Filariasisis a tropical disease that affects 1.2 billion people around the world. It is a debilitating disease that affects people in Brazil, India, most of Central Africa. The following paragraphs will cover information related to this dangerous disease called filariasis.
What is Flariasis?
Filariasis is a parasitic disease that is caused by roundworms. These threadlike worms belong to the Filaroidea type. They are spread by black flies and mosquitoes. These filarial nematodes are divided into three groups. This division of the eight known human parasites is done according to the part of the body they occupy.
- Lymphatic filariasis is caused by worms that occupy the lymphatic system. Elephantiasis is the disease caused by this parasitic infection.
- Subcutaneous filariasis is caused by worms that occupy the subcutaneous layer of the skin. It leads to river blindness.
- Serous cavity filariasis is caused by worms that occupy the serous cavity of the abdomen.
Symptoms of Filariasis
The symptoms of filariasis are different according to its manifestation. In most cases, the disease is asymptomatic, even if microfilaremia are detected.
Symptoms of Acute Infection
- Localized symptoms such as lymphadenitis,lymphangitis, epididymitis, orchitis
- The affected area is painful, tender, red and swollen
Symptoms of Chronic Infection
- Lesions on the genitourinary system
- The lower limbs are a usually involved, however, breasts in females and upper limbs may be involved
- Hydrocele formation due to infection by Wulchereriabancrofti
- Skin rashes, urticarial papules due to subcutaneous worms
- Blindness due to Onchocerca volvulus infection of the eye
The filarial nematode worms have a complex life cycle. There are 5 stages in the life cycle of the human filarial nematode. The male and female mate and the female give birth to live microfilariae. There are 1000’s of such microfilariae born at a time. During a blood meal, the vector insect, like mosquito picks up these worms and it is in the vector body they molt and develop into larvae. When this mosquito bites another healthy human, the larvae are transferred into the dermis. After about a year, the larvae undergoes two more stages and matures as an adult worm.
Blood tests to identify the worm on Giemsa stain. The ‘gold standard’ is followed with the help of the finger prick test. Blood collection is carried out at specific times, according to the feeding time of the vector insects. In case of some worms that do not use blood, skin snips are used for diagnosis. Membrane filter, sedimentation technique, Knott’s concentration method, polymerase chain reaction (PCR) is used for detection of worms for making the diagnosis.
The main treatment for filariasis is the use of diethylcarbamazine (DEC). The drug acts on the microfilariae killing them all. However, its activity is limited on the adult worms. Other drugs such as mebendazole and flubendazole may be used.
Filariasis causes poor health of the sufferer. They are less productive and causes long-term disability. Death rarely occurs due to filariasis. If you notice any swelling on the genitals or extremities, seek prompt medical care, especially if youhave travelled to a to the affected areas in the world or live in such regions.
Written by: Saptakee sengupta
Date last updated: April 06, 2015