wide spectrum of clinical manifestations, ranging from carrier state with no evident disease to chronic incapacitating illness.
- Earliest manifestations are seen during the stage of invasion (when the infective larvae enter the body and undergo development). It mainly causes constitutional symptoms due to hypersensitivity reaction.
- Characteristic manifestations of filariasis are due to obstruction of lymph vessels and nodes. Depending on the sites affected,
The clinical manifestations vary:
- lymphadenitis
- lymphangitis
- filarial fever
- hydrocoele
- lymphoedema
- elephantiasis and
- occult filariasis, e.g., tropical pulmonary eosinophilia (due to hypersensitivity reaction to filarial antigens) Diagnosis is usually made on clinical grounds alone in an endemic area.
Diagnosis
- By demonstration of microfilariae in the blood at night after about a year from the time of infection.
- Antifilarial antibodies are positive in 95% of patients.
- Indirect evidence such as eosinophilia.
- Calcified worm may be seen in the radiograph.
Treatment
Diethylcarbamazine (DEC) kills microfilariae and adult worms. Dose: 9-12 mg/kg daily in divided doses for 14 to 21 days. The course may be repeated twice at intervals of 4-6 weeks. Antihistamines and corticosteroids may be required to control the allergic phenomenon.