Antibiotic resistance threat grows

It is widely accepted that antibiotics are over-used

A US study has found that the risk of developing an antibiotic-resistant infection rose by about a third from 1995 to 1998.

The finding adds to growing evidence that the overuse of antibiotics is creating a new generation of superbugs immune to current medicines.

Streptococcus pneumoniae is a nasty bug that really does cause a lot of disease

Dr Nigel Higson, Primary Care Virology Group

The research focused on the bacteria Streptococcus pneumoniae, the most commonly identified cause of meningitis, pneumonia and middle ear infections in the US.

In 1998, 14% of those who develop a Streptococcus pneumoniae infection had a form that was resistant to at least three different types of antibiotics.

This compared to just 9% in 1995.

The research was led by Dr Cynthia Whitney, of the US Centers for Disease Control and Prevention in Atlanta.

She said: "Multidrug-resistant pneumococci are common and are increasing."

About 160 million antibiotic prescriptions are written in the US each year.

An editorial in the New England Journal of Medicine, which published the research, says that about half of these prescriptions are unnecessary.

A similar amount of antibiotics is fed to animals each year.

Nationwide samples

The research is based on tests of 3,475 samples from 1998 from across the US.

The researchers found 24% of the bacteria in the samples were resistant to penicillin.

In Tennessee, the figure was 35%, while in New York and California the figure was just 15%.

Once the bacteria had adapted to fight off penicillin, the researchers found, they were likely to be able to withstand the onslaught of other types of antibiotics as well.

Scientists say greater care is needed in the use of antibiotics so that bacteria have less of an opportunity to evolve resistance.

However, they also argue that it might be necessary to immunise people against pneumococcal infections.

A vaccine, already used for adults, recently has become available to young children in the US.

In their editorial, Dr Richard Wenzel and Dr Michael Edmond, of Virginia Commonwealth University in Richmond, said routinely immunising infants in the US would prevent 53,000 cases of pneumonia, 12,000 cases of meningitis and 110 deaths each year.

The elderly and those with weak immune systems also face a high risk of death or illness from pneumococcal infections.

They wrote: "We need to reassess policies on antibiotic use while changing our approach to include vaccinations against pneumococcal infections of all children over the age of 4, all adults over age 65, and all people with HIV infection."

UK situation

The UK has no routine vaccination programme for Streptococcus pneumoniae.

Department of Health guidelines recommend that the vaccine which is effective against many of the strains of pneumococcus is given to high risk patients, for instance those with chronic heart disease, diabetes or liver failure.

Dr Nigel Higson, chairman of the Primary Care Virology Group, said a more effective vaccine was due to come on stream later this year.

He said the guidelines would then probably be changed to recommend that all children and adults over 65 received the vaccine.

He told BBC News Online: "Streptococcus pneumoniae is a nasty bug that really does cause a lot of disease.

"To try to vaccinate specific patients is very difficult for GPs, and it would be better to have a policy of giving it to all people within a specific age group."

The Department of Health has asked doctors to cut down on the non-essential use of antibiotics.

It has launched an Antimicrobial Resistance Strategy to try to combat the problem.