This week is World Antibiotic Awareness Week, an initiative by the WHO to increase global awareness of antibiotic resistance. In 2016, the United Nations General Assembly discussed the threat of antibiotic resistance. This is only the fourth time that the United Nations General Assembly discussed a health-related issue, highlighting the importance of antibiotic resistance. Why is antibiotic resistance such an important issue?
To understand the problem of antibiotic resistance, we need to go back about a century. About a hundred years ago, before the discovery of antibiotics, bacterial infections were one of the leading causes of morbidity and mortality. Even minor cuts and injuries, if infected, could be life threatening. However, this all changed with the discovery of penicillin in the 1920s. Discovery of penicillin was followed by the discovery various classes of antibiotics, in an era commonly referred to as the ‘golden era of antibiotic discovery.’
With our ability to treat bacterial infections, life expectancy increased dramatically. For example life expectancy of Canadians has increased by almost 25 years from 1921 (before the discovery of penicillin) to 2011. Antibiotics also allowed tremendous advancements in modern medicine and complicated medical procedures, including treatment of cancer and carrying out of various surgeries without the risk of infections. However, with the discovery of different classes of antibiotics and their increased (and irresponsible) use, reports of bacterial resistance to antibiotics began to become more and more common. Nevertheless, since we were fairly successful at discovery of new antibiotics during the golden era, antibiotic resistance was not considered a serious problem.
Things started to change in late 1970s when the discovery of new antibiotics almost came to a standstill. It appeared that we had exhausted all resources needed to discover new antibiotics, at least those that were readily available. This was the beginning of the current era of ‘antibiotic-discovery void.’ In the present day, the problem of antibiotic resistance continues to grow, and stories of patients dying of untreatable infections are becoming more common. In less than one hundred years since antibiotic discovery, we appear to be headed back to the pre-antibiotic era.
Some recent projections on the impact of antibiotic-resistant infections on human health paint a grim picture. It is estimated that if the situation does not change, antibiotic-resistant infections will result in 10 million deaths globally per year by 2050. This is more than the deaths caused today by cancer and road accidents combined! Antibiotic-resistant infections also come at a tremendous economic cost. Their treatment often requires extended hospital stays, administration of more expensive drugs, quarantine, additional hospital staff, etc., which is very expensive. It is projected that the impact of the antibiotic-resistant infections will result in a global GDP loss of more than one hundred trillion dollars by 2050.
So why aren’t more pharmaceutical companies working towards the discovery of new antibiotics? There are two major reasons for this. Firstly, finding an ideal antibiotic molecule is not easy. Antibiotic molecules must demonstrate selective toxicity which allows them to kill the bacterial cell with minimal harm to the human cells. Once all the low hanging fruits were picked during the golden era of antibiotic discovery, finding an effective antibiotic that causes little or no harm to humans has become increasingly difficult. However, there are some encouraging findings from research groups around the world that have reported promising lead antibiotic molecules. So why are these not being pursued by big pharma? The second major reason that pharmaceutical companies are not interested in the discovery of new antibiotics is that antibiotics are not the class of drugs that would fit the definition of a profitable business model. The course of antibiotic prescription is short – about a week as opposed to drugs that are used to treat chronic health conditions. Also, if an antibiotic molecule is effective, it is wise to use it prudently to avoid or at least delay the development of resistance. The cost of developing a new drug now exceeds 2.5 billion dollars, and the only ways for a pharmaceutical company to recoup their investment from developing an antibiotic would be from higher prescription rates for antibiotics or by making antibiotics extremely expensive. We know that neither of these two options are viable.
So what can be done? It is clear that better incentives are needed to encourage pharmaceutical companies to carry out antibiotic discovery efforts. Without the involvement of big pharma, developing a new antibiotic for clinical use is extremely difficult. However, we as individuals can do our share to at least slow down the development of antibiotic resistance. Antibiotic overuse and misuse is a major driver of antibiotic resistance. For example, 50% of antibiotic prescriptions to treat acute respiratory conditions, such as sinus infections, middle ear infections, pharyngitis, and the common cold are unnecessary since many of these are viral illnesses against which antibiotics are ineffective. Therefore, appropriate prescription of antibiotics is central to prevent misuse of antibiotics. Further, 70% of clinically-relevant antibiotics are used in animals. Antibiotics in animals are used to treat infections but the majority of usage is as growth promoters for rapid growth of animals. This extremely high use of clinically-relevant antibiotics in animals is a concern, as prevalence of antibiotics in the environment can and does select for antibiotic resistant bacteria. We as consumers can make our contribution towards the prudent use of antibiotics by carefully choosing antibiotic-free food.
Antibiotic resistance is a global problem that impacts everyone of us. Efforts towards discovery of new effective antibiotics need our support more than ever. Moreover, we can all do our part towards tackling this problem and it starts with the responsible use of antibiotics.
Dr. Ayush Kumar