The age of antimicrobial resistance

In the short story “Micro-age” (1998), science fiction writer Cixin Liu imagines a distant future where a faction of humans downsized themselves through genetic engineering and nanotechnology to the size of bacteria. For a time, the “micro-humans” coexisted with the “macro-humans,” until a civil war ensued between them. The micro-humans won, with their soldiers easily paratrooping into the eyes of the enemies en route to their brains—and creeping through their computer systems undetected. Requiring far less resources than their “gigantic” forebears, the micro-humans thrived on Earth, carrying the banner of humanity forward.

The idea that intelligent life, let alone humanity, can exist on a nanoscale is of course incredible, but Liu’s story can very well be a parable of how microbial life possesses huge advantages over “macro-life forms,” ourselves included. In fact, some scientists claim that even today, bacteria have the upper hand. Beyond their superior biological characteristics (i.e., faster reproduction and mutation), there are trillions of bacterial cells within every human being, making us virtual colonies of microbes.

Most of these “human microbiota” are harmless, but not all. Bacteria are responsible for a host of human diseases—from tuberculosis and pneumonia to malaria and leprosy. Viruses cause many more, including HIV, dengue, ebola, and bird flu. On top of these, around 20 percent of cancers are also hypothesized as having an infectious origin.

One of the greatest achievements of biomedicine is “germ theory”—the idea that microbes are responsible for many diseases. This late-19th-century insight gave rise to a 20th-century breakthrough: the discovery of antibiotics, or drugs that could actually kill those microbes and consequently cure previously incurable diseases, like malaria and TB.

But for all their great promise, antibiotics did not end the microbial threat. An antibiotic may kill 99 bacteria out of 100, but the lone survivor could still replicate, passing on the features that allowed it to resist antibiotics: This is a simplified illustration of what we call antimicrobial resistance. This problem is magnified in hospitals, where the most resistant of microbes thrive, necessitating strong and costly antibiotics if a patient is confirmed or even just suspected to be infected by them.

Even for these strong antibiotics, however, some bacteria have developed resistance. The recent report of the Nevada woman who died because 26 different antibiotics failed to treat her infection illustrates how pharmaceutical development has become a desperate race against time.

Our modern age presents both difficulties and opportunities. On one hand, the advent of globalized travel has meant that virulent microbes can spread much more easily.

On the other hand, as the elimination of smallpox shows, humans are not entirely powerless: Bacteria may be able to mutate faster, but our technological evolution is formidable.

Even so, the growing threats suggest that science is struggling to catch up. TB, which is difficult to treat to begin with, now has strains called “extensively drug-resistant tuberculosis” (XDR-TB), which require two years of costly medications to treat.

We already know what we need to do. Healthcare workers should only prescribe antibiotics when these are truly needed (studies show that up to half of our antibiotic use is unnecessary). Patients, for their part, should use antibiotics only when prescribed and complete the full duration of the treatment even when they feel cured. These simple-sounding measures are actually difficult to put into practice because patients expect doctors to prescribe medicines, and many doctors feel obliged to do so. Patients, moreover, take it upon themselves to improvise and experiment with medicines sans medical advice. Thus, more vigorous and concerted action is required for this little-known but urgent threat to our health.

Make no mistake about it: The microbes are here to stay—and humanity needs serious work if it intends to do so, too.

Gideon Lasco (www.gideonlasco.com) is a medical doctor and anthropologist.