I would certainly consult with a trusted physician with a masters degree in public health, such as you are aware Dr. McCullough has, regarding epidemiology.
Most people I've known who hold an MPH are veterinarians. I actually wouldn't ask them for medical advice.
Epidemiology is the science of tracking down and identifying the cause/source of disease. It is not strictly related to infectious disease. An epidemiologist might, for example, be tasked with tracking down the source of an outbreak of radiation injuries or chemical exposures in an area.
If I am sick with an infectious disease--e.g. leptospirosis--I don't want to consult an epidemiologist. While knowing where the disease came from might be academically interesting, I'm far more interested in consulting a doctor with experience in treating infectious disease. I wouldn't ask for a consult with a cardiologist to get treated for leptospirosis.
Public health is vitally important, but many of the people involved are not physicians or health care providers in any capacity.