Specific human infectious diseases, including bartonellosis/felinosis, tuberculosis, actinomycosis, etc. are a group of infectious diseases caused by a certain etiology agent and at present without so specific clinical manifestation. The lack of more accurate laboratory tests, the difficulty in culturing the pathogen and the need for histopathology prevent their rapid diagnosis and contribute to the non-recognition of these diseases. Because they are rarely detected, there are no statistics on their etiology and frequency. There has been no updated extensive epidemiological study of the various manifestations of these diseases. As our knowledge of the microbiological, pathological and clinical spectrum expands, more and more questions develop. So, the aim of the proposes special issue is to present different case reports, reviews, original articles and research works in which the wide range of clinical symptoms and the non-specific course of these pathologies are summarized. With the discovery of more diverse clinical presentations, up-to-date information on their patterns of occurrence, frequency and distribution will be comprehensively discussed and presented to the clinicians and surgeons. The main goal of the issue is to fill the significant gap in our knowledge of effective therapy for more complex consequences of specific human infections. Whit the support of the recent information that will be collected in this issue an evidence based therapeutic decisions will determine patients’ management. Finally, clinicians should always include this spectrum of diseases in the differential diagnosis, especially in cases in which there is no response to the applied conventional treatment. The more so as, this spectrum of diseases can mimic not only other infections but even neoplasms leading to problems in recognizing them and therefore to misdiagnosis and patient mistreatment respectively.