induce, due to massive larval killing, a strong inflammatory response. Treatment of ocular toxocariasis is more difficult and usually consists of measures to prevent progressive damage to the eye. Epidemiology Humans are accidental hosts of Toxocara, yet toxocariasis is seen throughout the world. Most cases of toxocariasis are seen in people under the age of twenty. Seroprevalence is higher in developing countries, but can be considerable in first world countries, as well. In Bali, St. Lucia, Nepal and other countries, seroprevalence is over fifty percent. Previous to 2007, the U.S. seroprevalence was thought to be around 5% in children. However, Won et al. discovered that U.S. seroprevalence is actually 14% for the population at large. In many countries, toxocariasis is considered very rare. Approximately 10,000 clinical cases are seen a year in the U.S., with ten percent being OLM. Permanent vision loss occurs in 700 of these cases. Young children are at the greatest risk of infection because they play outside and tend to place contaminated objects and dirt in their mouths. Dog ownership is another known risk factor for transmission. There is also a significant correlation between high Toxocara antibody titers and epilepsy in children. Parasitic loads as high as 300 larvae in a single gram of liver have been noted in humans. The "excretory–secretory antigens of larvae ... released from their outer epicuticle coat [and] ... readily sloughed off when bound by specific antibodies" incite the host's immune response. The tipping point between development of VLM and OLM is believed to be between 100 and 200 larvae. The lighter infection in OLM is believed to stimulate a lower immune response and allow for migration of a larva into the eye. Larvae are thought to enter the eye through the optic nerve, central retinal artery, short posterior ciliary arteries, soft tissues, or cerebrospinal fluid. Ocular granulomas that form around a larva typically are peripheral in the retina or optic disc. Visceral larva migrans seems to affect children aged 1–4 more often while ocular larva migrans more frequently affects children aged 7–8. Between 4.6% and 23% of US children have been infected with the dog roundworm egg. This number is much higher in other parts of the world, in tropical countries there is seroprevalence of up to 80–90%, such as Colombia, where up to 81% of children have been infected, or Honduras where seroprevalence among school-age children was reported to