Fever of unknown origin in the setting of HIV infection: guidelines for a rational approach

Fever of unknown origin constitutes a common problem in HIV-infected patients that, paradoxically, has received little attention in the literature. A review on this topic collecting data from different series showed that mycobacterial infections, particularly tuberculosis, were responsible for the fever in more than half of the patients. However, the relative frequencies of the different etiologies may vary substantially depending on the local prevalences of certain infections. With the notable exception of tuberculosis, which may develop at any stage of HIV infection, fever of unknown origin usually presents in patients with advanced disease when the CD4 cell count is below 100/microliter. In this overview we stress, from a practical point of view, some points to be considered in the evaluation of the HIV-infected patient who presents with fever of unknown origin, as well as the usefulness and yield of several diagnostic procedures.