Risks for tuberculosis in Kazakhstan: implications for prevention

Subspecies typing on the example of klebsiella pneumoniae isolated from patients with pulmonary tuberculosis

OBJECTIVE

Aim: The purpose of this study was to evaluate sub-species typing by matrix-activated laser desorption/ionisation mass spectrometry on the example of Klebsiella pneumoniae isolated from patients with pulmonary tuberculosis in Karaganda region..

PATIENTS AND METHODS

Materials and Methods: This study evaluated the potential of MALDI-TOF MS for epidemiological identification of Klebsiella pneumoniae isolated from pulmonary tuberculosis patients in Karaganda region. A total of 47 strains of Klebsiella pneumoniae obtained between 2015 and 2019 were typed. Mass spectra were taken using Microflex LT MALDI-TOF (Bruker) according to standard procedure.

RESULTS

Results: As a result, MALDI-TOF evaluation of subspecies typing on the example of Klebsiella pneumoniae isolated from patients with pulmonary tuberculosis in Karaganda region, predominantly showed the diversity of isolates, indicating their out-of-hospital nature. Based on all available information, including facts, sources, and experimental results, it can be reasonably concluded that the current study of Klebsiella pneumoniae does not provide a complete picture of the epidemiology of this microorganism.

CONCLUSION

Conclusions: The current study provided a limited opportunity to investigate the genetic structure and diversity of Klebsiella pneumoniae subspecies more accurately. The findings suggest that the time-of-flight laser-ionisation ablation mass spectrometry method with magnetic focusing is more likely to detect differences in external characteristics between individual specimens of the same species than internal genetic variation in the microorganisms under study. The practical relevance of this study is to inform the development of more effective infection control strategies in clinical practice and infection control.

[Association between treatment outcome and age in tuberculosis and diabetes patients: a population analysis]

BACKGROUND

The undoubted importance of this work lies in the fact that for the first time in the Republic of Kazakhstan, an analysis is being made of the relationship between age and treatment outcome in patients with a comorbid diagnosis of tuberculosis and diabetes mellitus.

PURPOSE OF THE STUDY

Identification of the correlation between the age of patients with tuberculosis with diabetes mellitus and the outcome of treatment.

MATERIALS AND METHODS

Cross-sectional retrospective study of 2,125 patients with TB and diabetes mellitus out of a total of 43,807 of all patients diagnosed with TB (2017-2019). The study analyzed the data of patients with comorbidity from all regions of Kazakhstan (data from 14 regions and 3 cities of republican significance) (2017-2019).

RESULTS

A high prevalence of tuberculosis morbidity with a concomitant diagnosis of diabetes mellitus in the age group from 45 to 64 years was revealed. This group consisted of 1193 patients out of 2115 (56.4% of the total number of patients with tuberculosis and diabetes mellitus). The average age of all studied patients with DM was 54.7±13.4 years. There is a positive correlation between age and treatment outcome in TB patients. Mortality was higher in the age group over 45 years old - OR95%CI = 0.213 [0.019-2.362], p - 0.0000015 (p < 0.05).

Diabetes mellitus and tuberculosis, a systematic review and meta-analysis with sensitivity analysis for studies comparable for confounders

INTRODUCTION

Meta-analyses conducted so far on the association between diabetes mellitus (DM) and the tuberculosis (TB) development risk did not sufficiently take confounders into account in their estimates. The objective of this systematic review was to determine whether DM is associated with an increased risk of developing TB with a sensitivity analyses incorporating a wider range of confounders including age, gender, alcohol consumption, smoke exposure, and other comorbidities.

METHODS

Pubmed, Embase, Web of Science and Global Index Medicus were queried from inception until October 2020. Without any restriction to time of study, geographical location, and DM and TB diagnosis approaches, all observational studies that presented data for associations between DM and TB were included. Studies with no abstract or complete text, duplicates, and studies with wrong designs (review, case report, case series, comment on an article, and editorial) or populations were excluded. The odds ratios (OR) and their 95% confidence intervals were estimated by a random-effect model.

RESULTS

The electronic and manual searches yielded 12,796 articles of which 47 were used in our study (23 case control, 14 cross-sectional and 10 cohort studies) involving 503,760 cases (DM or TB patients) and 3,596,845 controls. The size of the combined effect of TB risk in the presence of DM was OR = 2.3, 95% CI = [2.0-2.7], I2 = 94.2%. This statistically significant association was maintained in cohort (OR = 2.0, CI 95% = [1.5-2.4], I2 = 94.3%), case control (OR = 2.4, CI 95% = [2.0-2.9], I2 = 93.0%) and cross-sectional studies (OR = 2.5, CI 95% = [1.8-3.5], I2 = 95.2%). The association between DM and TB was also maintained in the sensitivity analysis including only studies with similar proportions of confounders between cases and controls. The substantial heterogeneity observed was mainly explained by the differences between geographic regions.

CONCLUSIONS

DM is associated with an increased risk of developing latent and active TB. To further explore the role of DM in the development of TB, more investigations of the biological mechanisms by which DM increases the risk of TB are needed.

REVIEW REGISTRATION

PROSPERO, CRD42021216815.

Genetic factors associated with obesity risks in a Kazakhstani population

Objectives

There is limited published literature on the genetic risks of chronic inflammatory related disease (eg, obesity and cardiovascular disease) among the Central Asia population. The aim is to determine potential genetic loci as risk factors for obesity for the Kazakhstani population.

Setting

Kazakhstan.

Participants

One hundred and sixty-three Kazakhstani nationals (ethnic groups: both Russians and Kazakhs) were recruited for the cross-sectional study. Linear regression models, adjusted for confounding factors, were used to examine the genetic associations of single nucleotide polymorphisms (SNPs) in 19 genetic loci with obesity (73 obese/overweight individuals and 90 controls).

Results

Overall, logistic regression analyses revealed genotypes C/T in CRP (rs1205), A/C in AGTR1 (rs5186), A/G in CBS (rs234706), G/G in FUT2 (rs602662), A/G in PAI-1 (rs1799889), G/T (rs1801131) and A/G (rs1801133) in MTHFR genes significantly decrease risk of overweight/obesity. After stratification for ethnicity, rs234706 was significantly associated with overweight/obesity in both Russians and Kazakhs, while rs1800871 was significant in Kazakhs only.

Conclusions

This study revealed that variations in SNPs known to be associated with cardiovascular health can also contribute to the risks of developing obesity in the population of Kazakhstan.

Knowledge and attitudes towards ambulatory treatment of tuberculоsis in Kazakhstan

BACKGROUND

Ambulatory based treatment of tuberculosis has been recently introduced in Kazakhstan. We sought to assess the attitudes of the general population, TB patients and their household members towards ambulatory TB treatment and identify how knowledge of TB is associated with these attitudes.

METHODS

New pulmonary TB cases and their household and community controls were recruited from three regions of Kazakhstan in 2012-2014. 1083 participants completed audio computer-assisted self interviews to assess their knowledge of TB and attitudes towards ambulatory care. Mixed effects logistic regression models were used to identify factors associated with attitudes toward ambulatory TB treatment.

RESULTS

The proportion of people who considered ambulatory TB treatment as appropriate was very low (24.9%). Positive attitudes towards ambulatory TB treatment were significantly associated with region of residence, higher level of education, family support and experience with TB. The association between sufficient tuberculosis knowledge and favorable attitude toward ambulatory treatment was stronger among community controls compared to TB patients and their family members.

CONCLUSIONS

This study provides insight into attitudes toward ambulatory TB treatment among different groups and the specific influence of TB knowledge on these attitudes. Our findings can inform the process of integration of new TB treatment strategies and the development of appropriate education and advocacy programs in the general population.

Association of genetic variations in the vitamin D pathway with susceptibility to tuberculosis in Kazakhstan

Tuberculosis (TB) poses an important health challenge and a significant economic burden for Kazakhstan and in Central Asia. Recent findings show a number of immunological related processes and host Mycobacterium tuberculosis defense are impacted by a variety of genes of the human host including those that play a part in the vitamin D metabolism. We investigated the genetic variation of genes in the vitamin D metabolic pathway of a cohort 50 TB cases in Kazakhstan and compared them to 34 controls living in the same household with someone infected with TB. We specifically analyzed 11 SNPs belonging to the following genes: DHCR7, CYP2R1, GC-1, CYP24A1, CYP27A1, CYP27B1, VDR and TNFα. These genes play a number of different roles including synthesis, activation, delivery and binding of the activated vitamin D. Our preliminary results indicate significant association of VDR (vitamin D receptor) SNPs (rs1544410, BsmI, with OR = 0.425, CI 0.221-0.816, p = 0.009 and rs731236, TaqI with OR = 0.443, CI 0.228-0.859, p = 0.015) and CYP24A1 (rs6013897 with OR = 0.436, CI 0.191-0.996, p = 0.045) with TB. Interaction of genetic variation of VDR and CYP24A1 may impact susceptibility to TB. The findings provided initial clues to understand individual genetic differences in relation to susceptibility and protection to TB.

Cannabis use and the risk of tuberculosis: a systematic review

BACKGROUND

Cannabis has been identified as a possible risk factor in some tuberculosis (TB) outbreaks. As the most widely used (largely) illegal substance in Western countries this may be an important public health concern. We aim to systematically review the evidence on the association between cannabis use and TB (latent infection and active disease) to inform ongoing and future TB prevention and control strategies.

METHODS

We conducted a systematic review. We searched Ovid Medline, Embase and PsycInfo, together with the World Health Organization website and Google Scholar, for all years to January 2018. Reference lists and conference abstracts were hand-searched, a forward citation search was conducted on the Web of Science, and experts were contacted. Two authors independently screened studies for inclusion, extracted data and assessed risk of bias using an adapted version of ROBINS-I ("Risk of Bias in Non-randomised Studies - of Interventions"). Data were narratively synthesised.

RESULTS

Of 377 records identified, 11 studies were eligible. Study designs were heterogeneous. Six studies utilised a relevant comparator group. Four of these investigated the association between cannabis use and latent TB infection; all provided some evidence of an association, although only two of these had adjusted for confounders. The remaining two comparator studies investigated the association between cannabis use and active TB disease; neither found evidence of an association after adjusting for confounding. All six studies were at "Serious" risk of bias. The five studies which did not utilise a relevant comparator group were all indicative of TB outbreaks occurring among cannabis users, but the quality of the evidence was very weak.

CONCLUSIONS

Evidence for an association between cannabis use and TB acquisition is weak. The topic warrants further robust primary research including the collection of consistent and accurate exposure information, including cannabis use practices, dose and frequency, and adjustment for confounders.

Pulmonary Versus Extrapulmonary Tuberculosis Associated Factors: A Case-Case Study

BACKGROUND

Tuberculosis (TB) incidence remains low in health departments of Castellon and La Plana-Vila-real, but TB elimination is challenging. The objective of this study was to estimate associated factors of pulmonary tuberculosis (PTB) compared with extrapulmonary tuberculosis (ETB) and investigate epidemiological characteristics of these pathologies to orient control and prevention actions.

MATERIALS AND METHODS

A prospective case-case study was implemented by comparing PTB and ETB incidences during 2013-2016 from notification reports, epidemiological surveillance, and microbiological results of hospitals' laboratories Hospital General Castellon and La Plana-Vila-Real in the province of Castellon of Valencia region in Spain. In this design, cases were patients with PTB and controls were patients with ETB. Directed acyclic graph approach was used for selection of potential risk and confounding factors. Adjusted odds ratios (AORs) were estimated by logistic regression models.

RESULTS

The study included 136 patients with PTB and 57 patients with ETB, with microbiological confirmation of 93.4% and 52.6%, and the annual median of incidence rates were 7.5 and 3.1 per 100 000 inhabitants, respectively. In general, patients with PTB were younger with higher male proportion than patients with ETB. Risk factors of PTB were smoking tobacco (AOR = 3.98; 95% confidence interval [CI] = 1.66-9.56), social problems (social marginalization, homeless, residence in shelters for the poor, or stay in prison) (AOR = 3.39; 95% CI = 1.05-10.94), and contact with patients with TB (AOR = 2.51; 95% CI = 1.06-5.95). No-smoking tobacco and no-drug abuse interaction decrease PTB risk (AOR = 0.27; 95% CI = 0.12-0.64). From these results, specific measures of health promotion and prevention can be addressed.

CONCLUSIONS

The estimated associated factors of PTB may be prevented, and it was demonstrated that the case-case design is useful in the study of TB.

Risk of active tuberculosis among people with diabetes mellitus: systematic review and meta-analysis

OBJECTIVE

To assess the risk of active TB in people with DM and the factors associated with this risk.

METHODS

Systematic review and meta-analysis. We searched the literature for studies that reported the effect of DM on TB controlled for the effect of age. Studies that had not established the diagnosis of DM prior to detecting active TB were excluded. Study quality was assessed by Newcastle-Ottawa scale and we conducted a meta-analysis using random-effects models.

RESULTS

Of 14 studies (eight cohort and six case-control studies) that involved 22 616 623 participants met the selection criteria and were included in the analysis. There was substantial variation between studies in the estimates of the effect of DM on TB. However, the pooled estimates from seven high-quality studies showed that diabetic people have a 1.5-fold increased risk of developing active TB vs. those without DM (95%CI 1.28-1.76), with relatively small heterogeneity (I²  = 44%). The increased risk of TB was observed predominantly among DM populations with poor glycaemic control.

CONCLUSION

There is evidence suggesting an increased risk of developing TB among people with DM, and that improving glycaemic control in DM patients would reduce the risk of developing TB. An integrated approach is needed to control the dual burden of DM and TB.