pinworms

I've had pin worms for half a year, however they never seem to go away for long periods of time. I've had my house thoroughly cleaned several times each month and tried prescriptions, the pin worms then go away for a few weeks and then return. I have strict hygiene measures such as washing my hands when entering my house and before leaving it, i also do the basic of washing my hands after going to the toilet and do a hand clean every hour or so. I make sure to wipe down my device using screen cleaner before every use. I wash my bed at least once every week and clean the carpets with a hoover every week too. the kitchen surfaces and utensils are wiped down before each use and food is washed before being cooked. My shoes are taken off at the door so it's not like I'm treading it in through the house. I'm retired so I can't be getting them from work. I can't figure out how I'm continuously being infected with pin worms and I'm getting fed up.