As to whether or not I am making a difference, I think the honest answer is "I think so, at least on some days." I was working with a bright young man today editing a document, and showing him how to do some things in Word and Excel. After I showed him, he did it himself and teased me saying "Look! A transfer of skills!" Those are Peace Corps buzz words, but it was in fact true.
The closest example of where I work is Denver Health. My office is the administrative head for 4 health clinics and 5 health posts. Those clinics and health posts provide direct care to people here, and they are the only health resource available. So while I don't work with patients directly, I help the people who make sure there is staff and supplies, to provide the care.
I am taking a lot of responsibility for the data collection and analysis for our system. Those data we not only send to national in Gabs, but review to see if we need to add or subtract services to meet the health care needs of our people. Lots of sexually transmitted diseases? Let's plan some talks with local leaders and public education about it. A sudden rush of cases of little kids with diarrhea (which can be life threateneing) - let's staff up to provide care and also figure out what bug is going around so we can stop it. It is just good basic public health - not glamorous, but people can progress when they are sick. AIDS/HIV is a major part of the mix, but not all of it. And most days are different from each other, so I just pitch in to help with whatever needs done.
Fuggedabout that nonsense about "not in my job description!" That is also a model for everyone else.