Swimmer in Sea of Galilee Infected with Potentially Blinding Parasite

A 20-year-old man was hospitalized in central Israel with a Microsporidium infection in his eye after swimming in the Sea of Galilee during his summer vacation. The infection, which can potentially cause permanent vision loss, has left him experiencing pain and blurred vision for nearly three weeks.

His mother, identified only as Ilanit, told Walla that her son underwent intensive treatment, including two corneal epithelial scrapings and frequent eye drops, even at night. The family visited Ein Gev on July 24 and her son was at Kursi beach on July 31. Symptoms began about two weeks after his last visit to the lake. He was admitted to an eye emergency room on August 17, where doctors suspected Microsporidium based on a clinical examination. A PCR test later confirmed the diagnosis.

Microsporidium is a single-celled parasite found in water sources and sometimes mud. It can survive for extended periods in nature as spores until it infects a host. While not rare, the parasite is difficult to diagnose. In Israel, approximately 0.4% of eye keratitis cases are attributed to it, with about 40 cases likely linked to the Sea of Galilee reported in 2022. Three swimmers were infected in August 2023.

Infection occurs through direct contact of the eye with contaminated water, typically stagnant sources or mud puddles. Symptoms usually begin in one eye and include redness, a foreign body sensation, and sometimes decreased visual acuity. While most cases resolve on their own, in rare instances, the parasite can penetrate deeper into the cornea, leading to a severe infection that risks irreversible vision damage.

Medical attention is advised for anyone experiencing these symptoms after exposure to Sea of Galilee water. Antibiotic eye drops may be prescribed if infection is suspected. The recommendation to swim with goggles in the Sea of Galilee is likely to remain in effect as long as infection reports continue, especially during the busy summer season. Unlike natural water bodies, swimming pools are considered safe due to chlorine disinfection.