Assessing tuberculosis control priorities in high-burden settings: a modelling approach

Abstract

Background In the context of WHO's End TB strategy, there is a need to focus future control efforts on those interventions and innovations that would be most effective in accelerating declines in tuberculosis burden. Using a modelling approach to link the tuberculosis care cascade to transmission, we aimed to identify which improvements in the cascade would yield the greatest effect on incidence and mortality.Methods We engaged with national tuberculosis programmes in three country settings (India, Kenya, and Moldova) as illustrative examples of settings with a large private sector (India), a high HIV burden (Kenya), and a high burden of multidrug resistance (Moldova). We collated WHO country burden estimates, routine surveillance data, and tuberculosis prevalence surveys from 2011 (for India) and 2016 (for Kenya). Linking the tuberculosis care cascade to tuberculosis transmission using a mathematical model with Bayesian melding in each setting, we examined which cascade shortfalls would have the greatest effect on incidence and mortality, and how the cascade could be used to monitor future control efforts.Findings Modelling suggests that combined measures to strengthen the care cascade could reduce cumulative tuber culosis incidence by 38% (95% Bayesian credible intervals 27-43) in India, 31% (25-41) in Kenya, and 27% (17-41) in Moldova between 2018 and 2035. For both incidence and mortality, modelling suggests that the most important cascade losses are the proportion of patients visiting the private healthcare sector in India, missed diagnosis in health care settings in Kenya, and drug sensitivity testing in Moldova. In all settings, the most influential delay is the interval before a patient's first presentation for care. In future interventions, the proportion of individuals with tuberculosis who are on highquality treatment could offer a more robust monitoring tool than routine notifications of tuberculosis.Interpretation Linked to transmission, the care cascade can be valuable, not only for improving patient outcomes but also in identifying and monitoring programmatic priorities to reduce tuberculosis incidence and mortality.

Using hospital auxiliary worker and 24-h TB services as potential tools to overcome in-hospital TB delays: a quasi-experimental study

“…This result is in line with the evidence supporting that delays in TB diagnosis and treatment initiation are associated with the development of severe forms of TB disease [34,35] and TB mortality [7,[35][36][37]; therefore, prompt detection and proper anti-TB drug initiation are the key actions to avert morbimortality due to TB disease. In addition, promotion of task shifting and expansion of molecular diagnostic tools together with patient-centered high-quality TB services delivery are known as important tools to ensure effective TB infection prevention and control toward TB elimination [28,32,33,[38][39][40].…”

Building a tuberculosis-free world: The Lancet Commission on tuberculosis

“…Modelling analysis, commissioned for this report, provides some insight on the potential value of these and other measures in three different country settings, each with distinct challenges in tuberculosis control: India (with a large private sector), Kenya (with HIV coinfection), and Moldova (with a high burden of multidrug-resistant tuberculosis). The full analysis is provided by Vesga and colleagues 142 in a modelling study done in collaboration with this Commission. The example of Kenya is shown in figure 3: in this setting, patient pathway analysis has already identified the scarcity of diagnostic facilities as a key challenge.…”

“…Detailed methods used to model these scenarios are available in Vesga and colleagues. 142 In most LMICs, private providers are an important source of health care for people of all socioeconomic groups, often offering accessibility and convenience not provided in the public system. Strictly speaking, private is synonymous with non-state and includes the for-profit as well as the non-profit sectors (ie, NGOs and faith-based organisations [FBOs]).…”

Comparative analysis of the effectiveness of tuberculosis prophylaxis in patients with HIV/AIDS treated with isoniazid

“…From among 41 countries with a high level of infection with tuberculosis/HIV, this therapy is available in only 14 countries [15,16]. In 2017, only 3% of the total expenditures on HIV in the EECA region were allocated for programmes focused on the TB/HIV population [17].…”