Final answer:
Mycobacterium avium complex in humans can lead to symptoms similar to tuberculosis, including the formation of granulomatous lesions in the lungs that may calcify. Patients can experience a cough, skin rash, abdominal pain, and diarrhea, and immunocompromised individuals are at risk of serious complications due to possible dissemination of the bacteria.
Step-by-step explanation:
The clinical presentation of Mycobacterium avium complex in humans often shares similarities with that of tuberculosis. After the inhalation of spores, the bacteria are phagocytized by alveolar macrophages in the lungs. Inside these macrophages, the bacteria can survive and multiply, leading to the formation of granulomatous lesions. These can calcify, forming complexes akin to the Ghon complexes seen in tuberculosis. For many individuals, the infection may remain asymptomatic; however, symptoms such as cough, which can sometimes be bloody, skin rash, abdominal pain, and diarrhea may develop. In those with weakened immune systems, Mycobacterium avium complex can disseminate, resulting in serious, and potentially fatal, complications.
In addition, similar to tuberculosis, histoplasmosis affected individuals may experience chronic infections, and reactivation could occur. Dissemination to other organs, such as the liver or spleen, is possible. While infections can be self-limiting, in cases of disseminated disease, antifungal agents like amphotericin B, ketoconazole, and itraconazole may be necessary, especially in immunocompromised patients.