Let’s say that you’re a physician working in a rural setting in, say, Pennsylvania. And let’s say that you see a lot of migrant workers from Latin America and the Caribbean. Now, let’s say that one of them comes to you with gastric discomfort and some other signs of maybe a stomach ulcer. Would you do a test for H. pylori, and would you treat for it? And what if the patient didn’t have any gastric discomfort but had a stool culture for other symptoms, and the culture came back positive for H. pylori?
Well, here’s where medicine and public health come together and give some interesting results. Based on epidemiological data compiled and published by public health authorities, physicians in the United States are likely to think that a positive H. pylori test with signs and symptoms of an ulcer mean that treating the infection will treat the ulcer. (Of course, I’m generalizing. Different physicians have different approaches to how they treat their patients.) But what if you’re a physician in another country? Or you’re treating a population that grew up in another country?
H. pylori colonization/infection is incredibly common the world over. The prevalence varies by the place in the world where you live and your ethnicity. Basically, if you live in developing countries, you get colonized at an early age, via the fecal-oral route, and the bacteria becomes part of your normal flora. It is then unlikely to cause disease unless you get sick with something that messes with that balance in your “microbiome.” The microbiome is the group of bacteria that make up what’s inside and outside of you that is not you (not human cells).
If this stadium is you, imagine all these people being normal flora, then get them all riled up.
Photo credit: marcp_dmoz / Foter.com / CC BY-NC-SA
So, what if you have a person come in with signs and symptoms of an ulcer, and they’re from a country where it is likely that the H. pylori inside them are from when they were kids, i.e. normal flora and not pathogens? That is, do you treat that infection?
These are the questions that ran through a recent discussion on H. pylori as it relates to ulcers. And it was a very interesting discussion. (Thanks to the “science mobbers” who sent me some suggestions via Twitter.) This discussion brought to my mind the very important and interesting discussions that will come in my career in public health. Providers will want to test and treat the individual while public health recommendations are based on populations. This creates a sort of friction, and not just in this topic. (For example, do you vaccinate according to a population-based schedule, or according to what your patients’ parents want?)
We’ll see how that goes.