A Study for the Ocular Toxocariasis Patients With the Pulmonary Toxocariasis, and Ocular Toxocariasis Cohort

Toxocara canis (also known as dog roundworm) is wide-reaching parasite of dogs and other canids. It can spread between animals such as cats, pigs and cows by ingestion of worm eggs from the feces of an infected animal. In humans, two pathways of infection are known: first, ingestion of the eggs and second, larvae encapsulated in the tissues of the infected animal. The encapsulated larvae hatch in the small intestine and pass through the barrier to the portal vein, the liver, the lung, the eye, etc. and remain as encapsulated larvae or survive for a period of time. Infection into humans has been reported through ingestion of uncooked liver of cows, pigs, sheep, chickens, and meat (muscle). When encapsulated larvae migrate to the body such as lungs, eosinophils activate and proliferate to eliminate the parasites. They can be expressed as ground glass opacity (GGO) or nodular lesion by aggregated eosinophils, which are mistaken for lung cancer or pneumonia to be investigated. Asthma exacerbation, cough and other symptoms of respiratory system could be revealed, but often asymptomatic. In this study, the investigators defined pulmonary toxocariasis (PT) as a positive form of serum toxocara Ab and migrating pulmonary GGOs or nodular lesions in chest diagnostic image tests (chest X-ray, chest CT) from the patient. Also ocular toxocariasis (OT) is defined by the clinical manifestation of intraocular infection by Toxocara larvae with a positive result of serum toxocara Ab. Clinical manifestations of OT may also cause blindness of peripheral granuloma, optic neuritis, chorioretinitis, conjunctivitis, keratitis, iridocyclitis and cataract. The investigators want to investigate the incidence of OT associated with PT in patients with chest diagnostic image tests (chest X-ray, chest CT) with migrating GGOs or nodular lesions. Also a cohort study is to track the results of treatment for diagnosed OT patients.