Identifying research priorities on infections in older adults: proceedings of an interdisciplinary workshop.

BACKGROUND: Infections pose a substantial burden to the health of older adults. In this report, we describe the proceedings of a workshop to formulate and prioritize research questions about infections in older adults using an interdisciplinary approach. METHODS: Researchers from four sectors (basic science, clinical sciences, health services and epidemiology/determinants of health) and representatives from various Canadian local, provincial, and federal stakeholder groups were invited to a two-day workshop. Five multi-disciplinary groups and stakeholders from each of three healthcare settings (long term, acute care and community) discussed research priorities for each of the settings. Five to ten research questions were identified for each setting. RESULTS: The research questions proposed ranged from risk factors and outcomes for different infections to the effect of nutrition on infection and the role of alternative and complementary medicine in treating infections. Health service issues included barriers to immunization, prolongation of hospital length of stay by infection, use of care paths for managing infections, and decision-making in determining the site of care for individuals with infections. Clinical questions included risk factor assessment for infection, the effectiveness of preventative strategies, and technology evaluation. Epidemiologic issues included the challenge of achieving a better understanding of respiratory infections in the community and determining the prevalence of colonization with multi-resistant bacteria. CONCLUSIONS: The questions are of direct relevance to researchers in a wide variety of fields. Bringing together a multi-disciplinary group of researchers to frame and prioritize research questions about aging is feasible, participants valued the opinions of people working in other areas.

Oropharyngeal candidiasis in patients with human immunodeficiency virus: correlation of clinical outcome with in vitro resistance, serum azole levels, and immunosuppression.

Azole-resistant thrush has emerged as a problem in people who are infected with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS), especially those who have low CD4 cell counts who have had a previous relapse of oral candidiasis, and in those who require long-term suppressive antifungal therapy. Because of the development of a standardized methodology for antifungal susceptibility testing and interpretive criteria for resistance testing, studies of the clinical predictive value of in vitro results are possible. In this study, 61% of organisms isolated from patients who were receiving azole therapy and who had clinically resistant thrush had minimal inhibitory concentration values that would classify the isolate as "resistant" or "susceptible dose dependent." In contrast, 86% of isolates from patients with thrush that was clinically responsive to an azole were classified in vitro as "susceptible" or "susceptible dose dependent." No resistant isolates were detected in samples obtained from asymptomatic control patients who were not exposed to azole drugs. Serum levels of azole and CD4 cell counts were also important parameters with regard to prediction of response. We conclude that in vivo and in vitro correlations compare favorably to studies of susceptibility testing in bacteria.

Broth microdilution testing of Haemophilus influenzae with haemophilus test medium versus lysed horse blood broth. Canadian Haemophilus Study Group.

Broth microdilution testing of 702 community-acquired isolates of Haemophilus influenzae from across Canada was performed with both Mueller-Hinton broth supplemented with 3% lysed horse blood broth (LHB) (BBL Microbiology Systems, Cockeysville, Md.) and haemophilus test medium (HTM). The prevalence of beta-lactamase production was found to be 26% with no regional variation. MICs determined with LHB tended to be higher than those with HTM, but interpretive errors due to these differences were observed only rarely with trimethoprim-sulfamethoxazole (n = 5), cefaclor (n = 8), and cefamandole (n = 3). The interobserver variability in MIC determinations was found to be greater when LHB was used than when HTM was used. There was no difference in intraobserver variability between the two medium formulations. beta-Lactamase-positive isolates developed false resistance to amoxicillin-clavulanate 2 weeks after microdilution panels of both types of medium were stored at -20 degrees C but not when panels were stored at -70 degrees C. In conclusion, this study supports the use of HTM rather than LHB for sensitivity testing of H. influenzae because of its lower rate of interobserver variability and its ability to support the growth of these organisms, which is comparable to that of LHB.