We will have no drugs to treat infections

The discovery of penicillin by Sir Alexander Fleming in 1928 and its subsequent use to fight bacterial infections in 1945 changed the history of medicine.

This was followed by the development and widespread use of effective antimicrobial agents, which along with better sanitation (hygiene) and vaccination, was responsible for substantial reduction in deaths from infectious diseases.

Antimicrobials are naturally occurring molecules used by microorganisms like fungi to secure their ecologic niche. The mass production of antimicrobials gave humanity temporary advantage over these microorganisms (bugs), but this also resulted in the development of drug resistance.

The problem of drug resistance and “multi-drug resistant organisms” (MDRO) is a growing concern worldwide. In India, the threat is more serious because antibiotics are available “across the counter”, sometimes without prescription, and this results in misuse.

The indiscriminate use of antimicrobials is common and antibiotics prescriptions are often based on information provided by medical representatives, rather than on the clinical condition of the patient and knowledge of pharmacology. Medical practitioners feel safe under the “antibiotic umbrella”. In many instances, viral infections are treated with antimicrobials in inappropriate doses to save costs, promoting the development of resistance.  Antimicrobials are also used in the animal husbandry industry.

The development of antibiotic resistance is related to their use.  The mechanisms of drug resistance and the transfer of these resistance factors in bacteria are complex. In some instances, resistance has been shown as soon as an antibiotic is introduced for use. Some of the genes responsible for drug resistance are called “jumping genes”, because they are transferred from one bacterium to another, even of two different genera.

By virtue of the extensive use of antimicrobials in hospitals, they are considered the “epicenters” of drug resistant microorganisms. Patients who harbor these organisms carry them to the “community”.

In both hospitals and in the community, these organisms once introduced, can spread like wildfire.

The single most effective means of controlling this spread from person to person is by augmenting simple infection control measures like “hand hygiene”.The current rate of increase in resistance to antimicrobials is alarming. If this continues, we will soon have no drugs to treat infections! Moreover, the pace of antimicrobial drug development has markedly slowed in the last 20 years (US FDA approval of new antibacterial agents decreased 56% from 1983 to 2002).The time is ripe for a new awakening and it is imperative to make the best use of the currently available antimicrobials.

A rational approach to this huge problem is through an effective “antibiotic policy” or what is better described by the medical community as “antimicrobial stewardship program”. These policies and programs focus on the judicious use of antimicrobials to provide better patient outcomes (results), better patient safety through reduced risk of side effects (adverse effects), cost effective treatment and reduction or stabilization in the levels of drug resistant microorganisms.

Antimicrobial stewardship programs include interventions that promote the rational use of antimicrobials through education of healthcare providers and patients, clinical guidelines defining the appropriate use of specific antimicrobials for specific conditions and organisms.

They also involve processes to review antibiotic prescriptions by doctors, restrictive use of certain antimicrobial agents in hospitals only on approval, computer based support and the cycling of antibiotics.

The clinical microbiologist plays a pivotal role and is responsible for the timely delivery of reports on the cause of an infection and the choice of the antimicrobial agent. Local data on the prevalence of multidrug resistant organisms forms the backbone of the policy.

Infection control is important to prevent the spread of these MDRO from one case to another and from the healthcare provider to the patients. Any antimicrobial stewardship program should be integrated with the infection control program which helps reduce antimicrobial resistance, evaluate the efficacy of the program and improve patient outcomes.

In conclusion, in this war against the microbes and drug resistance the healthcare providers and the pharmaceutical industry must enter a renewed partnership to understand the relationship between antimicrobial use and resistance and promote antimicrobial stewardship programs.

 The writer is professor and head, Dept of Microbiology, Tata Memorial Hospital