Best American Science and Nature Writing 2014, edited by Pulitzer-winning writer and professor Deborah Blum, features two pieces that remind us how public-health interventions can become less effective if we as a society don’t use them appropriately — and, based on the spelling of the authors’ last names, they’re right next to each other in the anthology. Maryn McKenna’s “Imaging the Post-Antibiotics Futre,” published in Medium, and Seth Mnookin’s “The Return of Measles” from the Boston Globe Magazine warn that diseases we thought we’d conquered could easily return and become major killers once again.

McKenna, author of SUPERBUG: The Fatal Menace of MRSA and the Superbug blog at Wired, has written extensively about the rise of antibiotic-resistant bacteria. She notes in her Medium piece that 80% of the antibiotics sold in the US are used in agriculture, and that a growing body of research links the use of antibiotics in livestock to the emergence of these resistant organisms. The 20% of US antibiotics prescribed to humans also play a role; inappropriate prescriptions (e.g., for viruses that won’t respond to antibiotics) and patients’ failure to take complete courses of the drugs also contribute to resistant bacteria’s rise. This, McKenna explains, will have severe repercussions for healthcare:

Without the protection offered by antibiotics, entire categories of medical practice would be rethought.

Many treatments require suppressing the immune system, to help destroy cancer or to keep a transplanted organ viable. That suppression makes people unusually vulnerable to infection. Antibiotics reduce the threat; without them, chemotherapy or radiation treatment would be as dangerous as the cancers they seek to cure.

… Antibiotics are administered prophylactically before operations as major as open-heart surgery and as routine as Caesarean sections and prostate biopsies. Without the drugs, the risks posed by those operations, and the likelihood that physicians would perform them, will change.

Mnookin, author of The Panic Virus: The True Story Behind the Vaccine-Autism Controversy and associate director of MIT’s Graduate Program in Science Writing, focuses in his piece on measles — which, he notes, might not sound as terrifying as AIDS or Ebola, but which frightens public-health officials because it has a transmission rate of 90%. A timeline accompanying the article notes that in 2000, “a panel of experts declared measles eliminated in this country.” Now, though, more children’s parents are citing religious or philosophical reasons for not getting their children vaccinated, and these families are often clustered in the same geographic areas. That means that a single child with measles could potentially spread the disease to several unvaccinated classmates or neighbors. Public-health officials must respond swiftly to each new measles case, identifying people who could have been exposed and checking their vaccination status.

Mnookin gives the example of a recent “all-hands-on-deck” response from the Massachusetts Department of Health when two unconnected patients presented at hospitals with active measles infections. Such responses are important, and not cheap. Mnookin writes:

As the containment efforts illustrate, the fact that there haven’t been any recent deaths in the United States doesn’t mean measles isn’t having a real impact on the economy or on public health. One of the reasons [director of Massachusetts’ Division of Epidemiology and Immunization Larry] Madoff oversaw an effort in Massachusetts to contact everyone who might have been exposed was to make sure they were OK. Another was to identify anyone who wasn’t vaccinated so they could “isolate themselves and be out of work and out of school.”

The state isn’t releasing estimates for the total cost of these two infections, but a 2010 study in Pediatrics quantified the expense of containing a 2008 outbreak in San Diego in which 11 children were infected — and another 839 people were exposed. That cost the public sector $124,517, an average of more than $10,000 per infection. These are costs borne by all of us: Every tax dollar spent containing measles is a dollar not spent on other public health initiatives.

Developing a new antibiotic or vaccine can take massive investments of time and money, but once it’s done, it’s done. By contrast, assuring the ongoing appropriate use of drugs and vaccines by the entire country is a neverending task. It’s easy for lawmakers and the public to forget that public health requires ongoing investments, even if it doesn’t result in headline-grabbing achievements. As these two pieces remind us, though, failing to be vigilant on how we use our medical breakthroughs can mean they no longer protect us as well as they used to.