Nosocomial infections in human immunodeficiency virus type 1 (HIV-1) infected and AIDS patients: major microorganisms and immunological profile

Antiretroviral therapy advances have proportioned to AIDS patients a survival increase. At the same time, the permanence of the seropositive people in the nosocomial environment becomes common not only by the adverse reactions caused by this therapy, but also by several opportunistic diseases that take them into and out of hospital environment. During the hospital permanence, the patients expose their impaired immune system to the nosocomial virulent microorganisms, and acquire destructive nosocomial infections that sometimes can be lethal. Among several hospital syndromes described, little is known about infections in immunocompromised patients and how their immune system is able to determine the course of the infection. The objective of this study was to describe the major microorganisms involved in the nosocomial infections of HIV-1 seropositive patients associated with their immunological status. The survey was carried out with the Hospital Infection Control Service records, from University Hospital, Londrina, Paraná, Southern of Brazil, during the period from July 2003 to July 2004. From all the cases studied (n=969), 24 patients (2.5%) had AIDS diagnosis and a half of them was women with the mean of CD4(+) T cells counts of 158/mm(3). The main topography of the infection was pulmonary (50.0%) and the main isolated microorganisms were Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. A major incidence of infection was observed in patients with CD4(+) T cells counts lower than 50/mm(3). The study of the relationship between the impairment of the immune system and infectious agents could provide a better healthcare of people living with HIV/AIDS and advances into the nosocomial infection control systems.