Tuberculosis In Mongolia Research Articles

Epidemiology of tuberculosis in Mongolia: analysis of surveillance data, 2015-2019.

Mongolia has a high tuberculosis (TB) burden. Data from routine paper-based surveillance were used to describe the epidemiology of TB in Mongolia; the data included testing presumptive TB cases, TB notifications, drug-resistant cases, treatment outcomes and notifications in prisoners. The proportion of the population tested for TB increased between 2015 and 2019. The number and rate per 100 000 population of TB notifications decreased between 2015 and 2018 and then increased in 2019. Most TB notifications in 2019 were in the capital, Ulaanbaatar (59.3%), followed by the central (16.8%), Khangai (10.4%), east (8.5%) and west (5.0%) regions. About half of TB notifications nationally were bacteriologically confirmed (45.4% in 2015, 48.1% in 2019), with the proportion of bacteriologically confirmed TB per province or district varying from 0% to 66%. High TB notification rates were observed in 2019 for males aged 15-54 years (202 per 100 000 population) and females aged 15-34 years (190 per 100 000 population). Treatment success for all forms of TB was 90% in 2019 but was below the 90% target for bacteriologically confirmed cases. Between 2015 and 2019, the number of RR/MDR-TB notifications ranged from 265 to 211. The Mongolian National Tuberculosis Programme needs to continue its efforts in TB control, to further increase the programmatic impact and reduce the TB burden. It is recommended that Mongolia continue to increase TB screening, the use of Xpert testing, contact investigations and preventive treatments, and targeting interventions to the high-burden areas identified in this subnational analysis.

Patient delay and health system delay of patients with newly diagnosed pulmonary tuberculosis in Mongolia, 2016-2017.

ABSTRACTAlthough diagnosis and treatment of tuberculosis (TB) have been improved in many countries, delays in the diagnosis and treatment remain problematic in resource-limited countries. This study aimed to identify factors affecting delays in TB care in Mongolia. Data on TB cases registered from January 2016 to December 2017 were obtained from the national registry of TB at the Department of TB Surveillance and Research in National Center for Communicable Disease. The total number of TB cases registered in these two years was 8,166, including 3,267 cases of newly diagnosed pulmonary TB. Pulmonary TB cases (1,836 males and 1,431 females) were analyzed to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Patient delays longer than the median (28 days) were significantly associated with patient age >32 years (aOR=1.31, 95%CI: 1.14–1.51), residence in areas other than Ulaanbaatar (aimags) (aOR=1.38, 95%CI: 1.20–1.59), and smear-negative (aOR=0.57, 95%CI: 0.47–0.69). Health system delays longer than the median (7 days) were significantly associated with patient age >32 years (aOR=1.16, 95%CI: 1.00–1.33), residence in aimags (aOR=0.82, 95%CI: 0.71–0.95), special facilities including a prison hospital (aOR=4.40, 95%CI: 2.42–7.83), registration in 2017 relative to 2016 (aOR=0.83, 95%CI: 0.71–0.95), and smear-negative (aOR=1.72, 95%CI: 1.42–2.07). Total delays longer than the median (45 days) were significantly associated with patient age >32 years (aOR=1.39, 95%CI: 1.21–1.60), residence in aimags (aOR=1.27, 95%CI: 1.11–1.47), and smear-negative (aOR=0.74, 95%CI: 0.62–0.90). To shorten the total delay, improvement of the access to medical facilities in aimags is necessary.

Transborder molecular analysis of drug‐resistant tuberculosis in Mongolia and Eastern Siberia, Russia

Eastern Siberia (Russia) and Mongolia are borderline regions in Asia with a high incidence of tuberculosis (TB). In this study, we investigated the transborder transmission of Mycobacterium tuberculosis with a focus on endemic and epidemic clones and drug resistance. M. tuberculosis isolates (287 from Mongolia and 754 from Russia) were collected using cross-sectional population-based surveys between 2010 and 2016. The isolates were genotyped using 24 variable number of tandem repeat (VNTR) loci and by testing of the key markers to discriminate within the Beijing genotype. All isolates were divided into 427 MIRU-types that were assigned to Lineage 2 (Beijing) and Lineage 4 (Ural, Haarlem, Latin American-Mediterranean [LAM], S, unclassified). The Beijing genotype was dominant in both countries (69% in Russia, 75% in Mongolia). However, the Beijing isolates differed significantly between the countries, in terms of the identified subtypes. LAM was the most common non-Beijing genotype (11.1% in Mongolia and 14.9% in Russia) and LAM isolates mostly belonged to the LAM-RUS branch in both countries. The MDR rate was higher in Russia than in Mongolia among newly diagnosed patients: 29.4% versus 5.6% (p < 0.001). In Mongolia, the MDR rate was similar in Beijing (29.7%) and non-Beijing (27.5%) genotypes. In Russia, a higher MDR rate was observed in (i) Beijing compared to non-Beijing (48.7% versus 38.3%, p = 0.03) and (ii) Beijing B0/W148 compared to Beijing Central Asian/Russian (63.4% versus 37.3%, p<0.001). In conclusion, the M. tuberculosis population structure in Mongolia was shaped by mainly historical interaction with China (dominance of the Beijing genotype) and Northern Eurasia (presence of the LAM-RUS branch). In contrast, the transborder transmission of M. tuberculosis since the 1990s between Mongolia and its neighbors has been negligible, and the adverse trends of MDR-TB in Russia did not impact the current situation in Mongolia. This article is protected by copyright. All rights reserved.

Childhood Tuberculosis in Mongolia: Trends and Estimates, 2010-2030.

Mongolia was listed among the 30 countries with a high tuberculosis burden in 2021. Approximately 10-11% of the tuberculosis cases are of children, which is higher than the global average (6.0%). As children are a vulnerable population, it is important to understand the current situation and prioritize the development of tuberculosis prevention strategies. However, only few studies have addressed childhood tuberculosis in Mongolia. Therefore, we aimed to describe the characteristics of childhood tuberculosis and to show its trends and estimates in Mongolia. We performed descriptive and trend analyses on secondary data from the National Center for Communicable Diseases from 2010 to 2020. A total of 4,242 childhood tuberculosis cases, compiled from nine districts of the capital city and 21 provinces, were analyzed. We found that tuberculosis occurred more frequently in school-age children, and 71.8% of the all cases were an extrapulmonary tuberculosis. Trend analysis revealed that childhood tuberculosis continuously increased with fluctuations from 2018 onwards. The central region, including the capital city of Ulaanbaatar, is the most tuberculosis-burdened. Childhood tuberculosis is estimated to increase in the central region and decrease in the others from 2021 to 2030. Our findings showed that the national childhood tuberculosis trend is increasing, although there are differences in the pattern between regions. Further studies are needed to identify the determinant factors of regional differences, and age-specific public health interventions, such as scale-up screening and preventive treatment, are in demand in high-prevalence areas.

Molecular epidemiology of multidrug resistant tuberculosis in Mongolia and Eastern Siberia: two independent dissemination processes for dominant strains

Mongolia and Russia are among the countries with the high tuberculosis (TB) burden. The prevalence of tuberculosis, including multidrug-resistant tuberculosis (MDR), in Eastern Siberia bordering Mongolia is significantly higher than in the European part of Russia. In addition, unlike Mongolia, Eastern Siberia is characterized by a high prevalence of HIV infection. The cross-border spread of socially significant infections in these countries seems to occur due to their wide-range cooperation and cultural exchange. Whereas the HIV infection has no epidemiological significance for Mongolia at the moment, tuberculosis, however, has a similar prevalence on both sides of the border. The aim was to evaluate the cross-border MDR M. tuberculosis distribution in Mongolia and Eastern Siberia by using molecular genetic data. Materials and methods. A total of 1045 M. tuberculosis strains isolated in Mongolia (291) and the three regions of Eastern Siberia (754) were studied by using the MIRU-VNTR-24 loci genotyping. The CC2/W148 and CC1 subtypes were identified by the specific deletion in the kdpD gene and SNP in the pks17 gene at position 1887060, respectively. Phylogenetic analysis of MIRU-VNTR patterns was carried out by generating UPGMA tree and maximum likelihood tree. Results. The Beijing genotype was found in 75.3% (219/291) and 69.0% (520/754) from Mongolian and East Siberian collection, respectively. Common minor genotypes were LAM (11.0% and 15.1%), T (10.3% and 4.5%), and Haarlem (1.4% and 2.4%) found in Mongolia and Eastern Siberia, respectively. The genotypes S (1.3%) and Ural (5.0%) were found solely in the Russia-derived samples. The main epidemic Beijing subtypes in each country belonged to different clonal complexes (CC): the majority of Mongolian Beijing strains displayed profiles 342-32, 3819-32, 1773-32 MLVA types and belonged to the CC4 subtype; Russian Beijing strains mainly belonged to the CC1 (43.7% — 227/520) and CC2/W148 (34.8% — 181/520) subtypes. The MDR level and distribution patterns differed significantly between Mongolia and Eastern Siberia. Modeling of Beijing strain expansion evidences about extremely subtle contribution of the M. tuberculosis cross-border transmission between Mongolia and Russia. The phylogenetic reconstruction of Beijing CC4 subtype evolution in Mongolia suggests that its distribution is primarily associated with China and other countries of the Western Pacific Region. Three main phylogenetic branches of CC4 subtype were traced, which probably spread throughout Mongolia in the 11—12th centuries. It may be assumed that spreading of the epidemic Beijing CC4 subtype might occur in two stages: early period — emergence of ancestral CC4 variants in Mongolia or their introduction from China (they are homologous to the strains preserved in the Chinese population), later period — dissemination due to the active exchange of M. tuberculosis with countries of Southeast Asia, but not Russia. Conclusion. Using MIRU-VNTR-24 genotyping as well as classification according to specific single nucleotide polymorphisms specific to certain Beijing subtypes, it allowed to describe separate patterns of the epidemic variants spread in Mongolia and Russia. It has been demonstrated that emergence and spread of MDR-TB in Mongolia are entirely iatrogenic in nature, while the epidemic subtypes of the Beijing genotype (subtypes CC1 and CC2/W148) contribute markedly into the MDR-TB spreading in Eastern Siberia.

Genetic Mutations Associated with Isoniazid Resistance in Mycobacterium tuberculosis in Mongolia.

Globally, mutations in the katG gene account for the majority of isoniazid-resistant strains of Mycobacterium tuberculosis Buyankhishig et al. analyzed a limited number of Mycobacterium tuberculosis strains in Mongolia and found that isoniazid resistance was mainly attributable to inhA mutations (B. Buyankhishig, T. Oyuntuya, B. Tserelmaa, J. Sarantuya, et al., Int J Mycobacteriol 1:40-44, 2012, https://doi.org/10.1016/j.ijmyco.2012.01.007). The GenoType MTBDRplus assay was performed for isolates collected in the First National Tuberculosis Prevalence Survey and the Third Anti-Tuberculosis Drug Resistance Survey to investigate genetic mutations associated with isoniazid resistance in Mycobacterium tuberculosis in Mongolia. Of the 409 isoniazid-resistant isolates detected by the GenoType MTBDRplus assay, 127 (31.1%) were resistant to rifampin, 294 (71.9%) had inhA mutations without katG mutations, 113 (27.6%) had katG mutations without inhA mutations, and 2 (0.5%) had mutations in both the inhA and katG genes. Of the 115 strains with any katG mutation, 114 (99.1%) had mutations in codon 315 (S315T). Of the 296 strains with any inhA mutation, 290 (98.0%) had a C15T mutation. The proportions of isoniazid-resistant strains with katG mutations were 25.3% among new cases and 36.2% among retreatment cases (P = 0.03) and 17.0% among rifampin-susceptible strains and 52.8% among rifampin-resistant strains (P < 0.01). Rifampin resistance was significantly associated with the katG mutation (adjusted odds ratio, 5.36; 95% confidence interval [CI], 3.3 to 8.67, P < 0.001). Mutations in inhA predominated in isoniazid-resistant tuberculosis in Mongolia. However, the proportion of katG mutations in isolates from previously treated cases was higher than in those from new cases, and the proportion in cases with rifampin resistance was higher than in cases without rifampin resistance.

Molecular-Genetic Features of Tuberculosis in Mongolia and in Russian Bordering Regions

A comparative molecular epidemiological analysis of the population structure of Mycobacterium tuberculosis in Mongolia and the neighboring regions of Russia was conducted. The aim was the determining of mutual influence the TB in the studied countries. Selected samples of the Mongolian (309 strains) and Russian (933 strains) cohorts of Mycobacterium tuberculosis were carried out based on the results of genotyping (used deletion analysis for RD 105/207, MIRU-VNTR 24 genotyping and subtyping of the clone CC2/W148 by the specific deletion in the kdpD gene). The results of the study indicate the isolation of transmission of TB infection in Mongolia, despite the activity of the historically formed migration between Mongolia and Russia: in the studied territories, the genotypic spectrum is qualitatively different. The subtypes CC1, CC2 and BL7 of the genotype Beijing predominate in the Russian territories (Buryatia, Zabaykalsky Krai and Irkutsk Region), and the CC4 subtype of the genotype Beijing presents in Mongolia (64.5%). The molecular genetic structure of Mycobacterium tuberculosis has no significant differences in the borderlands with Russia and in the central provinces of Mongolia.

Implementation of the Xpert MTB/RIF assay for tuberculosis in Mongolia: a qualitative exploration of barriers and enablers.

ObjectiveThe aim of our study was to identify barriers and enablers to implementation of the Xpert MTB/RIF test within Mongolia’s National Tuberculosis Program.MethodsTwenty-foursemi-structured interviews were conducted between June and September 2015 with laboratory staff and tuberculosis physicians in Mongolia’s capital Ulaanbaatar and regional towns where Xpert MTB/RIF testing had been implemented. Interviews were recorded, transcribed, translated and analysed thematically using NVIVO qualitative analysis software.ResultsEight laboratory staff (five from the National Tuberculosis Reference Laboratory in Ulaanbaatar and three from provincial laboratories) and sixteen tuberculosis physicians (five from the Mongolian National Center for Communicable Diseases in Ulaanbaatar, four from district tuberculosis clinics in Ulaanbaatar and seven from provincial tuberculosis clinics) were interviewed. Major barriers to Xpert MTB/RIF implementation identified were: lack of awareness of program guidelines; inadequate staffing arrangements; problems with cartridge supply management; lack of local repair options for the Xpert machines; lack of regular formal training; paper based system; delayed treatment initiation due to consensus meeting and poor sample quality. Enablers to Xpert MTB/RIF implementation included availability of guidelines in the local language; provision of extra laboratory staff, shift working arrangements and additional modules; capacity for troubleshooting internally; access to experts; opportunities for peer learning; common understanding of diagnostic algorithms and decentralised testing.ConclusionOur study identified a number of barriers and enablers to implementation of Xpert MTB/RIF in the Mongolian National Tuberculosis Program. Lessons learned from this study can help to facilitate implementation of Xpert MTB/RIF in other Mongolian locations as well as other low-and middle-income countries.

Transmission of multi-drug resistant tuberculosis in Mongolia is driven by Beijing strains of Mycobacterium tuberculosis resistant to all first-line drugs

Mongolia has high and rising rates of multi-drug resistant tuberculosis (MDR-TB). Spatio-temporal and programmatic evidence suggests a major contribution from MDR-TB transmission, but genotypic evidence has not been assessed. All MDR-TB cases identified during 2012 were examined. Demographic and bacteriological data were obtained from the National Tuberculosis Reference Laboratory. Isolates of Mycobacterium tuberculosis from culture-confirmed category 1 treatment failures were genotyped using 24-loci mycobacterium interspersed repetitive unit (MIRU-24) analysis. Of the 210 MDR-TB cases identified, 115 (54.8%) were treatment failures (34.8% category 1; 20.0% category 2). Streptomycin resistance was present in 156 (74.3%) cases; including 55/73 (75.3%) category 1 treatment failures who had never been exposed to streptomycin. Among category 1 treatment failures, Beijing lineage strains predominated (88.0%; 59/67 of genotyped isolates). MIRU-24 clustering was documented in 62.7% (42/67) of strains; 55.2% (37/67) remained clustered when drug susceptibility test results were considered. In total 59.5% (25/42) of clustered strains were Beijing lineage and demonstrated in-vitro resistance to all first-line drugs tested. The MDR-TB epidemic in Mongolia appears to be driven by primary transmission of Beijing lineage strains resistant to all first-line drugs. Enhanced infection control strategies together with early MDR-TB case detection and appropriate treatment are necessary to limit escalation of the MDR-TB epidemic.

Rapid molecular testing for multi-resistant tuberculosis in Mongolia: A diagnostic accuracy study

ObjectiveThe aim of this study was to assess the performance of a molecular line probe assay, GenoType® MTBDRplus, for rapid detection of rifampicin and isoniazid resistance in the Mongolian situation. The sensitivity and specificity of GenoType® MTBDRplus to detect rifampicin and isoniazid resistance-associated mutations in culture specimens and directly in smear-positive clinical specimens was examined. Method218 MDR-TB subjects aged between 14 and 75years old from eight districts in Ulaanbaatar city (between July 2009 and May 2010) were included in this study .The GenoType Mycobacterium tuberculosis drug resistance first line (MTBDR plus) assay (Hain Life-science, Nehren, Germany) was tested on 109 clinical isolates and directly on 41 sputum specimens for the ability to detect the resistances. Results were compared with conventional culture and drug susceptibility testing on solid medium. ResultsThe high correlation of the results from GenoType® MTBDRplus and conventional drug susceptibility testing was obtained from this study. The results clearly showed a high performance of GenoType® MTBDRplus with almost 100% accuracy for all the important indicators, such as sensitivity, specificity, positive and negative predictive values and detection of rifampicin resistance. Discrepancies were obtained in comparison with DNA sequencing results. ConclusionsThe Genotype® MTBDRplus assay was demonstrated as a rapid, reliable and highly accurate tool for early detection of MDR-TB through examining smear positive cases.

Structure of the M. tuberculosis population in Mongolia according to the results of genotyping of large-sequence polymorphisms

We performed genotyping of 112 tuberculosis agent isolates from patients suffering from lung tuberculosis in Mongolia using the RD9, RD7, TbD1, RD105, and RD750 loci. Genotypes of all the obtained isolates were characterized by preservation of the RD9, RD7, and RD750 loci and by a deletion in the locus TbD1. A deletion of RD105 was found in 65 (58%) isolates. The isolates were classified into two groups, East Asian and European-American ones, by the results of genotyping.

P2-458 A descriptive study on the tuberculosis in Mongolia

IntroductionTuberculosis (TB) is highly prevalent in Mongolia, where approximately 4000 TB cases reported each year. The goal of this study is to determine the incidence of tuberculosis particularly MDR-TB cases...

Time trend in incidence and mortality of tuberculosis and characteristics of notified tuberculosis patients in urban area of Mongolia

Recent Mongolian political, social and economic changes have had a great impact on its health care system and tuberculosis control program. The objective of this study is to assess time trend in incidence and mortality of tuberculosis and characteristics of notified tuberculosis cases in Mongolia. 1) Data on statistics of tuberculosis are obtained from reports of the National Tuberculosis Center in Mongolia. The mortality of tuberculosis in Mongolia shows a downward trend during 1985-1995. The number of notified tuberculosis cases had gradually decreased during 1985-1989. It suddenly dropped in 1990 and was the lowest in 1993. After that, about two fold increase in the notified cases was observed in recent three years from 1993 to 1995. Such a large fluctuation in the number of notified cases after 1990 is unlikely to be associated with the epidemiologic situation of tuberculosis, but rather due to a reporting bias. The shortage of drugs and economic hardship prevented patients from consulting medical facilities. The shortage of drugs also prevented doctors from notifying patients to the tuberculosis registry, because the notification did not lead to treating the disease. The improvement of health care system and the supply of essential drugs since 1994 seems to contribute to the increase in the number of notified cases. 2) The study subjects include 618 patients who were diagnosed as active tuberculosis at ten tuberculosis specialized facilities in Ulaanbaatar, Mongolia from May 1995 to March 1996. Patients were interviewed about their demographic factors and their medical records were reviewed. Fifty one percent of the cases were female. The mean age was 26.9 years old. Ninety percent of the cases underwent chest X-ray examination, while 72% of the cases underwent bacteriological examination and only 21% were confirmed bacteriologically. It is necessary to improve the quality control of sputum smear examination and the validity of diagnosis of tuberculosis in Mongolia. As for treatment regimens, only 29% of the cases were being treated with at least four drugs (isoniazid, rifampicin, pyrazinamide, ethambutol and/or streptomycin). It is needed to provide directly observed treatment using the WHO recommended standard regimen to at least smear positive tuberculosis cases.