A Chinese man lost one eye after swatting a fly with his bare hand on his eyelid.
Swatting a moth fly with his hand led to a bacterial infection… Eye removed to prevent infection
According to the South China Morning Post (SCMP), Mr. Wu, who lives in Shenzhen, southern Guangdong province, was recently swarmed by a drain fly around his face. When the fly landed on his left eyelid, he instinctively swatted it with his hand and inadvertently rubbed his eye with the same hand.
About an hour later, his left eye became red and swollen, and he experienced severe pain. When he went to the hospital, he was diagnosed with seasonal conjunctivitis.
Despite taking medication, his condition deteriorated, and his vision dropped to 0.02. He also developed severe ulcers around his eye.
Eventually, the medical team removed his left eye to prevent the bacteria from spreading to his brain.
There have been previous cases of infections caused by drain flies in China. In October 2018, a 97-year-old woman in Shandong province, eastern China, developed a secondary infection after a drain fly landed on her wound.
Meanwhile, the fly that Mr. Wu swatted is commonly found in dark, damp drains, bathtubs, and sinks. It is known to carry many bacteria.
“Don’t swat insects near your eyes with your hands; instead, chase them away and take preventive measures.”
According to the Hygienic Insect Classification Information Book published by the Korea Disease Control and Prevention Agency, drain flies appear from April to November, with peak activity in May and June. During the day, they rest on the walls of humid bathrooms where sunlight does not reach.
Drain flies have spread in South Korea, but no infections have been reported. The primary issue is their persistent presence, which necessitates ongoing control efforts. Moth fly eggs are tiny—approximately 0.2 mm (0.0079 inches)—which makes them difficult to detect. Furthermore, these flies mature into adults in about two weeks, allowing for rapid population growth if not managed early.
Drain flies congregate in damp places, such as bathroom floors, sink drains, and wall crevices, where their larvae feed on accumulated bacteria and organic matter.
To eliminate drain flies, it’s crucial to target the larvae first. They cannot survive temperatures above 29°C (84.2°F) or in dry conditions with humidity below 58%.
Regularly pouring boiled water over 60°C (143.6°F) down the drain can effectively kill larvae. It’s also crucial to thoroughly clean drains and walls to prevent the buildup of organic matter, or slime, which serves as food for the larvae. Use bleach and a cleaning brush to scrub every corner. Additionally, ventilating the bathroom frequently to keep it dry can help prevent future infestations.
Another method is to spray insecticide where drain flies are present. Pyrethroid-based insecticides are commonly used to eliminate drain flies. However, avoid excessive inhalation of insecticides. If spraying in a confined space like a bathroom, ventilate it thoroughly before re-entering. If the insecticide gets on your skin, wash it off immediately with soap. If it gets into your eyes, rinse thoroughly with running water for about 20 minutes as soon as possible.
