Authors (including presenting author) :
CHING H C R (1), FUNG S C K (1), CHAN W S (1), LAM K M (1), WAN H T (1)
Affiliation :
(1) Infection Control Team, UCH, HKSAR
Introduction :
Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent colonizer of the skin and mucosa of humans. The organism has been considered as a major nosocomial pathogen in healthcare facilities. Data analysis showed Old Age Home Residents (OAHRs) contributed half of the MRSA carriers among hospitalized patients aged over 65 years in Hong Kong, with the prevalence in OAHRs increased from 2.8% in 2005 to 32.2% in 2015. MRSA bacteraemia rate is the Key Performance Indicator (KPI) for infection control in the Hospital Authority (HA). Hospital acquired MRSA bacteraemia is defined as the number of MRSA detected from blood collected 48 hours after admission in acute beds per 1,000 patient days. The UCH Infection Control Team (ICT) observed that the rate remained high since 2023 (0.091) and reached 0.098 in 2Q 2024. These were significantly higher than HA average of 0.072 and 0.081 during the same periods.
Objectives :
To control the hospital-acquired MRSA bacteraemia rate in UCH.
Methodology :
ICT conducted a comprehensive investigation to look for the sources of hospital-acquired MRSA bacteremia. It was found that the main sources of were from pneumonia (22.69%), skin & soft tissue infections (15.13%) and catheter site related infections (8.4%). Majority of the infections involved elderly aged over 65 or from old aged homes (OAH). The infection rates were highest during demand surge in 1Q, and sometimes 2Q of the year. The greatest challenges included overcrowded ward environment and high proportion of fragile and dependent elderly patient in our catchment area, as well as manpower issue for patient bathing.
In collaboration with the ward staff and the pharmacists, the following control measures were implemented in 3Q 2024:
1. Additional manpower was provided to offer admission bathing to known MRSA carriers and all OAH residents using 4% chlorhexidine (CHG) solution or CHG wipe as soon as possible, preferably before change to patient clothes to reduce environmental contamination
2. Suppressive therapy for all patients with positive MRSA cultures from any sites to reduce the risk of bacteremia or transmission to other patients. The 5 days regimen consists of 10% povidone-iodine nasal ointment and chlorhexidine bath or wipe was used.
3. Encourage sit out or prop up patients for feeding to prevent aspiration
Result & Outcome :
The rate of MRSA bacteraemia detected after 48 hours of admission in acute beds per 1,000 acute patient days decreased to 0.060 and 0.040 at 3Q and 4Q 2024 respectively.
Conclusion:
This study showed that resource support from management and joint efforts from various departments are instrumental in the control of MRSA in hospital setting. Decrease in MRSA bacterial load from high risk patients via antiseptic bathing before environmental contamination, as well as suppressive therapy for active MRSA patients are crucial measures.
