Andrew Jermy travels with Hugh Pennington on the arc of humanity's long, troubled relationship with microorganisms.
Have Bacteria Won?
- Hugh Pennington
Before opening Hugh Pennington's Have Bacteria Won?, readers of newspaper headlines might presume that his answer is 'yes'. But for the most part, the eminent bacteriologist comes to the opposite conclusion in this thought-provoking study that documents the history of human interactions with infectious disease and how current fears of impending doom have developed.
Pennington draws on personal experience and illuminating case studies — such as the United Kingdom's experience with bovine spongiform encephalopathy (BSE) and variant Creutzfeldt–Jakob disease — to show how the public perception and clinical reality of infectious disease can be at odds. He upbraids researchers, journalists and editors (such as me) for using the hyperbolic language of war (fight, struggle, arms race) to describe our relationship with the microorganisms that colonize and infect our bodies. Such language injects drama and elevates the importance of events, much more than dry but accurate descriptions of the consequences of interactions between microbe, host, immune response and treatment.
As a result, the fear of microbial life in the collective mind is often vastly out of proportion to the risk. As Pennington puts it, “the media behave like a cheap refracting telescope, focusing on an object of interest but magnifying it with a good deal of aberration and fuzziness at the edges”. Witness the media hysteria in 2014 when US nurse Kaci Hickox returned to Maine from Sierra Leone after working with Médecins Sans Frontières (also known as Doctors Without Borders). Hickox was wrongly suspected of infection with Ebola, and her return set in train legal proceedings relating to her quarantine.
Oddly, Pennington then fails to heed his own critique about rhetoric. He tours some of our “victories” (against smallpox, diphtheria and syphilis); the “advance” of microorganisms such as Escherichia coli and MRSA — methicillin-resistant Staphylococcus aureus — through horizontal transfer of toxin-encoding genes or selection for antibiotic resistance; and the “battles” in which human actions have helped microorganisms (including Salmonella and the organisms that cause anthrax and legionnaires' disease). He deftly weaves historical vignettes into the greater journey. These include early efforts to control smallpox in the eighteenth century, led by Lady Mary Wortley Montagu, US minister Cotton Mather and latterly Edward Jenner; the benefits of improved water availability (originally intended to support trade and fight fire); sanitation, diet and pasteurization in the nineteenth century; and on to the discovery of antibiotics in the twentieth century, right up to outbreaks of carbapenem-resistant Enterobacteriaceae and severe acute respiratory syndrome (SARS) coronavirus in the modern era. The arc of that story and Pennington's accessible prose grip throughout.
Pennington points out that infection with antibiotic-resistant bacteria is not new. It has followed closely in the footsteps of all antibiotics since penicillin — discovered by Alexander Fleming in 1928 — was developed as a treatment by Howard Florey and Ernst Chain. In another bout of debunking, Pennington argues that predictions of a coming antibiotics Armageddon leading to a substantial increase in infection-related deaths are greatly exaggerated. On this point, I take a more cautious line. It is true that careful management and aseptic technique can have an important role in husbanding a dwindling supply of drugs effective against the most serious infections. However, Pennington does not devote sufficient space to the factors that have led the antibiotic-development pipeline to dry up in recent years.
He almost trivializes the difficulties in identifying relevant natural products or chemical constructs and developing them into usable drugs, simply writing: “New antimicrobials will be very welcome. Getting them ready for rollout will be expensive and will take years.” And he skates over structural problems in the pharmaceutical industry: we urge pharma to develop antimicrobials while simultaneously planning to limit their use drastically. In the twentieth century, drugs came along in time to take over when resistance arose; whether that will be the future pattern is uncertain.
Pennington also skimps on coverage of microscopic eukaryotic pathogens, such as the malarial parasite Plasmodium falciparum or the fungi that cause cryptococcal meningitis. His only mention of malaria is in relation to Nobel-prizewinning Austrian physician Julius Wagner-Jauregg's use of Plasmodium infection as an experimental antimicrobial agent to trigger the inflammation necessary to kill Treponema, the spirochaete that causes syphilis. Yet malaria currently kills more than 500,000 people a year, and the spread in southeast Asia of resistance to the only effective antimalarials is of global concern.
As Pennington admits, Have Bacteria Won? is intentionally biased by his personal experience as an infectious-disease specialist working in the United Kingdom. It would be unreasonable to expect comprehensive coverage in an overview for the generalist. But he could have better explored the idea that developed countries are over-fearful about infectious diseases, whereas developing nations — struggling with poor sanitation and inadequate clean water, nutrition and health care — are at greater, and globally significant, risk.
The book's title notwithstanding, Pennington extends his analyses to diseases caused by viruses, prions and eukaryotic parasites. Microbiologists grind their teeth when a well-intentioned news report refers to a bacterial infection as caused by a virus, or vice versa, so why sow more confusion? However, these few concerns do not detract from what is an entertaining and very well-written primer on the human–microbe relationship — one of the oldest pairings on Earth.