Antibiotics Less Effective Than Ever, Says WHO

"Until recently, antibiotics were regarded as the solution to many infectious diseases. Today they are becoming less and less effective as resistance to them spreads," said WHO Director General Hiroshi Najakima, considering the issue at the Assembly last week.

It is one of the main dangers facing world health today, warns the 1996 World Health Report. "The resistance of diseases to antimicrobials has increased dramatically in the last decade, with a deadly impact on the control of diseases such as tuberculosis, malaria, cholera, dysentery and pneumonia," it says.

A new class of antibiotics is urgently needed but drug manufacturers are only now beginning to understand this. They had stopped antibiotic development, preferring to develop other drugs which are more profitable.

"Drug companies concentrated on cardiovasculars and abandoned infectious diseases," says Professor Stuart Levy of Boston Tufts University.

Patients given cardiovascular medication such as beta blockers will take it for the rest of their lives while people with infections will only need a drug for the duration of their illness, which is usually no longer than a week or two, he explains.

However the situation is expected to change soon, largely because of growing concern in the U.S. at an increasing number of cases of resistance to vancomycin, widely viewed as "the drug of last resort." It is used to treat blood infections caused by a family of bacteria known as enterococci.

Because enterococci are resistant to other drugs as well, physicians are finding themselves with no treatments to offer some patients and some researchers are warning of a major epidemic.

Mitchell Cohen, director of the CDC's Division of Bacterial and Mycotic Diseases, says that vancomycin-resistant strains might "spread in individual hospitals and based on our past experiences spread between hospitals." Many scientists believe that it is just a matter of time before staphylococci acquire resistance to vancomycin as well.

However Levy warns that the problem may not be so easily solved. "There have been no new drugs for the last two years. All the ones that have been done in the 1990s are modifications of existing drugs, so whatever resistance developed in the old ones is carrying over to the new ones."

The only long-term solution, he says, is to be cautious in prescribing antibiotics so that bacteria that are susceptible to drugs have a chance to come back and replace those that are resistant.

Levy is author of the book "The Antibiotic Paradox" and has long tried to publicize the problem of overprescribed antibiotics. He points out that it took a generation to drive home the dangers of smoking, and even then it was with decidedly mixed results.

Doctors alone cannot solve the problem, he says, because often patients do not use antibiotics properly. Many people stockpile prescription drugs and use them indiscriminately to treat colds.

Antibiotic resistance is not a new phenomenon in bacteria and was first recognized as early as 1940 in cases of resistance of E Coli to penicillin.

Development of resistance is a basic part of the defense mechanism of bacteria. Scientists have found bacteria resistant to tetracycline and streptomycin in soil and human stool samples from the Solomon Islands where antimicrobial agents had never been used in the population, indicating that resistance was not simply a consequence of use, but an integral part of a bacterium's own defense system, enhancing its ability to survive in hostile environments.

Infectious diseases currently kill over 17 million people a year and are the main cause of premature death worldwide. Many of the common diseases such as pneumonia, which kills over four million people a year, and tuberculosis, which kills over three million, are now resistant to many antibiotics.

WHO is already reinforcing its activities to establish a system for monitoring resistance of selected bacteria to specific antimicrobial agents at local, national and global levels.

Although many countries have individual antimicrobial resistance surveillance systems, the results of epidemiological analysis are often not passed on to local physicians in a way that helps them choose the best antibiotic therapy for their patients.

WHO plans to establish within the next two years a core of about 30 to 50 laboratories worldwide to generate internationally verified, standardized results on trends in the susceptibility of important bacteria to specific antimicrobials.

Training courses are planned in nine countries in Africa and Asia in 1996 and 1997. Manuals are to be produced to help microbiologists in analyzing and reporting their local resistance findings to physicians.

The long term aim is to strengthen the capacities of WHO member countries to detect and contain the emergence of major multi-drug resistant bacteria.