African eye worm

African Eye Worm The African eye worm, also known as Loa loa filariasis, is a parasitic infection caused by the nematode Loa loa. This disease is endemic to certain regions of West and Central Africa and is transmitted to humans through the bite of infected deer flies, specifically those of the genus Chrysops.

Overview

Loa loa is a filarial nematode that resides in the subcutaneous tissue of humans. The adult worms can migrate through the body, often crossing the conjunctiva of the eye, which gives the disease its name. The presence of the worm in the eye can cause significant discomfort and irritation.

Transmission

The transmission of Loa loa occurs through the bite of an infected deer fly. When the fly bites a human, it deposits larvae that mature into adult worms within the host. These adult worms can live for several years, during which they produce microfilariae that circulate in the bloodstream.

Symptoms

The symptoms of Loa loa infection can vary, but they often include:

• Calabar swellings: These are localized, non-painful swellings that occur as a result of the body's immune response to the migrating adult worms.
• Eye symptoms: The migration of the worm across the eye can cause itching, pain, and visible movement of the worm under the conjunctiva.
• General symptoms: Some individuals may experience fatigue, joint pain, and itching.

Diagnosis

Diagnosis of Loa loa infection is typically made through:

• Blood tests: Detection of microfilariae in the blood, especially during the day when they are most abundant.
• Clinical observation: Noting the presence of Calabar swellings or observing the worm in the eye.

Treatment

Treatment of Loa loa infection can be challenging due to potential complications. The main treatments include:

• Diethylcarbamazine (DEC): This is the primary drug used to kill the adult worms and microfilariae.
• Surgical removal: In some cases, the worm can be surgically removed from the eye or other accessible areas.

Prevention

Preventive measures focus on reducing exposure to the bites of deer flies. These include:

• Use of insect repellent
• Wearing protective clothing
• Avoiding areas with high fly populations during peak biting times

Epidemiology

Loa loa is endemic to the rainforests of West and Central Africa. The disease is particularly prevalent in Cameroon, Gabon, and the Democratic Republic of the Congo.

See Also

• Filarial diseases
• Parasitic infections
• Tropical medicine
• Taylor, M. J., Hoerauf, A., & Bockarie, M. (2010). Lymphatic filariasis and onchocerciasis. The Lancet, 376(9747), 1175-1185.
• Zour , H. G. M., et al. (2011). The geographic distribution of Loa loa in Africa: Results of large-scale implementation of the Rapid Assessment Procedure for Loiasis (RAPLOA). PLoS Neglected Tropical Diseases, 5(6), e1210.

NIH genetic and rare disease info

• NIH info on African eye worm

African eye worm is a rare disease.