Can be a difficult disease to pin down at times. I had it in 2006 - the erythema migrans ('bullseye') rash made the dx easy (have a photo somewhere). I didn't have much of a febrile illness & was not incapacitated. Never saw a tick. Your situation: deer tick ("confirmed"?) bite attached for sufficient period followed by febrile illness after typical interval (?) - but no rash and negative Lyme...back to puzzling unless perhaps one has made oneself an expert on Lyme symptomatology and dx, incl various blood screenings and false positives and negatives.
If you had young kids around (incl college students too tho seems less likely), febrile illness as such could mean nonspecific viral infection - wheres and hows unknown.
It could be a nonspecific viral infection. I did have slight chills about three days prior to fever onset. I noticed "non-sweating" during 2 hour run but did not give it much attention. Then after onset: interesting symptom. Nightly, whenever I manage to fall into deep sleep it was like my sweat faucet turned on big time. So much so that when I awoke (usually around 4 am) , body, clothes and bed were all soaked! But head was clear and I felt feverless. But immediately thereafter fever, fatigue, heavy head etc. started to turn on again, and sweat turned off; on to a new cycle...
Anyway I am much better now, normal temp., energy about 70% back, coughing is milder with small mucus release; head is clear.
My PCV added a third week of doxycycline.
Time to go for a walk with Jena.
We are getting ready for a 3 day holiday stay at the Eagle Mt. House in Jackson, where Nancy's family will join us for the turkey feast and overnight stay. Now I can look forward to this.
Enjoy Jackson. Remember last Thanksgiving's giving of snow! Saw a display on Wilson Bentley (a Vermonter) yesterday, the first person to photograph snowflakes and, presumably, an ardent lover of snow.