Performance of Xpert® MTB/RIF and Determine™ TB-LAM Ag in HIV-infected adults in peri-urban sites in Zambia.

SETTING: Peri-urban health facilities providing HIV and TB care in Zambia. OBJECTIVE: To evaluate 1) the impact of Xpert® MTB/RIF on time-to-diagnosis, treatment initiation, and outcomes among adult people living with HIV (PLHIV) on antiretroviral therapy (ART); and 2) the diagnostic performance of Xpert and Determine™ TB-LAM Ag assays. DESIGN: Quasi-experimental study design with the first cohort evaluated per standard-of-care (SOC; first sputum tested using smear microscopy) and the second cohort per an algorithm using Xpert as initial test (intervention phase; IP). Xpert testing was provided onsite in Chongwe District, while samples were transported 5-10 km in Kafue District. TB was confirmed using mycobacterial culture. RESULTS: Among 1350 PLHIV enrolled, 156 (15.4%) had confirmed TB. Time from TB evaluation to diagnosis (P = 0.018), and from evaluation to treatment initiation (P = 0.03) was significantly shorter for IP than for SOC. There was no difference in all-cause mortality (7.0% vs. 8.6%). TB-LAM Ag showed higher sensitivity with lower CD4 cell count: 81.8% at CD4 < 50 cells/mm3 vs. 31.7% overall. CONCLUSION: Xpert improved time to diagnosis and treatment initiation, but there was no difference in all-cause mortality. High sensitivity of Determine TB-LAM Ag at lower CD4 count supports increased use in settings providing care to PLHIV, particularly with advanced HIV disease.

Electronic tuberculosis surveillance systems: a tool for managing today's TB programs.

The World Health Organization (WHO) released the Stop TB Strategy in 2006, along with a revised version of the tuberculosis (TB) recording and reporting forms and register. These publications illustrate the need for an enhanced TB surveillance system that will include such key elements as rapid assessment of the quality of DOTS services; integration and response to the human immunodeficiency virus/acquired immune-deficiency syndrome (HIV/AIDS) epidemic; TB control challenges, such as increased smear-negative and extra-pulmonary TB and multidrug-resistant TB (MDR-TB); increased engagement of all care providers, such as private health care services and the community; and promotion of research to support program improvement. Electronic surveillance systems utilize computer technology to facilitate the capture, transfer and reporting of the WHO-recommended TB data elements. Electronic surveillance offers several potential advantages over the traditional paper-based systems used in many low-resource settings, such as improved data quality and completeness, more feasible links to other health care programs, quality-enhanced data entry and analysis features and increased data security. These advantages must, however, be weighed against the requirements and costs of electronic surveillance, including implementation and support of a quality paper-based surveillance system and the additional costs associated with infrastructure, training and human resources for the implementation and continuing support of an electronic system. Using examples from three different electronic TB surveillance systems that are being implemented in various resource-limited settings, this article demonstrates the feasibility, requirements and value of such systems to support the WHO-recommended enhancement of TB surveillance.

Use of a computerized tuberculosis register for automated generation of case finding, sputum conversion, and treatment outcome reports.

SETTING: Tuberculosis (TB) rates in southern Africa have increased dramatically in recent years. Provision of accurate data for surveillance, program management, and supervision is increasingly essential. OBJECTIVE: To develop software that would provide more efficient collection, compilation, and analysis of TB data on an ongoing basis. DESIGN: The 'Electronic TB Register' is a user-friendly, Epi-Info based software program based on the WHO/IUATLD format of recording and reporting. Individual records from the TB registry are entered in a program that provides interactive support. The software provides several patient management and supervision functions, such as lists of defaulters. Finally, it generates standard quarterly and annual reports on case-finding, sputum conversion, and cohort analysis, and provides graphs of trends and maps of TB indicators. RESULTS: The 'Electronic TB Register' software has been successfully implemented in five pilot projects in southern Africa. User acceptance has been high and quality of data has improved, although timeliness remains unchanged. Factors critical for success include a functioning, paper-based system, involvement of staff from the TB program, health information systems, and health facilities, ongoing training, and backup support. CONCLUSIONS: The 'Electronic TB Register' is a potentially powerful tool for surveillance, management, and supervision for countries with well-functioning paper-based recording and reporting systems.

Transmission of Mycobacterium tuberculosis through casual contact with an infectious case.

BACKGROUND: An ongoing restriction fragment length polymorphism study of Mycobacterium tuberculosis isolates from tuberculosis cases showed an identical 12-band IS6110 pattern unique to 3 unrelated patients (Patients A-C) diagnosed as having tuberculosis within a 9-month period. METHODS: In an attempt to identify epidemiologic links between the 3 patients, we performed site visits to the retail business work site of patient A and conducted detailed interviews with all 3 patients and their contacts. RESULTS: Patient B had visited patient A's work site 3 times during patient A's infectious period, spending no more than 15 minutes each time. Patient C visited patient A's work site on 6 to 10 occasions during this period for no more than 45 minutes at any one time. There were no other epidemiologic links between these 3 cases other than the contact at the store. Contact investigation identified 4 tuberculin skin test conversions among 8 (50%) of patient A's coworkers, 6 positive tests among 15 household contacts (40%), and 8 positive tests among 16 identified customers who were casual contacts (50%). Patient B and patient C were most likely infected by patient A during one of their brief visits to patient A's work site. CONCLUSIONS: These data demonstrate that some tuberculosis is spread through casual contact not normally pursued in traditional contact investigations and that, in certain situations, M tuberculosis can be transmitted despite minimal duration of exposure. In addition, this outbreak emphasizes the importance of DNA fingerprinting data for identifying unusual transmission in unexpected settings.

Relapse rates after short-course (6-month) treatment of tuberculosis in HIV-infected and uninfected persons.

OBJECTIVE: To determine the rate of tuberculosis relapse among HIV-seropositive and -seronegative persons treated for active tuberculosis with short-course (6-month) therapy. DESIGN: Consecutive cohort study. SETTING: City of Baltimore tuberculosis clinic. PATIENTS: Tuberculosis patients treated between 1 January 1993 and 31 December 1996. INTERVENTION: Patients received 2 months of isoniazid, rifampin, pyrazinamide and ethambutol followed by 4 months of isoniazid and rifampin. MAIN OUTCOME MEASURE: Passive follow-up for tuberculosis relapse was performed through September 30, 1998. RESULTS: There were 423 cases of tuberculosis during the study period; 280 patients completed a 6-month course of therapy. Therapy was directly-observed for 94% of patients. Of those who completed therapy, 47 (17%) were HIV-seropositive, 127 (45%) were HIV-seronegative, and 106 (38%) had unknown HIV status. HIV-infected patients required more time to complete therapy (median 225 versus 205 days; P = 0.04) but converted sputum culture to negative within the same time period (median 77 versus 72 days; P = 0.43) as HIV-seronegative or unknown patients. Relapse occurred in three out of 47 (6.4%) HIV-infected patients compared to seven out of 127 (5.5%) HIV-seronegative patients (P = 1.0). Relapse rates also did not differ when HIV-seropositive patients were compared with HIV-seronegative and patients with unknown HIV status (6.4% versus 3.0%; P = 0.38). Of the 10 patients with tuberculosis relapse, restriction fragment length polymorphism data were available for five; all five relapse isolates matched the initial isolate. CONCLUSIONS: These results support current recommendations to treat tuberculosis in HIV-infected patients with short-course (6-month) therapy.