Forecasting the impact of population ageing on tuberculosis incidence

High all-cause mortality and increasing proportion of older adults with tuberculosis in Texas, 2008-2020

Pulmonary tuberculosis (PTB) elimination efforts must consider the global growth of the ageing population. Here we used TB surveillance data from Texas, United States (2008-2020; total n = 10656) to identify unique characteristics and outcomes in older adults (OA, ≥65 years) with PTB, compared to young adults (YA, 18-39 years) or middle-aged adults (40-64 years). We found that the proportion of OA with PTB increased from 15% in 2008 to 24% in 2020 (trend p < 0.05). Diabetes was highly prevalent in OA (32%) but not associated with adverse outcomes. Death was 13-fold higher in OA compared to YA and was 7% at the time of diagnosis which suggests diagnostic delays. However, once TB was suspected, we found no differences in culture, smear, or nucleic acid detection of mycobacteria (although less lung cavitations) in OA. During treatment, OA had less drug-resistant TB, few adverse reactions and adhered with TB treatment. We recommend training healthcare workers to 'think TB' in OA, for prompt treatment initiation to diminish deaths. Furthermore, OA should be added as a priority group to the latent TB treatment guidelines by the World Health Organization, to prevent TB disease in this highly vulnerable group.

Tuberculosis presentation and outcomes in older Hispanic adults from Tamaulipas, Mexico

Older people are at high risk of developing and dying from pulmonary infections like tuberculosis (TB), but there are few studies among them, particularly in Hispanics. To address these gaps, we sought to identify host factors associated with TB and adverse treatment outcomes in older Hispanics by conducting a cross-sectional study of TB surveillance data from Tamaulipas, Mexico (2006-2013; n = 8381). Multivariable logistic regressions were assessed for older adults (OA ≥65 years) when compared to young (YA, 18-39 years) and middle-aged adults (40-64 years). We found that the OA had features associated with a less complicated TB (e.g., lower prevalence of extra-pulmonary TB and less likely to abandon treatment or have drug resistant TB), and yet, were more likely to die during TB treatment (adj-OR 3.9, 95% 2.5, 5.25). Among the OA, excess alcohol use and low body mass index increased their odds of death during TB treatment, while a higher number of reported contacts (social support) was protective. Diabetes was not associated with adverse outcomes in OA. Although older age is a predictor of death during TB disease, OA are not prioritized by the World Health Organization for latent TB infection screening and treatment during contact investigations. With safer, short-course latent TB infection treatment available, we propose the inclusion of OA as a high-risk group in latent TB management guidelines.

Disease Transmission by Patients With Subclinical Tuberculosis

BACKGROUND

Subclinical tuberculosis has been increasingly recognized as a separate state in the spectrum of the disease. However, evidence on the transmissibility of subclinical tuberculosis is still inconclusive.

METHODS

We re-analyzed the data from the 2007 combined tuberculosis prevalence and tuberculin surveys in Vietnam. Poisson regression with robust standard errors was conducted to assess the effect of clinical presentation of individuals with tuberculosis in the household on tuberculin skin test (TST) positivity among children aged 6-14 years who participated in the tuberculin survey, adjusting for child's age, smear status of the index patient, and other covariates.

RESULTS

In the multivariate analysis, we found significantly increased risks for TST positivity in children living with patients with clinical, smear-positive tuberculosis, compared with those living with individuals without tuberculosis (adjusted risk ratio [aRR]: 3.04; 95% confidence interval [CI]: 2.00-4.63) and with those living with patients with subclinical tuberculosis, adjusting for index smear status (aRR: 2.26; 95% CI: 1.03-4.96). Among children aged 6-10 years, those living with patients with clinical, smear-positive tuberculosis and those living with patients with subclinical, smear-positive tuberculosis had similarly increased risks of TST positivity compared with those living with individuals without tuberculosis (aRRs [95% CI] of 3.56 [1.91-6.62] and 3.11 [1.44-6.72], respectively).

CONCLUSIONS

Our findings support the hypothesis that smear-positive subclinical tuberculosis contributes to Mycobacterium tuberculosis transmission. To eliminate tuberculosis in 2035, control strategies need to address subclinical presentations of the disease.

Prevalence of latent tuberculosis infection among participants of the national LTBI screening program in South Korea - A problem of low coverage rate with current LTBI strategy

Background

The Government of South Korea launched a national preemptive latent tuberculosis infection (LTBI) screening program in 2016, including more than 1. 6 million population in congregate settings. The objective of this study was to analyze LTBI prevalence and its risk factors in each setting. Additionally, the proportion of LTBI pool covered by the current national LTBI strategy was investigated.

Methods

Database for results of interferon gamma release assay (IGRA), X-ray, and baseline demographic information was linked with National Health Information Database, national tuberculosis (TB) surveillance database, and national contact investigation database. Participants were categorized into three groups: Group A, workers of postpartum care centers, social welfare facilities and educational institutions; Group B, first year students in high school and out-of-school youths; and Group C, inmates of correctional facilities. Relative risks of LTBI by sex, age, place of living, income level, and comorbidities were calculated.

Results

A total of 444,394 participants in Group A, 272,224 participants in Group B, and 11,511 participants in Group C who participated in the national LTBI screening program between 2017 and 2018 were included, with LTBI prevalence of 20.7, 2.0, and 33.2%, respectively. Age was the single most important risk factor in Group A and Group C. Low-income level was another risk factor commonly identified in all groups. Among participants with positive IGRA results, 2.7, 4.4, and 3.3% in Groups A, B and C, respectively, had past TB exposure history since 2013. Current LTBI guideline targeting high or moderate TB risk disease covered 6.5, 0.6, and 1.1% of participants with positive IGRA results in Groups A, B and C, respectively.

Conclusion

Only a small proportion of participants with positive IGRA results could be covered by the current LTBI strategy. Expansion of LTBI strategy by identifying further high-TB risk group in the general population is required.

Tuberculosis epidemiological trend in Sousse, Tunisia during twenty years (2000-2019)

Describe the epidemiology of tuberculosis in the last two decades (2000-2019) in the East region of Tunisia (city of Sousse). This was a descriptive retrospective analysis of notified incident cases of tuberculosis from 2000 to 2019 in Sousse Governorate, Tunisia. The data collection was done via the regional registry of tuberculosis. Stata software was used to characterize the socio-demographic and clinical profile of tuberculosis, to calculate its incidence, mortality and fatality rates and to determine predictive factors of mortality. R software was used to analyze the chronological trend of tuberculosis incidence and mortality. A total of 2606 incident cases of tuberculosis were declared from 2000 to 2019 in Sousse. The mean age was 39 ± 19 years with a sex ratio (male/female) of 1.19. Only one case was HIV positive among the total 2606 incident cases. Extra-pulmonary tuberculosis was the most recorded (1,534 cases, 58.9%). The mean annual case notification and deaths were 130 and four respectively. After adjusting for confounders, individuals with pulmonary tuberculosis were 1.9 significantly more likely to die from tuberculosis compared to those suffering from extra-pulmonary tuberculosis. There was a trend of increasing mortality with increasing age. The association was statistically significant only for those above 60 years' old who had 12.5 times higher odds of dying compared to those below 60 years. After adjusting for age and gender, with every year there was an increase in the total incidence rate (+0.35 per 100,000) with p = 0.005 and in the extra-pulmonary incidence (+0.27 per 100,000), with p = 0.001. This study demonstrated the increasing trend of tuberculosis in Sousse, Tunisia from 2000 to 2019. The national program against tuberculosis should enhance community knowledge and centralize the national and regional epidemiological information for better epidemiological surveillance.

The Prevalence of Mycobacterium tuberculosis Infection Among Cancer Patients Receiving Chemotherapy in a Tertiary Care Center

OBJECTIVE

To estimate the prevalence of tuberculosis (TB) infection among patients receiving cancer chemotherapy and to identify risk factors for latent TB reactivation.

METHODS

A cross-sectional study was conducted at a tertiary care center in Jeddah, Saudi Arabia. Patients were surveyed for TB risk factors, their records were reviewed for previous TB infection or disease, and blood samples were collected for interferon-gamma release assays (IGRAs).

RESULTS

A total of 203 patients were included. One hundred and twenty-five were females (62%). Median age was 52 years, and mean age was significantly higher in positive IGRA patients compared to negative IGRA (57.32 vs. 47.27; p = 0.009). Twenty-five patients (12.3%) had evidence of TB infection, 16 (68%) among them had a latent TB infection, while the rest received treatment for an active TB disease. The rate of active disease among cancer patients was 8 (3.9%). Additionally, 92% (23) of those with positive IGRA had solid cancers (p = 0.007), and all active TB cases occurred in this group of solid cancers.

CONCLUSION

TB prevalence was higher in chemotherapy patients compared to the general Saudi population. Patients with solid tumors and older age had a greater risk of developing the infection, signifying the importance of preventing TB and malignancy coexistence by initiating screening policies in cancer patients.

Tuberculosis forecasting and temporal trends by sex and age in a high endemic city in northeastern Brazil: where were we before the Covid-19 pandemic?

Background

The aim of this study was to describe the temporal trend of tuberculosis cases according to sex and age group and evidence the level of disease before the Covid-19 pandemic in a TB high endemic city.

Methods

This was a time series study carried out in a city in northeast Brazil. The population was composed of cases of tuberculosis, excluding those with HIV-positive status, reported between the years 2002 and 2018. An exploratory analysis of the monthly rates of tuberculosis detection, smoothed according to sex and age group, was performed. Subsequently, the progression of the trend and prediction of the disease were also characterized according to these aspects. For the trends forecast, the seasonal autoregressive linear integrated moving average (ARIMA) model and the usual Box-Jenkins method were used to choose the most appropriate models.

Results

A total of 1620 cases of tuberculosis were reported, with an incidence of 49.7 cases per 100,000 inhabitants in men and 34.0 per 100,000 in women. Regarding the incidence for both sexes, there was a decreasing trend, which was similar for age. Evidence resulting from the application of the time series shows a decreasing trend in the years 2002–2018, with a trend of stability.

Conclusions

The study evidenced a decreasing trend in tuberculosis, even before the Covid-19 pandemic, for both sex and age; however, in a step really slow from that recommended by the World Health Organization. According to the results, the disease would have achieved a level of stability in the city next years, however it might have been aggravated by the pandemic. These findings are relevant to evidence the serious behavior and trends of TB in a high endemic scenario considering a context prior to the Covid-19 pandemic.

Patient pathways of tuberculosis care-seeking and treatment: an individual-level analysis of National Health Insurance data in Taiwan

Introduction

Patients with tuberculosis (TB) often experience difficulties in accessing diagnosis and treatment. Patient pathway analysis identifies mismatches between TB patient care-seeking patterns and service coverage, but to date, studies have only employed cross-sectional aggregate data.

Methods

We developed an algorithmic approach to analyse and interpret patient-level routine data on healthcare use and to construct patients’ pathways from initial care-seeking to treatment outcome. We applied this to patients with TB in a simple random sample of one million patients’ records in the Taiwan National Health Insurance database. We analysed heterogeneity in pathway patterns, delays, service coverage and patient flows between different health system levels.

Results

We constructed 7255 pathways for 6258 patients. Patients most commonly initially sought care at the primary clinic level, where the capacity for diagnosing TB patients was 12%, before eventually initiating treatment at higher levels. Patient pathways are extremely heterogeneous prior to diagnosis, with the 10% most complex pathways accounting for 48% of all clinical encounters, and 55% of those pathways yet to initiate treatment after a year. Extended consideration of alternative diagnoses was more common for patients aged 65 years or older and for patients with chronic lung disease.

Conclusion

Our study demonstrates that longitudinal analysis of routine individual-level healthcare data can be used to generate a detailed picture of TB care-seeking pathways. This allows an understanding of several temporal aspects of care pathways, including lead times to care and the variability in patient pathways.

Population aging and trends of pulmonary tuberculosis incidence in the elderly

BACKGROUND

To explore population aging and the epidemic trend of pulmonary tuberculosis (PTB) in the elderly, and provide a basis for the prevention and control of pulmonary tuberculosis among the elderly.

METHODS

We collected clinical information of 239,707 newly active PTB patients in Shandong Province from 2005 to 2017. We analyzed and compared the clinical characteristics, reported incidence and temporal trend of PTB among the elderly group (≥60 years) and the non-elderly group (< 60 years) through logistic model and Join-point regression model.

RESULTS

Among the total PTB cases, 77,192(32.2%) were elderly. Compared with non-elderly patients, newly active elderly PTB patients account for a greater proportion of male cases (OR 1.688, 95% CI 1.656-1.722), rural population cases (OR 3.411, 95% CI 3.320-3.505) and bacteriologically confirmed PTB cases (OR 1.213, 95%CI 1.193-1.234). The annual reported incidence of total, elderly, pulmonary bacteriologically confirmed cases were 35.21, 68.84, 35.63 (per 100,000), respectively. The annual reported incidence of PTB in the whole population, the elderly group and the non-elderly group has shown a slow downward trend since 2008. The joinpoint regression model showed that the overall reported incidence of PTB in the elderly significantly decreased from 2007 to 2017 (APC = -5.3, P < 0.05). The reported incidence of bacteriologically confirmed PTB among elderly patients declined rapidly from 2005 to 2014(2005-2010 APC = -7.2%, P < 0.05; 2010-2014 APC = -22.6%, P < 0.05; 2014-2017 APC = -9.0%, P = 0.1). The reported incidence of clinically diagnosed PTB among elderly patients from 2005 to 2017 (11.48-38.42/100,000) increased by about 235%. It rose significantly from 2007 to 2014 (APC = 9.4, P<0.05).

CONCLUSIONS

Compared with the non-elderly population, the reported incidence of PTB in the elderly population is higher. The main burden of PTB will shift to the elderly, men, rural population, and clinically diagnosed patients. With the intensification of aging, more researches on elderly PTB prevention and treatment will facilitate the realization of the global tuberculosis (TB) control targets.

Forecasting tuberculosis using diabetes-related google trends data

Online activity-based data can be used to aid infectious disease forecasting. Our aim was to exploit the converging nature of the tuberculosis (TB) and diabetes epidemics to forecast TB case numbers. Thus, we extended TB prediction models based on traditional data with diabetes-related Google searches. We obtained data on the weekly case numbers of TB in Germany from June 8th, 2014, to May 5th, 2019. Internet search data were obtained from a Google Trends (GTD) search for 'diabetes' to the corresponding interval. A seasonal autoregressive moving average (SARIMA) model (0,1,1) (1,0,0) [52] was selected to describe the weekly TB case numbers with and without GTD as an external regressor. We cross-validated the SARIMA models to obtain the root mean squared errors (RMSE). We repeated this procedure with autoregressive feed-forward neural network (NNAR) models using 5-fold cross-validation. To simulate a data-poor surveillance setting, we also tested traditional and GTD-extended models against a hold-out dataset using a decreased 52-week-long period with missing values for training. Cross-validation resulted in an RMSE of 20.83 for the traditional model and 18.56 for the GTD-extended model. Cross-validation of the NNAR models showed a mean RMSE of 19.49 for the traditional model and 18.99 for the GTD-extended model. When we tested the models trained on a decreased dataset with missing values, the GTD-extended models achieved significantly better prediction than the traditional models (p < 0.001). The GTD-extended models outperformed the traditional models in all assessed model evaluation parameters. Using online activity-based data regarding diabetes can improve TB forecasting, but further validation is warranted.

Secular Seasonality and Trend Forecasting of Tuberculosis Incidence Rate in China Using the Advanced Error-Trend-Seasonal Framework

Objective

Tuberculosis (TB) is a major public health problem in China, and contriving a long-term forecast is a useful aid for better launching prevention initiatives. Regrettably, such a forecasting method with robust and accurate performance is still lacking. Here, we aim to investigate its potential of the error-trend-seasonal (ETS) framework through a series of comparative experiments to analyze and forecast its secular epidemic seasonality and trends of TB incidence in China.

Methods

We collected the TB incidence data from January 1997 to August 2019, and then partitioning the data into eight different training and testing subsamples. Thereafter, we constructed the ETS and seasonal autoregressive integrated moving average (SARIMA) models based on the training subsamples, and multiple performance indices including the mean absolute deviation, mean absolute percentage error, root-mean-squared error, and mean error rate were adopted to assess their simulation and projection effects.

Results

In the light of the above performance measures, the ETS models provided a pronounced improvement for the long-term seasonality and trend forecasting in TB incidence rate over the SARIMA models, be it in various training or testing subsets apart from the 48-step ahead forecasting. The descriptive results to the data revealed that TB incidence showed notable seasonal characteristics with predominant peaks of spring and early summer and began to be plunging at on average 3.722% per year since 2008. However, this rate reduced to 2.613% per year since 2015 and furthermore such a trend would be predicted to continue in years ahead.

Conclusion

The ETS framework has the ability to conduct long-term forecasting for TB incidence, which may be beneficial for the long-term planning of the TB prevention and control. Additionally, considering the predicted dropping rate of TB morbidity, more particular strategies should be formulated to dramatically accelerate progress towards the goals of the End TB Strategy.