Healthcare Worker-Mediated Cross-Transmission: A Systematic Analysis and Intervention Following a Carbapenem-Resistant Acinetobacter baumannii Outbreak in a Cardiac Tertiary Care Center

INTRODUCTION: Carbapenem-resistant Acinetobacter baumannii (CRAB) presents a critical threat in intensive care settings, with outbreaks leading to significant morbidity and mortality. In November 2025, a cardiac tertiary care center in Karachi, Pakistan experienced a CRAB outbreak involving seven patients across the intensive care unit (ICU) and coronary care unit (CCU), manifesting as central line-associated bloodstream infections (CLABSIs) and hospital-acquired pneumonia (HAP). METHODS Following an Infection Control Committee meeting on 27th November 2025, a targeted, one-month intensive Infection Prevention and Control (IPC) surveillance program was initiated from 1st -31st December 2025. A senior infection control nurse was deployed exclusively during evening shifts to observe, document, and provide immediate spot teaching sessions on IPC breaches across all clinical areas, including ICU, CCU, operation rooms (OR), and dialysis units. Surveillance focused on hand hygiene, personal protective equipment (PPE) use, transmission-based precautions, environmental cleaning, and reprocessing of medical devices. RESULTS IPC surveillance documented 309 instances of spot teaching across 64, 85, 73, and 87 healthcare workers in four successive weeks. Persistent, systemic non-compliance was identified, including incorrect PPE use especially in OR and during isolation precautions, improper sharps and waste disposal, delayed isolation initiation, and critical lapses in the reprocessing of equipment such as bougie catheters and oxygen bottles. Significant environmental issues, including rusted equipment and alarming hygiene failures, were also recorded. The outbreak was successfully controlled, with no new CRAB cases reported during and after the surveillance period. CONCLUSION The strategic reinforcement of IPC surveillance during evening shifts, coupled with real-time corrective feedback, was instrumental in identifying and addressing latent systemic failures and behavioral non-compliance that contributed to the outbreak. This study underscores the necessity of continuous, proactive IPC monitoring beyond routine hours and highlights the role of immediate, on-the-spot education in effecting behavioral change and sustaining a culture of safety.