There’s been a steady stream of reports in the news about methacillin-resistant Staph. aureus. It’s not a new problem, but (like other nasty infections) it does get a lot of press when the media start paying attention. Works in reverse, too – on the viral front, have you noticed the much reduced number of bird-flu-will-kill-us-all stories this year as we head toward winter? This despite the likelihood of bird flu killing us all being as high (or low) as ever, as far as I can tell.
But the resistant bacteria problem is certainly no joke, and there doesn’t seem to be any reason why it won’t gradually get worse over time. It struck me the other day that antiinfectives, as a drug research field, might be moving toward a similar spot to oncology. In both cases, you have a problem with rapidly multiplying cells, giving you a serious medical outcome - often in cancer, and increasingly with infections. The average tumor is a lot more worrisome than the average infection, of course, but that’s something we can only say with confidence in the industrialized world, and we've only been able to say it for the last sixty or seventy years. As cancer gradually becomes more manageable and infections gradually become less so, the two might eventually meet – or even switch places, which would be bad news indeed. (In some genetically bottlenecked species, in fact, the two problems can overlap, which is fortunately extremely unlikely in humans).
There are, of course, a lot of differences between the two fields, not least of which is that you’re fighting human cells in one case and prokaryotes (or worse, viruses) in the other. But many of those differences actually come out making infectious diseases look worse. The transmissibility of bacteria and viruses make them serious contenders for causing havoc, as they have innumerable times in human history, and they can grow more quickly in vivo than any cancer. It’s only the fact that public health measures allow then to be contained, and the fact that we’ve had useful therapies for many of them, that makes people downrate the infectious agents. If either (or both) of those change, we’re going to be rethinking our priorities pretty quickly.
What this means for drug development is that some researchers will have to rethink their attitudes towards antiinfective drugs. For serious infections, we're going to have to think about these projects the way we've traditionally thought of oncology agents - last-ditch therapies for deadly conditions. Anticancer therapies have long had more latitude in their side effects, therapeutic ratios, and dosing regimes, and antibiotics for resistant infections are in the same position. For some years now, there's been a problem that new drugs in this field would perforce have small markets, since they'd be used only when existing agents fail. That market may not be as small as it used to be. . .