Enhanced TB Screening to Determine the Prevalence and Incidence of TB in Patients With HIV
This study will examine an enhanced protocol to systematically screen a cohort of 400 new HIV clinic enrollees for prevalence and 1-year incidence of tuberculosis (TB).
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Enhanced TB Screening to Determine the Prevalence and Incidence of TB in a Cohort of HIV Clinic Patients in Lusaka, Zambia|
- Prevalence of undiagnosed TB in those with HIV. [ Time Frame: Enrollment screening visit ] [ Designated as safety issue: No ]Among the cohort of 400 new enrollees at the clinic, all will be tested for TB at the specified time points using enhanced TB screening. Initial diagnosis will use smear microscopy and culture. Chest X-ray will be performed on the second day of enrollment. Presumptive Diagnosis: As culture results will take several days or weeks to become available, a presumptive diagnosis will be made based on history and physical exam, symptoms, smear microscopy and chest radiography results. All patients who are smear-positive by at least one sample will be diagnosed with TB per national guidelines. Patients who are smear-negative or suspected of extra-pulmonary TB based on clinical or radiographic findings may be treated empirically for TB at the discretion of a clinical or medical officer. Sputum samples will also be sent for testing at the end of the study with the Xpert MTB/RIF assay.
- Incidence of TB in a cohort of HIV clinic patients screened as 'TB negative'. [ Time Frame: enrollment, 3, 6, 9 and 12 month visits. ] [ Designated as safety issue: No ]To account for patients who are censored prior to 12 months of follow-up, the incidence of TB will be calculated as a rate. Each patient will contribute follow-up time until they are censored, are diagnosed with TB, or have been in the study for 12 months. Patients who were diagnosed with TB at enrollment will not be included.
- Performance of diagnostic measures [ Time Frame: Days 1, 2, 3; Months 3, 6 9 and 12 ] [ Designated as safety issue: No ]The performance of symptom screening, light microscopy, fluorescence microscopy, chest x-ray, and Xpert MTB/RIF assay compared to culture of sputum and other fluids in HIV-infected patients will be evaluated using data analysis methods.
- Cost-effectiveness of each screening/diagnostic tool. [ Time Frame: Days 1, 2, 3 and months 3, 6, 9 and 12 ] [ Designated as safety issue: No ]The primary outcomes of each diagnostic tool (or combination of diagnostic tools) that will be assessed are: cost per case diagnosed/detected, cost per patient cured, cost per case averted. For instance, the cost per case of active TB detected using the "null" or gold standard screening option will be calculated and compared to the cost per case of active TB detected using each of the other screening options.
- Clinical outcomes [ Time Frame: up to 12 months post-enrollment ] [ Designated as safety issue: No ]Clinical outcomes will be measured in a cohort of HIV-infected patients and TB/HIV co-infected patients during the first 12 months of HIV care including but not limited to mortality, immune recovery and development of other opportunistic infections.
Biospecimen Retention: Samples With DNA
Additional samples (10 ml blood, and 20 ml urine) will be stored in the specimen repository at the CIDRZ laboratory for future studies. For patients who agree to provide samples for the repository and are diagnosed with TB, isolates from positive cultures (blood, urine, and/or sputum) will also be stored in the repository.
|Study Start Date:||October 2011|
|Study Completion Date:||May 2013|
|Primary Completion Date:||September 2012 (Final data collection date for primary outcome measure)|
new HIV clinic enrollees
All new enrollees to a Lusaka HIV clinic will receive a full TB work-up.
Other: Comprehensive TB screening
All enrollees will receive a comprehensive TB screening regardless of symptom presentation.
Zambia is a high burden country for both HIV and TB infection and HIV clinic enrollees are a high-risk group for active TB. Current Zambian Ministry of Health screening protocols are symptom-based even though active case-finding studies in HIV-infected populations have shown that symptoms are not always predictive of active TB. As a result, there may be a significant amount of un-diagnosed TB among HIV-infected Zambians even in the context of accessing HIV care. This study will examine an enhanced protocol to systematically screen a cohort of 400 new HIV clinic enrollees for prevalence and 1-year incidence of TB using symptoms, light and fluorescence microscopy, chest radiography and TB culture of sputum and extra-pulmonary fluids (when indicated). In addition, the sensitivity, specificity and cost-effectiveness of each diagnostic tool will be evaluated.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02043067
|Kalingalinga HIV Care and Treatment Clinic|
|Principal Investigator:||Stewart Reid, MD||CIDRZ; University of North Carolina at Chapel Hill|