The leaves definitely have developed a fungal infection. I wonder what caused the problem to "explode" like that. Can you try to determine if the pest you have noticed is Azalea Bark Scale? Common in July-ish and it secretes a honeydew that sort of looks like in the picture and which helps fungual infections develop.

Otherwise, is your weather promoting high humidity levels? Or do you do overhead watering on the leaves? How much water do you give them per watering?

luis:

Thank you for your reply.

I will check on the bark scale.

The droplets on the leaves are there because I had just sprayed the plants with All Season's Spray Oil in a desperate attempt to help them out.

VERY HIGH humidity levels here this summer.

We do spray with water to water that area.

I do not do the watering, so I will have to ask my other half how long he waters at each time.

I will now hit them with a fungicide spray in the morning and hope that helps - how often should one treat them with the fungicide?

Thanks!

If this is honeydew from scale, try using water and your hand to remove it. You can apply dormant and-or horticultural oils to control nymphs and-or crawler adults.

The link below has pictures to help you Id some azalea pests.

PS - I suggest watering the soil, not the leaves.

Here is a link that might be useful: Azalea Pest Information From Clemson University