Prevalence of pulmonary tuberculosis in Tibet Autonomous Region, China, 2014

Spatial and temporal analysis and forecasting of TB reported incidence in western China

OBJECTIVE

Tuberculosis (TB) remains an important public health concern in western China. This study aimed to explore and analyze the spatial and temporal distribution characteristics of TB reported incidence in 12 provinces and municipalities in western China and to construct the optimal models for prediction, which would provide a reference for the prevention and control of TB and the optimization of related health policies.

METHODS

We collected monthly data on TB reported incidence in 12 provinces and municipalities in western China and used ArcGIS software to analyze the spatial and temporal distribution characteristics of TB reported incidence. We applied the seasonal index method for the seasonal analysis of TB reported incidence and then established the SARIMA and Holt-Winters models for TB reported incidence in 12 provinces and municipalities in western China.

RESULTS

The reported incidence of TB in 12 provinces and municipalities in western China showed apparent spatial clustering characteristics, and Moran's I was greater than 0 (p < 0.05) over 8 years during the reporting period. Among them, Tibet was the hotspot for TB incidence in 12 provinces and municipalities in western China. The reported incidence of TB in 12 provinces and municipalities in western China from 2004 to 2018 showed clear seasonal characteristics, with seasonal indices greater than 100% in both the first and second quarters. The optimal models constructed for TB reported incidence in 12 provinces and municipalities in western China all passed white noise test (p > 0.05).

CONCLUSIONS

As a hotspot of reported TB incidence, Tibet should continue to strengthen government leadership and policy support, explore TB intervention strategies and causes. The optimal prediction models we developed for reported TB incidence in 12 provinces and municipalities in western China were different.

Exploring opportunities to strengthen rural tuberculosis health service delivery: a qualitative study with health workers in Tibet autonomous region, China

OBJECTIVES

This qualitative study aimed to explore opportunities to strengthen tuberculosis (TB) health service delivery from the perspectives of health workers providing TB care in Shigatse prefecture of Tibet Autonomous Region, China.

DESIGN

Qualitative research, semi-structured in-depth interviews.

SETTING

The TB care ecosystem in Shigatse, including primary and community care.

PARTICIPANTS

Participants: 37 semi-structured interviews were conducted with village doctors (14), township doctors and nurses (14), county hospital doctors (7) and Shigatse Centre for Disease Control staff (2).

RESULTS

The three main themes reported include (1) the importance of training primary and community health workers to identify people with symptoms of TB, ensure TB is diagnosed and link people with TB to further care; (2) the need to engage community health workers to ensure retention in care and adherence to TB medications; and (3) the opportunity for innovative technologies to support coordinated care, retention in care and adherence to medication in Shigatse.

CONCLUSIONS

The quality of TB care could be improved across the care cascade in Tibet and other high-burden, remote settings by strengthening primary care through ongoing training, greater support and inclusion of community health workers and by leveraging technology to create a circle of care. Future formative and implementation research should include the perspectives of health workers at all levels to improve care organisation and delivery.

The Evolution and Transmission Dynamics of Multidrug-Resistant Tuberculosis in an Isolated High-Plateau Population of Tibet, China

On the Tibetan Plateau, most tuberculosis is caused by indigenous Mycobacterium tuberculosis strains with a monophyletic structure and high-level drug resistance. This study investigated the emergence, evolution, and transmission dynamics of multidrug-resistant tuberculosis (MDR-TB) in Tibet. The whole-genome sequences of 576 clinical strains from Tibet were analyzed with the TB-profiler tool to identify drug-resistance mutations. The evolution of the drug resistance was then inferred based on maximum-likelihood phylogeny and dated trees that traced the serial acquisition of mutations conferring resistance to different drugs. Among the 576 clinical M. tuberculosis strains, 346 (60.1%) carried at least 1 resistance-conferring mutation and 231 (40.1%) were MDR-TB. Using a pairwise distance of 50 single nucleotide polymorphisms (SNPs), most strains (89.9%, 518/576) were phylogenetically separated into 50 long-term transmission clusters. Eleven large drug-resistant clusters contained 76.1% (176/231) of the local multidrug-resistant strains. A total of 85.2% of the isoniazid-resistant strains were highly transmitted with an average of 6.6 cases per cluster, of which most shared the mutation KatG Ser315Thr. A lower proportion (71.6%) of multidrug-resistant strains were transmitted, with an average cluster size of 2.9 cases. The isoniazid-resistant clusters appear to have undergone substantial bacterial population growth in the 1970s to 1990s and then subsequently accumulated multiple rifampicin-resistance mutations and caused the current local MDR-TB burden. These findings highlight the importance of detecting and curing isoniazid-resistant strains to prevent the emergence of endemic MDR-TB. IMPORTANCE Emerging isoniazid resistance in the 1970s allowed M. tuberculosis strains to spread and form into large multidrug-resistant tuberculosis clusters in the isolated plateau of Tibet, China. The epidemic was driven by the high risk of transmission as well as the potential of acquiring further drug resistance from isoniazid-resistant strains. Eleven large drug-resistant clusters consisted of the majority of local multidrug-resistant cases. Among the clusters, isoniazid resistance overwhelmingly evolved before all the other resistance types. A large bacterial population growth of isoniazid-resistant clusters occurred between 1970s and 1990s, which subsequently accumulated rifampicin-resistance-conferring mutations in parallel and accounted for the local multidrug-resistant tuberculosis burden. The results of our study indicate that it may be possible to restrict MDR-TB evolution and dissemination by prioritizing screening for isoniazid (INH)-resistant TB strains before they become MDR-TB and by adopting measures that can limit their transmission.

A retrospective analysis of 25 cases of Addison's disease caused by adrenal tuberculosis in Tibet and review of related literature

Background

To investigate the clinical characteristics of Addison's disease caused by adrenal tuberculosis in Tibet. After the anti-tuberculosis treatment, the clinical features between continuous glucocorticoid therapy and glucocorticoid withdrawal were analyzed.

Methods

Clinical data of patients with Addison's disease caused by adrenal tuberculosis diagnosed in The People's Hospital of Tibet Autonomous Region from January 2015 to October 2021 were collected and analyzed. All patients were taking anti-tuberculosis and glucocorticoids replacement therapy, and the root cause of the disease was analyzed following prognosis observations.

Results

There were 25 patients (24 Tibetan and 1 Han patient) with Addison's disease caused by adrenal tuberculosis, including 18 males and 7 females. A total of 21 cases were followed up successfully, of which 13 cases discontinued anti-tuberculosis drugs successfully, 6 cases discontinued glucocorticoid therapy among the rest, 6 cases continued anti-tuberculosis + glucocorticoid replacement therapy, and 2 cases died.

Conclusion

Early diagnosis and proper anti-tuberculosis treatment can improve the prognosis of patients with adrenal tuberculosis. Moreover, screening and educating Tibetan people regarding the potential risk and adversities of adrenal tuberculosis is crucial for eradicating the disease.

Symptom- and chest-radiography screening for active pulmonary tuberculosis in HIV-negative adults and adults with unknown HIV status

BACKGROUND

Systematic screening in high-burden settings is recommended as a strategy for early detection of pulmonary tuberculosis disease, reducing mortality, morbidity and transmission, and improving equity in access to care. Questioning for symptoms and chest radiography (CXR) have historically been the most widely available tools to screen for tuberculosis disease. Their accuracy is important for the design of tuberculosis screening programmes and determines, in combination with the accuracy of confirmatory diagnostic tests, the yield of a screening programme and the burden on individuals and the health service.

OBJECTIVES

To assess the sensitivity and specificity of questioning for the presence of one or more tuberculosis symptoms or symptom combinations, CXR, and combinations of these as screening tools for detecting bacteriologically confirmed pulmonary tuberculosis disease in HIV-negative adults and adults with unknown HIV status who are considered eligible for systematic screening for tuberculosis disease. Second, to investigate sources of heterogeneity, especially in relation to regional, epidemiological, and demographic characteristics of the study populations.

SEARCH METHODS

We searched the MEDLINE, Embase, LILACS, and HTA (Health Technology Assessment) databases using pre-specified search terms and consulted experts for unpublished reports, for the period 1992 to 2018. The search date was 10 December 2018. This search was repeated on 2 July 2021.

SELECTION CRITERIA

Studies were eligible if participants were screened for tuberculosis disease using symptom questions, or abnormalities on CXR, or both, and were offered confirmatory testing with a reference standard. We included studies if diagnostic two-by-two tables could be generated for one or more index tests, even if not all participants were subjected to a microbacteriological reference standard. We excluded studies evaluating self-reporting of symptoms.

DATA COLLECTION AND ANALYSIS

We categorized symptom and CXR index tests according to commonly used definitions. We assessed the methodological quality of included studies using the QUADAS-2 instrument. We examined the forest plots and receiver operating characteristic plots visually for heterogeneity. We estimated summary sensitivities and specificities (and 95% confidence intervals (CI)) for each index test using bivariate random-effects methods. We analyzed potential sources of heterogeneity in a hierarchical mixed-model.

MAIN RESULTS

The electronic database search identified 9473 titles and abstracts. Through expert consultation, we identified 31 reports on national tuberculosis prevalence surveys as eligible (of which eight were already captured in the search of the electronic databases), and we identified 957 potentially relevant articles through reference checking. After removal of duplicates, we assessed 10,415 titles and abstracts, of which we identified 430 (4%) for full text review, whereafter we excluded 364 articles. In total, 66 articles provided data on 59 studies. We assessed the 2 July 2021 search results; seven studies were potentially eligible but would make no material difference to the review findings or grading of the evidence, and were not added in this edition of the review. We judged most studies at high risk of bias in one or more domains, most commonly because of incorporation bias and verification bias. We judged applicability concerns low in more than 80% of studies in all three domains. The three most common symptom index tests, cough for two or more weeks (41 studies), any cough (21 studies), and any tuberculosis symptom (29 studies), showed a summary sensitivity of 42.1% (95% CI 36.6% to 47.7%), 51.3% (95% CI 42.8% to 59.7%), and 70.6% (95% CI 61.7% to 78.2%, all very low-certainty evidence), and a specificity of 94.4% (95% CI 92.6% to 95.8%, high-certainty evidence), 87.6% (95% CI 81.6% to 91.8%, low-certainty evidence), and 65.1% (95% CI 53.3% to 75.4%, low-certainty evidence), respectively. The data on symptom index tests were more heterogenous than those for CXR. The studies on any tuberculosis symptom were the most heterogeneous, but had the lowest number of variables explaining this variation. Symptom index tests also showed regional variation. The summary sensitivity of any CXR abnormality (23 studies) was 94.7% (95% CI 92.2% to 96.4%, very low-certainty evidence) and 84.8% (95% CI 76.7% to 90.4%, low-certainty evidence) for CXR abnormalities suggestive of tuberculosis (19 studies), and specificity was 89.1% (95% CI 85.6% to 91.8%, low-certainty evidence) and 95.6% (95% CI 92.6% to 97.4%, high-certainty evidence), respectively. Sensitivity was more heterogenous than specificity, and could be explained by regional variation. The addition of cough for two or more weeks, whether to any (pulmonary) CXR abnormality or to CXR abnormalities suggestive of tuberculosis, resulted in a summary sensitivity and specificity of 99.2% (95% CI 96.8% to 99.8%) and 84.9% (95% CI 81.2% to 88.1%) (15 studies; certainty of evidence not assessed).

AUTHORS' CONCLUSIONS

The summary estimates of the symptom and CXR index tests may inform the choice of screening and diagnostic algorithms in any given setting or country where screening for tuberculosis is being implemented. The high sensitivity of CXR index tests, with or without symptom questions in parallel, suggests a high yield of persons with tuberculosis disease. However, additional considerations will determine the design of screening and diagnostic algorithms, such as the availability and accessibility of CXR facilities or the resources to fund them, and the need for more or fewer diagnostic tests to confirm the diagnosis (depending on screening test specificity), which also has resource implications. These review findings should be interpreted with caution due to methodological limitations in the included studies and regional variation in sensitivity and specificity. The sensitivity and specificity of an index test in a specific setting cannot be predicted with great precision due to heterogeneity. This should be borne in mind when planning for and implementing tuberculosis screening programmes.

The unbalanced risk of pulmonary tuberculosis in China at subnational scale: A spatio-temporal analysis (Preprint)

Background

China has one of the highest tuberculosis (TB) burdens in the world. However, the unbalanced spatial and temporal trends of TB risk at a fine level remain unclear.

Objective

We aimed to investigate the unbalanced risks of pulmonary tuberculosis (PTB) at different levels and how they evolved from both temporal and spatial aspects using PTB notification data from 2851 counties over a decade in China.

Methods

County-level notified PTB case data were collected from 2009 to 2018 in mainland China. A Bayesian hierarchical model was constructed to analyze the unbalanced spatiotemporal patterns of PTB notification rates during this period at subnational scales. The Gini coefficient was calculated to assess the inequality of the relative risk (RR) of PTB across counties.

Results

From 2009 to 2018, the number of notified PTB cases in mainland China decreased from 946,086 to 747,700. The average number of PTB cases in counties was 301 (SD 26) and the overall average notification rate was 60 (SD 6) per 100,000 people. There were obvious regional differences in the RRs for PTB (Gini coefficient 0.32, 95% CI 0.31-0.33). Xinjiang had the highest PTB notification rate, with a multiyear average of 155/100,000 (RR 2.3, 95% CI 1.6-2.8; P<.001), followed by Guizhou (117/100,000; RR 1.8, 95% CI 1.3-1.9; P<.001) and Tibet (108/100,000; RR 1.7, 95% CI 1.3-2.1; P<.001). The RR for PTB showed a steady downward trend. Gansu (local trend [LT] 0.95, 95% CI 0.93-0.96; P<.001) and Shanxi (LT 0.94, 95% CI 0.92-0.96; P<.001) experienced the fastest declines. However, the RRs for PTB in the western region (such as counties in Xinjiang, Guizhou, and Tibet) were significantly higher than those in the eastern and central regions (P<.001), and the decline rate of the RR for PTB was lower than the overall level (P<.001).

Conclusions

PTB risk showed significant regional inequality among counties in China, and western China presented a high plateau of disease burden. Improvements in economic and medical service levels are required to boost PTB case detection and eventually reduce PTB risk in the whole country.

A qualitative study of perspectives on access to tuberculosis health services in Xigaze, China

Background

Tuberculosis (TB) is a major global health threat and the leading infectious disease cause of death worldwide. Access to and retention in TB care remains a challenge for patients, particularly those living in rural and remote settings. This qualitative study explored barriers and facilitators to accessing and maintaining contact with TB care services in communities in Xigaze (Shigatse) prefecture, Xizang Autonomous Region (Tibet Autonomous Region), China from the perspective of persons impacted by TB.

Methods

We conduced in-depth interviews with 23 participants impacted by TB in four rural districts in Xigaze prefecture, Xizang Autonomous Region, China between April 2019 and November 2020. Interviews were conducted in Tibetan and Mandarin, transcribed in Mandarin and translated into English. Transcripts were checked against recordings by native Tibetan and Mandarin speakers. QSR NVivo12 software was used for framework analysis guided by an access to care conceptual framework by Levesque et al.

Results

Overall patients reported low awareness of and an indifferent attitude towards TB, although all reported understanding the need to adhere to treatment. Participants reported complex pathways to care, often requiring visits to multiple healthcare facilities. Some participants reported visiting traditional Tibetan medicine (TTM) providers. Participants reported various barriers to accessing care including challenges physically reaching care, out-of-pocket payments for tests, diagnostics and transport. Barriers to maintaining care included medication side effects and worry about treatment effectiveness. Enablers to accessing care identified included knowledge or past experience with TB, integrated models of TTM and western care, supportive village doctors who conducted home visits, free TB treatment and other subsidies, as well as having family support with care and social support as barriers and facilitators to maintaining treatment.

Conclusions

We identified barriers and facilitators to accessing services in rural communities in Xigaze from the perspective of persons impacted by TB. Challenges include complex pathways to care, travel distances, wait times and low awareness. Tuberculosis care in the region could be strengthened by ongoing culturally tailored educational campaigns to increase awareness, partnerships with TTM providers, providing comprehensive treatment subsidies and strengthening the role of family members in comprehensive TB care.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-021-00906-4.

Factors Influencing Medication Nonadherence to Pulmonary Tuberculosis Treatment in Tibet, China: A Qualitative Study from the Patient Perspective

PURPOSE

Medication nonadherence is one of the most significant obstacles to tuberculosis (TB) control worldwide. Identification of the factors associated with medication nonadherence is important. However, few related studies have been carried out in Tibet. This study aimed to explore factors influencing medication nonadherence to pulmonary TB (PTB) treatment in Tibet, China, from the patient perspective.

PATIENTS AND METHODS

In this qualitative study, seventeen PTB patients in Tibet were recruited by purposive and maximum variation sampling methods. In-depth semistructured interviews were conducted to collect data on factors influencing medication nonadherence, and Colaizzi's seven-step method was used to analyze the data.

RESULTS

The medication nonadherence of PTB patients in Tibet was influenced by one or a combination of the following four factors. First, patient-related factors included a lack of knowledge of PTB treatment, poor self-management capability, poor self-regulation capability and misperception of health condition. Second, a medication-related factor was medication side effects. Third, health service-related factors included the poor treatment skills of doctors in primary hospitals and a lack of directly observed treatment (DOT). Last, sociocultural factors included the effect of traditional Tibetan medicine, lack of family member support and discrimination.

CONCLUSION

Multiple interplaying factors influenced medication nonadherence during PTB treatment in Tibet, and the main influencing factors were a lack of knowledge about PTB treatment, poor self-management capability, and the effect of traditional Tibetan medicine. TB health workers in Tibet should provide permanently viewable PTB treatment knowledge materials to PTB patients when oral health education is conducted, find feasible alternative strategies to DOT and establish links to traditional Tibetan medicine hospitals.

Protocol for a randomised controlled trial to evaluate the effectiveness of improving tuberculosis patients' treatment adherence via electronic monitors and an app versus usual care in Tibet

BACKGROUND

Treatment non-adherence is a serious challenge to effective tuberculosis (TB) control in Tibet. In this study we will pilot and evaluate the effectiveness of using new electronic monitors (e-monitors) and a smartphone app to improve treatment adherence among new pulmonary TB patients in Tibet.

METHODS

We will use a multicentre, parallel-group, individually randomised controlled, superiority trial with blinded outcome evaluation and unblinded treatment. We will randomise new pulmonary TB outpatients (aged ≥ 15 years old and free from communication impairment) from Shigatse, Tibet to either the intervention or control arm in a 1:1 ratio at the time of their diagnosis. All patients will be treated according to the World Health Organisation standard 6-month TB treatment regimen and the China National TB programme guidelines. Intervention arm patients will be given their medication via e-monitors that have automatic voice reminders, and record medication adherence data and share it with health staff via Cloud connection. Intervention patients will also be encouraged to receive smartphone-based video-observed treatment if their adherence is problematic. Control arm patients will receive their medication in e-monitors that will collect medication adherence history, but will have their reminder function deactivated and are not linked to the app. The primary outcome is the rate of poor adherence, measured monthly during treatment as a binary indicator where poor adherence means missing ≥ 20% of doses in a month. We will conduct a qualitative process evaluation to explore operational questions regarding acceptability, cultural appropriateness and burden of technology use, as well as a cost-effectiveness analysis and an analysis of the long-term effects of the intervention on TB control.

DISCUSSION

Our study is one of the first trials to evaluate the use of e-monitors and smartphone apps for customised treatment support in low- and middle-income countries (LMICs). All intervention activities are designed to be embedded into routine TB care with strong local ownership. Through the trial we intend to understand the feasibility of our intervention, its effectiveness, its cost-effectiveness and its long-term impacts to inform future scale-up in remote areas of China and other LMICs.

TRIAL REGISTRATION

Current Controlled Trials, ID: ISRCTN52132803 . Registered on 9 November 2018.