Proactive infection control measures

Infection control is an often neglected clinical subject in Hong Kong until the outbreak of severe acute respiratory syndrome (SARS) in 2003. A total of eight healthcare workers, including four medical doctors, succumbed as a result of nosocomial acquisition of SARS-coronavirus (SARS-CoV) at the time. Since then, the importance of infection control practice was much better appreciated by the frontline healthcare workers, as it can be a matter of life-or-death. My thesis summarized our research on the proactive infection control measures to prevent nosocomial transmission of respiratory and gastrointestinal viruses, to control emerging and endemic antibiotic-resistant bacteria, and on the management of unprecedented infection outbreaks in the hospital. Promotion of hand hygiene is the cornerstone of proactive infection control measures. By adopting the concept and practice of directly-observed hand hygiene, we demonstrated successful control of outbreaks and prevention for both respiratory and gastroenteritis viruses. Introduction of electronic devices for continuous monitoring of hand hygiene compliance in high risk clinical areas provides an opportunity for immediate feedback and timely education to frontline staffs. The global dissemination of multiple drug resistant organisms (MDROs) such as methicillin-resistant Staphylococcus aureus (MRSA), community-associated MRSA (CA-MRSA), vancomycin-resistant enterococcus (VRE), hypervirulent clone of Clostridium difficile, extended-spectrum beta-lactamase (ESBL) producing organisms, and the recently described carbapenem-resistant enterobacteriaceae (CRE), pose a great challenge to the infection control professionals. In Hong Kong, MRSA has been endemic for more than two decades. Although we proved that the appropriate use of single room isolation and hand hygiene can significantly reduce the incidence of nosocomial MRSA in the adult intensive care unit, the isolation facilities remain limited in the general medical and surgical units. Innovations are much in need to manage this old and persistent problem. Therefore, we demonstrated that use of antibiotics, in particular beta-lactams and fluoroquinolones, could increase the risk of environmental contamination by increasing microbial density of MRSA in the anterior nares by 2-3 log10 in as little as 1 week. We also found that some MRSA strains such as spa types t1081 and t037 were more transmissible. Based on these findings, we prioritized our isolation facilities for those patients who are heavily colonized or infected with highly transmissible spa-type t1081, especially when they are receiving antibiotic therapy. Along with our enhancement of hand hygiene practices and antibiotic stewardship program, the incidence of MRSA bacteremia per 1000-patient-days was the lowest among the seven hospital clusters in Hong Kong. We believe that our experience in the control of the MRSA can be extended to contain the spread of CA-MRSA and other MDROs. Besides the prevailing infectious diseases with high endemicity, we have to be vigilant against other potential outbreaks due to uncommon micro-organisms such as the polymicrobial outbreak in patients undergoing intermittent peritoneal dialysis caused by hospital renovation, the unprecedented outbreak of intestinal mucormycosis caused by Rhizopus microsporous among the patients with hematological malignancy, and the nosocomial outbreak of legionellosis in our locality. Extensive outbreak investigations were performed, which demonstrated that environmental factors were also important in causing nosocomial outbreaks.published_or_final_versionMicrobiologyMasterDoctor of Medicin