Cases involving one of the nastiest bugs, called methicillin-resistant Staphylococcus aureus (MRSA), have risen 12-fold in the last eight years. Resistant strains of S. aureus now account for 37 per cent of all cases of blood poisoning caused by the bacteria compared with 3 per cent in 1991.
The Public Health Laboratory Service (PHLS), which monitors new infections, has long warned of the growth of resistant bacteria due to over-prescription of antibiotics. Yesterday, Professor Brian Duerden, deputy director of the service, said: "MRSA has now reached epidemic proportions in blood- poisoning cases. The increased capacity of the most serious forms to resist antibiotics means measures must be taken on wards to prevent transmission to vulnerable patients precisely because of its broad capacity to spread."
Worry is centring on two particularly virulent strains of MRSA - numbers 15 and 16 - which can cause serious illness. Deaths caused by MRSA, however, are mostly in patients who are already seriously ill and have lowered immunity.
Hospitals across the country are being told to step up their infection- control procedures to prevent spread of the bug. Staff are being warned to wash their hands between treating patients, and to take special care with those already seriously ill. "Hand-washing is the single most important strategy," a PHLS spokesman said.
The problem of antibiotic-resistant infections has been growing for more than a decade but repeated warnings by the PHLS have fallen on deaf ears. It is caused by the over-prescription of antibiotics which prompts bacteria - which have an unrivalled capacity to adapt to their environment - to develop resistance. The PHLS has argued that antibiotics must be used sparingly and the newer ones not given to animals but reserved for human use.
The first evidence that the level of antibiotic prescription by GPs affects the growth of resistance in their own patients is published in the British Medical Journal. A study of 190 surgeries in Wales found the number of prescriptions for the antibiotic amoxicillin written by GPs varied from 61 courses per 1,000 patients each year to 912 courses.
The researchers tested the urine of patients being treated for urinary- tract infections for the presence of antibiotic-resistant bugs, mostly Escherichia coli. They found that patients with the highest levels of the resistant bacteria - up to 70 per cent - were from surgeries which prescribed the most antibiotics.
Dr Tony Howard, director of the PHLS in Wales and an author of the study, said: "This shows for the first time that there is a link between the antibiotics a GP surgery prescribes and antibiotic resistance patterns in the bugs isolated from the surgery's patients."
MRSA is the resistant form of S. aureus, a common bug carried in the noses of about one-third of the population. It causes boils, wound infections and, in severe cases, septicaemia.