Tuberculosis in China: A longitudinal predictive model of the general population and recommendations for achieving WHO goals

Global analysis of an age-structured tuberculosis model with an application to Jiangsu, China

Diagnostic delay for TB infected individuals and the lack of TB vaccines for adults are the main challenges to achieve the goals of WHO by 2050. In order to evaluate the impacts of diagnostic delay and vaccination for adults on prevalence of TB, we propose an age-structured model with latent age and infection age, and we incorporate Mycobacterium TB in the environment and vaccination into the model. Diagnostic delay is indicated by the age of infection before receiving treatment. The threshold dynamics are established in terms of the basic reproduction number R 0 . WhenR 0 < 1 , the disease-free equilibrium is globally asymptotically stable, which means that TB epidemic will die out; WhenR 0 = 1 , the disease-free equilibrium is globally attractive; there exists a unique endemic equilibrium and the endemic equilibrium is globally attractive whenR 0 > 1 . We estimate that the basic reproduction numberR 0 = 0.5320 (95% CI (0.3060, 0.7556)) in Jiangsu Province, which means that TB epidemic will die out. However, we find that the annual number of new TB cases by 2050 is 1,151 (95%CI: (138, 8,014)), which means that it is challenging to achieve the goal of WHO by 2050. To this end, we evaluate the possibility of achieving the goals of WHO if we start vaccinating adults and reduce diagnostic delay in 2025. Our results demonstrate that when the diagnostic delay is reduced from longer than four months to four months, or 20% adults are vaccinated, the goal of WHO in 2050 can be achieved, and 73,137 (95%CI: (23,906, 234,086)) and 54,828 (95%CI: (15,811, 206,468)) individuals will be prevented from being infected from 2025 to 2050, respectively. The modeling approaches and simulation results used in this work can help policymakers design control measures to reduce the prevalence of TB.

Breakthrough of chemiluminescence-based LAM urine test beyond HIV-positive individuals: Clinical diagnostic value of pulmonary tuberculosis in the general population

To investigate the diagnostic value of a novel high-sensitivity urine lipoarabinomannan (LAM) test (chemiluminescence-based) for active tuberculosis in the general population. A retrospective study was conducted on 250 clinical suspected tuberculosis patients who were HIV-negative and visited the Fourth People's Hospital of Foshan from January 2022 to December 2022. Among them, there were 135 cases of pulmonary tuberculosis, 34 cases of extrapulmonary tuberculosis, and 81 cases of non-tuberculosis. Urine samples were collected for LAM antigen detection before treatment, and laboratory data of sputum smear acid-fast staining (smear method), sputum culture, and GeneXpert method were collected. Using clinical diagnosis as the reference standard, the diagnostic efficacy of 4 methods for detecting active tuberculosis was evaluated. For the 135 cases of pulmonary tuberculosis, the sensitivity of sputum smears, sputm culture, sputm GeneXpert method, and urine LAM were 29.6% (40/135), 45.9% (62/135), 59.3% (80/135), and 51.9% (70/135), respectively. The combination of LAM + GeneXpert and LAM + culture had the highest sensitivity for detecting active pulmonary tuberculosis, which were 71.0% and 78.2%, respectively. For the detection of sputum culture-negative pulmonary tuberculosis, the positive rates of smear, GeneXpert, and LAM were 0.0% (0/73), 53.4% (39/73), and 52.1% (38/73), respectively. LAM + smear and LAM + Genexpert could detect 52.1% and 68.5% of sputum culture-negative patients, respectively. The high-sensitivity urine LAM test holds promise for tuberculosis diagnosis in the general population. It demonstrates high-sensitivity, enabling the detection of sputum culture-negative pulmonary tuberculosis patients. Furthermore, when combined with existing methods, it can enhance the overall detection rate.

Population-based active screening strategy contributes to the prevention and control of tuberculosis

Despite the achievements obtained worldwide in the control of tuberculosis in recent years, many countries and regions including China still face challenges such as low diagnosis rate, high missed diagnosis rate, and delayed diagnosis of the disease. The discovery strategy of tuberculosis in China has changed from "active discovery by X-ray examination" to "passive discovery by self-referral due to symptoms", and currently the approach is integrated involving self-referral due to symptoms, active screening, and physical examination. Active screening could help to identify early asymptomatic and untreated cases. With the development of molecular biology and artificial intelligence-assisted diagnosis technology, there are more options for active screening among the large-scale populations. Although the implementation cost of a population-based active screening strategy is high, it has great value in social benefits, and active screening in special populations can obtain better benefits. Active screening of tuberculosis is an important component of the disease control. It is suggested that active screening strategies should be optimized according to the specific conditions of the regions to ultimately ensure the benefit of the tuberculosis control.

Assessment of Knowledge, Attitudes, and Practices (KAP): Public Health and Economic Burden of Tuberculosis in Jarso District of West Wollega Zone, Oromia, Western Ethiopia

Tuberculosis is a communicable mycobacterial disease of humans and animals caused by members of Mycobacterium tuberculosis complex, highly impacting the public health and economy of the country in endemic areas. Retrospective and cross-sectional study was conducted between March and August 2021. For knowledge, attitude, and practices study, five villages were randomly selected using simple random sampling. To quantify the public health burden, one-year data were collected from Jarso Health Center, and unregistered patients were identified using snowball method, and the estimation was based on disability-adjusted life years. Younger age groups (18-40 years) had shown 105.8 times more odds of knowledge towards tuberculosis than the older (>60 years). Moreover, tertiary levels of education had 9395.1 times more odds of knowledge towards tuberculosis compared to illiterates. The estimated economic burden was 7,731.25US$. Of the 51 tuberculosis patients, two died from the disease, resulting in 45.03 disability-adjusted life years. Communities of the study district were heard about tuberculosis, however, unaware of the cause and sources of the infection. Therefore, further strategic and continuous community-based health education and awareness should be given for effective control and prevention of tuberculosis in the study area.

Incidence of pulmonary tuberculosis under the regular COVID-19 epidemic prevention and control in China

Background

The COVID-19 pandemic has driven public health intervention strategies, including keeping social distance, wearing masks in crowded places, and having good health habits, to prevent the transmission of the novel coronavirus (SARS-CoV-2). However, it is unknown whether the use of these intervention strategies influences morbidity in other human infectious diseases, such as tuberculosis.

Methods

In this study, three prediction models were constructed to compare variations in PTB incidences after January 2020 without or with intervention includes strict and regular interventions, when the COVID-19 outbreak began in China. The non-interventional model was developed with an autoregressive integrated moving average (ARIMA) model that was trained with the monthly incidence of PTB in China from January 2005 to December 2019. The interventional model was established using an ARIMA model with a continuing intervention function that was trained with the monthly PTB incidence in China from January 2020 to December 2020.

Results

Starting with the assumption that no COVID-19 outbreak had occurred in China, PTB incidence was predicted, and then the actual incidence was compared with the predicted incidence. A remarkable overall decline in PTB incidence from January 2020 to December 2020 was observed, which was likely due to the potential influence of intervention policies for COVID-19. If the same intervention strategy is applied for the next 2 years, the monthly PTB incidence would reduce on average by about 1.03 per 100,000 people each month compared with the incidence predicted by the non-interventional model. The annual incidence estimated 59.15 under regular intervention per 100,000 in 2021, and the value would decline to 50.65 with strict interventions.

Conclusions

Our models quantified the potential knock-on effect on PTB incidence of the intervention strategy used to control the transmission of COVID-19 in China. Combined with the feasibility of the strategies, these results suggested that continuous regular interventions would play important roles in the future prevention and control of PTB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07620-y.

Prevalence trends of latent tuberculosis infection at the global, regional, and country levels from 1990-2019

OBJECTIVES

To track the prevalence trends of latent tuberculosis infection (LTBI) at the global, regional, and national levels.

METHODS

Data on the prevalence of LTBI were extracted from the Global Burden of Disease database. The average annual percent change (AAPC) was estimated by joinpoint regression and was used to evaluate the epidemic of the disease.

RESULTS

Globally, the prevalence rate of LTBI decreased from 30.66% in 1990 to 23.67% in 2019, with an AAPC of -0.9%. The prevalence rate of LTBI varied from 5.02% (Jordan) to 48.35% (Uganda) in 1990 and from 2.51% (Jordan) to 43.75% (Vietnam) in 2019 at the country level. The prevalence decreased in all the six World Health Organization (WHO) regions and in most countries, with the AAPC ranging from -0.5% in the Western Pacific Region to -2.1% in the European Region and from -4.3% (Bhutan) to -0.1% (Malaysia, Myanmar, South Africa, Tokelau, and Vietnam), respectively. Disparities were also observed among different sex and age groups.

CONCLUSION

The prevalence of LTBI decreased slightly worldwide in the last three decades, but the decrease is slow and not sufficient to meet the targets of WHO tuberculosis elimination. Much more effort and progress should be made in order to decrease the prevalence of LTBI.

Evaluating Strategies For Tuberculosis to Achieve the Goals of WHO in China: A Seasonal Age-Structured Model Study

Although great progress has been made in the prevention and mitigation of TB in the past 20 years, China is still the third largest contributor to the global burden of new TB cases, accounting for 833,000 new cases in 2019. Improved mitigation strategies, such as vaccines, diagnostics, and treatment, are needed to meet goals of WHO. Given the huge variability in the prevalence of TB across age-groups in China, the vaccination, diagnostic techniques, and treatment for different age-groups may have different effects. Moreover, the statistics data of TB cases show significant seasonal fluctuations in China. In view of the above facts, we propose a non-autonomous differential equation model with age structure and seasonal transmission rate. We derive the basic reproduction number, [Formula: see text], and prove that the unique disease-free periodic solution, [Formula: see text] is globally asymptotically stable when [Formula: see text], while the disease is uniformly persistent and at least one positive periodic solution exists when [Formula: see text]. We estimate that the basic reproduction number [Formula: see text] ([Formula: see text]), which means that TB is uniformly persistent. Our results demonstrate that vaccinating susceptible individuals whose ages are over 65 and between 20 and 24 is much more effective in reducing the prevalence of TB, and each of the improved vaccination strategy, diagnostic strategy, and treatment strategy leads to substantial reductions in the prevalence of TB per 100,000 individuals compared with current approaches, and the combination of the three strategies is more effective. Scenario A (i.e., coverage rate [Formula: see text], diagnosis rate [Formula: see text], relapse rate [Formula: see text]) is the best and can reduce the prevalence of TB per 100,000 individuals by [Formula: see text] and [Formula: see text] in 2035 and 2050, respectively. Although the improved strategies will significantly reduce the incidence rate of TB, it is challenging to achieve the goal of WHO in 2050. Our findings can provide guidance for public health authorities in projecting effective mitigation strategies of TB.

Risk of prevalence of latent tuberculosis infection in health care workers-an idiographic meta-analysis from a Chinese perspective

Background

China is one of the countries sharing the major burden of tuberculosis (TB) in the world. Health care workers (HCWs) are subject to a high risk of occupational latent tuberculosis infection (LTBI)-an asymptomatic state of TB disease. However, the heterogenic composition of healthcare professionals in terms of nature of their work leads to the inconsistency in predicting the prevalence of LTBI amongst them. Furthermore, the global statistics do not account for the analysis conducted within the Chinese population. Our study reflects a systemic and epidemiological meta-analysis to investigate the risk of contracting LTBI by the HCWs of China.

Methods

A systematic review of the literature was performed to identify studies reporting LTBI prevalence or incidence among HCWs and a control groups in China. Risk of infection, as well as subgroup analysis was calculated by pooled effect estimates. Review Manager 5.0 was used to perform the meta-analyses.

Results

Twenty studies containing 9,654 HCWs met the inclusion criteria. The average prevalence of LTBI among HCWs was 51.5%, ranging from 27.9-88.8%. HCWs had a higher risk of prevalence of LTBI than the control groups [odds ratio (OR), 1.78, 95% confidence interval (CI), 1.46-2.16]. In the subgroup analysis, the prevalence of LTBI in HCWs with respect to the control groups was observed to be highest in Eastern China (OR, 2.05; 95% CI, 1.35-3.11). Furthermore, the pooled OR for LTBI was 1.90 and 1.65 separately from the results of the tuberculin skin test (TST) and the interferon-gamma release assay. Lastly, upon comparing the HCWs with the control groups from the community and the nosocomial source, it was observed that the pooled OR favored for the prevalence of LTBI, which was primarily community-sourced (3.12 and 1.54). HCWs had an increased risk of prevalence of LTBI than the control groups, both in general hospitals and TB specific hospitals (pooled OR 2.4 and 1.57).

Conclusions

Risk of LTBI infection among HCWs is relatively high in China, especially in the eastern region, predisposed by the cumulative exposure to Mycobacterium tuberculosis from the community and the general hospitals. Overall, our data reflects an alarming risk posed to our HCWs, and calls for immediate reforms at the policy levels, so as to implement effective screening and treatment of affected HCWs in China.

Application of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis and treatment of mediastinal lymph node tuberculous abscess: a case report and literature review

Background

This study aimed to report the experience of diagnosis and treatment of one rare case of mediastinal lymph node tuberculous abscess (MLNTA) using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

Case presentation

An 18-year-old female patient was hospitalized in the Affiliated Hospital of Xuzhou Medical University in November 2017, due to intermittent left chest pain. She was suspected of infecting tuberculosis (TB) and thus received anti-TB treatment. Since April 1, 2018, she began to exhibit symptoms of chest distress. The patient was then admitted to Shanghai Pulmonary Hospital and continued receiving systemic anti-TB treatment during the whole course. On April 11, 2018, she received EBUS-TBNA to puncture pus and inject isoniazid. Simultaneously, the pus was sent for cytopathological and bacteriological examination, both supporting the diagnosis of TB in the patient. On April 24 and May 10, she received two times of EBUS-TBNA treatment. The symptoms of chest distress were relieved, but granulomatous neoplasm occurred at the EBUS-TBNA site on the trachea wall. The patient then received local clamp removal and cryotherapy on May 29 and Jul 19, respectively. Chest computed tomography (CT) reexamination on September 28 revealed that the MLNTA lesion had been completely absorbed, and electronic bronchoscopic reexamination on September 30 demonstrated that the granulomatous neoplasm on the trachea wall was entirely invisible.

Conclusions

Using EBUS-TBNA to puncture and aspirate pus and inject drugs can be effectively used to diagnose and treat MLNTA, which provides a new, less invasive, safe and reliable method for diagnosis and treatment of MLNTA.

Rising challenge of multidrug-resistant tuberculosis in China: a predictive study using Markov modeling

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is on the rise in China. This study used a dynamic Markov model to predict the longitudinal trends of MDR-TB in China by 2050 and to assess the effects of alternative control measures.

METHODS

Eight states of tuberculosis transmission were set up in the Markov model using a hypothetical cohort of 100 000 people. The prevalence of MDR-TB and bacteriologically confirmed drug-susceptible tuberculosis (DS-TB+) were simulated and MDR-TB was stratified into whether the disease was treated with the recommended regimen or not.

RESULTS

Without any intervention changes to current conditions, the prevalence of DS-TB+ was projected to decline 67.7% by 2050, decreasing to 20 per 100 000 people, whereas that of MDR-TB was expected to triple to 58/100 000. Furthermore, 86.2% of the MDR-TB cases would be left untreated by the year of 2050. In the case where MDR-TB detection rate reaches 50% or 70% at 5% per year, the decline in prevalence of MDR-TB would be 25.9 and 36.2% respectively. In the case where treatment coverage was improved to 70% or 100% at 5% per year, MDR-TB prevalence in 2050 would decrease by 13.8 and 24.1%, respectively. If both detection rate and treatment coverage reach 70%, the prevalence of MDR-TB by 2050 would be reduced to 28/100 000 by a 51.7% reduction.

CONCLUSIONS

MDR-TB, especially untreated MDR-TB, would rise rapidly under China's current MDR-TB control strategies. Interventions designed to promote effective detection and treatment of MDR-TB are imperative in the fights against MDR-TB epidemics.

Age-targeted tuberculosis vaccination in China and implications for vaccine development: a modelling study

BACKGROUND

Tuberculosis is the leading single-pathogen cause of death worldwide, and China has the third largest number of cases worldwide. New tools, such as new vaccines, are needed to meet WHO tuberculosis goals. Tuberculosis vaccine development strategies mostly target infants or adolescents, but given China's ageing epidemic, vaccinating older people might be important. We modelled the potential impact of new tuberculosis vaccines in China targeting adolescents (15-19 years) or older adults (60-64 years) with varying vaccine characteristics to inform strategic vaccine development.

METHODS

A Mycobacterium tuberculosis transmission model was calibrated to age-stratified demographic and epidemiological data from China. Varying scenarios of vaccine implementation (age targeting [adolescents or older adults] and coverage [30% or 70%]) and characteristics (efficacy [40%, 60%, or 80%], duration of protection [10 years or 20 years], and host infection status required for efficacy [pre-infection, post-infection in latency, post-infection in latency or recovered, or pre-infection and post-infection]) were assessed. Primary outcomes were tuberculosis incidence and mortality rate reduction in 2050 in each vaccine scenario compared with the baseline (no new vaccine) scenario and cumulative number needed to vaccinate (NNV) per case or death averted, 2025-50.

FINDINGS

By 2050, results suggest that 74·5% (uncertainty interval [UI] 70·2-78·6) of incident tuberculosis cases in China would occur in people aged 65 years or older, and 75·1% (66·8-80·7) of all cases would be due to reactivation, rather than new infection. All vaccine profiles delivered to older adults had higher population-level impact (reduction of incidence and mortality rates) and lower NNV per case and per death averted than if delivered to adolescents. For an intermediate vaccine scenario of 60% efficacy, 10-year protection, and 70% coverage, the reduction of tuberculosis incidence rates with older adult vaccination was 1·9 times (UI 1·5-2·6) to 157·5 times (119·3-225·6) greater than with adolescent vaccination, and the NNV was 0·011 times (0·008-0·014) to 0·796 times (0·632-0·970) lower. Furthermore, with older adult vaccination, post-infection vaccines provided substantially greater mortality and incidence rate reductions than pre-infection vaccines.

INTERPRETATION

Adolescent-targeted tuberculosis vaccines, the focus of many development plans, would have only a small impact in ageing, reactivation-driven epidemics such as those in China. Instead, an efficacious post-infection vaccine delivered to older adults will be crucial to maximise population-level impact in this setting and would provide an important contribution towards achieving WHO goals. Older adults should be included in tuberculosis vaccine clinical development and implementation planning.

FUNDING

Aeras and UK MRC.

Optimize Transfer Learning for Lung Diseases in Bronchoscopy Using a New Concept: Sequential Fine-Tuning

Bronchoscopy inspection, as a follow-up procedure next to the radiological imaging, plays a key role in the diagnosis and treatment design for lung disease patients. When performing bronchoscopy, doctors have to make a decision immediately whether to perform a biopsy. Because biopsies may cause uncontrollable and life-threatening bleeding of the lung tissue, thus doctors need to be selective with biopsies. In this paper, to help doctors to be more selective on biopsies and provide a second opinion on diagnosis, we propose a computer-aided diagnosis (CAD) system for lung diseases, including cancers and tuberculosis (TB). Based on transfer learning (TL), we propose a novel TL method on the top of DenseNet: sequential fine-tuning (SFT). Compared with traditional fine-tuning (FT) methods, our method achieves the best performance. In a data set of recruited 81 normal cases, 76 TB cases and 277 lung cancer cases, SFT provided an overall accuracy of 82% while other traditional TL methods achieved an accuracy from 70% to 74%. The detection accuracy of SFT for cancers, TB, and normal cases are 87%, 54%, and 91%, respectively. This indicates that the CAD system has the potential to improve lung disease diagnosis accuracy in bronchoscopy and it may be used to be more selective with biopsies.