Hello and welcome,
Thanks for your query.
is well known in every home nowadays. But, it wasn't so previously, and so, there were numerous undiagnosed cases in the past. There is a possibility that some of you husbands ancestors did have diabetes, but were undiagnosed. Yet, this is only food for thought.
What we need to worry about more than the diet is to keep his blood sugar levels within the normal range, and yes, diet is one of the most important contributor to that. But, as you have described a healthy lifestyle being followed by your husband, it could not help us much here.
What I advice is for you to consult a diabetologist/Physician who will monitor your husbands blood sugar levels and advice medications to keep his blood sugar under control.
Infections are common during diabetes (uncontrolled), as will resolve once we get the blood sugar to a normal range, but might also require short course of antibiotics to terminate the infection.
Being an Indian myself I am well aware about the various eateries and food items we have on a daily basis that could contribute to the blood sugar. When you do visit a doctor for the diabetes, request for a consultation with a nutritionist who will also guide you through the proper and safe management of diabetes.
I hope I have succeeded in answering your questions, you could write back to us anytime for further clarifications.