Scientists are often asked to assist with “peer review.” This happens when an editor at a science journal invites a scientist to review a manuscript for which the scientist has documented expertise. Those of us who have been around for awhile probably receive multiple invitations every week and commonly review 20-40 manuscripts every year. For most journals, the process is “anonymous” because if a reviewer is required to reveal their identity this is likely to have an impact on the degree of “critical review” even if this is an unconscious bias. Some journals allow reviewers to self-identify, but most do not.
Reviewers are not allowed to divulge the contents of a paper that is under review (or that was reviewed and rejected). Not long ago I reviewed a paper that had some interesting data, but some of the far-reaching conclusions were unsubstantiated. I obviously can’t provide any details, but from a 32,000-foot perspective this was a paper about antibiotic-resistant bacteria in impoverished rural communities outside of the United States, which happens to be a topic that I study.
The authors collected stool samples from people and found a relatively high prevalence of bacteria (Escherichia coli or “E. coli”) that were resistant to several “classic” antibiotics (e.g., sulfa drugs). Given this finding, one of the authors’ conclusions employed a common refrain that the high prevalence of antibiotic resistant bacteria was due to “misuse” of antibiotics in these communities and that efforts should be directed to instill better practices.
At one level this makes sense because antibiotic use does favor strains of bacteria that are resistant to the antibiotics being used. Nevertheless, how should “misuse” be defined? In communities where people are at a high risk of acquiring potentially deadly infections (particularly for the elderly and infants), how can using an antibiotic be defined as “misuse”? Even if antibiotics are routinely taken without medical guidance, access to healthcare may be challenging and self-medication with antibiotics has probably saved countless lives. Claiming that high prevalence is always caused by “misuse” ignores the realities that people face in impoverished communities and can come across as naïve, paternalistic and potentially imperialistic. This also ignores important cultural and contextual variables as I will explain.
To the author’s credit, they removed the imperialistic overtones and, with other corrections, the paper has been published. The point of this story is that things are rarely as simple as they may seem, and we should be very cognizant of such possibilities. In the case of antibiotic-resistant bacteria, people living in desperate conditions face far greater challenges than what the majority of us experience in the Pacific Northwest.
In fact, more studies are finding that the risk of being colonized by antibiotic-resistant strains of E. coli really depends on where you live. For example, a recent country-scale study published in the journal Lancet Planetary Health found that if you live in ideal conditions where infrastructure is sound (e.g., functioning water and sanitation systems), governance does not suffer from significant corruption, and public health expenditures are relatively high, then the prevalence of antibiotic-resistant bacteria is lower and using antibiotics becomes a clear risk factor for being colonized by antibiotic-resistant bacteria. Furthermore, with improved conditions disease burden is lower and, presumably, there is less demand for self-administered antibiotics.
That is, when conditions are ideal the “intuitive model” where antibiotic use drives antibiotic resistance makes sense.
In contrast, when infrastructure is compromised, when governance is corrupt, and when public health investment is limited, then people are much more likely to be colonized by antibiotic-resistant strains of bacteria such as E. coli regardless of antibiotic use practices.
At the household scale, the prevalence of antibiotic resistance is driven by hygiene and sanitation variables. Explanatory variables are mostly related to risks of bacterial transmission such as sharing water sources for the household with livestock and wildlife, and consuming unboiled and unpasteurized milk.
One implication of these findings is that if we focus all of our attention on “how” antibiotics are used in these communities, transmission factors are likely to swamp any benefits from such stewardship. Furthermore, these findings give added impetus to invest international support in governance, infrastructure and public health because such investments help in the fight against antibiotic-resistant pathogens. That’s good for the residents of impoverished communities and good for America as well – after all, there are over 230 million international flights to and from the U.S. annually, meaning these resistant bacteria are traversing the globe in mass numbers on a daily basis.
Douglas Call is a microbiologist. He and his family have lived on the Palouse for more than 20 years.