As worrisome as the AMR crisis is the risk of disrupting the ecological system within our bodies due to non-judicious uses of antimicrobials. Indeed, all of us have a microbiome of bacteria (and a much smaller number of viruses, yeasts, and amoebas) that outnumbers the cells of our bodies by the approximate ratio of ten to one. They live and work synergistically with our bodies in an adaptive community of which we are part. One of the functions performed by this microbiome is the ‘tutoring’ of the acquired immune system.
The essence of the problems is that microbial drugs themselves fail to discriminate between harmful bacteria and beneficial bacteria. By using antimicrobial drugs to tackle diseases, we are inadvertently destroying bacteria that we need in order to maintain a healthy balance. Expressing grave concern over such a ‘friendly-fire’ situation, Julie Segre of the National Human Genome Research Institute said: “I would like to lose the language of warfare. It does a disservice to all the bacteria that have co-evolved with us and are maintaining the health of our bodies.” AMR is a threat to global public health, but nowhere is it as stark as in India. The portents are really ominous as it is the world’s largest consumer of antibiotics.
According to a report in The Lancet, in 2010, India consumed about 13 billion units, followed by China’s 10 billion, and the USA’s almost 7 billion units. The mortality rate due to infections is around 417 per one lakh persons. In Europe, around 25,000 people die every year from AMR bacteria contracted in hospitals, while the Centers for Disease Control and Prevention (CDC), US, estimated that antibiotic-resistant bacteria cause two million ailments and around 23,000 deaths a year in the US.
In the not-too-distant future, people going in for basic surgeries may have to weigh the risk of contracting an infection for which there is no cure. According to The Review on Antimicrobial Resistance, commissioned by the British Government, by 2050 and every year, AMR is likely to claim 317,000 lives in North America, 390,000 in Europe and over 4 million in Asia and Africa.
Use of antibiotics is no more restricted to humans. Nor is it limited to treating diseases. To cater to the growing demand, even poultry farmers use feed containing a variety of antibiotics, vitamins and other feed supplements. Non-therapeutic uses of antibiotics act as growth promoters as they kill microbes in the intestine and thus help absorb feed nutrients better, resulting in weight gain.
Indiscriminate and routine use of antibiotics in low doses during the chicken’s short lifecycle of 35-42 days for faster growth promotes the growth of AMR bacteria. Poultry farmers also ignore the mandatory withdrawal period, as a result of which high levels of antibiotics residues infect farm workers, meat plant workers and people in general along with the resistant bacteria.
Consumers also encounter resistant bacteria while handling meat and consuming undercooked meat. Antibiotic residue and resistant bacteria in waste can pollute the soil, streams, ponds, groundwater and transfer resistance to other bacteria through horizontal transfer of genes. Poultry farms are reservoirs of multi-drug resistant bacteria. The fish that we eat contains a cocktail of antibiotics. Those antibiotics that are important for humans are also added to the feed or ponds even when symptoms of infections or injury are detected in only a small quantity of fish.
A CSE team recently visited six key fish producing districts in West Bengal and detected rampant use of antibiotics in aquaculture for non-therapeutic purposes and growth-promotion. The aquaculture waste is also directly discharged into canal and agricultural fields untreated, thus increasing the risk of antibiotic resistance in the environment.
Resistance to antibiotics by those who had never used antibiotics are often reported. In those cases it is the prime source of AMR bacteria that could have infected them. Governments worldwide are adopting regulations to control the use of anti-microbials. Several EU countries have curbed AMR substantially by banning indiscriminate use of drugs.
But in case of India the attitude appears to be perfunctory. In 2007, the Bureau of Indian Standards (BIS) recommended that systemic antibiotics must not be used in poultry feed. In 2011 the Food Safety and Standards Authority of India (FSSAI) had set maximum residue limits for antibiotics in sea-food and prohibited the use of certain others in sea-food processing units.
But there are no prescribed standards for the domestic poultry industry. The national policy on containment of AMR has been finalized, but it does not focus on antibiotic resistance emanating from the large-scale use of antibiotics in animals. The government can follow Denmark’s example by eliminating antibiotics in the meat and dairy industry. Humans are facing an ‘antibiotic apocalypse’.
What we urgently need is a plan of action to prevent the misuse of antimicrobial drugs through awareness campaigns, devising tests that can reveal if a patient actually needs them, and also scouting for new ones. New categories of antimicrobial drugs were discovered during the 1980s. Since the late 1980s we are witnessing a void in the discover of antibiotics.
Therefore, it is essential to preserve the efficacy of the existing drugs. Coupling antimicrobial drugs with anti-genetic transfer agents could eliminate the need to ration drugs. If we can strategically develop a gene that enables strains of resistant microbes to eat our food instead of our flesh, they will be effectively disarmed. The most outstanding feature of life’s history is the constant domination of microbes as they are capable of developing new strategies every now and then for their survival.
Citing the ‘catastrophic threat’ of AMR, the World Health Organisation has warned that it could lead to ‘a return to the pre-antibiotic era’, where curable infections proved to be fatal. Mere paper-cuts can kill and superbugs could easily wipe out humanity. In the light of the legendary resilience of microbes, the least that humans can do is to keep them at bay by waging a limited war.
In the continuing epic struggle with microbes we are in critical need for novel strategies to boost the antimicrobial arsenal. But in any event we should not forget what the evolutionary biologist Stephen Jay Gould once said: “We live in the age of bacteria… as it was in the beginning, is now, and ever shall be, until the world ends”.
(The writer is a retired IAS officer)