Discuss antimicrobial resistance as a public health problem.

Antimicrobial Resistance as a Public Health Problem

• Why IT IS A public health problem of the first order — it threatens to reverse a century of medical progress, since surgery, chemotherapy, transplantation, intensive care and neonatal care all depend on effective antibiotics
• Resistance is unlike most public health problems in one important respect — the harm of an individual prescription falls on other people and on future patients, not on the person treated. It is a classic tragedy of the commons, in which each individually reasonable decision degrades a shared resource
• INDIA is of particular concern, having among the highest antibiotic consumption in the world, together with high rates of carbapenem resistance and the emergence of colistin resistance
• The drivers in the human sector — over-prescribing, especially antibiotics for viral upper respiratory infection and for ordinary acute diarrhoea; over-the-counter sale without prescription, which remains widespread despite regulation; incomplete courses and self-medication with leftover drugs; use of broad-spectrum agents where a narrow one would do; patient expectation and pressure; poor diagnostic support, so treatment is empirical; and substandard and counterfeit drugs delivering sub-therapeutic doses
• The drivers outside the human sector, which are frequently omitted from answers and account for the larger share by volume:
• Animal husbandry and aquaculture, where antibiotics are used not to treat disease but as growth promoters and for routine prophylaxis in healthy animals — and a majority of global antibiotic consumption by tonnage is in animals, not humans
• Environmental contamination — pharmaceutical manufacturing effluent, hospital sewage and farm run-off creating reservoirs of resistance genes in water and soil
• Poor sanitation and infection control, which allow resistant organisms to spread once they arise
• The mechanisms in brief — enzymatic inactivation (beta-lactamases, ESBLs, carbapenemases such as NDM-1); altered target site; reduced permeability; and efflux pumps; with resistance genes spread horizontally between species on plasmids and transposons, so resistance need not evolve afresh in each organism
• The response — antimicrobial stewardship, whose principles should be listed:
• Prescribe only when a bacterial infection is likely
• Send cultures before starting antibiotics, since afterwards they are frequently uninformative
• Use the narrowest effective agent, and DE-escalate once sensitivities are known
• Give the correct dose for the shortest effective duration, since evidence increasingly supports shorter courses
• Review at 48 to 72 hours and stop, switch or step down
• Switch from intravenous to oral as soon as the patient allows
• Follow local antibiotic policy based on local antibiogram data, since resistance patterns differ between hospitals and between wards
• Reserve last-line agents, which the WHO AWaRe classification formalises as access, watch and reserve groups
• The access group should form the bulk of prescribing, and WHO has set a target that at least 60% of consumption should be from it
• The broader measures required — surveillance of resistance and of consumption; infection prevention and control, and immunisation, which reduce the need for antibiotics in the first place; regulation of over-the-counter sale; banning growth promoters in animals; control of manufacturing effluent; water, sanitation and hygiene; public and prescriber education; and research into new agents, rapid diagnostics and alternatives
• The INDIAN framework — the national action plan on AMR; the national programme on AMR containment with its surveillance network; schedule H1, which requires a prescription and a maintained register for specified antibiotics; and the Red Line campaign, marking such medicines with a red line on the pack to signal that they must not be taken without a prescription
• The honest conclusion — NO new class of antibiotic will solve this, since resistance follows every new agent within a few years; the problem is one of behaviour, regulation and agriculture, and must be solved there
• The harm falls on other people and future patients, which makes this a tragedy of the commons rather than a clinical choice
• Most antibiotic tonnage goes into animals, so a purely medical response addresses the smaller half
• Send cultures before starting antibiotics, since afterwards they are frequently uninformative
• De-escalate once sensitivities are known, and switch from intravenous to oral as soon as the patient allows
• Shorter courses are increasingly supported by evidence, contrary to the traditional insistence on completing long ones
• Follow local antibiogram data, since resistance patterns differ between hospitals and even between wards
• Access, Watch and Reserve is the AWaRe classification, with a target that most prescribing comes from Access
• Resistance genes travel on plasmids, so resistance need not evolve afresh in each species
• Growth promoters in healthy animals are a major driver, and banning them is a public health measure
• Manufacturing effluent seeds the environment with resistance genes, which regulation rather than medicine must address
• Schedule H1 requires a prescription and register, and the Red Line campaign marks such packs visibly
• No new antibiotic class will solve this, since resistance follows every agent within a few years