Despite the slight drop in 2008, our conclusion, based on multivariate results, is that the overall incidence of bacteraemia rose slightly during this period, especially after 2004. This is consistent with data suggesting an increase in MRSA during this time interval [12,14]. The organism-specific bacteraemia rates reported in this study are consistent with previous findings in the literature that support the predominance of S. aureus, coagulase-negative staphylococci and S. pneumoniae as pathogens in bacteraemia among HIV-infected patients Sorafenib molecular weight in developed countries [2,8,15–19]. This contrasts with studies conducted in the developing world, particularly in

Africa and Southeast Asia, which document higher rates of Salmonella species bacteraemia [3,20]. The incidence of S. aureus decreased in recent years; however, the incidence of bacteraemia NOS increased. The high proportion of bacteraemia NOS makes it difficult to interpret Rapamycin chemical structure trends in organism-specific rates. When we examined

all bacteraemia-NOS episodes at one of the largest sites, we found that the most common organism cultured was S. aureus (38%) followed by other Staphylococcus (18%). Of the total cases of S. aureus bacteraemia, 61% were MRSA. The high proportion of MRSA bacteraemia is consistent with other studies demonstrating an increasing prevalence of MRSA bacteraemia in HIV-infected

patients in recent years [12]. Unfortunately, the specific ICD-9 code for MRSA was implemented only in 2008 and did not appear in the data for previous years, so we were not able to subdivide our general category for S. aureus bacteraemia by antibiotic sensitivity. To the extent that the rise in bacteraemia-NOS admissions is attributable to MRSA, the results Tau-protein kinase point to a growing problem, with potentially adverse effects on morbidity, mortality and treatment expenditures. Consistent with prior studies, IDU was a strong, independent risk factor for bacteraemia [5,7,11]. This association was significant, even though our measure reflects a history of IDU, and not necessarily current IDU. Skin-popping, use of dirty needles and inadequate skin cleaning among IDUs may promote bacterial infection [21]. Previous investigations have also demonstrated an association between IDU and S. aureus bacteraemia in HIV-infected individuals [22]. Evidence suggests that the reason for this association may be, in part, the higher rates of nasal colonization by MRSA and S. aureus in IDUs [23–25]. Because this study relied on administrative data, we were unable to examine a link between bacterial nasal colonization and subsequent development of bacteraemia in this population. Black, but not Hispanic, patients were more likely to have a bacteraemia diagnosis than White patients.