Here you will learn about the “Filariasis symptoms life cycle”.It is a nematode disease. In this disease, the Larva of microfilariae is the main source. Filarial worms are long and thin. It attacks the lymphatic system and subcutaneous connective tissue.

Most nematodes produce microfilariae in the blood of the host.

Filariasis has two main types as

1. Onchocerca Volvulus
2. Mansonella Streptocerca

These species of filaria inhabit the dermis and subcutaneous tissue.

Which parasite (vector) causes elephantiasis?

The cause of elephantiasis is Wuchereria bancrofti. This species occurs in Pakistan. Other species do not exist. Man is the definitive host while the Mosquito genus CULEX is intermediate.

Filaria has separate sex. They live in pairs, therefore they block the lymphatic ducts resulting in Elephantiasis.

What are the symptoms of Filariasis?

1. Swelling of the body parts, which are affected by the parasite as shown in the picture.
2. If the urinary system is affected scrotal swelling occurs. There will be pain and swelling while urinating. Cloudy or bloody urine will be observed.

What is the life cycle of Filariasis (Elephantiasis)

1. Culex mosquitoes take a blood meal from infected people. It ingest Microfilaria. This microfilaria penetrates into the midgut and goes to the thoracic muscle of the mosquito.
2. In the thoracic muscle, this develops into the first stage, then third-stage larvae (Infective stage).
3. This L3 form larva migrates to the proboscis.
4. When this mosquito bites a healthy human, it transforms the L3 larvae. L3 forms inhabitants in lymphatic ducts and develops into adults.
5. Adults produce sheathed microfilaria into lymph and blood. It moves from the lymph duct to the bloodstream freely.

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What is the Laboratory Diagnosis of Filariasis (Elephantiasis)

For the diagnosis of filarial infection, parasite demonstration is the accurate means. Blood should be collected around midnight (at this time parasites are mostly present in the blood). There are three methods for parasite demonstration.

1. Thin Film Preparation
2. Thick Film Preparation
3. Concentration method

Thin Film Preparation method

Thin film smear prepared. Examine under a microscope first at low power and then at high power for more detail.

Thick Film Preparation

Prepare film and stain with Giemsa for better results. Hematoxylin and eosin stain can be parasite demonstrations. For this purpose, the smear should be air-dried and fixed with an al quantity of ether and alcohol for ten minutes. Dried and stained like a histology specimen.

Concentration Method

In this method, blood should be centrifuged after collection in a tube containing 2% acetic acid. It should be mixed thoroughly. After centrifugation, the deposit was examined under a coverslip. Here you will observe actively moving microfilaria.

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