Realizing the "40 by 2022" Commitment from the United Nations High-Level Meeting on the Fight to End Tuberculosis: What Will It Take to Meet Rapid Diagnostic Testing Needs?

The potential gains from full adoption of World Health Organization (WHO)-recommended rapid diagnostics (WRDs) for tuberculosis (TB) are significant, but there is no current analysis of the additional investment needed to reach this goal. We sought to estimate the necessary investment in instruments, tests, and money, using Xpert MTB/RIF (Xpert), which detects (MTB) and tests for resistance to rifampicin (RIF), as an example. An existing calculator for TB diagnostic needs was adapted to estimate the Xpert needs for a group of 24 countries with high TB burdens.

Emergence of drug resistance in patients with tuberculosis cared for by the Indian health-care system: a dynamic modelling study.

Background: India has the highest number of patients with tuberculosis and multidrug-resistant tuberculosis in the world. We used a transmission model to project the emergence of drug resistance in India due to incorrect tuberculosis management practices in multiple sectors, including public and private providers, chemists, and non-allopathic practitioners.

Methods: We constructed a dynamic Markov model to represent India's tuberculosis epidemic, including a probabilistic framework reflecting complex treatment-seeking pathways.

Rolling Out Xpert MTB/RIF for TB Detection in HIV-Infected Populations:An Opportunity for Systems Strengthening.

Background: To eliminate preventable deaths, disease and suffering due to tuberculosis (TB), improved diagnostic capacity is critical. The Cepheid Xpert MTB/RIF assay is recommended by the World Health Organization as the initial diagnostic test for people with suspected HIV-associated TB. However, despite high expectations, its scale-up in real-world settings has faced challenges, often due to the systems that support it.

Modeling the impact of tuberculosis interventions on epidemiologic outcomes and health system costs.

Background: Tuberculosis (TB) programs must invest in a variety of TB specific activities in order to reach ambitious global targets. Uncertainty exists surrounding the potential impact of each of these activities. The objective of our study was to model different interventions and quantify their impact on epidemiologic outcomes and costs from the health system perspective.

Advances in tuberculosis diagnostics: the Xpert MTB/RIF assay and future prospects for a point-of-care test.

Rapid progress has been made in the development of new diagnostic assays for tuberculosis in recent years. New technologies have been developed and assessed, and are now being implemented. The Xpert MTB/RIF assay, which enables simultaneous detection of Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance, was endorsed by WHO in December, 2010.

GeneXpert for TB diagnosis: planned and purposeful implementation.

Xpert MTB/RIF is a major advance for TB diagnostics, especially for multidrug-resistant (MDR) TB and HIV-associated TB. But implementation concerns including cost, technical support requirements, and challenging demands of providing second-line TB drugs for diagnosed MDR-TB cases call for gradual, careful introduction based on country circumstances.

Opportunities and challenges for cost-efficient implementation of new point-of-care diagnostics for HIV and tuberculosis.

Stakeholders agree that supporting high-quality diagnostics is essential if we are to continue to make strides in the fight against human immunodeficiency virus (HIV) and tuberculosis. Despite the need to strengthen existing laboratory infrastructure, which includes expanding and developing new laboratories, there are clear diagnostic needs where conventional laboratory support is insufficient. Regarding HIV, rapid point-of-care (POC) testing for initial HIV diagnosis has been successful, but several needs remain.

Missed opportunities for tuberculosis prevention in New York City, 2003.

Background: Proper management and prevention can radically decrease the incidence of tuberculosis (TB). To further decrease TB cases in New York City, every opportunity for prevention must be utilized. This study sought to identify patients whose disease could have been prevented and describe missed opportunities for TB prevention.

Trends in drug-resistant Mycobacterium tuberculosis in New York City, 1991-2003.

Background: Two drug-resistance surveys showed a very high prevalence of drug resistance among isolates obtained from patients with tuberculosis in 1991 and 1994 in New York, New York.

Methods: A cross-sectional survey in April 1997 and a survey of incident cases in April-June 2003 were conducted. The trend in the proportion of drug resistance in the 4 surveys was examined separately for prevalent and incident cases.

Universal genotyping in tuberculosis control program, New York City, 2001-2003.

In 2001, New York City implemented genotyping to its tuberculosis (TB) control activities by using IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping to type isolates from culture-positive TB patients. Results are used to identify previously unknown links among genotypically clustered patients, unidentified sites of transmission, and potential false-positive cultures. From 2001 to 2003, spoligotype and IS6110-based RFLP results were obtained for 90.