Antibiotic resistance: why we need to care
Antibiotic resistance: why we need to care
During the twentieth century, improvements in hygienic conditions, the creation of vaccines and widespread vaccination programs and the development of antibiotics have had a huge impact on life expectancy and quality of life worldwide. Antibiotics are one of the major breakthroughs of modern medicine. The existence of antibiotics has made many of our current “medical miracles” possible: organ transplants, cancer treatments, therapies which beneficially modify our immune system (for diseases such as rheumatoid arthritis, psoriasis or Crohn’s disease, for instance) and complicated surgical procedures. Without antibiotics, the infection complications of these medical interventions would be too frequent, harmful and possibly lethal.
Dr. Andrew Gibbons is an Oral and Maxillofacial Surgeon working in NHS England. He gives his point of view on the risk antibiotic resistance poses to his practice.
“I’ve had patients who’ve responded badly to antibiotics, but so far there’s always been a stronger antibiotic available, although with stronger side-effects as well. Currently, with facial trauma, we can close wounds quickly without a great risk of infection, often helped by antibiotics.
However, without effective antibiotics, this would be too dangerous in “dirty” wounds. We’d have to leave these wounds open for longer for new healthy tissue to form, and this would have a great impact on the aesthetic result. Implants are often used in reconstructive surgery. Without antibiotics, there is an additional risk of implant-associated infections.
Unfortunately, this frequent use of antibiotics is not the best way to control antibiotic resistance, and despite the high standard of infection control measures, even more preventive actions are necessary. A major shift in thinking is needed, a change in surgical attitude.”
Our over-use and misuse of antibiotics in humans, animals and agriculture, has led to the widespread rise of antibiotic resistance: in livestock, food, hospitals, and the community at large. Growing human and animal populations — along with increasing international trade and travel — have accelerated the transfer and spread of resistant strains of bacteria, turning them into a global concern. When these resistant strains cause an infection, it is no longer a simple matter of prescribing the “usual” antibiotics. Common infections (such as pneumonia, as well as skin and urine infections), when caused by antibiotic-resistant bacteria, are increasingly difficult to treat and threaten rising numbers of people across the world.
Over-use and misuse of antibiotics
Antibiotics save millions of human and animal lives worldwide every year, but in many cases they are misused or unnecessarily consumed. In developed countries, between 10 and 20 courses of antibiotics are prescribed to children before the age of 18 years.(61) Furthermore, it has been demonstrated that up to 50% of all antibiotics prescribed in human medicine are not needed or not prescribed appropriately.(2)
Global consumption of antibiotics in human medicine rose by 36% between 2000 and 2010.(57) This general figure masks declining use in some countries and rapid growth in others. The combination of limited health-care systems and rising incomes to spend on drugs makes emerging countries especially susceptible to overconsumption. Brazil, Russia, India, China and South Africa accounted for three quarters of the global increase in demand for antibiotics between 2000 and 2010, while annual per-person consumption of antibiotics varied by more than a factor of 10 across all middle and high-income countries.(57)
Despite the ban of antibiotics as growth promoters for livestock in some countries, such as the member states of the EU, the total veterinary use of several classes of antibiotics has steadily increased in several countries. In 2010, the world used about 63,000 tons of antibiotics to raise cows, chickens and pigs.(58) Taking note of the surge in antibiotic resistance, some industries have pre-empted government decisions and made voluntary decisions to restrict the use of antibiotics. For instance, several food companies in the USA have recently decided to phase out the use of antibiotics which are important for human health in the farming of chickens. In France, following a ban by the pig industry of the use of 3rd and 4th generation cephalosporins, the consumption of those antibiotics decreased by 62% between 2010 and 2012.(59) It is widely accepted that improved disease prevention measures and reduced animal stress can avoid the need for antibiotics while enhancing animal welfare.
The use of antibiotics on crops is worth mentioning, even if total quantities remain low. Pears, apples and other rosaceous plants are vulnerable to “fire blight” (caused by the bacteria Erwinia amylovora). Broad-spectrum antibiotics (such as streptomycin or oxytetracycline), which are active against a wide variety of bacteria and resemble some antibiotics used for humans, are sometimes used on trees to prevent or treat infection by fire blight.(60)
- In Europe, the use of antibiotics as alleged growth promoters for food-producing animals has been banned since 2006. But such a use for antibiotics is still allowed in many other countries.
- Antibiotics are still mistakenly used to treat viral infections, for which they have no effect.
- Antibiotic regimens are too often not followed as prescribed. When people stop taking their pills as symptoms clear up, it potentially allows resistant bacteria to develop.
- In some cases, antibiotics may be taken by patients as self-medication (for instance to treat upper respiratory tract infections, the majority of which are caused by viruses for which antibiotics are ineffective). This can also lead to generation of resistant bacteria.
- Access to antibiotics is too easy in many countries (“over the counter” without a medical prescription).
The increased consumption of antibiotics is also a cause of concern because a proportion of this quantity will eventually appear in the environment. This is because antibiotics are seldom fully metabolised, either by humans or by animals, and can show up in their urine and feces. In the case of livestock, antibiotics are usually administered orally in the feed, then they are only partially digested and appear in the feces which may be used as manure and then spread onto agricultural fields. These drug residues can leach into the soil, contaminating water resources and our food supply. A study has also shown that residues of tetracycline antibiotics have an unexpected effect on the development of many life forms and can potentially reduce the growth of plants.(64) Beyond the fact that antibiotic residues can cause allergic reactions, a major concern stems from these residues being present at relatively low concentrations, which facilitates the emergence of antibiotic-resistant bacteria during contact.
Other effects of antibiotics on humans
The nature and intensity of side effects caused by antibiotics vary considerably from one person to another. They depend on the class of antibiotic used, and on whether other drugs are being taken at the same time. Skin rashes, allergies, diarrhoea or an imbalance of the intestinal flora are among the most common side effects of antibiotics.(65)
In fact, bacteria are key components of our “inner and outer self”. Our digestive tract and our skin (including the mouth, nose, ears, etc.) are covered by trillions of bacteria which outnumber our own cells 10-fold. These bacteria, which live in close contact with us, are termed the “microbiota” or the “microbiome”. They weigh a total of approximately 1.5 kilograms and perform many functions vital to human health and survival: they digest food, produce anti-inflammatory chemicals and compounds, and train the immune system to distinguish “friend from foe”. In fact, they play so many key roles in our metabolism that some scientists compare the microbiota to an organ. In this view, the human body is a complex ecosystem including numerous collaborating and competing microbial species.(66) Many antibiotics may eradicate or alter the useful bacteria that help us metabolize food efficiently, keep our body surfaces and mucous membranes (mouth, nose, genital tract) healthy or maintain healthy skin. All of the effects of this change in the microbiome by antibiotics are not known, but many such consequences have been well-documented such as overgrowth of yeast or diarrhea.
Every time we take antibiotics or use them in animals, we create a selection pressure on bacteria to mutate or take on new genes in order to survive the antibiotic effect.
The first report by WHO’s Global Antimicrobial Resistance Surveillance System (GLASS) has revealed widespread and high levels of resistance in 25 high-income, 20 middle-income and 7 low-income countries. (GLASS report: Early implementation 2016-2017)
- Lack of awareness about the issue, among the general public, prescribers, politicians, and the media.
- Inadequate waste management and poor water sanitation.
- Poor infection prevention and control practices (such as lack of hand-washing and hand hygiene to avoid the spread of infections in healthcare settings).
- Insufficient diagnostic tools for the rapid and reliable detection of resistance.
- Lack of vaccines for some important infections.
- Lack of antibiotics to treat infections caused by multi-drug resistant bacteria.
- Weak or absent antibiotic resistance surveillance programs to track the number and type of antibiotic-resistant infections in a given area, city, country or global region.
- Lack of a comprehensive, uniform and coordinated response among all countries
In India, a child dies every nine minutes from an infection caused by antibiotic resistant bacteria.(1) In the European Union and the USA, some 48,000 people die every year because of antibiotic resistance.(4),(5) In all probability, these are underestimates of the numbers of deaths because of the lack of consistent universal surveillance.
As well as causing increased mortality, infections by resistant bacteria are more difficult to treat and are more likely to complicate many aspects of a hospitalization.
The detection of antibiotic-resistant bacteria in the hospital environment or in a particular patient can lead to the increased need for isolation wards, cancellation or delay of treatments and surgery, as well as other costly and impactful consequences to the healthcare system. In fact, doctors increasingly worry that antibiotics, when used prior to a risky medical procedure to prevent infectious complications, may no longer function to prevent these infections. Under these circumstances, and faced with the current dearth of new antibiotics, they may have to avoid or reduce high-risk but life-saving medical procedures. When treating such antibiotic-resistant infections, clinicians may have limited therapy options - the use of more toxic options or combining multiple antibiotics, which can cause increased side effects.
- Treatment failure leading to chronic problems
- Increased morbidity (disability, poor outcomes) and mortality
- Adverse effects of alternative treatments (potentially less effective, possibly more toxic)
- Relapse of the infection after treatment
- Increased spread of antibiotic-resistant bacteria and their associated community- and healthcare-acquired infections
- Increased use of antibiotics
- Lack of availability of clinically effective antibiotics
- Longer and more complicated stays in hospital
- Excess healthcare costs
- Decreased societal productivity
The impact of antibiotic resistance on lives, health systems and economies is considerable and will continue to grow. Some estimates of the economic effects have been published, and the findings are disturbing. For example, the yearly cost to the US health system alone has been estimated at 21 to 34 billion dollars, as well as more than 8 million extra days in the hospital.(7) In the EU, resistance to antibiotics costs an estimated €1.5 billion per year.(8) Medical costs are only part of the economic equation: reduced employment and income, and increased national healthcare spending also have to be taken into account in assessing the financial impact. The EU estimates that resistance to antibiotics causes 600 million days of lost productivity each year, whereas in Thailand some researchers estimate that it leads to US$2 billion of productivity losses per year.(9) The O’Neill report estimates that by 2050, antibiotic resistance may lead to US$100 trillion in induced world GDP loss.(10)
According to the World Bank, without antibiotic resistance containment, the annual costs could become as massive as those of the global financial crisis that started in 2008. Moreover, the Sustainable Development Goals for 2030 – such as ending poverty, ending hunger, ensuring healthy lives, reducing inequality, and revitalizing global partnerships – are likely to remain unachieved.(72)