No new disease for azaleas.  Instead, azaleas have a new insect pest – azalea lace bugs – that were officially recognized in 2009.  Since then, the lace bugs have spread far and wide locally.  They’re very small insects that live and feed on the underside of azalea leaves. (They also damage some rhododendrons in the same way.) Lace bugs typically hatch in April or May, then feed through the summer, gradually changing the plant from a vibrant green to one that appears close to dying.  But they will survive.  And the following spring, the new growth appears and everything appears fine again, but only until the eggs hatch, and the new youngsters begin to feed.  This publication will provide further insights: Azalea Lace Bug - http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/40424/em9066.pdf

 

As for the chewed leaves, my guesses would include deer (however they typically eat the entire end do the branch) and rabbits. We can perhaps improve the odds of determining who it is if you send me several pictures. You can attach 3 images to your reply.  Please submit an overall view showing the plant and its surroundings; a midway shot; and a close-up of a branch which has representative damage.  I look forward to receiving your pictures!

Here's more information about the damaged azalea leaves:

Perhaps the culprits eating your azalea leaves are sawfly larvae (youngsters). They’ll be difficult to see because they are the same green color as the leaves. They look very similar to caterpillars (“worms”) and are less than a half-inch long. Look for them on the edges of the leaves. (Or on what remains of the leaves!) If you see small brown specks, it’s sawfly frass (excrement); the sawflies should be nearby. If the shrub is a reasonable size, handpicking works. (If you’re squeamish, use a tweezers.) Or flick them into a cup of soapy water. Another option is a harsh water spray to blast them off the plant. And if you decide to use a spray, know that both azadirachtin (neem extract) and spinosad A&D are considered organic choices. See “Azalea Sawflies” http://hyg.ipm.illinois.edu/article.php?id=572 and “Azalea sawflies” http://www.extension.umn.edu/garden/insects/find/azalea-sawflies/

As I suggested earlier, please send me an image of a branch on an affected shrub. A close-up view of about 10 inches or so should display the damage and the sawflies well (if the latter are still present).

I haven't been ignoring your follow-up emails; just couldn't respond as we are in the process of putting a loved one into a special care home, doing a garage sale, selling the house, etc.! I believe what is chewing on my azalea is the lace bug, but I don't see any sign of what is causing it. I did take pictures and then later in the day took some more placing a dark background behind the damage and saw a beetle (?) bug of some sort on another leaf. The damage is mainly in the back and seems to have subsided and the whole azalea has not been consumed for the time being. All I can see on the leaves are little white things, and there aren't very many. The neighbors large tree overhead deposits burrs every year, and I don't know if that might be the culprit.

Thank you for sending the images.  The shrub appears to be in generally good condition but the damaged branch reveals obviously chewed leaves. The time period matches that for the azalea sawfly but we would need to see the critters to verify  the ID before treatment is suggested. Because the damage doesn’t seem to be spreading, plan to mark next year’s calendar to check for damage.  If you find any chewers then, please send new images of the damage and the critter(s).  It would be helpful if you again respond to this inquiry.

 

The image of the single leaf shows damage that probably occurred while the leaf was developing. It was likely an environmental glitch of no concern.

I don't see any evidence of the azalea lace bug in any of your pictures.