Ocular Larva Migrans: A Severe Manifestation of an Unseen Epidemic

Abstract

Toxocara canis and Toxocara cati, which infect dogs and cats respectively, may cause infection in humans with a wide spectrum of clinical symptoms and morbidity. Prevalence studies have suggested more widespread affliction than indicated by level of awareness among clinicians in endemic areas. Transmission in the United States continues with seroprevalence estimates identified as high as 22 % in some low-income communities. Best known for causing hepatitis and pneumonitis associated with the syndrome called visceral larva migrans, toxocariasis can also cause debilitating vision loss via ocular larva migrans and is considered a cause of preventable vision loss. While not a common manifestation of toxocariasis, the severity of this condition and its predilection for affecting children warrants increased attention. Herein, we review current knowledge of ocular larva migrans epidemiology, presentation, diagnosis, and treatment.

Soil-Transmitted Helminths in the USA: a Review of Five Common Parasites and Future Directions for Avenues of Enhanced Epidemiologic Inquiry

“…[ 37 ] 2016: 14-month-old canine with hookworm invasion of the brainstem, TX ( Ancylostoma spp. ) [ 38 ] Trichuris trichiura (whipworm) unavailable Highest: 55.2% in 366 Native born School children ages 6–12, KY Lowest:: 0.5% in 3729 Caucasian school children ages 5–15, GA unavailable Strongyloides stercoralis 68,000 – 100,000[ 26 ] Highest: 3.8% in 366 Native born School children ages 6–12, KY Lowest: 0% in 439 School children ages 10–14, KY 2020: 68-year -old man with COVID-19 infection immigrating 20 years prior from Ecuador, CT 2020: 16.5% positive serology in 97 individuals from a community with failing sanitation/poverty, central TX (75% with no travel history) [ 13 ••] 2017: 61-year old US-born man with HIV coinfection, no significant travel history, CT [ 11 ] 2017: 7.3% stool samples from 55 individuals in area of failing sanitation and poverty, Lowndes County, AL [ 24 ] 2013: 1.9% in 378 positive serology from persons presenting to Remote Area Medical Clinics, KY (only 1 positive participant had significant travel history) [ 28 ] Toxocara canis , T. cati 1.3–2.8 million [ 26 ] unavailable 2019: 3-year-old girl with OLM, previously healthy presenting with blurry vision and headache, AK [ 33 ] 2017: 5.2% positive serology from 11 individuals testing positive for any GI parasites in area of failing sanitation and poverty, Lowndes County, AL [ 24 ] 2015–2016: 66.7% contamination with eggs & larvae in 10/15 soil samples from the Bronx, 38.9% in 7/18 soil samples from Staten Island, 33.3% in 6/18 soil samples from Queens, 30.8% 4/13 soil samples from Brooklyn, 29.6% in 8/27 soil samples from Manhattan, NY [ 39 ] 2014: 4.6% egg positive fecal samples from 523,934 cats and 1.8% egg positive fecal samples from 2,750,718 dogs, national [ 40 ] 2014: 75-year-old female with pulmonary toxocariasis (only travel history 15 years prior to Caribbean), NJ [ 41 ] 2011–2014: 5.1% overall seroprevalence from 13,509 individuals from NHANES 2011–2014, national [ 42 ] 2009–2010: 68 case reports of OLM in individuals aged 1–60, national [ 43 ] …”

Characterization of the parasite-induced lesions in the posterior segment of the eye

“…The method of choice for routine diagnosis is the enzyme-linked immunosorbent assay (ELISA) using the excretory-secretory antigens of infective larvae of T. canis . [ 38 42 ] Imaging modalities can provide additional information in many patients. [ 43 ] Optical coherence tomography of posterior granulomas usually demonstrates a highly reflective mass located above retinal pigment epithelium.…”

Ocular toxocariasis: a neglected parasitic disease in Egypt

“…Also, there are some difficulties in the serological diagnosis concerning Toxocara antigen production or the highly expensive commercial diagnostic kits which are utilized only for research studies. The consequence of ocular toxocariasis and the potential under-reporting cases, based on seroprevalence studies, make ocular toxocariasis worthy of more medical awareness (Hare and Franco-Paredes 2014). This review discussed the pathogenesis, clinical manifestations, diagnosis, and treatment of ocular toxocariasis.…”