What part of the body is the infection affecting? Upper respiratory or lower? Is he on immunosuppresants as well? Did they do a CBC - complete blood count to see what his WBC, white blood count is?

If he is on immunosuppressants, he may not to be able to fight the infection as well as before MG. Did they give you antibiotics? Are they on the list of approved to be used with MG?

If he is on immunosupprssants and his WBC cannot fight the infection, he may need an anti-viral as well and a stronger antibiotic.

In my opinion, that fever is too high for too long. You should consult with both your primary care physician and neurologist. Please give them a call.

Hope he is better soon,
Kathie