Loa loa: Difference between revisions

Latest revision as of 03:56, 13 February 2025

A parasitic worm causing loiasis in humans

Loa loa, commonly known as the African eye worm, is a parasitic worm that causes loiasis in humans. It is a member of the nematode family Onchocercidae.

Life Cycle[edit]

The life cycle of Loa loa involves both a human host and an insect vector. The adult worms live in the subcutaneous tissue of humans, where they can migrate through the body. Female worms release microfilariae into the bloodstream, which are then taken up by Chrysops flies, the vector, during a blood meal.

Inside the fly, the microfilariae develop into infective larvae over a period of 10-12 days. When the fly bites another human, the larvae are transmitted and mature into adult worms, completing the cycle.

Clinical Manifestations[edit]

Loiasis is characterized by the migration of adult worms through the subcutaneous tissues, often visible in the conjunctiva of the eye, leading to the name "eye worm." Symptoms include localized swelling known as Calabar swelling, itching, and pain. The presence of the worm in the eye can cause irritation and discomfort.

Diagnosis[edit]

Diagnosis of loiasis is typically made by identifying the microfilariae in a blood smear, usually taken during the day when the microfilariae are most active. Serological tests and imaging may also be used to detect the presence of adult worms.

Treatment[edit]

The treatment of loiasis involves the use of antiparasitic medications such as diethylcarbamazine (DEC), which is effective against both adult worms and microfilariae. Care must be taken due to potential severe reactions in patients with high microfilarial loads.

Prevention[edit]

Preventive measures include avoiding bites from the Chrysops fly by using insect repellent, wearing protective clothing, and implementing vector control strategies.

Related pages[edit]

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-'''Loa loa''' is a [[parasitic worm]] that is transmitted to humans through the bite of a [[deer fly]] or [[mango fly]], which are the primary vectors. This condition, known as loiasis, or African eye worm, primarily affects residents and visitors to West and Central Africa. Loa loa is one of the three main [[filariasis|filarial]] nematode species that cause disease in humans, the others being ''[[Wuchereria bancrofti]]'' and ''[[Brugia malayi]]'', which cause [[lymphatic filariasis]].
+{{Short description|A parasitic worm causing loiasis in humans}}
+{{Taxobox
+| name = Loa loa
+| image = Loa_Loa.jpg
+| image_caption = ''Loa loa'' adult worm
+| regnum = [[Animalia]]
+| phylum = [[Nematoda]]
+| classis = [[Secernentea]]
+| ordo = [[Spirurida]]
+| familia = [[Onchocercidae]]
+| genus = ''[[Loa (genus)|Loa]]''
+| species = '''''L. loa'''''
+| binomial = ''Loa loa''
+| binomial_authority = (Cobbold, 1864)
+}}
-==Transmission==
+'''''Loa loa''''', commonly known as the African eye worm, is a [[parasitic worm]] that causes [[loiasis]] in humans. It is a member of the [[Nematoda|nematode]] family [[Onchocercidae]].
-The life cycle of ''Loa loa'' involves two hosts: humans, where the adult worms mature, and the deer or mango flies, which belong to the genus ''[[Chrysops]]''. The transmission cycle begins when a person is bitten by an infected fly. During the blood meal, the fly introduces the larval stage of the worm, known as microfilariae, into the human host. These larvae then migrate through the host's body, maturing into adult worms over several months. Adult worms can live up to 17 years within the human host.
-==Symptoms and Diagnosis==
+==Life Cycle==
-The presence of ''Loa loa'' in the human body can cause a variety of symptoms, ranging from mild to severe. Common symptoms include localized swellings known as Calabar swellings, itching, hives, and fatigue. One of the most notable symptoms is the migration of the adult worm across the eye, which can be seen moving under the skin or across the conjunctiva of the eye, leading to the common name "African eye worm."
+The life cycle of ''Loa loa'' involves both a human host and an insect vector. The adult worms live in the subcutaneous tissue of humans, where they can migrate through the body. Female worms release microfilariae into the bloodstream, which are then taken up by [[Chrysops]] flies, the vector, during a blood meal.
-Diagnosis of loiasis is typically made through the detection of microfilariae in the blood, although this can be challenging due to the periodicity of the microfilariae's appearance in the bloodstream. Other diagnostic methods include imaging techniques to visualize adult worms and serological tests to detect antibodies or antigens related to ''Loa loa''.
+[[File:Loa_Loa.jpg|thumb|right|''Loa loa'' adult worm]]
+Inside the fly, the microfilariae develop into infective larvae over a period of 10-12 days. When the fly bites another human, the larvae are transmitted and mature into adult worms, completing the cycle.
+==Clinical Manifestations==
+Loiasis is characterized by the migration of adult worms through the subcutaneous tissues, often visible in the [[conjunctiva]] of the eye, leading to the name "eye worm." Symptoms include localized swelling known as [[Calabar swelling]], itching, and pain. The presence of the worm in the eye can cause irritation and discomfort.
+==Diagnosis==
+Diagnosis of loiasis is typically made by identifying the microfilariae in a blood smear, usually taken during the day when the microfilariae are most active. Serological tests and imaging may also be used to detect the presence of adult worms.
 ==Treatment==
-The treatment of loiasis involves the administration of antiparasitic medications, with [[diethylcarbamazine]] (DEC) being the drug of choice. However, treatment must be approached with caution, as killing the worms can lead to severe allergic or inflammatory reactions, especially in individuals with high worm burdens. In some cases, surgical removal of adult worms may be necessary, particularly when they migrate across the eye.
+The treatment of loiasis involves the use of antiparasitic medications such as [[diethylcarbamazine]] (DEC), which is effective against both adult worms and microfilariae. Care must be taken due to potential severe reactions in patients with high microfilarial loads.
 ==Prevention==
-Preventive measures against ''Loa loa'' infection are primarily aimed at reducing human contact with the vector flies. This includes wearing protective clothing, using insect repellent, and avoiding exposure in endemic areas during peak biting times of the flies. There is currently no vaccine available for loiasis.
+Preventive measures include avoiding bites from the [[Chrysops]] fly by using insect repellent, wearing protective clothing, and implementing vector control strategies.
-==Epidemiology==
-Loiasis is endemic to rainforest and swamp regions of West and Central Africa. The disease affects millions of people in these areas, with certain communities having a high prevalence of infection. The distribution and prevalence of loiasis are closely tied to the habitat of the ''Chrysops'' flies, which are the sole vectors of ''Loa loa''.
-==Public Health Impact==
-The public health impact of loiasis is significant in endemic regions, where it can cause considerable morbidity. While the disease is not typically fatal, it can lead to chronic discomfort, social stigma, and economic hardship for affected individuals. Additionally, the presence of ''Loa loa'' can complicate the mass administration of drugs aimed at controlling other filarial diseases, such as [[onchocerciasis]] and lymphatic filariasis, due to the risk of severe adverse reactions.
-[[Category:Parasitic diseases]]
+==Related pages==
-[[Category:Tropical diseases]]
+* [[Loiasis]]
-[[Category:Nematodes]]
+* [[Nematoda]]
-[[Category:Health in Africa]]
+* [[Parasitic worm]]
+* [[Onchocercidae]]
-{{Medicine-stub}}
+[[Category:Parasitic nematodes of humans]]
+[[Category:Onchocercidae]]