If you notice these symptoms on an opossum in your area you may want to shut your pet door and keep your pets indoors until the animal has been dealt with.

There are also behavioral changes that can indicate the animal is not healthy. If the animal is lethargic this can indicate it is sick. Sick opossums are more dangerous than their healthy counterparts. They are able to spread disease through their bites, scratches, and feces.
If you believe there is a sick possum somewhere near your home, the best thing you could possibly do is get in contact with your local animal control team. They take animal illness incredibly seriously as a sick opossum can infect your pets, farm animals, and even you and your family with whatever diseases they may be carrying.

If you find a dead opossum you should proceed with extreme caution before moving and removing its body from where you found it. Make sure you wear all appropriate PPE.