Second Noble Truth

I am reading multiple interpretations of the 2nd noble truth. Most of the sources indicate that it is craving, desires, wanting. Some sources talk about wrong understanding of reality and itself, clouded judgement, not understanding the nature of the mind. Question: If there is a sick child, suffering and in pain, what is the cause there? Child didn't have a chance to have desires and wrong cravings yet, its just an innocent child. Of course, there is karma, child is sick because of previous karma. But nowhere I saw the source stating that cause of suffering is karma repaying, especially for a child, just starting new life. Can someone please refer me to a source explaining that? Mostly we have a very detailed description of the 1st noble truth: life is suffering (sickness, death, old age, the whole life disappointments, departures, not getting what person wants, losing something/someone...etc) And a jump to cravings/desires explaining that suffering in the 2nd noble truth. But imho it doesn't explain all the suffering, only some. Can someone please clarify. Thank you!