Comparative assessment of methicillin resistant Staphylococcus aureus diagnostic assays for use in resource-limited settings.

BACKGROUND: The rise of methicillin-resistant Staphylococcus aureus (MRSA) is a global health concern. Paucity of data on MRSA carriage prevalence and diagnostic methods in resource-limited settings hampers efforts to define the problem and plan an appropriate response. Additionally, high variability in cost and logistical characteristics of MRSA screening methods may impede infection control efforts. We compared the performance of locally-available chromogenic agar BD CHROMagar MRSA II and two PCR-based assays (Hain GenoQuick MRSA and Cepheid Xpert SA Complete) for the detection of asymptomatic MRSA carriage in nasal swabs. RESULTS: During 2015, we enrolled 500 patients from five hospital wards at a Ugandan regional referral hospital. We found 30% prevalence of methicillin-sensitive Staphylococcus aureus (MSSA) nasal carriage, and 5.4% MRSA nasal carriage prevalence. Compared to a composite reference standard defined as a positive test result on any one of the three assays, Hain GenoQuick MRSA demonstrated the highest sensitivity (96%) followed by direct plating on CHROMagar at (70%), with the lowest sensitivity observed with Xpert SA Complete (52%). Cepheid Xpert provided the most rapid results (< 1 h) but was the most expensive (US $45-50/test). Substantially more labor was required for the Hain GenoQuick MRSA compared to Xpert SA Complete or CHROMagar tests. CONCLUSION: MRSA nasal carriage prevalence rates were low, and high diagnostic sensitivity was achieved using Hain GenoQuick MRSA. Chromogenic media had significantly lower sensitivity, but may represent a viable local option given its lower cost compared to PCR-based assays.

Case management is associated with improved antiretroviral adherence and CD4+ cell counts in homeless and marginally housed individuals with HIV infection.

BACKGROUND: Case management (CM) coordinates care for persons with complex health care needs. It is not known whether CM is effective at improving biological outcomes among homeless and marginally housed persons with human immunodeficiency virus (HIV) infection. Our goal was to determine whether CM is associated with reduced acute medical care use and improved biological outcomes in homeless and marginally housed persons with HIV infection. METHODS: We conducted a prospective observational cohort study in a probability-based community sample of HIV-infected homeless and marginally housed adults in San Francisco, California. The primary independent variable was CM, defined as none or rare (any CM in 25% but 75%). The dependent variables were 3 self-reported health service use measures (receipt of primary care, emergency department visits and hospitalizations, and antiretroviral therapy adherence) and 2 biological measures (increase in CD4(+) cell count of >or=50% and geometric mean HIV load of or=50% improvements in CD4(+) cell count. CM was not associated with geometric HIV load <400 copies/mL when antiretroviral therapy adherence was included in the model. Study limitations include a lack of randomization. CONCLUSION: CM may be a successful method to improve adherence to antiretroviral therapy and biological outcomes among HIV-infected homeless and marginally housed adults.

The price of adherence: qualitative findings from HIV positive individuals purchasing fixed-dose combination generic HIV antiretroviral therapy in Kampala, Uganda.

Contrary to early expectations, recent studies have shown near-perfect adherence to HIV antiretrovirals in sub-Saharan Africa We conducted qualitative interviews with patients purchasing low-cost, generic antiretroviral therapy to better understand the social dynamics underlying these findings. We found that concerns for family well-being motivate adherence, yet, the financial sacrifices necessary to secure therapy may paradoxically undermine family welfare. We suggest that missed doses may be more due to a failure to access medication rather than a failure to adhere to medications, and that structural rather than behavioral interventions may be most useful to insure optimal treatment response.

Reliability and validity of the SF-36 in HIV-infected homeless and marginally housed individuals.

OBJECTIVE: To assess the reliability and validity of the Short-Form 36 (SF-36) health survey as a health status indicator among HIV-infected homeless and marginally housed (HMH) individuals. METHODS: Between July 1996 and May 2000, a sample of HMH individuals completed interviews that included the SF-36. Responses to the SF-36 were analyzed for missing data, range, internal consistency, and construct validity. RESULTS: Among 330 individuals interviewed, 83% were male, 43% were African-American, and the median age was 39 years. All internal consistency reliability coefficients exceeded 0.70, all item-scale correlations exceeded 0.40, all items were more strongly correlated with their hypothesized scale than any other scale, and all reliability coefficients exceeded inter-scale correlations for the same scale. Three of four physical health scales were significantly associated with CD4 cell count and HIV viral load. All scales were significantly associated with depression. DISCUSSION: We found that scales were internally consistent, items correlated to an acceptable degree with their hypothesized scales, items were distinct from other scales, physical scales were associated with CD4 cell count and viral load, and all scales were associated with depression. These analyses provide evidence for the reliability and validity of the SF-36 as a measure of health status in HIV-positive HMH individuals.

A computer-based assessment detects regimen misunderstandings and nonadherence for patients on HIV antiretroviral therapy.

Accurately assessing nonadherence is a necessary first step toward improving adherence to highly active antiretroviral therapy (HAART). Patient self report is the most practical method for assessing adherence in clinical settings, but may produce unreliable and invalid results unless optimally performed. A computer-assisted, self-administered interview (CASI) may improve the disclosure of medication nonadherence by providing a neutral and seemingly private interview. One hundred and ten patients completed a computer program which assessed their understanding of and adherence to HIV medications and produced a report for their providers. Eleven providers of these patients completed a questionnaire describing their patients' medication regimens and estimating adherence. Patients completed a written exit survey and providers completed an exit interview to assess the acceptability of our CASI-based assessment. More than half of patients (54%) made at least one error in reporting their medication regimen. Providers tended to overestimate their patients' adherence and correctly classified only 24% of nonadherent patients at the 80% adherence level. Computerized HIV medication adherence assessment is feasible and acceptable to patients and providers. Clinical tools that can accurately and efficiently detect important medication errors and nonadherence, and alert providers to these problems, will help ensure the health of HIV-seropositive patients.

Provider assessment of adherence to HIV antiretroviral therapy.

BACKGROUND: Adherence assessment is an essential component of monitoring HIV antiretroviral therapy. Prior studies suggest that medical providers frequently estimate individual patient adherence inaccurately. OBJECTIVE: We compared provider estimates of nonadherence to antiretroviral therapy with unannounced pill counts and structured patient interviews to determine the accuracy of adherence information obtained by providers and patients. DESIGN, SETTING, AND PARTICIPANTS: Comparison of three adherence measures in homeless or marginally housed persons receiving HIV antiretroviral therapy (n = 45) and their providers (n = 35). MEASUREMENTS: Provider estimate of percentage of pills taken; three successive patient structured reports of number of doses missed in the last 3 days; and three successive unannounced pill counts. RESULTS: 13% (95% confidence interval [CI], 4%-22%) of patients were not following their regimen as directed. Provider-adherence estimate explained only 26% (95% CI, 6%-47%) of the variation in pill count adherence, whereas patient report explained 72% (95% CI, 52%-96%). The sensitivity and specificity of provider estimates of nonadherence, defined as <80% of pills taken by pill count, were 40% and 85%, respectively. The sensitivity and specificity of patient interview were 72% and 95%, respectively. CONCLUSIONS: Provider estimate of adherence was inaccurate whereas structured patient report was more closely related to pill count. Structured assessment over several short intervals may improve accuracy of adherence assessment in clinical practice.

Adherence to protease inhibitors, HIV-1 viral load, and development of drug resistance in an indigent population.

OBJECTIVE: To examine the relationship between adherence, viral suppression and antiretroviral resistance in HIV-infected homeless and marginally housed people on protease inhibitor (PI) therapy. DESIGN AND SETTING: A cross-sectional analysis of subjects in an observational prospective cohort systematically sampled from free meal lines, homeless shelters and low-income, single-room occupancy (SRO) hotels. PARTICIPANTS: Thirty-four HIV-infected people with a median of 12 months of PI therapy. MAIN OUTCOMES: Adherence measured by periodic unannounced pill counts, electronic medication monitoring, and self-report; HIV RNA viral load; and HIV-1 genotypic changes associated with drug resistance. RESULTS: Median adherence was 89, 73, and 67% by self-report, pill count, and electronic medication monitor, respectively. Thirty-eight per cent of the population had over 90% adherence by pill count. Depending on the measure, adherence explained 36-65% of the variation in concurrent HIV RNA levels. The three adherence measures were closely related. Of 20 genotyped patients who received a new reverse transcriptase inhibitor (RTI) when starting a PI, three had primary protease gene substitutions. Of 12 genotyped patients who received a PI without a new RTI, six had primary protease gene substitutions (P < 0.03). CONCLUSION: A substantial proportion of homeless and marginally housed individuals had good adherence to PI therapy. A strong relationship was found between independent methods of measuring adherence and concurrent viral suppression. PI resistance was more closely related to the failure to change RTI when starting a PI than to the level of adherence.