Isolation precautions: special considerations for immunocompromised hosts.

Purpose of review: To summarize current approaches to isolation precautions and infection prevention and control (IPC) practices in immunocompromised hosts, including patients with hematologic malignancies, those receiving cellular therapies, and transplant recipients, with attention to variability in evidence and practice.

Recent findings: Standard and transmission-based precautions remain foundational but often require adaptation for immunocompromised populations due to increased infection severity, prolonged pathogen shedding, and heightened transmissibility. Protective environments, including HEPA (high-efficiency particulate air) filtration and positive pressure rooms, may be of benefit for the highest risk populations but are resource-intensive and inconsistently applied. Emerging data support strategies such as universal masking to reduce respiratory viral infections (RVIs) and tailored transmission-based precautions. The role of multidrug-resistant organism (MDRO) screening and isolation continues to evolve, with mixed evidence and reconsideration of prior practices. Enhanced environmental cleaning and no-touch disinfection technologies hold potential but lack consistent outcome data. Several long-standing practices, including the neutropenic diet, are increasingly being re-evaluated.

Summary: IPC in immunocompromised patients is complex and multifaceted, with limited high-quality evidence guiding practice resulting in significant practice variability. A shift toward individualized, risk-adapted strategies - balancing risk mitigation, resource utilization, and patient-centered care - will ultimately optimize outcomes.