On the front line of HIV virological monitoring: barriers and facilitators from a provider perspective in resource-limited settings.

Scale-up of viral load (VL) monitoring for HIV-infected patients on antiretroviral therapy (ART) is a priority in many resource-limited settings, and ART providers are critical to effective program implementation. We explored provider-perceived barriers and facilitators of VL monitoring. We interviewed all providers (n = 17) engaged in a public health evaluation of dried blood spots for VL monitoring at five ART clinics in Malawi. All ART clinics were housed within district hospitals. We grouped themes at patient, provider, facility, system, and policy levels. Providers emphasized their desire for improved ART monitoring strategies, and frustration in response to restrictive policies for determining which patients were eligible to receive VL monitoring. Although many providers pled for expansion of monitoring to include all persons on ART, regardless of time on ART, the most salient provider-perceived barrier to VL monitoring implementation was the pressure of work associated with monitoring activities. The work burden was exacerbated by inefficient data management systems, highlighting a critical interaction between provider-, facility-, and system-level factors. Lack of integration between laboratory and clinical systems complicated the process for alerting providers when results were available, and these communication gaps were intensified by poor facility connectivity. Centralized second-line ART distribution was also noted as a barrier: providers reported that the time and expenses required for patients to collect second-line ART frequently obstructed referral. However, provider empowerment emerged as an unexpected facilitator of VL monitoring. For many providers, this was the first time they used an objective marker of ART response to guide clinical management. Providers' knowledge of a patient's virological status increased confidence in adherence counseling and clinical decision-making. Results from our study provide unique insight into provider perceptions of VL monitoring and indicate the importance of policies responsive to individual and environmental challenges of VL monitoring program implementation. Findings may inform scale-up by helping policy-makers identify strategies to improve feasibility and sustainability of VL monitoring.

A modelling framework to support the selection and implementation of new tuberculosis diagnostic tools.

Efforts to stimulate technological innovation in the diagnosis of tuberculosis (TB) have resulted in the recent introduction of several novel diagnostic tools. As these products come to market, policy makers must make difficult decisions about which of the available tools to implement. This choice should depend not only on the test characteristics (e.g., sensitivity and specificity) of the tools, but also on how they will be used within the existing health care infrastructure. Accordingly, policy makers choosing between diagnostic strategies must decide: 1) What is the best combination of tools to select? 2)Who should be tested with the new tools? and 3)Will these tools complement or replace existing diagnostics? The best choice of diagnostic strategy will likely vary between settings with different epidemiology (e.g., levels of TB incidence, human immunodeficiency virus co-infection and drug-resistant TB) and structural and resource constraints (e.g., existing diagnostic pathways, human resources and laboratory capacity). We propose a joint modelling framework that includes a tuberculosis (TB) transmission component (a dynamic epidemiological model) and a health system component (an operational systems model) to support diagnostic strategy decisions. This modelling approach captures the complex feedback loops in this system: new diagnostic strategies alter the demands on and performance of health systems that impact TB transmission dynamics which, in turn, result in further changes to demands on the health system. We demonstrate the use of a simplified model to support the rational choice of a diagnostic strategy based on health systems requirements, patient outcomes and population-level TB impact.

Changes in Escherichia coli resistance to co-trimoxazole in tuberculosis patients and in relation to co-trimoxazole prophylaxis in Thyolo, Malawi.

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out in 1999 and 2001 to determine (i) whether faecal Escherichia coli resistance to co-trimoxazole in TB patients changed with time, and (ii) whether the resistance pattern was different in HIV-positive TB patients who were taking co-trimoxazole prophylaxis. Co-trimoxazole resistance among E. coli isolates in TB patients at the time of registration was 60% in 1999 and 77% in 2001 (P < 0.01). Resistance was 89% among HIV-infected TB patients (receiving cotrimoxazole), while in HIV-negative patients (receiving anti-TB therapy alone) it was 62% (P < 0.001). The study shows a significant increase of E. coli resistance to co-trimoxazole in TB patients which is particularly prominent in HIV-infected patients on co-trimoxazole prophylaxis. Since a high degree of plasmid-mediated transfer of resistance exists between E. coli and the Salmonella species, these findings could herald limitations on the short- and long-term benefits to be expected from the use of co-trimoxazole prophylaxis in preventing non-typhoid Salmonella bacteraemia and enteritis in HIV-infected TB patients in Malawi.

An audit of urine culture results at Queen Elizabeth Central Hospital (QECH) in 1994-95 and 1999-2001.

We conducted a retrospective audit of urine cultures at the Queen Elizabeth Central Hospital (QECH), Blantyre. The aims of the audit were to determine the common organisms cultured from urine, in 1994-5 and in 1999-2001, and the sensitivity of these organisms to the first and second line drugs used in the management of urinary tract infection (UTI) in Malawi. A total of 401 samples were studied. One hundred and thirty-six of these grew isolates that were considered pathogenic. E. coli was isolated in 50% of the cultures. Isolates were sensitive to cotrimoxazole and nitrofurantoin (the recommended first-line treatments in Malawi) in only 13% and 48% of cultures, and sensitive to gentamicin in 40% and augmentin in 20% of cases. Levels of drug resistance did not differ between 1994 and 2001. Antibiotic policies for the management of UTI need to be reviewed in the light of the high isolate resistance to the two first line drugs used in the treatment of UTI in Malawi.

Changes in Escherichia coli resistance to co-trimoxazole in tuberculosis patients and in relation to co-trimoxazole prophylaxis in Thyolo, Malawi.

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out to determine i) whether faecal Escherichia coli (E.coli) resistance to co-trimoxazole in TB patients changed with time and ii) whether the resistance pattern was different in HIV positive TB patients who were taking co-trimoxazole prophylaxis. Co-trimoxazole resistance among E.coli isolates in TB patients at the time of registration was 60% in 1999 and 77% in 2001 (p<0.01). Resistance was 89% among HIV-infected TB patients (receiving co-trimoxazole), while in HIV negative patients (receiving anti-TB therapy alone) it was 62% (p<0.001). The study shows a significant increase of E.coli resistance to co-trimoxazole in TB patients which is particularly prominent in HIV infected patients on co-trimoxazole prophylaxis. Since a high degree of plasmid-mediated transfer of resistance exists between E.coli and the Salmonella species, these findings could herald limitations on the short and long term benefits to be anticipated from the use of co-trimoxazole prophylaxis in preventing non-typhoidal salmonella bacteraemia and enteritis in HIV infected TB patients in Malawi.