Ocular larva migrans (OLM) is caused by T. canis and rarely by T. cati [1] [2]. The infection is acquired by humans after ingesting the larvae or eggs of the parasite through improperly cooked meat or food contaminated by feces of animals [1] [2] [3]. The ingested larvae migrate through the intestinal walls to enter the systemic circulation and travel to various organs causing inflammation locally [1] [2]. Toxocariasis can be asymptomatic or can cause severe disease either systemically (visceral larva migrans) or in the eye (OLM) based on the migration of the larvae, inflammatory response in the host, and parasitic load [1].

The disease is prevalent in children as well as adults [4] [5] [6] and is one of the most important causes of loss of visual acuity in children [3]. Typically OLM is unilateral [7] and its lesions are classified [5] depending on their locations as posterior pole granulomas, peripheral granulomas, endophthalmitis, and atypical.

Granuloma of the posterior pole is the commonest manifestation [8] and presents as a yellow or white mass at the posterior pole of the eye with or without inflammation and pigmentation accompanied by haziness of the vitreous [5]. This leads to swelling of the macula with visual disturbances.

Pigmentation and edema [5] around a peripheral retinal nodule can be seen as a "snowbank" [9] and the nodule can pull on the retina causing holes and detachment.

Endophthalmitis due to the parasite presents more often in younger patients [10] as a tender, red, inflamed eye [5] with panuveitis advancing to hypopyon and vitreous infiltrates [5].

Optic nerve head inflammation with optic neuritis can be seen in atypical cases. Other features in these patients are subretinal space larvae, chorioretinitis [1] [3] [9], conjunctivitis, corneal and inflammation and nodules in the iris, cataracts [1] and subcapsular lenticular opacities [11].

Loss of vision in OLM can be due to granuloma associated retinal injury, inflammation of other intraocular structures and associated comorbidities [10].

• Fever

  In a few people who are infected with high numbers of Toxocara larvae or have repeated infections, the larvae can travel through parts of the body such as the liver, lungs, or central nervous system and cause symptoms such as fever, coughing, enlarged [cdc.gov]

  VLM syndrome was described in some children who presented with fever, hepatomegaly, pulmonary infiltration and peripheral eosinophilia as a result of Toxocara canis infection ( Beaver et al ., 1952 ; Uhlíková et al ., 1996 ). [content.sciendo.com]

  Bacteria[edit] Vibrio cholerae (cholera) Clostridium difficile (pseudomembranous enterocolitis) Shigella (shigellosis / bacillary dysentery)[4] Salmonella typhii (typhoid fever)[5] Vibrio parahaemolyticus[6] Escherichia coli[7] Campylobacter[8] Viruses [en.wikipedia.org]

  VLM syndrome including one or more of the following: eosinophilia associated with fever, general malaise, abdominal pain, headache, cough, anorexia, wheezing, hepatomegaly, anaemia, leucocytosis, dermatologic manifestations as prurit or urticaria, pulmonary [ijmm.org]

• Macula

  This leads to swelling of the macula with visual disturbances. Pigmentation and edema around a peripheral retinal nodule can be seen as a "snowbank" and the nodule can pull on the retina causing holes and detachment. [symptoma.com]

• Blurred Vision

  Visualization on retinal exam is uncommon. 5 Case A 33 yo man who returned from Iraq noted blurred vision and photophobia in his left eye. [slideplayer.com]

• Night Blindness

  The first signs and symptoms are night blindness, restriction of the visual field and peripheral pigment epithelial changes. [academia.edu]

Diagnosis of OLM depends on typical clinical features seen on ocular examination, detection of Toxocara larvae antibodies in serum with enzyme-linked immunosorbent assay (ELISA) [10] and histopathological examination. An ophthalmic examination will reveal granulomas at the posterior pole of the eyeball or retinal periphery. Ultrasonography can be performed in patients with endophthalmitis if a fundal examination is difficult due to the haziness of the vitreous. In addition to Toxocara larvae antibodies, ELISA identification of intraocular fluid antitoxocara antibodies and serum immunoglobulin E are performed to diagnose the disease.

Histopathological examination of affected tissues and demonstration of parasite larvae is the gold standard test for the diagnosis of OLM. However, biopsy of ocular tissue is difficult and so currently, the diagnosis relies on clinical findings and detecting larval antibodies [1] [3] [5].

Computed tomography (CT) scan and magnetic resonance imaging (MRI) in OLM may show several nodules with size up to 1 centimeter or little above.

• Toxocara Canis

  canis and T. cati. [medical-dictionary.thefreedictionary.com]

  Parasitic infection with Toxocara canis is uncommon and visualization of larva is difficult to discern. [slideplayer.com]

  Date/Time Thumbnail Dimensions User Comment current 08:35, 28 October 2008 3,072 × 2,048 (412 KB) Enableuser ( talk | contribs ) {{Information |Description={{en|1=Ocular larva migrans granuloma via toxocara canis infection from newborn puppies, onset [commons.wikimedia.org]

  To investigate the role of Toxocara canis in posterior uveitis of undetermined origin. Retrospective case-study. [scienceopen.com]

  Vancouver Author BibTeX @article{9fc0e71a779a4fe9a7d4752f18443f87, title = "Toxocarose ophtalmique; {\`a} propos d'une observation clinique (Larva migrans oculaire)", keywords = "B780-tropical-medicine, Helminthic diseases, Toxocariasis, Toxocara canis [pure.itg.be]

• Toxocara Cati

  Abstract Toxocara canis, Toxocara cati and Ascaris suum are roundworms of dogs, cats and pigs, respectively, that can also infect humans. These zoonotic helminths have a worldwide distribution and are also endemic in the Netherlands. [ncbi.nlm.nih.gov]

  Nematodes causing such zoonotic infections are Baylisascaris procyonis, Toxocara canis, Toxocara cati, and Ascaris suum. [en.wikipedia.org]

  TOXOCARA Problem Toxocariasis (visceral larva migrans, ocular larva migrans) is a widely under-reported parasitic infection caused by the migrating larvae of the nematode roundworms Toxocara canis and, less commonly, Toxocara cati. [cellabs.com.au]

  Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ ) Definition (NCI) A parasitic infection caused by Toxocara. Humans are infected by the larvae of Toxocara canis and Toxocara cati from dogs and cats respectively. [fpnotebook.com]

  Reporte de caso Resumen (en_US) Introduction: Toxocariasis is a zoonosis caused by the Toxocara canis and Toxocara cati nematodes larvae. These are intestinal parasites found in canids and felids, respectively. [revistas.unal.edu.co]

Reference is easy thanks to a unique 3-part structure covering general aspects of treatment; reviews of every agent; and details of treatments of particular infections. [books.google.com]

Treatment Treatment is primarily medical and is focused on preventing damage and visual loss due to the inflammatory reaction in the eye caused by the presence of the larva and the formation of secondary membranes. [news-medical.net]

Treatment with vitrectomy, albendazole, and acyclovir resulted in mild improvement of visual acuity. [ncbi.nlm.nih.gov]

Treatment resulted in an improved visual acuity in all patients. Mean initial Snellen visual acuity was 20/40, and mean final acuity was 20/20. [liebertpub.com]

Treatment is with albendazole and steroids, although the prognosis is generally poor. This parasite can also cause ocular larva migrans (OLM) which usually presents as diffuse unilateral subacute neuroretinitis (DUSN). [einstein.pure.elsevier.com]

Well-timed vitrectomy is a suitable therapy for vitro-retinal complications in ocular toxocariasis to improve prognosis and to confirm the diagnosis. [8] Ophthalmologists need to be made aware of the ocular toxocariasis - especially in children and young [ijmm.org]

Initial evaluation for etiologic causes was nondiagnostic. Serology for anti-Baylisascaris procyonis antibodies in serum and vitreous fluid were both positive. Polymerase chain reaction (PCR) of vitreous fluid was positive for HSV-2. [ncbi.nlm.nih.gov]

It was concluded that B. procyonis larvae have marked ability to produce OLM in subhuman primates following oral infection and should be considered as a possible etiology in human ocular disease. [iovs.arvojournals.org]

Initial evaluation for etiologic causes was nondiagnostic. Serology for anti- Baylisascaris procyonis antibodies in serum and vitreous fluid were both positive. Polymerase chain reaction (PCR) of vitreous fluid was positive for HSV-2. [ajtmh.org]

Diagnosis is made by recovering and identifying larvae in or from the tissues, epidemiological history, serology, and imaging of the central nervous system. Treatment is with albendazole and steroids, although the prognosis is generally poor. [einstein.pure.elsevier.com]

Complications The eye involvement can cause the following inflammatory disorders: endophthalmitis uveitis chorioretinitis Epidemiology In contrast to visceral larva migrans, ocular toxocariasis usually develops in older children or young adults with no [ipfs.io]

It discusses the epidemiological and clinical aspects of each disease in detail and illustrates the biology and life cycle of the causatory organism, as well as the pathology associated with infection and details of the treatment and long term management [books.google.com]

Abstract Twenty-four patients with serologically confirmed toxocaral ocular larva migrans (OLM) and 24 age- and sex-matched controls were the subjects of an epidemiologic study. [ncbi.nlm.nih.gov]

Complications[edit] The eye involvement can cause the following inflammatory disorders: endophthalmitis uveitis chorioretinitis Epidemiology[edit] In contrast to visceral larva migrans, ocular toxocariasis usually develops in older children or young adults [en.wikipedia.org]

Pathophysiology Children contract Toxocara infections by ingesting embryonated eggs. The larvae hatch in the small intestine, invade the mucosa, and enter the portal system. [emedicine.medscape.com]

Preventive measures would include such things as safely clearing “raccoon latrines,” washing hands after contact with soil, and vigilance with small children. [reliasmedia.com]

Rather than only concentrating on human feces, animal feces should also be included in the F-diagram.[2] The sanitation and hygiene barriers when placed correctly prevent the transmission of an infection through hands, water and food. [en.wikipedia.org]

Vitreoretinal surgery is useful and indicated to remove vitreous opacities and epiretinal membranes, to prevent and to treat retinal detachment. [medsci.org]

Possible mechanisms preventing a conclusive immunological response to the organism are discussed. Full text Full text is available as a scanned copy of the original print version. [ncbi.nlm.nih.gov]

Treatment Treatment is primarily medical and is focused on preventing damage and visual loss due to the inflammatory reaction in the eye caused by the presence of the larva and the formation of secondary membranes. [news-medical.net]

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