Tetanus is a potentially fatal disease that affects the nervous system. It's caused by bacteria known as Clostridium tetani, which produce spores in dead tissue, such as carrion and animal excrement. So it might occasionally be found on fingernails or blades of grass.
The infectologist is a medical specialist and diseases caused by infectious agents such as bacteria, viruses, fungi and parasites.
Remember that for the proper selection of health professional that treats tetanus you must consider the nature, severity and symptoms you are presenting.