Species-based comparison of disease severity and risk factors for disseminated Candida infections in pediatric patients.

BACKGROUND: Pediatric Candida infections are associated with worse clinical outcomes and increased costs. Yet, it is not definitively known if particular species are associated with more severe illness. Differential risk factor exposures among the species group may also exist. We aimed to determine whether certain Candida species are more strongly associated with worse outcomes, and whether certain risk factors more strongly predispose patients to infection with certain species. METHODS: Microbiology lab records from patients seen from 2003 to 2010 at an urban children's hospital were reviewed for invasive or disseminated Candida infections. Data on measures of disease severity/outcome and risk factors were abstracted and analyzed to determine differences associated with various Candida species. RESULTS: Exactly 106 cases of infection were analyzed. Non-albicans species were associated with a significantly longer length of stay postdiagnosis (P=0.03), as well as longer treatment (P=0.02). Candida albicans was associated with a higher number of antihypotensive medications required (P=0.03) and length of mechanical ventilation postdiagnosis (P=0.05). Candida tropicalis was associated with the highest mortality (45.5%). Hypotension, which was found to be significantly associated with concurrent infection, was significantly associated with increased risk of mortality (odds ratio =5.85, P=0.005). Initial choice of antifungal therapy was not associated with differences in eventual patient mortality. Multivariate logistic regression modeling revealed a trend toward C. albicans infection in patients receiving antineoplastic chemotherapy and non-albicans infection in patients with >96 hours mechanical ventilation. CONCLUSION: Interspecies differences may exist for Candida in terms of disease severity and risk factors. Underlying morbidity and the role of concurrent infections may play a key role in poor outcomes.

Evaluation of a hepatitis A immunization program.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of a hepatitis A vaccine requirement targeted at child-care center attendees 2-5 years of age in Maricopa County, AZ. A case-control study conducted before implementation in 1997 found that individuals with hepatitis A were 6 times more likely to have worked in or attended a child-care center than were matched controls, and 40% of hepatitis A cases were attributable to attending or working in a child-care center. METHODS: A case-control study was conducted postimplementation in 1999. Cases were individuals reported to surveillance staff between August 1, 1999 and April 30, 2000. Cases were included if they met the Centers for Disease Control and Prevention hepatitis A surveillance case definition. Each case (n = 72) was matched to 2 controls (n = 144) based on age and neighborhood. RESULTS: Cases were more likely to have had contact with a hepatitis A case [odds ratio (OR), 7.04; 95% confidence interval (CI), 1.96, 25.31] than were their matched controls in the unadjusted analysis. Individuals with direct contact with a child-care center (OR 0.221; CI 0.05, 0.99) were protected against disease. In the multivariate analysis, contact with a hepatitis A case (OR 5.63; CI 1.22, 25.91) was significantly associated with disease, and the protective effect of education (OR 0.19; CI 0.06, 0.60) remained significant. CONCLUSION: The results of this study suggest the vaccination requirement had some impact on the epidemiology of hepatitis A in Maricopa County. The risk associated with child-care centers seen in the 1997 study is no longer significantly associated with hepatitis A disease.

Estimating HIV incidence and detection rates from surveillance data.

BACKGROUND: Markov models that incorporate HIV test information can increase precision in estimates of new infections and permit the estimation of detection rates. The purpose of this study was to assess the functioning of a Markov model for estimating new HIV infections and HIV detection rates in Louisiana using surveillance data. METHODS: We expanded a discrete-time Markov model by accounting for the change in AIDS case definition made by the Centers for Disease Control and Prevention in 1993. The model was applied to quarterly HIV/AIDS surveillance data reported in Louisiana from 1981 to 1996 for various exposure and demographic subgroups. When modeling subgroups defined by exposure categories, we adjusted for the high proportion of missing exposure information among recent cases. We ascertained sensitivity to changes in various model assumptions. RESULTS: The model was able to produce results consistent with other sources of information in the state. Estimates of new infections indicated a transition of the HIV epidemic in Louisiana from (1) predominantly white men and men who have sex with men to (2) women, blacks, and high-risk heterosexuals. The model estimated that 61% of all HIV/AIDS cases were detected and reported by 1996, yet half of all HIV/non-AIDS cases were yet to be detected. Sensitivity analyses demonstrated that the model was robust to several uncertainties. CONCLUSIONS: In general, the methodology provided a useful and flexible alternative for estimating infection and detection trends using data from a U.S. surveillance program. Its use for estimating current infection will need further exploration to address assumptions related to newer treatments.

HIV/AIDS prevention programs: methodologies and insights from the dynamic modeling literature.

Given the quickly changing landscapes of both global HIV infection and the HIV prevention literature, it has become increasingly difficult to identify or design an effective HIV prevention program. The authors discuss methods of selecting an appropriate program so that readers can critically evaluate the literature and create a suitable program for their unique setting. The intent of this article is to provide the reader with analytic modeling tools and methodology to search effectively the literature so that an appropriate and successful HIV prevention program can by selected by an organization or project team.