21 Nov, 2018
The first antibiotic was discovered almost 9 decades ago and one after the other there have been new discoveries. But these drugs are being rendered ineffective as more and more micro-organisms are developing ways to outsmart them. These bugs are loosely known as 'superbugs’ as if they have developed super powers to resist drugs used against them.
The mechanism of antimicrobial resistance (AMR) is broadly classified into intrinsic and acquired. Intrinsic resistance confers the bug with the ability to not get killed by the drugs either by being impermeable, forming a biofilm, efflux of drugs or by enzymatic activation and destruction. The acquired resistance develops after exposure to the drug and can be due to target site modifications, adaptation of alternative metabolic pathway, efflux and enzymatic activation and destruction. These changes which occur at genetic levels in the microbes gives them the superpower to resist even the strongest of antibiotics like carbapenems.
Antimicrobial resistance is a global threat and is not limited to developing countries only. In fact in Europe, infections due to these super bugs kill around 33,000 people each year as reported by European Centre for Disease Control (ECDC) recently. This is alarming as around 75 percent of the burden of superbug disease is due to infections contracted in hospitals and health clinics - known as healthcare-associated infections (HAIs). Also almost 70 percent of the bacteria which cause infections are now resistant to one or more antibiotics. The ECDC study, 'Attributable deaths and disability- adjusted life-years caused by infections with antibiotic- resistant bacteria in the EU and the European Economic Area in 2015' was published in The Lancet in the first week of November 2018. The included antibiotic resistance-bacterium combinations were colistin-resistant, carbapenem-resistant, or multidrug-resistant Acinetobacter spp; vancomycin-resistant Enterococcus faecalis and Enterococcus faecium; colistin-resistant, carbapenem-resistant, or third-generation cephalosporin-resistant Escherichia coli; colistin-resistant, carbapenem-resistant, or third-generation cephalosporin-resistant Klebsiella pneumoniae; colistin-resistant, carbapenem-resistant, or multidrug-resistant Pseudomonas aeruginosa; methicillin-resistant Staphylococcus aureus (MRSA); and penicillin-resistant and macrolide-resistant Streptococcus pneumoniae. Five types of infection: bloodstream infections (BSIs), urinary tract infections, respiratory tract infections, surgical site infections, and other infections were included. One of the conclusions of this study was that 170 DALYs per 100?000 population are lost due to antimicrobial resistance which is similar to the combined burden of three major infectious diseases (influenza, tuberculosis, and HIV), which was 183 DALYs per 100?000 population.
World Health Organization (WHO) Global report of surveillance on antibiotic resistance in 2014 showed that antimicrobial resistance in each bacteria–antibacterial drug combination based on at least 30 tested bacterial isolates was 79%. This proportion ranged from 56% to 92% across the regions, and between 56% and 90% for the different bacteria–antibacterial drug resistance combinations. Sixty-six percent of member states contributed their national data for the same. WHO’s new Global Antimicrobial Surveillance System (GLASS) launched in October 2015 reveals widespread occurrence of antibiotic resistance among 500,000 people with suspected bacterial infections across 22 countries.
Drug resistant superbugs are a major global health care threat and policies need to be made at global level with coordination at national level. Surveillance system and collection of data is of paramount importance to understand the emerging mechanisms of AMR and accordingly control measures can be taken. Many of these infections can be fatal and hence there is a need to take corrective measures to decrease antimicrobial resistance at the global level. There are many countries across Europe (especially Italy and Germany), United States, Canada and South Africa where antibiotic resistance is rampant but data from many developing countries like India is not available hence we just know about the tip of iceberg.
The health care system worldwide have time and again understood that the process of development of antimicrobial resistance needs to be slowed down. The misuse and overuse of antibiotics accelerates this process. As also the improper use of antibiotics in animal husbandry and agriculture. Factors like poor hygiene, sanitation and inadequate infection control in health care setups are also contributory. WHO, Food and Agriculture Organization of the United Nations (FAO), the World Organisation for Animal Health (OIE) have together opted for the 'ONE HEALTH' approach to promote optimal use of antibiotics in both animals and humans to fight against this threatening antimicrobial resistance.
|