The decline of antibiotics

The discovery that penicillin could kill bacteria in the 1930’s paved the way for the development of a range of drugs called antibiotics, which specifically target and destroy bacteria. Antibiotics work by attacking important chemical pathways in the bacteria that they use to survive and divide. Since their discovery, antibiotics have been a miracle cure - treating skin infections, lung infections, sexually transmitted diseases, TB and pneumonia. Before antibiotics, infection was the main cause of death after surgery, and the rise of antibiotics has reduced this risk. Until recently, antibiotics were extremely effective at wiping out bacterial infections. But now the bacteria are getting the upper hand.

Bacteria are resilient, and survive in extreme conditions from the icy Antarctic to superhot volcanic lakes to the dark recesses of our gut. Many species of bacteria live alongside our own cells, helping us digest food and protecting us from viruses and other bacteria. The number of bacteria colonising our skin and gut far outnumber our own cells. Harmful bacteria, like the ones that cause TB, pneumonia and cholera, are spread through person to person contact, touching surfaces, or through food and water.

When exposed to changes in their environment or a toxin, like an antibiotic, bacteria that can’t tolerate the drug die, leaving a gap for those that can. The surviving bacteria pass their resistant abilities on to the next generation when they divide, and to other bacteria by exchanging genes. Since bacteria divide at a very fast rate—from about 20 minutes with the common E.coli to 12 to 24 hours for some gut bacteria—you can imagine how quickly resistance can spread through a population.

We are seeing this rise of antibiotic resistant bacteria more and more. First, there was methicillin-resistant Staphylococcus aureus, MRSA, which was a common skin bacteria that became resistant to a group of broad-spectrum antibiotics. It is now found in most hospitals, and can be very difficult to treat. We also have multi-drug resistant TB (MDR-TB) that appeared, which was followed by extremely drug resistant TB (XDR-TB), both of which have made TB treatment longer and less effective. Recently a new resistant gene, NDM-1, found in India has raised some alarms. It passes easily between different types of bacteria, making them resistant to most antibiotics. Resistant strains of bacteria need longer treatments and more toxic antibiotics, becoming a bigger health risk.

There are a several reasons why resistant strains of bacteria have been able to claim a foothold. A properly prescribed course of antibiotics is designed to kill off all bacteria, leaving little chance for resistant bacteria to develop. If the course is stopped too soon, or if the antibiotic is prescribed for the wrong reasons, then the bacteria get a chance to adapt to it, which makes misused antibiotics worse than no antibiotics at all.

Patients often stop treatment before completing their course of antibiotics because they start to feel better, or because they can’t afford to complete the treatment, or because the full course of antibiotics isn’t always available. Added to these problems is the sharing of prescriptions between patients, and the use of cheaper—and often ineffective—antibiotics bought through illegal means.

Over the years, many doctors have treated infections with antibiotics before properly diagnosing their cause. In resource-limited settings, this is because doctors are pushed for time in treating patients, and often don’t have the equipment to do the proper tests to identify what is causing the infection.

Another cause for the rise in antibiotic resistance is the over-prescribing of antibiotics, which are given for a simple cough or cold. These mild infections more than likely get better on their own, and are more often caused by viruses. The more antibiotics are prescribed, the more chances bacteria get to adapt to them. Antibiotics should not be the first step in treating the sniffles. Possibly the worst culprits are well-off patients, who pressure doctors into prescribing medication for mild infections to justify their visit.

Once the bacteria have developed antibiotic resistance, they have also been able to hitch a ride on global travellers and taken to new parts of the world. The NDM-1 gene is spreading out from India this way, and into new types of bacteria. Cases of bacteria with the NDM-1 gene have been reported in South Africa.

What is worrying is that we have had few new, successful antibiotics on the market. For 30 years - we’ve been trying to adapt what we have to beat the bacteria, but this approach isn’t effective with resistant strains. Our first line antibiotics have become less effective, leaving us exposed to resistant bacteria. Margaret Chan of the World Health Organisation recently said about antimicrobial resistance, “in terms of new replacement antibiotics, the pipeline is virtually dry … The cupboard is nearly bare.”

There are concerns that soon our antibiotics will stop working completely. This will not only put us more at risk for getting infections, but it will make diseases like TB impossible to treat. Routine surgical operations like removing an appendix will become dangerous because of the risk of exposure to bacteria, and even a simple scrape or cut could leave us vulnerable.

What’s more, the financial incentive for pharmaceutical companies to develop new antibiotics is low. Even if a new generation of antibiotics were developed, the current poor use of antibiotics by both doctors and patients will make new antibiotics useless quickly, before the financial rewards are reaped.

We have to change how we use antibiotics. There is a push to develop better, faster and cheaper ways to diagnose diseases so that the proper treatment is prescribed. Doctors need good guidance on how to prescribe antibiotics effectively and in teaching patients how to take antibiotics correctly. The spread of infection can also be limited by having good hygiene: washing hands frequently and not sharing personal items like toothbrushes, which is challenging when people who are most vulnerable to infections don’t have access to running water or good sanitation.

We can prolong the power of antibiotics by using them cautiously. This will buy us some time to find alternatives.