Filarioidea

File:Microfilaria of Dirofilaria immitis (Heartworms) Surrounded by Neoplastic Lymphocytes

Filarioidea is a superfamily of parasitic roundworms (nematodes) known as filarial worms. These worms are responsible for a group of diseases called filariasis in humans and other animals. They are transmitted by various species of arthropods, particularly mosquitoes and black flies.

Taxonomy

Filarioidea belongs to the order Spirurida within the class Secernentea. The superfamily includes several genera, with the most notable being:

• Wuchereria
• Brugia
• Onchocerca
• Loa

Life Cycle

The life cycle of filarial worms involves two hosts: a definitive host (usually a mammal) and an intermediate host (an arthropod). The adult worms reside in the definitive host, where they produce microfilariae. These microfilariae are ingested by the intermediate host during a blood meal. Inside the intermediate host, the microfilariae develop into infective larvae, which are then transmitted to a new definitive host during subsequent blood meals.

Diseases

Filarioidea is responsible for several significant diseases, including:

• Lymphatic filariasis: Caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori. It leads to severe swelling and disfigurement, commonly known as elephantiasis.
• Onchocerciasis: Also known as river blindness, caused by Onchocerca volvulus. It can lead to severe itching, skin changes, and blindness.
• Loiasis: Caused by Loa loa, also known as the African eye worm. It can cause localized swelling and eye problems.

Diagnosis and Treatment

Diagnosis of filarial infections typically involves the detection of microfilariae in blood samples or skin snips. Serological tests and molecular techniques such as PCR are also used. Treatment usually includes antiparasitic medications such as ivermectin, albendazole, and diethylcarbamazine.

Prevention

Preventive measures include vector control strategies such as the use of insecticide-treated nets, indoor residual spraying, and mass drug administration programs to reduce the prevalence of the disease in endemic areas.

See Also

• Nematode
• Parasitology
• Vector (epidemiology)
• Tropical diseases