The recent-transmission of Mycobacterium tuberculosis strains among Iranian and Afghan relapse cases: a DNA-fingerprinting using RFLP and spoligotyping

Determination of genetic diversity of multidrug-resistant Mycobacterium tuberculosis strains in Turkey using 15 locus MIRU-VNTR and spoligotyping methods

Tuberculosis (TB) remains the leading cause of deaths from infectious disease worldwide. Nowadays, the tendency of Mycobacterium tuberculosis complex (MTBC) to spread between continents due to uncontrolled migration movements shows that TB is a global health problem. The number of studies for the detection of MTBC strains' epidemiological features in areas with TB spread risk using molecular-based methods such as spoligotyping and Mycobacterial Interspersed Repetitive Unit (MIRU) Variable Number Tandem Repeats (VNTR) at the clonal level is insufficient. In this study, it was aimed to determine the phylogenetic relationships of MTBC strains at the species level by spoligotyping and 15 locus MIRU-VNTR (MIRU-VNTR₁₅) molecular methods of 96 multidrug-resistant (MDR) MTBC strains isolated from sputum samples of patients with a preliminary diagnosis of pulmonary TB or suspected contact history those sent to National Tuberculosis Reference Laboratory from the centers that are members of the Tuberculosis Laboratory Surveillance Network. The phylogenetic relationship between 96 MDR-TB strains was investigated with the combination of bead-based spoligotyping and MIRU-VNTR₁₅ methods on the MAGPIX® Milliplex Map device. In this study, it was determined that the T1 family is more common in our country and LAM7-TUR family is less common than the Beijing family unlike other studies. It was determined that the strains in the same cluster had different locus profiles, and there was no transmission from the same clone in the clonal typing we performed with spoligotyping and MIRU-VNTR₁₅.

Health condition of Afghan refugees residing in Iran in comparison to Germany: a systematic review of empirical studies

BACKGROUND

The re-emerging dominance of the Taliban in Afghanistan in 2021 caused a new wave of Afghan refugees heading Iran and neighboring countries. Iran in the Middle East and Germany in Europe are two major host countries to the largest populations of Afghan refugees. In both countries, several studies have been done to assess the health condition of refugees.

OBJECTIVES

To systematically review the existing literature to identify similarities and differences of health conditions of Afghan refugees living in the two countries, and to synthesize evidence on the health status and health care access of these populations.

METHODS

Related electronic databases and grey literature of Iran and Germany on the health of Afghan refugees were scanned and searched up for the period 2000-2020. Key terms were formed by combining "Afghan refugees or immigrants or populations or asylum seekers", "Physical or mental health", "Healthcare service or access or use", "Iran or Germany". Empirical studies were considered if they contained samples of Afghan refugees with particular outcomes for Afghans. Results were categorized for both countries in the three main areas of physical health, mental health, and access/use of healthcare services.

RESULTS

Nine hundred twenty-two documents were extracted, of which 75 full-texts were finally reviewed. 60 documents belonged to the health condition of Afghan refugees residing in Iran including 43 in physical health, 6 in mental health, 8 in healthcare access and use, and 3 in multiple aspects of health, and 15 belonged to Germany including 7 in physical health, 4 in mental health, 2 in healthcare access and use, and 2 in multiple aspects of health. A less explicit evaluation of the overall health condition of Afghan refugees was observable, particularly for Germany. While matches on the study subject exist for both countries, in comparison to Germany, we extracted more quantitative and qualitative health studies on Afghan refugees of the mentioned areas from Iran. German health studies were rare, less qualitative, and more on the health condition of diverse refugee groups in general.

CONCLUSIONS

Wide gaps and unanswered questions related to mental health and overall health status of the Afghan refugee population are observable, especially in Germany. Our systematic review identified the gap in evidence, which we would recommend to bridge using a wider lens to comprehensively assess the overall condition of refugees considering associations between health and socio-economic and cultural determinants instead of a one-dimensional approach. Further, within health studies on refugee populations, we recommend stratification of results by the country of origin to capture the within-group diversity among refugees with different countries of origin.

Risk factors for types of recurrent tuberculosis (reactivation versus reinfection): A global systematic review and meta-analysis

BACKGROUND

The purpose of this meta-analysis (PROSPERO number: CRD42021243204) is to perform extensive and penetrating analyses on the risk factors associated with reactivation or reinfection.

METHODS

We searched PubMed and Embase using search terms. Risk factors (including sex, length of time between first onset and recurrent diagnosis, extrapulmonary tuberculosis, sputum smear, pulmonary cavity, Beijing family strains, diabetes, HIV infection, history of imprisonment, and immigration) were analyzed. The pooled risk ratio (RR) and 95% confidence interval (CI) were calculated with STATA 15.1. Heterogeneity was evaluated by I² and P values.

RESULTS

The meta-analysis included 25 studies with a total of 1,477 patients. After subgroup analysis, sensitivity analysis, and testing for publication bias, it was concluded that time spanning less than two years (RR=1.56, 95% CI: 1.33-1.85) was a risk factor for endogenous reactivation, while coinfection with HIV (RR=0.72, 95% CI: 0.63-0.83), Beijing family genotype (RR=0.46, 95% CI: 0.32-0.67), history of imprisonment (RR=0.36, 95% CI: 0.16-0.81) and immigration (RR=0.66, 95% CI: 0.53-0.82) were associated with exogenous reinfection.

CONCLUSIONS

The recurrence interval is a risk factor for the endogenous reactivation of tuberculosis. Infection with Beijing family strains, coinfection with HIV, imprisonment, and immigration contribute to the risk of exogenous reinfection.

How Molecular Epidemiology Can Affect Tuberculosis Control in the Middle East Countries: A Systematic Review and Meta-Analysis

BACKGROUND

Nowadays, due to the incidence of specific strains of Mycobacterium tuberculosis and also an increase in the rate of drug resistant-TB, the mortality rate has been increased by this disease. The identification of common strains in the region, as well as the sources of transmission, is essential to control the disease, which is possible by using molecular epidemiology.

OBJECTIVES

In this survey, the studies utilizing the spoligotyping method in Muslim Middle East countries are reviewed to determine their role in the control of TB.

METHODS

All studies conducted from 2005 to June 2016 were considered systematically in three electronic databases out of which 23 studies were finally selected.

RESULTS

The average rate of clustering was 84% and the rate of recent transmission varied from 21.7% to 92.4%. The incidence of Beijing strains has been found to be rising in the abovementioned countries. In Iran and Saudi Arabia known as immigration and labour-hosting countries, respectively, rapid transmittable and drug-resistant Beijing strains were higher than those in other Muslim Middle East countries.

CONCLUSION

Considering the incidence of highly virulent strains, due to the increase in immigration and people infected with HIV, tuberculosis, especially drug-resistant form, careful monitoring is needed.

Variation in Mycobacterium tuberculosis population structure in Iran: a systemic review and meta-analysis

Background

Acquiring comprehensive insight into the dynamics of Mycobacterium tuberculosis (Mtb) population structure is an essential step to adopt effective tuberculosis (TB) control strategies and improve therapeutic methods and vaccines. Accordingly, we performed this systematic review and meta-analysis to determine the overall prevalence of Mtb genotypes/ sublineages in Iran.

Methods

We carried out a comprehensive literature search using the international databases of MEDLINE and Scopus as well as Iranian databases. Articles published until April 2020 were selected based on the PRISMA flow diagram. The overall prevalence of the Mtb genotypes/sublineage in Iran was determined using the random effects or fixed effect model. The metafor R package and MedCalc software were employed for performing this meta-analysis.

Results

We identified 34 studies for inclusion in this study, containing 8329 clinical samples. Based on the pooled prevalence of the Mtb genotypes, NEW1 (21.94, 95% CI: 16.41–28.05%), CAS (19.21, 95% CI: 14.95–23.86%), EAI (12.95, 95% CI: 7.58–19.47%), and T (12.16, 95% CI: 9.18–15.50%) were characterized as the dominant circulating genotypes in Iran. West African (L 5/6), Cameroon, TUR and H37Rv were identified as genotypes with the lowest prevalence in Iran (< 2%). The highest pooled prevalence rates of multidrug-resistant strains were related to Beijing (2.52, 95% CI) and CAS (1.21, 95% CI).

Conclusions

This systematic review showed that Mtb populations are genetically diverse in Iran, and further studies are needed to gain a better insight into the national diversity of Mtb populations and their drug resistance pattern.

Role of Immigration in Tuberculosis Transmission to Iran: A Systematic Review

Background:

Today, because of increasing immigration and the prevalence of drug-resistant tuberculosis in Iran, identifying intra-community cases is necessary in the country. It will be possible through the use of molecular epidemiologic methods. In this inquiry, in order to determine the role of immigrants in the transmission of specific strains to Iran, the studies have been examined which had been conducted based on molecular epidemiologic methods among Iranians and non-Iranians people.

Methods:

All studies from 1997 to the end of March 2017 were examined in three databases of PubMed, Scopus, and Google Scholar and finally, 16 studies were selected.

Results:

The common clustering rate between Iranians and non-Iranians was determined to be 19.8, and the intra-community recent transmission rate was from 0% to 49% with average of 18.1%. The rate of multidrug-resistant tuberculosis (MDR-TB) was 12.5%, which was higher among immigrants, especially Afghans, and a significant number of the strains were Beijing.

Conclusions:

The studies have shown that migrants, especially Afghans, are more effective in transmitting specific strains of tuberculosis to migratory areas. To control tuberculosis, it is necessary to register of immigrant's health information, while enter to the country, so that, by doing appropriate diagnostic tests, the curing the patients, the transmission of tuberculosis to the country would be prevented.

Prevalence of tuberculosis and multidrug resistant tuberculosis in the Middle East Region

INTRODUCTION

Prevalence of TB and MDR-TB varies considerably among various regions of World Health Organization (WHO) and also among individual countries within each region. Many Middle Eastern countries have war/civil war-like situations, refugees from war-torn countries or dynamic expatriate population from TB endemic countries which will likely affect the END-TB strategy launched by the WHO in 2015. Areas covered: The data for each of 17 countries comprising the Middle East were analyzed for estimated incidence of TB, number of notified TB cases, mortality rate, and rate of MDR-TB in new and previously treated TB cases as reported by WHO. Data from national surveys or surveillance studies from individual countries were also analyzed for incidence of MDR-TB in new and previously treated TB patients and compared with the estimated data by WHO. Expert commentary: Several Middle Eastern countries have low/intermediate incidence rate and are striving for TB elimination. Reaching pre-elimination (< 1 TB case per 100 000 population) stage will require testing and treatment of latent TB infection in groups at high risk of reactivation and effective treatment of drug-susceptible and drug-resistant TB cases. Large numbers of refugees, expatriate workers, or confounding noncommunicable diseases in some countries pose major challenges in achieving progress toward TB elimination.

Challenge in direct Spoligotyping of Mycobacterium tuberculosis: a problematic issue in the region with high prevalence of polyclonal infections

OBJECTIVE

Based on our recent studies the prevalence of polyclonal infection in tuberculosis clinical specimens is more than 50% in Tehran, Iran. With this background, Spoligotyping was performed on clinical specimens and their respective cultures, and we examined whether mixed infections interfere with the results or not.

RESULTS

Based on the Spoligotyping pattern, among the fourteen patients, 57.1% had different genotypes in clinical samples and their respective cultures. These discrepant patterns were suggestive of polyclonal infections in clinical samples with possible overlapping Spoligotype patterns. We propose that in societies with high mixed infections (e.g. Iran), direct Spoligotyping on clinical samples can be controversial.

Migration and tuberculosis transmission in a middle-income country: a cross-sectional study in a central area of São Paulo, Brazil

BACKGROUND

Little is known about the impact of growing migration on the pattern of tuberculosis (TB) transmission in middle-income countries. We estimated TB recent transmission and its associated factors and investigated the presence of cross-transmission between South American migrants and Brazilians.

METHODS

We studied a convenient sample of cases of people with pulmonary TB in a central area of São Paulo, Brazil, diagnosed between 2013 and 2014. Cases with similar restriction fragment length polymorphism (IS6110-RFLP) patterns of their Mycobacterium tuberculosis complex isolates were grouped in clusters (recent transmission). Clusters with both Brazilian and South American migrants were considered mixed (cross-transmission). Risk factors for recent transmission were studied using logistic regression.

RESULTS

Isolates from 347 cases were included, 76.7% from Brazilians and 23.3% from South American migrants. Fifty clusters were identified, which included 43% South American migrants and 60.2% Brazilians (odds ratio = 0.50, 95% confidence interval = 0.30-0.83). Twelve cross-transmission clusters were identified, involving 24.6% of all clustered cases and 13.8% of all genotyped cases, with migrants accounting for either an equal part or fewer cases in 11/12 mixed clusters.

CONCLUSIONS

Our results suggest that TB disease following recent transmission is more common among Brazilians, especially among those belonging to high-risk groups, such as drug users. Cross-transmission between migrants and Brazilians was present, but we found limited contributions from migrants to Brazilians in central areas of São Paulo and vice versa.

The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis

Global tuberculosis incidence has declined marginally over the past decade, and tuberculosis remains out of control in several parts of the world including Africa and Asia. Although tuberculosis control has been effective in some regions of the world, these gains are threatened by the increasing burden of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. XDR tuberculosis has evolved in several tuberculosis-endemic countries to drug-incurable or programmatically incurable tuberculosis (totally drug-resistant tuberculosis). This poses several challenges similar to those encountered in the pre-chemotherapy era, including the inability to cure tuberculosis, high mortality, and the need for alternative methods to prevent disease transmission. This phenomenon mirrors the worldwide increase in antimicrobial resistance and the emergence of other MDR pathogens, such as malaria, HIV, and Gram-negative bacteria. MDR and XDR tuberculosis are associated with high morbidity and substantial mortality, are a threat to health-care workers, prohibitively expensive to treat, and are therefore a serious public health problem. In this Commission, we examine several aspects of drug-resistant tuberculosis. The traditional view that acquired resistance to antituberculous drugs is driven by poor compliance and programmatic failure is now being questioned, and several lines of evidence suggest that alternative mechanisms-including pharmacokinetic variability, induction of efflux pumps that transport the drug out of cells, and suboptimal drug penetration into tuberculosis lesions-are likely crucial to the pathogenesis of drug-resistant tuberculosis. These factors have implications for the design of new interventions, drug delivery and dosing mechanisms, and public health policy. We discuss epidemiology and transmission dynamics, including new insights into the fundamental biology of transmission, and we review the utility of newer diagnostic tools, including molecular tests and next-generation whole-genome sequencing, and their potential for clinical effectiveness. Relevant research priorities are highlighted, including optimal medical and surgical management, the role of newer and repurposed drugs (including bedaquiline, delamanid, and linezolid), pharmacokinetic and pharmacodynamic considerations, preventive strategies (such as prophylaxis in MDR and XDR contacts), palliative and patient-orientated care aspects, and medicolegal and ethical issues.

Tuberculosis Control and Role of Molecular Epidemiology Studies in Iran: A Systematic Review

BACKGROUND

Today because of immigration, HIV pandemic and spread of drug resistant tuberculosis, mortality caused by tuberculosis (TB) has increased. To control the disease it is essential to identify the sources of the infection and patterns of transmission. This becomes possible through using molecular epidemiology methods.

MATERIALS AND METHODS

This research reviewed studies based on IS6110-restriction fragment length polymorphism (IS6110-RFLP) as a primary method to recognize the role of molecular epidemiology researches in managing TB in Iran. Within 1995-2015 all human population based studies which had use IS6110-RFLP as the primary method systematically reviewed.

RESULTS

At the end, 11 articles were selected. The mean clustering rate obtained was 28.1%. The rate of recent transmission was variable from 2% to 49% and the mean value was determined 17%.

CONCLUSION

The studies revealed that in Iran both reactivation and recent transmission were significant in developing new cases of TB. Yet, reactivation plays greater role. If the matter is supervised insufficiently and carelessly, because of increasing rate of drug resistant TB, immigration of HIV infected individuals, TB especially drug resistant TB will be problematic in the near future.

Molecular typing methods used in studies of Mycobacterium tuberculosis in Iran: a systematic review

BACKGROUND AND OBJECTIVES

Molecular typing methods are important and useful tools to assess the transmission, diversity of strains and differentiation between new infections and relapses which can effectively help in controlling infections. The aim of this study was to evaluate the molecular typing methods which have been used in Iran. By evaluating the results and discriminatory power of each method, we can assign appropriate weight to each technique and ultimately offer a common strategy for future epidemiological studies.

METHOD

We searched several databases to identify studies addressing Mycobacterium tuberculosis molecular epidemiology in Iran. Hunter-Gaston discrimination index (HGDI) was used to evaluate the discriminatory power in each method. Relevant articles were selected and analyzed; HGDI index was calculated for each technique.

RESULTS

The most common genotyping methods used in the articles were RFLP, MIRU-VNTR, spoligotyping, PFGE and RAPD-PCR. The most frequently techniques were IS6110-RFLP, MIRU-VNTR and spoligotyping alone or in combination. The highest discrimination power (average HGDI: 0.9916) was obtained by RFLP followed by MIRU-VNTR (average HGDI: 0.9638) and spoligotyping (average HGDI: 0.9041) respectively.

CONCLUSION

Combination of MIRU-VNTR with spoligotyping can be recommended for large-scale genotyping in Iran. It seems appropriate to consider spoligotyping as the first technique for screening followed by other techniques with higher discrimination power such as MIRU-VNTR or IS6110-RFLP.

First-Line Anti-Tubercular Drug Resistance of Mycobacterium tuberculosis in IRAN: A Systematic Review

BACKGROUND

The spread of drug-resistant tuberculosis (TB) is one of the major public health problems through the world. Surveillance of anti-TB drug resistance is essential for monitoring of TB control strategies. The occurrence of drug resistance, particularly multi-drug resistance Mycobacterium tuberculosis (MDR), defined as resistance to at least rifampicin (RIF) and isoniazid (INH), has become a significant public health dilemma. The status of drug-resistance TB in Iran, one of the eastern Mediterranean countries locating between Azerbaijan and Armenia and high-TB burden countries (such as Afghanistan and Pakistan) has been reported inconsistently. Therefore, the aim of this study was to summarize reports of first-line anti-tubercular drug resistance in M. tuberculosis in Iran.

MATERIAL AND METHODS

We systematically reviewed published studies on drug-resistant M. tuberculosis in Iran. The search terms were "Mycobacterium tuberculosis susceptibility" or "Mycobacterium tuberculosis resistant" and Iran.

RESULTS

Fifty-two eligible articles, published during 1998-2014, were included in this review. Most of the studies were conducted in Tehran. The most common used laboratory method for detecting M. tuberculosis drug resistant was Agar proportion. The highest resistance to first-line drugs was seen in Tehran, the capital city of Iran. The average prevalence of isoniazid (INH), rifampin (RIF), streptomycin (SM), and ethambotol (EMB) resistance via Agar proportion method in Tehran was 26, 23, 22.5, and 16%, respectively. In general, resistance to INH was more common than RIF, SM, and EMB in Tehran Conclusions: In conclusion, this systematic review summarized the prevalence and distribution of first-line anti-tubercular drug resistance of M. tuberculosis in Iran. Our results suggested that effective strategies to minimize the acquired drug resistance, to control the transmission of resistance and improve the diagnosis measures for TB control in Iran.

Mycobacterium tuberculosis phylogeography in the context of human migration and pathogen's pathobiology: Insights from Beijing and Ural families

Here, I review the population structure and phylogeography of the two contrasting families of Mycobacterium tuberculosis, Beijing and Ural, in the context of strain pathobiology and human history and migration. Proprietary database (12-loci MIRU-VNTR profiles of 3067 Beijing genotype isolates) was subjected to phylogenetic and statistical analysis. The highest rate (90%) and diversity (HGI 0.80-0.95) of the Beijing genotype in North China suggest it to be its area of origin. Under VNTR-based MDS analysis the interpopulation genetic distances correlated with geography over uninterrupted landmasses. In contrast, large water distances together with long time generated remarkable outliers. Weak and less expected affinities of the distant M. tuberculosis populations may reflect hidden epidemiological links due to unknown migration. Association with drug-resistance or increased virulence/transmissibility along with particular human migration flows shape global dissemination of some Beijing clones. The paucity of data on the Ural genotype prevents from high-resolution analysis that was mainly based on the available spoligotyping data. The North/East Pontic area marked with the highest prevalence of the Ural family may have been the area of its origin and primary dispersal in Eurasia. Ural strains are not marked by increased pathogenic capacities, increased transmissibility and association with drug resistance (but most recent reports describe an alarming increase of MDR Ural strains in some parts of eastern Europe and northwestern Russia). Large-scale SNP or WGS population-based studies targeting strains from indigenous populations and, eventually, analysis of ancient DNA will better test these hypotheses. Host genetics factors likely play the most prominent role in differential dissemination of particular M. tuberculosis genotypes.

Major infectious diseases affecting the Afghan immigrant population of Iran: a systematic review and meta-analysis

OBJECTIVES

As Afghans make up the largest group of foreign nationals in Iran, the aim of this study was to assess the proportion of Afghan immigrants among those afflicted by the most prevalent infectious diseases in Iran.

METHODS

National and international online scientific databases were searched through November 2013. The reference lists of included studies were also searched. All descriptive studies concerning the most common infectious diseases in Iran, including tuberculosis, multiple-drug-resistant tuberculosis, malaria, cholera, Crimean-Congo hemorrhagic fever, leishmaniasis, and hepatitis B were retrieved. The nationality of patients was not considered. The selection of studies and data extraction was performed separately by two authors. Results were reported using a random effect model with a 95% confidence interval (CI).

RESULTS

The overall proportion of Afghan immigrants with the aforementioned infectious diseases was 29% (95% CI, 21 to 37). According to a stratified analysis, the proportion of Afghan immigrants afflicted with tuberculosis was (29%), multiple-drug-resistant tuberculosis (56%), malaria (40%), cholera (8%), Crimean-Congo hemorrhagic fever (25%), leishmaniasis (7%), and hepatitis B (14%).

CONCLUSIONS

It is highly recommended to monitor the health status of the Afghan immigrants when entering Iran, to reduce the spread of communicable diseases, which are viewed as serious in international health regulations.

Prevalence and occurrence rate of Mycobacterium tuberculosis Haarlem family multi-drug resistant in the worldwide population: A systematic review and meta-analysis

BACKGROUND

Transmission of Mycobacterium tuberculosis (M. tuberculosis) can occur in different ways. Furthermore, drug resistant in M. tuberculosis family is a major problem that creates obstacles in treatment and control of tuberculosis (TB) in the world. One of the most prevalent families of M. tuberculosis is Haarlem, and it is associated with drug resistant. Our objectives of this study were to determine the prevalence and occurrence rate of M. tuberculosis Haarlem family multi-drug resistant (MDR) in the worldwide using meta-analysis based on a systematic review that performed on published articles.

MATERIALS AND METHODS

Data sources of this study were 78 original articles (2002-2012) that were published in the literatures in several databases including PubMed, Science Direct, Google Scholar, Biological abstracts, ISI web of knowledge and IranMedex. The articles were systematically reviewed for prevalence and rate of MDR. Data were analyzed using meta-analysis and random effects models with the software package Meta R, Version 2.13 (P < 0.10).

RESULTS

Final analysis included 28601 persons in 78 articles. The highest and lowest occurrence rate of Haarlem family in M. tuberculosis was in Hungary in 2006 (66.20%) with negative MDR-TB and in China in 2010 (0.8%), respectively. From 2002 to 2012, the lowest rate of prevalence was in 2010, and the highest prevalence rate was in 2012. Also 1.076% were positive for MDR and 9.22% were negative (confidence interval: 95%).0020.

CONCLUSION

Many articles and studies are performed in this field globally, and we only chose some of them. Further studies are needed to be done in this field. Our study showed that M. tuberculosis Haarlem family is prevalent in European countries. According to the presence of MDR that was seen in our results, effective control programs are needed to control the spread of drug-resistant strains, especially Haarlem family.

Extensive Genetic Diversity among Clinical Isolates of Mycobacterium tuberculosis in Central Province of Iran

Human tuberculosis caused by Mycobacterium tuberculosis (Mtb) remains a significant disease in many countries. According to Iran's borders with Afghanistan and Pakistan, which are among the 22 high burden countries around the world, this study was conducted to analyze the current molecular epidemiology of tuberculosis and survey genetic diversity of Mtb strains in Markazi Province in center of Iran. In this experimental study, 75 sputum specimens and one gastric lavage from all smear-positive TB patients admitted to the public hospitals across the Markazi Province were cultured on specific mycobacterial culture media. Genomic DNA was digested by PvuII and transferred to positively charged nylon membrane by southern blotting method and hybridization by PGRS and DR probes. Genotyping of the isolates by PGRS-RFLP and DR-RFLP displayed a wide range of genetic diversity as 25 and 26 genotypes were identified, respectively. Generally speaking, despite the relatively limited number of isolates in the study, high age of patients and also large heterogeneity found in the setting are both in opposition to active circulation of Mtb strains between patients under study either Iranian or Afghan nationals. Thus, it seems that reactivation of latent infection has had the main role in the spread of tuberculosis.

Estimation of Recent Transmission of Mycobacterium Tuberculosis Strains among Iranian and Afghan Immigrants: A Cluster-Based Study

BACKGROUND

Iran has extended borders with high-TB burden countries (Afghanistan and Pakistan) and immigrations of these populations influences TB distribution in the region and threatens the control strategies. The aim of this study was to evaluate the extent of recent TB transmission among Iranian and Afghan cases.

MATERIALS AND METHODS

Spoligotyping and 15-locus variable number tandem repeat (VNTR) typing were applied to genotype 102 MTB isolates (2009 to 2010). Phylogenetic relationships were analysed by two methods: a cluster-graph method and a minimum spanning tree (MST) method. Furthermore, evaluation of recent TB transmission was assessed with three indices including, RTIn, RTIn-1 and TMI.

RESULTS

Using molecular typing, 35 different spoligotypes were detected among the studied isolates. Seventy seven cases (75.4%) were distributed into 10 clusters and the remaining 25 (24.5%) isolates had a unique pattern. The cluster sizes also ranged from 2 to 21 isolates. The most frequent spoligotype in our populations belong to Haarlem (n=30, 29.4%) followed by CAS (n= 29, 28.4%) and Beijing (n=16, 15.6%) lineages. The used indices give the following values: RTIn = 0.75, RTIn-1 = 0.65 and TMI = 0.24.

CONCLUSION

The low rate of TB transmission in our findings (24%) showed that the mode of TB transmission in Iran is mostly associated with reactivation of a previous TB infection and that recently a transmitted disease has a minor role. However, the increasing incidence of the intra-community transmission in recent years highlights the need for establishing new strategies for control of TB.

Lessons from the profile of kidney diseases among Afghan refugees

BACKGROUND

Due to a paucity of research on the profile of kidney diseases among refugee populations, specifically Afghan refugees in Iran, this study aimed to illustrate the pattern of kidney disease among Afghan refugees in Iran and create a database for evaluating the performance of future health services.

MATERIAL AND METHODS

This was a retrospective cross sectional study, in which we collected the demographics and profile of kidney diseases among Afghan refugees between 2005 and 2010 from referrals to the United Nations High Commissioner for Refugees (UNHCR) offices in Iran.

RESULTS

The total number of referrals in this group of diseases was 3193 out of 23 152 with 41.5% female and 58.5% male. Regarding age distribution, 10.5% were 0-14 years of age, 78% were 15-59, and 11.5% were ≥60. The most common health referral for females and males (0-14) was end-stage renal disease (ESRD), accounting for 34.6%. This was also the main reason of referrals for females and males aged 15-59, accounting for 73.5% and 66.6%, respectively, and in both sexes in the ≥60 age range it was 63.1%.

CONCLUSIONS

The pattern of our renal clinic referrals may gradually change to ESRD, which is associated with a huge economic burden. The need to provide health insurance to everyone or reform the health care system to provide coverage for more of the population can be justified and would improve cost effectiveness.

Prevalence of Beijing family in Mycobacterium tuberculosis in world population: Systematic Review and Meta-Analysis

BACKGROUND

In this present study we decided to consider the prevalence and distribution of Beijing family in the world using meta-analysis based on systematic review of articles published and relation with drug resistance, which will provide more detailed information to clearly overview the status of this family and transmission of TB.

METHODS

This study used the most available article published in literature database including PubMed, Science direct, Web of Science, Google Scholar, Biological abs, Iranmedex, and SID systematically reviewed prevalence of Beijing family. Data analyzed using meta-analysis with random effects models.

RESULTS

Final analyses included 264 samples that have been selected from 2811 studies. Overall Beijing family prevalence in world was estimated to be 33.2% (95% CI 31.4-35.2). Corresponding estimates by continent were Asia 44.7% (39.5-49.8), Europe 27.9% (25.6-30.1), Africa 12·5% (8.9-16.2), and America 8.9% (6.9-10.9). In all world regions, Beijing families were associated with drug resistance 81.37%.

CONCLUSIONS

According to the results, prevalence of Beijing family in Asia is higher than similar studies in other parts of the world and this family is associated with drug resistance. Effective control program is needed in world to control the spread of drug resistance strains specially Beijing family.

Determining the Latent Tuberculosis Infection by IFN - γ Elispot Assay in Healthcare Workers From University Hospitals of Shiraz, South West of Iran

Background

Classical screening methods are incapable to properly detect LTBI (Latent TB Infection) and HCWs (Healthcare Workers) are at the high risk of exposure. Only few reports estimated the prevalence of LTBI among Iranian HCWs and they mostly used the TST (Tuberculin Skin Test), rather than assessing the response against TB-specific antigens.

Objectives

The current study aimed to determine the frequency of IFN - γ producing blood cells of microbiology and radiology ward technicians by an in-house IFN - γ ELISPOT assay in the University hospitals of Shiraz University of Medical Sciences (SUMS) against recombinant ESAT - 6 and PPD antigens.

Materials and Methods

89 HCWs from medical laboratory and radiology departments of Shiraz University of Medical Sciences’ hospitals, South of Iran, were screened for LTBI. To achieve the goal, an in-house IFN - γ (Interferon - gamma) ELISPOT (Enzyme Linked ImmunoSpot) assay was used to detect the reactivity against ESAT - 6 (Early Secreted Antigen Target protein - 6) and the PPD (Purified Protein Derivate).

Results

Almost 8% of the personnel showed positive TST (over 10 mm) reaction while 29% of them had considerable T - cell reactivity against PPD in ELISPOT assays. However, the ESAT - 6 reactivity was found only in one case of HCWs. No correlation was found between the patterns of the reactions and the age or the duration of the employment or previous vaccination history of the participants. The ELISPOT results were not correlated with the TST results.

Conclusions

Considering the hindrance of TST, the IFN - γ ESAT - 6 ELISPOT assay, even in forms of in-house tests, could replace traditional methods to properly spot the LTBI among the high risk groups from Iran’s health system.

CD271(+) bone marrow mesenchymal stem cells may provide a niche for dormant Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) can persist in hostile intracellular microenvironments evading immune cells and drug treatment. However, the protective cellular niches where Mtb persists remain unclear. We report that Mtb may maintain long-term intracellular viability in a human bone marrow (BM)-derived CD271(+)/CD45(-) mesenchymal stem cell (BM-MSC) population in vitro. We also report that Mtb resides in an equivalent population of BM-MSCs in a mouse model of dormant tuberculosis infection. Viable Mtb was detected in CD271(+)/CD45(-) BM-MSCs isolated from individuals who had successfully completed months of anti-Mtb drug treatment. These results suggest that CD271(+) BM-MSCs may provide a long-term protective intracellular niche in the host in which dormant Mtb can reside.

Molecular Epidemiology Analysis of TB in Five Regional States of Iran

BACKGROUND

The increasing prevalence of TB drug resistant strains in absence of recent transmission evidence, highlights the need for an improved control program, coupled with a need to improve detection rate and early diagnosis. IS6110-RFLP is a means of genotyping TB clinical samples. In this study IS6110- RFLP was used for specification and quick tracking of TB infection source, transmission and reactivation of infection, in Iran.

MATERIALS AND METHODS

This study was carried out on 258 TB patients from Tehran, Mashhad, Isfahan, Shiraz and Ahwaz. DNA from positive cultures was extracted and digested by PVUII restriction enzyme. The digested sequences were separated based on the size on agar gel and then southern Blot was transferred on the membrane. IS6110 probe was marked by HRD and hybridized to the target parts along genome.

RESULTS

Sixty-one strains (24%) showed similar patterns (Recent transmission) and 197 strains (76%) showed different IS6110 patterns (Reactivation). Average number of IS6110 copies was between 10-11 bands. Frequency of IS6110 similar pattern was 11.46 in Afghan immigrants and 10.68 in Iranians.

CONCLUSION

High diversity of IS6110, indicates that 76% of the patients have been infected through reactivation by different sources, while 24% have been infected due to recent transmission. Observing different antibiogram patterns in patients infected with the same strain indicated vast transmission of a single strain in the society. A susceptible strain can be changed into mono drug resistant and MDR strain in the transition period.

A retrospective study of demographic parameters and major health referrals among Afghan refugees in Iran

Introduction

For nearly three decades, the two neighboring countries of Iran and Pakistan hosted millions of Afghans. Today, Afghans still represent the largest group of refugees in the world. This feature has greatly influenced provision of health care for this population. Due to a paucity of research on the health status of Afghan refugees in Iran, this study aim to make a vista on the pattern of different common diseases among Afghan refugees in Iran and use it as an index for performance evaluation of future health services to them.

Methods

This is a retrospective cross sectional study, in which we collected the demographic and medical data between 2005 and 2010 from referrals to the United Nations High Commissioner for Refugees (UNHCR) offices in Iran. We also considered a comparative review of the burden of disease estimates by the World Health Organization (WHO) for Afghanistan and Iran.

Results

Total numbers of referrals were 23,152 with 52.6% Female and 47.66% male. 29% were 0–14 years of age, 54% were 15–59, and 17% were 60+. The most common health referral for females and males (0–14) was perinatal diseases (15.16%, 15.2%, respectively). In the females (15–59) it was ophthalmic diseases (13.65%), and for males it was nephropathies (21.4%), and in both sexes (60+) age range it was ophthalmic diseases (21.3%, 19.9%, respectively). The largest ethnic group of afghan refugees in this study was Hazara (55%) followed by Tajik (14%), Fars (12%), Sadat (9%), and 10% others. Ophthalmic diseases were the major cause of referrals by Hazara, Tajik, Fars, and Sadat groups with 26%, 20%, 26%, and 27% respectively. Referrals by pashtun group were mostly for neoplasms (17%), among Uzbek group it was nephropathies (26%), and in Baluch group Hematopoietic disorders (25%).

Conclusion

These data indicate higher referral rate for women 15–59 years of old and people in 60+ with ophthalmic diseases, neoplasms, and nephropathies. Even given certain intrinsic limitations of such a study, we believe these unique findings are worth further explanation. This implies the need for public health researchers to pursue prospective studies in these areas.

Testing for the presence of Mycobacterium tuberculosis Beijing genotype strains in Syrian samples

The Beijing family of Mycobacterium tuberculosis (MTB) has been reported to have an exceptional capacity to spread tuberculosis (TB) and induce multi-drug resistance. A method has been developed to distinguish this family from the rest of the MTB families through real-time DNA amplification and subsequent analysis of the melting point of an amplicon. Two pools of multi-drug resistant (MDR) MTB samples collected at two different time periods from various regions in Syria have been selected. This preliminary screening indicated a complete absence of the Beijing family in all samples. This research presents an effective differentiation of bacterial Beijing strains, with minimal effort and cost through analysis of differential amplicon melting points.

The emergence of Beijing genotype of Mycobacterium tuberculosis in the Kingdom of Saudi Arabia

OBJECTIVE

To investigate the prevalence of Beijing genotype strains of Mycobacterium tuberculosis in the Kingdom of Saudi Arabia.

METHODS

We analyzed the available data on a total of 1505 strains isolated during 2002-2005.

RESULTS

Spoligotyping results revealed that Beijing family isolates represented 4.5% of all the isolates. Existence of Beijing clade is alarming as this family is known to be multi-drug resistant and transmissible.

CONCLUSIONS

This study showed that the occurrence of Beijing genotype is associated with young age and drug resistance. The Beijing strains affected both Saudi nationals as well as migrants originating in Asia. The Beijing clade could be responsible for the ongoing transmission of tuberculosis within the community.

Rapid Detection of Isoniazid Resistance in Mycobacterium tuberculosis by a Single Multiplex Allele-specific Polymerase Chain Reaction Assay

OBJECTIVE

Global surveillance has shown that drug resistant (DR) tuberculosis (TB) is widespread. Prompt detection of Mycobacterium tuberculosis drug resistance is essential for effective control of TB. The most frequent mutations associated with Isoniazid (INH) resistance in Mycobacterium are substitutions at codons 315 in the katG gene and the mabA-inhA promoter region (-15). This survey evaluated INH resistant-associated mutations in order to determine rapid detection of TB resistance.

MATERIALS AND METHODS

Through a descriptive cross- sectional study total of 96 sputum specimens were digested, examined microscopically for acid-fast bacilli and inoculated into Löwenstein-Jensen slants. Thereafter, the susceptibility and identification tests were performed on culture positive specimens. Subsequently, the strains were subjected to multiplex allele-specific polymerase chain reaction (MAS-PCR) targeting in the codons 315 in the katG gene and the mabA-inhA promoter region. Distinct PCR banding patterns were observed for different mutation profiles.

RESULTS

Drug susceptibility testing revealed that out of 96 available isolates, 30 (31.3%) were susceptible, 36 (37.5%) had multi-drug resistance (MDR-TB) and 30 (31.3%) showed mono- drug resistance. In comparison with the culture-based phenotypic drug susceptibility test, the sensitivity and specificity of MAS-PCR assay for drug resistance-related genetic mutations were 76.7% and 71.4%, respectively. The correlation between MAS-PCR and culture-based phenotypic drug susceptibility testing findings was 99.4%.

CONCLUSION

The profile of the isolates suggests a significant number of different DR strains with a high frequency of mutations at codon 315 of the katG gene. MAS-PCR provides a rapid, simple and cost-effective method for detecting MDR-TB.

Integration of Mycobacterium tuberculosis drug susceptibility testing and genotyping with epidemiological data analysis to gain insight into the epidemiology of drug-resistant tuberculosis in Malatya, Turkey

Drug-resistant tuberculosis (TB) presents a major challenge to global TB control. To gain a better understanding of drug-resistant TB epidemiology in Malatya, Turkey, we conducted the present study using 397 Mycobacterium tuberculosis clinical isolates collected from Malatya, Turkey, in recent years (2000-2007). Resistance to any anti-TB drug was found in 29% (114 of 397) of the study isolates, while the multidrug resistance (MDR) rate was approximately 4.5% (18 of 397). Resistances to isoniazid (15.5%) and streptomycin (13.4%) were about twice as high as resistance to rifampin (RMP) (6.3%) and ethambutol (EMB) (6.0%). Importantly, 28% (7 of 25) of the RMP-resistant isolates were non-MDR isolates, as when a significant proportion of RMP-resistant isolates in a population are non-MDR, the predictive value of molecular detection of RMP resistance for MDR can be significantly reduced. Both identical and varied drug resistance patterns were seen in the same genotyping-defined clusters, suggesting that both primary and acquired resistance have contributed to the drug-resistant TB epidemic in Malatya, Turkey. In addition, drug-resistant cases were found to be more likely to be males (odds ratio [95% confidence interval], 1.82 [1.13, 2.94]), suggesting a potential role of gender in the epidemiology of drug-resistant TB in the study population. This study demonstrates that the integration of drug susceptibility testing with genotyping and epidemiological data analysis represents a useful approach to studying the epidemiology of drug-resistant TB.

Mycobacterium tuberculosis genotypic diversity in pyrazinamide-resistant isolates of Iran

Pyrazinamide (PZA) is an important first-line drug used for the short-course treatment of tuberculosis in combination with isoniazid and rifampin. It has been reported that mutations in pncA gene correlate well with PZA resistance depending on the geographic area. On the other hand, different genotypes of Mycobacterium tuberculosis show different affinities to acquire resistance-related mutations. To determine the relative significance of various mutations in the pncA gene in Iranian PZA-resistant M. tuberculosis isolates and to analyze the association of different genotypes of M. tuberculosis with PZA resistance, 34 PZA-resistant M. tuberculosis isolates were analyzed for their pncA mutations using direct sequencing. These isolates were genotyped by IS6110 fingerprinting and spoligotyping methods. Mutations in the pncA gene were identified in 24 of 34 of these isolates (70.58%). No mutations were found in 10 PZA-resistant isolates, which implied that alternative mechanisms of resistance existed in these strains. PZA resistance was strongly (41.2%) associated with multidrug-resistant tuberculosis. Genotyping revealed the Central Asian (CAS) and East-African Indian families as the most prevalent families between PZA-monoresistant isolates versus the Beijing and Haarlem families which were the most frequent families between PZA including multidrug-resistant isolates.

Emergence of new forms of totally drug-resistant tuberculosis bacilli: super extensively drug-resistant tuberculosis or totally drug-resistant strains in iran

BACKGROUND

The study documented the emergence of new forms of resistant bacilli (totally drug-resistant [TDR] or super extensively drug-resistant [XDR] tuberculosis [TB] strains) among patients with multidrug-resistant TB (MDR-TB).

METHODS

Susceptibility testing against first- and second-line drugs was performed on isolated Mycobacterium tuberculosis strains. Subsequently, the strains identified as XDR or TDR M tuberculosis were subjected to spoligotyping and variable numbers of tandem repeats (VNTR).

RESULTS

Of 146 MDR-TB strains, 8 XDR isolates (5.4%) and 15 TDR isolates (10.3%) were identified. The remaining strains were either susceptible (67%) or had other resistant patterns (20%). Overall, the median of treatments and drugs previously received by MDR-TB patients was two courses of therapy of 15 months' duration with five drugs (isoniazid [INH], rifampicin [RF], streptomycin, ethambutol, and pyrazinamide). The median of in vitro drug resistance for all studied cases was INH and RF. The XDR or TDR strains were collected from both immigrants (Afghan, 30.4%; Azerbaijani, 8.6%; Iraqi, 4.3%) and Iranian (56.5%) MDR-TB cases. In such cases, the smear and cultures remained positive after 18 months of medium treatment with second-line drugs (ethionamide, para-aminosalicylic acid, cycloserine, ofloxacin, amikacin, and ciprofloxacin). Spoligotyping revealed Haarlem (39.1%), Beijing (21.7%), EAI (21.7%), and CAS (17.3%) superfamilies of M tuberculosis. These superfamilies had different VNTR profiles, which eliminated the recent transmission among MDR-TB cases.

CONCLUSIONS

The isolation of TDR strains from MDR-TB patients from different regional countries is alarming and underlines the possible dissemination of such strains in Asian countries. Now the next question is how one should control and treat such cases.