The Health Protection Agency has detected an increase in the number of urinary tract infections (UTIs) and cases of blood poisoning caused by strains of E. coli that are resistant to most antibiotics.
E. coli is a bacterial species which inhabits the intestinal tract of man and other warm-blooded animals. Although it poses no threat to human health, its presence in drinking water does indicate the presence of other, more dangerous bacteria.
The infections are caused by strains of the bacterium E. coli that produce extended-spectrum-beta-lactamases (ESBL). ESBLs are enzymes produced by bacteria, enabling them to destroy and therefore become resistant to certain antibiotics.
Although ESBL-producing E. coli still only account for a very small proportion of all UTIs, it is important that they are recognised rapidly by correct laboratory testing, so that appropriate antibiotic treatment can be given to patients.
As UTIs are not reported to the Agency through a mandatory scheme, and since not all ESBL-producing isolates are sent for investigation, it is not possible to give an exact figure for the number of these infections. However the reference laboratory saw only a few ESBL-producing E. coli per year prior to 2003, but has been sent over 400 samples, from over 60 UK sites in the past 12 months. The Agency has been analysing these reports and samples, and will publish its results in mid-August.
The Agency is aware that some patients who have suffered from these infections have unfortunately died. Because these patients may have had underlying medical conditions and may have already been receiving hospital treatment, it is difficult to say if the infection was a direct cause of their death or a contributory factor. To investigate this HPA specialists nationally and locally are working with others in the NHS and will report on its findings in the autumn.