• Study concludes active surveillance testing with molecular methods reduces transmission of MRSA among surgical patients
  
  
• Pandemic (H1N1) 2009 influenza: vaccination programme continues
  

Study concludes active surveillance testing with molecular methods reduces transmission of MRSA among surgical patients

Patient screening for carriage of methicillin-resistant Staphylococcus aureus (MRSA) using a rapid molecular test significantly reduces MRSA transmission when compared to standard culture based methods, according to research published in Clinical Microbiology and Infection by a team of researchers at The Heart of England NHS Foundation Trust. The NHS-sponsored study, “Reduction in the rate of methicillin-resistant Staphylococcus aureus acquisition in surgical wards by rapid screening for colonisation: a prospective, cross-over study”, appears in the February 2010 issue of the journal.

"This study provided a challenging test of the value of rapid versus slower culture-based methods for MRSA screening because of the limited availability of isolation rooms,” said Dr Peter Hawkey, professor of clinical and public health bacteriology, consultant medical microbiologist, West Midlands Health Protection Agency Public Health Laboratory, Heart of England NHS Foundation Trust. “We conclude that the introduction of MRSA screening using rapid tests and the protocol we have described can significantly reduce MRSA transmission.”

Led by researchers at the Heart of England NHS Foundation Trust, University of Birmingham, Health Protection Agency Birmingham Regional Laboratory and University of Warwick, the prospective cross-over study of nearly 11,000 patients admitted to seven surgical wards over 16 months, compared the impact of employing a rapid molecular test (BD GeneOhm™ MRSA assay) to conventional chromogenic culture media for detecting MRSA nasal carriage. Results of this study demonstrated a significant 1.5 fold-increased risk of MRSA acquisition when patients were screened with the culture method as compared with molecular testing. The mean time for reporting positive results for the rapid molecular test was 0.9 days versus 3.3 days for the chromogenic culture test. The study authors attribute the reductions in MRSA transmissions to this shortened time to test result.

Active surveillance testing seeks to identify patients who are carriers of MRSA but do not show visible symptoms or signs of MRSA infection [1]. Rapid identification of MRSA colonized patients at admission and during hospitalization allows for immediate implementation of contact precautions and other preventive measures to minimize infection risk to both colonized and non-colonized patients.

The study consisted of two eight-month cross-over periods in which patients were tested upon admission, every four days thereafter until discharged, by one of the two test methods. All wards practised the same infection control procedures, which were constant for the duration of the study. Patients with a positive test result were cared for with comprehensive infection prevention measures, which included isolation whenever possible and decolonization with nasal antibiotic and antibacterial body wash. Due to the limited availability of single rooms for patient isolation, the dominant intervention was early patient identification. The wards involved in this study had a high bed occupancy and low availability of isolation rooms, making it applicable to the majority of healthcare systems worldwide.

In the UK in the early 1990s, two percent of Staphylococcus aureus bacteremias were due to MRSA [1]. In 2005, the mean figure had reached 45 percent and UK levels of MRSA bloodstream infections ranked among the highest in Europe [1]. That same year, the Department of Health set a target to reduce MRSA bloodstream infections by 50 percent for all Acute Trusts by March 2008. The Code of Practice for the Prevention and Control of Health Care Associated Infections [2] states that the infection prevention and control policy should make provisions for pre-admission screening in addition to decontamination and isolation of colonized patients, and antibiotic prophylaxis for surgery. This study demonstrates that the use of rapid surveillance testing can further accelerate the reduction in MRSA transmission.

References

1. Boyce JM, Cookson B, Christiansen K, Hori S, Vuopio-Varkila J, Kocagöz S, et al. Methicillin-resistant Staphylococcus aureus. The Lancet Infectious Diseases 2005, 5(10), 653-663.

2. The Health Act 2006: Code of practice for the prevention and control of health care associated infections. London: Department of Health, 2006. Available at: www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/@dh/@en/documents/
digitalasset/dh_4139337.pdf.

 

Pandemic (H1N1) 2009 influenza: vaccination programme continues

The Chief Medical Officer for England has written to GPs, practice nurses, hospital doctors and lead nurses in PCTs about the continued importance of the pandemic H1N1 (2009) influenza vaccination programme that has gathered pace since Christmas as more people in the clinical at-risk groups have been vaccinated.

Some 4.54 million doses have been administered to date to people in the priority groups, including 518,000 doses given to healthy children over six months and under five years of age. The CMO notes, however, that uptake levels in the other parts of the United Kingdom and some European countries are higher than achieved in England and calls for awareness to be maintained about the continued delivery of the programme by the NHS.

Reference

1. Department of Health Central Alerting System. Pandemic H1N1 (2009) influenza vaccination programme, 18 February 2010. Available at: https://www.cas.dh.gov.uk/ViewAndAcknowledgment/viewAlert.aspx?AlertID=101352.