Hi jdssred, welcome to the board
Is your brother still being treated? What antibiotic and dose was he given? How long was he treated? What treatment is your wife taking?
Lyme disease is a multi-system bacterial infection caused from the bite of an infected tick. Besides Lyme disease, ticks can transmit several co-infections--Babesiosis, Ehrlichiosis (HME & HGE), Bartonella, and Mycoplasma. Many doctors do not understand Lyme and treat with outdated protocols. Lyme and tickborne infections need aggressive and often long-term treatment. Untreated or undertreated, these diseases can be chronic and debilitating.
It is very important for your wife and your brother to see a knowledgeable doctor so they can be tested for the co-infections and get the proper treatment. Where do you live?
Please read the "Lyme Disease Information" post on this board. I highly recommend the book "Everything You Need To Know About Lyme Disease." Make sure you get the 2nd edition. Lyme can be passsed through pregnancy and breastfeeding. Some Lyme doctors believe it can be sexually transmitted but from what I understand, there is no documentation of this. You may want to use a condom as a precaution.
The most important things you can do are to find a knowledgeable doctor and learn as much as you can. Your wife is very lucky to have such a caring, understanding husband.
If you post where you are located, I will recommend a Lyme doctor that is closest to you.