Helena;
So sorry to hear of the reaction in your brother. This site has a posting about the Lamm protocol and how to treat side effects. It decribes the seriousness of a systemic reaction and what antibiotic combination should be given to make sure your brother is getting the best meds possible. Type in "Lamm" in the search box and then go to #9 Lamm's protocol and you will find the description of how to treat side effects about half way down. Note that when someone has a systemic reaction it should be treatment aggressively with a combination of antibiotics and often steroids wit close observation. Measurements can be done to see if the infection is waning.
You also might go to bcgoncology.com (which is Dr. Lamm's site) and send him a full decription of what is going on (along with the exact meds he is on to fight the infection) via his "ask Dr. Lamm" section of the site. Ask for his good counsel. Lastly, not sure where your brother is located but he surely may need a second opinion fast from a major medical center that has seen a lot of BCG treatment in patients.
First things first, make sure he is getting the best care possible for the immediate threat, the infection. Then he needs experienced professionals that know how to affect his cancer therapy based upon his systemic reaction. Major med centers that have well regarded uro-ocology teams are the best approach for a comprehensive care plan going forward.
Hope this helps,
Deb