The study was carried out in 1999–2000 and had an overall IR of 778/100 000 PYO, which is very similar to our estimates. The study included few HIV-infected individuals and did not report on IRs according to HIV transmission group. A follow-up study from 2000 to 2006 by the same group [24] also identified HIV infection as a significant risk factor for SAB. However, in that study the relative risk conferred by HIV infection decreased from 23.7 to 17.1 over the two study periods, suggesting a similar decline in IR to that reported in the present study. Interestingly, they found that HCV infection was associated with an increased risk of SAB but were unable

to attribute this to liver disease or IDU. Our study did not address VX-770 concentration HCV infection per se but, as more than 90% of HIV-infected IDUs are or previously have been infected with HCV, the markedly increased IR among IDUs would suggest that HCV infection may be a marker of www.selleckchem.com/products/icg-001.html IDU. Our study provides new information as we report specific IRs and their changes over time according to HIV transmission group. Over the last decade, the degree of immune deficiency in HIV-infected individuals has diminished as a result of increased coverage of HAART [25]. The incidence of bacterial BSIs has similarly decreased [26,27]. In our study, lack of HAART was associated with a 2-fold increased

risk of SAB and, correspondingly, individuals who were virologically nonsuppressed were at an increased risk. MSM acquired SAB at a old lower CD4 cell count and

had a higher rate of HA SAB, indicating that these cases are probably caused by intravascular devices related to therapy for AIDS-associated diseases, as described previously [4,10,12]. IDUs predominantly acquired CA SAB at higher CD4 cell counts, suggesting that these cases are likely to be related to repeated injections. Further reductions in SAB IRs can be expected to be achieved by reducing immunodeficiency via increased HAART coverage, reducing the proportion of late presenters and encouraging sterile injecting methods among IDUs. Several studies have reported an increased risk of MRSA colonization and infection in HIV-infected individuals compared with the general population [28–32]. The prevalence of MRSA in Denmark is low [16] and, correspondingly, rates were low among HIV-infected individuals and comparable to those in the general population. The strengths of our study include the long study period, the population-based design, the use of nationwide cohorts of HIV-infected individuals, the nationwide registration of SAB and complete data on immigration, emigration and death. There was no evidence of outbreaks or common source infections among HIV-infected individuals during the study period based on phage types (data not shown). However, the study has some limitations. Of 15 clinical microbiological departments in Denmark, one department irregularly contributed with isolates; however, this laboratory covers only 6% of the Danish population [17].