It’s not necessary to do anything you want to do in medicine and honestly would not get you much more than a “hm that’s neat” in the residency application process for IM at least. What I’m saying is don’t do it for your resume. If you are driven and excited to do it and it will improve your general life satisfaction even if it does nothing for your resume, do it. Stated another way. If no one was ever going to know or care that you did it and you would still really want to do it, do it.
You will have more opportunities in future to go abroad and participate in activities more directly applicable to global health, if you want them.