This isn't just their problem but a Public Health problem. Most communities require reporting of infestations (usually done by pest control company).

The problem will get worse. And they will transfer to everywhere your parents go.

The standard procedures for treatment and eradication are:

- Putting everything that is cloth through the dryer on high heat. Select one to two week's worth of clothing and bag as needed and seal the remainder in garbage bags(keep everything sealed for a minimum 2 months).
- treatment (spraying) is done every 14 days. Most infestations require 3 treatments but depending on the extent of the infestation may require more (I had 4).
- do NOT throw anything infested out! It will only spread the infestation.

Do your parents live in a multi suite building? The neighbours (above, below, beside) will have to be notified in addition to the property manager. Most property management companies will pay for the pest control.

Okay, protect yourself....

Leave yourself some extra clothes in their/your garage so you can change before entering your own home. Toss the other clothes immediately into the dryer.

This is all very unpleasant but this is what needs to happen.