I'd say it's a so-so registration. Although dot-info is probably a second best possible extension for those keywords aside from .com, the domain seems too general to appeal to any specific medical group as is. SyphillisSymptoms.info and MeningitisSymptoms.info would probably have more end-user value.
To your credit, however, the domains is registered in a dozen extensions (albeit all the reg'd names are parked), has 3 years of history, and boasts nice overture/wordtracker numbers. I would suggest you brew a creative development idea, such as a service that asks the viewer which symptoms he/she feels and, based on what's entered, informs the user which condition he/she is most likely suffering, and what to do about it. This method of diagnosis is one of the hottest frontiers in AI research today.
Mid $xx undeveloped, but a little nurturing could go a long way towards pumping up its value.