Antibiotic resistance is sometimes referred to as the silent pandemic – a contagion that spreads without us really knowing its extent or severity. But research is in progress to find new ways of fighting bacteria. And as with COVID-19, everyone can help to reduce the spread – and save lives.

Imagine an elderly patient who’s given a new hip joint. The operation goes well, and the patient becomes more mobile again. But then an infection develops around the prosthesis. The infection is difficult to cure and turns out to be caused by MRSA, methicillin-resistant staphylococcus aureus. The infection is treated with more potent antibiotics, but the bacteria eventually reach the bloodstream in an escalating process and the patient dies of sepsis.

Or imagine a person with cancer who’s starting to put the disease behind them following surgery and chemotherapy. The prognosis is good. But then they get a stubborn cold that develops into pneumonia. This turns out to be caused by PNSP, penicillin-non-susceptible pneumococcus. This is an infection that can be treated with other antibiotics, but it takes a few days to investigate and the bacteria get the upper hand in the meantime, eventually leading to the patient’s death.

Or imagine a person admitted to hospital and recovering from pneumonia, which is sensitive to antibiotics. But then they contract a urinary tract infection caused by E. coli bacteria that have found their way in through a urinary catheter during their hospital stay. The bacteria are of a variant that can produce the enzyme ESBL. This makes them resistant to many antibiotics, but there are still some that work. Unfortunately, it turns out that these particular bacteria produce an enzyme of the ESBL-CARBA subgroup, and doctors are effectively left with no treatment options. The infection reaches the blood and the outcome is fatal.

This is happening all over the world, right now. It happens in Sweden, too.

Difficult to obtain reliable figures

But it’s hard to say exactly how often it happens. According to one estimate, around 700,000 people globally die each year as a result of antibiotic-resistant bacteria. This estimate was presented in 2019 by the Interagency Coordination Group of Antimicrobial Resistance (IACG), an expert group led by WHO on behalf of the UN.

Other estimates suggest even higher death rates. For example, a study was published in The Lancet in February 2022 using a new model for making assessments from existing sources. According to this estimate, 1.27 million people died in 2019 from infections that they would have survived if the bacteria had been sensitive to antibiotics.

As I said, it’s difficult to obtain reliable figures. One reason for this is that statistics on causes of death indicate diseases, such as sepsis – but they don’t usually indicate what kind of bacteria caused the sepsis. Moreover, many countries have insufficient resources to examine the bacteria in more detail, which means that accurate diagnosis falls by the wayside.

According to estimate in The Lancet, 75 per cent of these deaths were caused by six particularly worrying infections, such as MRSA, resistant pneumococci and different variants of resistant intestinal bacteria, such as E. coli. But back in 2017, WHO presented a list of resistant bacteria that should be prioritised when it comes to the development of new antibiotic varieties, for example. These two lists only overlap to an extent – which indicates just how much we need to know about which bacteria will threaten us in the future.

Relatively favourable situation in Sweden

So – what’s the situation in Sweden? More favourable. Sweden has a low incidence of resistant bacteria compared to the rest of the world. This is reflected, for example, in the reporting requirements under the Communicable Disease Act when a laboratory detects any of the following four infections in a sample: MRSA, PNSP, the intestinal bacterium VRE or ESBL and ESBL-CARBA-forming intestinal bacteria.

According to the latest Swedres-Svarm report in which the development of antibiotic resistance in Sweden is summarised by the National Veterinary Institute and the Public Health Agency of Sweden, the problem is most widespread for ESBL-forming intestinal bacteria, mainly E. coli bacteria but also Klebsiella. In 2020, more than 8,200 cases of infection or carrying of ESBL-forming intestinal bacteria were reported in Sweden, leading to sepsis in 727 cases.

Saving lives in these contexts requires treatment with antibiotics that target the bacteria.

And that’s the dance, that eternal tug-of-war between the healthcare system and the bacteria that cause disease: a patient carrying bacteria that are insensitive to a particular antibiotic is instead treated with a variety that still works. But over time, the bacteria develop resistance to that variety as well. The healthcare system will then change the antibiotic again – until, in a worst-case scenario, there are no more antibiotics left to use. This situation is close to occurring in the case of gonorrhoea. There, the first choice is now what used to be the last effective option.

For decades, few new antibiotics have reached the market. And those that have arrived are mainly variants of existing substances. These new variants may be useful in the short term, but the bacteria often develop resistance quickly due to the fact they’re closely related to other antibiotics that have already been used in healthcare for a long time.

At the same time, we’ve increased their use – which has given the bacteria more of a chance to develop resistance to them.

--Annika Lund