Loa loa microfilaria. Source: Arcari et al.Loa loa life cycle. Source: CDC
Find information on thousands of medical conditions and prescription drugs.

Loiasis

Loa loa filariasis (also loiasis and African eyeworm) is a skin and eye disease caused by the nematode worm, loa loa filaria. Humans contract this disease through the bite of a horsefly, also known as mango fly. The deer fly is also a vector of Loa loa. The disease can cause red itchy swellings below the skin called "Calabar swellings". The disease is treated with the drug diethylcarbamazine (DEC). more...

Home
Diseases
A
B
C
D
E
F
G
H
I
J
K
L
Amyotrophic lateral...
Bardet-Biedl syndrome
Labyrinthitis
Lafora disease
Landau-Kleffner syndrome
Langer-Giedion syndrome
Laryngeal papillomatosis
Laryngomalacia
Lassa fever
LCHAD deficiency
Leber optic atrophy
Ledderhose disease
Legg-Calvé-Perthes syndrome
Legionellosis
Legionnaire's disease
Leiomyoma
Leiomyosarcoma
Leishmaniasis
Lemierre's syndrome
Lennox-Gastaut syndrome
Leprechaunism
Leprophobia
Leprosy
Leptospirosis
Lesch-Nyhan syndrome
Leukemia
Leukocyte adhesion...
Leukodystrophy
Leukomalacia
Leukoplakia
LGS
Li-Fraumeni syndrome
Lichen planus
Ligyrophobia
Limb-girdle muscular...
Limnophobia
Linonophobia
Lipodystrophy
Lipoid congenital adrenal...
Liposarcoma
Lissencephaly
Lissencephaly syndrome...
Listeriosis
Liticaphobia
Liver cirrhosis
Lobster hand
Locked-In syndrome
Loiasis
Long QT Syndrome
Long QT syndrome type 1
Long QT syndrome type 2
Long QT syndrome type 3
LSA
Lung cancer
Lupus erythematosus
Lyell's syndrome
Lygophobia
Lyme disease
Lymphangioleiomyomatosis
Lymphedema
Lymphoma
Lymphosarcoma
Lysinuric protein...
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Medicines

Human loiasis geographical distribution is restricted to the rain forest and swamp forest areas of West Africa, being especially common in Cameroon and on the Ogowe River. Humans are the only known natural reservoir. It is estimated that 2-13 million humans are infected with the Loa loa larvae.

Life cycle

The vector for Loa loa filariasis are flies from two hematophagous species of the genus Chrysops, C. silacea and C. dimidiata. During a blood meal, an infected fly (genus Chrysops, day-biting flies) introduces third-stage filarial larvae onto the skin of the human host, where they penetrate into the bite wound. The larvae develop into adults that commonly reside in subcutaneous tissue. The female worms measure 40 to 70 mm in length and 0.5 mm in diameter, while the males measure 30 to 34 mm in length and 0.35 to 0.43 mm in diameter. Adults produce microfilariae measuring 250 to 300 μm by 6 to 8 μm, which are sheathed and have diurnal periodicity. Microfilariae have been recovered from spinal fluids, urine, and sputum. During the day they are found in peripheral blood, but during the noncirculation phase, they are found in the lungs. The fly ingests microfilariae during a blood meal. After ingestion, the microfilariae lose their sheaths and migrate from the fly's midgut through the hemocoel to the thoracic muscles of the arthropod. There the microfilariae develop into first-stage larvae and subsequently into third-stage infective larvae. The third-stage infective larvae migrate to the fly's proboscis and can infect another human when the fly takes a blood meal.

Clinical features

Lymphatic filariasis such as loiasis most often consists of asymptomatic microfilaremia. Some patients develop lymphatic dysfunction causing lymphedema. Episodic angioedema (Calabar swellings) in the arms and legs, caused by immune reactions are common. When chronic, they can form cyst-like enlargements of the connective tissue around the sheaths of muscle tendons, becoming very painful when moved. The swellings may last for 1-3 days, and may be accompanied by localized urticaria (skin eruptions) and pruritis (itching). Subconjunctival migration of an adult worm to the eyes can also occur frequently, in this is the reason Loa loa is also called the "African eye worm". The passage through the eyeball can be sensed, but it usually takes less than 15 min. Gender incidence of eyeworms have approximately the same frequency, but it tends to increase with age. Eosinophilia is often prominent in filarial infections. Dead worms may cause chronic abscesses, which may lead to the formation of granulomatous reactions and fibrosis.

Laboratory diagnosis

Identification of microfilariae by microscopic examination is the most practical diagnostic procedure. Examination of blood samples will allow identification of microfilariae of Loa loa. It is important to time the blood collection with the known periodicity of the microfilariae. The blood sample can be a thick smear, stained with Giemsa or hematoxylin and eosin (see staining (biology)). For increased sensitivity, concentration techniques can be used. These include centrifugation of the blood sample lyzed in 2% formalin (Knott's technique), or filtration through a Nucleopore® membrane.

Read more at Wikipedia.org


[List your site here Free!]


Infectious disease: Infectious diseases: Filariasis--bancroftian filariasis, Malayan filariasis, Loiasis (loa loa), onchocerciasis (river blindness) : ... the American Academy of Nurse Practitioners $20.00 Note on the further history of the case of Filaria loa previously reported to the Society
Case of Filaria loa, in which the parasite was removed from under the conjunctiva

Ivermectin in dermatology
Abstract Ivermectin, a broad-spectrum anti-parasitic agent first used in veterinary medicine, is active against numerous specie of helminths and arthropods.
Lipoma Excision
Lipomas are adipose tumors that are often located in the subcutaneous tissues of the head, neck, shoulders, and back. Lipomas have been identified in ...

Home Contact Resources Exchange Links ebay