We currently have effective medicines to cure almost every major infectious disease. But we risk losing these valuable drugs and our opportunity to eventually control many infectious diseases because of increasing antimicrobial resistance, says Dr. Gro Harbam Brundtland, former director general, WHO.
The publication of the paper entitled “emergence of a new antibiotic resistance mechanism in India, Pakistan, and UK: A molecular, biological, and epidemiological study” in the Lancet Infectious Diseases appeared online on 11th August 2010 has caused a widespread concern in the country on the reported prevalence of New Delhi metallo – ß-Lactamase 1 (NDM-1). The study reported the observation of NDM-1, the resistant bacteria gene, in 37 UK patients who had undergone elective and cosmetic surgery in India and two neighbouring countries. Though controversy over the NDM-1 continues, it has made the stakeholders to think of the remedial measures to prevent such occurrence of resistant microorganisms.
Ever since the findings of Louis Pasteur that many diseases were caused by bacteria and discovery of Penicillin by Sir Alexander Fleming and subsequent discovery of sulpha drugs and so on, the man’s fighting with major killer diseases become easier. The infectious diseases have been effectively combated by use of antimicrobial agents. The use of antimicrobials has greatly contributed to the decline of mortality and morbidity due to infectious diseases. But these antimicrobial agents are increasingly getting resistant against the pathogenic microorganisms. This becomes a public health issue.
Emergence of AMR
The emergence of Antimicrobial Resistance (AMR) is a natural biological phenomenon. All types of microorganisms like bacteria, fungi, viruses, and parasites develop resistance. The indiscriminate and improper use of antimicrobials results in a ‘survival of the fittest’ process for microbes that result in developing resistance to drugs. This occurs through mutation or by sharing DNA. Bacteria are particularly efficient at enhancing the effects of resistance because of their ability: to multiply very rapidly and transfer of resistant genes. They transfer their genes when they multiply. Resistance bacteria can also pass their resistant genes to other related bacteria through conjugation where by plasmids carrying genes jumps from one organism to another. Though traditionally it is believed that the non-lethal concentration of antimicrobials lead to AMR, the new study reports that antibiotics themselves too can cause ‘hypermutability’ through release of free radicals which causes mutation in DNA.
The infections caused due to resistant bacteria contribute to increased mortality and poor quality of life affected individuals. Besides this, it increases the financial cost of treatment, strain on health system and the risk of spreading such infection. The economic impact of AMR is enormous. The cost of treatment of multi drug resistant tuberculosis is 100 times higher than treating normal tuberculosis. The high cost of treating drug resistant infection may exceed the financial capacity of many individuals and hospitals. In early 1990’s, the outbreak of Typhoid fever (due to Salmonella typhi) was reported due to resistance. Around 83% of Typhoid cases were resistant to the chloramphenicol, the life saving drug of the period. Many deaths were reported.
Realising the global burden of AMR, the WHO has been urging its member states to ensure the development of a coherent, comprehensive and integrated national approach to implementing the strategies for containment of AMR and to monitor regularly the use of antimicrobials and the level of AMR in all relevant sectors. The increasing incidence of resistant microbes in hospital and community is an indication of the emerging AMR. The extent of resistance discovered by laboratory culture and sensitivity testing is only the tip of iceberg in terms of AMR prevalent in the community. The WHO has suggested 10 fold national strategies for containment of AMR:
1. The Government should constitute multidisciplinary task force to design policies and strategies to contain AMR. The task force would be responsible for implementing and monitoring population wide infection control pogrammes.
2. The Government should establish National Reference Microbiology Laboratory for coordinating a net work of reliable diagnostic microbiology laboratories for surveillance. This would ensure availability of reliable, good quality epidemiology data for developing interventional strategies.
3. The Public Education Programmes should be launched educating the community on preventing infections and reducing transmission of infectious diseases. This would help the people to take informed decision about preventing infections and their transmission.
4. The health service providers like doctors, pharmacists, nurses, and other paramedical workforce should be trained on diagnosis and management of infectious diseases, use of antimicrobials, containment of AMR, disease prevention and infection control. They should be made aware of the issues of AMR.
5. The Government should either develop or help developing evidence based clinical guidelines, Updating and using the essential medicines list for all level of care. This would provide uniform care and prevent the use of unnecessary antibiotics.
6. The health facilities should constitute Infection Control Committee taking all stakeholders as members to develop infection control strategies and implement them in health facilities.
7. The health facilities should constitute Drugs and Therapeutics Committee and Antimicrobial Subcommittee to promote rational use of medicines including safe and effective use of antibiotics.
8. Restricting the availability of antimicrobials either in open market or at various level of hospitals would help prevent unnecessary and inappropriate use of antimicrobials.
9. The Regulatory Authorities of the country should be empowered or strong enough to grant marketing authorisation only to antimicrobials that meet the international standards of quality, safety and efficacy.
10. The Government should control the use of non-human antimicrobials.
The discovery and availability of antimicrobials in the previous century led to spectacular gains in human health and increased life expectancy. The emergence of the AMR makes these antimicrobials ineffective. The problems of AMR were not felt earlier as the newer and newer antimicrobials were made available to treat untreatable resistant cases. Now the discovery of new antimicrobials is not an easy task. Antimicrobial resistance is one of the world’s most serious public health issues. If concerted efforts are not made by all concerned there is every likely that we may go back to the pre-antibiotic era and more people will die of infections than other conditions - a threat to humankind.
(The authors are with Dept of Pharmacy Practice, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu)