The NHS trust that operates Barnet Hospital has been officially named as the worst in the country for MRSA infection rates.

Figures released last week by the Department of Health show that Barnet and Chase Farm Hospitals NHS Trust has the highest rate of infection and the most patients infected by the superbug in the UK from April to September last year.

However, the trust, which also operates Chase Farm Hospital in Enfield, insists that the number of cases has halved since it spent more than £180,000 on hiring an infection control nurse and other staff, as well as bringing in a raft of new cleaning measures last autumn.

Barnet Hospital serves around two-thirds of patients in Hertsmere, and the Hertsmere Primary Care Trust (PCT), contributes around £18 million a year to the hospitals' trust.

Dr Mike Edwards, chairman of the PCT's professional executive committee said: "The level of MRSA infection between April and September 2004 was unacceptable and concerning.

"However, the trust has responded with a significant number of infection control actions which we are pleased have shown a significant reduction in the MRSA rate in the most recent months. This must be sustained to maintain PCT and public confidence.

"We believe this requires on-going leadership by the medical and nursing directors to ensure that all staff follow practices that protect patients."

John Reid, the Secretary of State for Health, recently visited Chase Farm Hospital and commended the staff on their approach to MRSA.

Nick Samuels, director of communications for the trust, said: "The figures are very misleading. Our figure has hugely improved over the last six months, thanks to the measures we brought in and the hard work of all the staff here. We know that the situation was bad very bad in fact and we have made real changes since then."

The Department of Health figures show that the trust reported 60 cases of MRSA between April and September.

MRSA, or Methicillin-resistant Staphylococcus Aureus, is a bacterial infection that exists on the skin of healthy people without harm but can cause fatal infections if it enters the bodies of vulnerable people.

It used to be treated with an antibiotic but has developed a resistance to standard drugs in the past 50 years.