Previous research has shown that negatively pressurized Airborne Infectious Isolation Rooms (AIIRs) can protect hospitals from fatal airborne pathogens such as tuberculosis. But this use of negative pressurization can simultaneously increase the chances of isolated patients contracting secondary infections, or healthcare-acquired infections (HAIs), caused by air blowing in from adjacent spaces. Research is needed to better assess the actual likelihood of secondary infections occurring in these scenarios so that steps can be taken to mitigate these risks.