First let's start off with the answer for this specific scenario:
Being only 1 month into the program, it is unlikely that you are at a significant enough weight that would warrant a deload. Additionally, with only 1 week of missed workouts, it is unlikely you have had a significant enough deterioration in strength to warrant a deload. Given this, unless your body tells you otherwise, you should repeat your previous session and then proceed as normal. Should you have difficulties repeating the previous workout, then deload 10% and work your way back up.
As far as the more generalized answer, that is rather tricky as there are a lot of different stages and scenarios where this answer will change. Generally speaking, when you are working in the heavier weights, safety and form should always come before progress. You cannot and should not attempt to progress to higher weights if it means sacrificing form and/or safety. This is why deloading is such a crucial tool. If you miss a week or two to sickness in the later stages when you are operating at heavy weights, then deloading should no longer be a question, it should be a reality. Go down by 10-20% and start over again, focusing on form and rebuilding muscle so you can get back to and break through your previous weight.