The diagnosis of Mycoplasma pneumonia can beconfirmed by two types of serological tests and I presume the one used in your case was a complement fixation test. There are at least two problems with it. First, it is not specific and raised titres can be found in a variety of neurological diseases and pancreatitis. Second, the titre remains raised for about a year after the condition has been treated. From what you have written, I am not convinced that your fever is caused by Mycoplasma. I can offer three reasons for my suspicion that something else is going on and needs to be investigated. First, your chest X-ray did not show any features of an atypical pneumonia or any other changes associated with Mycoplasma. Second, you have been adequately treated for Mycoplasma and you should not have had any further problems from it. Third, there are many other conditions which would give you the symptoms you have, and these should be explored in a hospital setting with systematic investigations. I am pleased to learn that your general health is good. Please discuss the possibility of conducting further investigations with your hospital consultant.