Changes in incidence and clinical features of tuberculosis with regard to the COVID-19 outbreak in Southern Iran

INTRODUCTION

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a significant global health threat. It results in substantial mortality and may be underrecognized due to insufficient screening and diagnostic challenges. Furthermore, TB's impact is closely linked to complex socioeconomic and healthcare factors. The COVID-19 pandemic has exacerbated these challenges due to similarities in clinical presentation and transmission dynamics with TB. Socioeconomic factors such as limited access to healthcare services, resource constraints, and social stigma further complicate TB management. Historically, TB faced increased burdens during natural disasters, wars, and pandemics. This study analyzes TB incidence changes, emphasizing the crucial need for timely diagnosis within the context of COVID-19 measures.

METHOD

This cross-sectional study, conducted at Shiraz's TB referral center in Southern Iran, covered the period from January 1, 2018, to December 31, 2022. We analyzed patient data, including epidemiological and demographic factors, clinical and radiological features, and treatment outcomes. Data were compared between the pre-COVID-19 pandemic era and the COVID-19 pandemic era (from March 2020), using standard and regression analyses. A P-value of less than 0.05 was considered statistically significant.

RESULTS

We analyzed 388 TB patients with a mean age of 48.38 ± 20.53 years, including 264 pulmonary cases (68.0%). The highest incidence of TB was recorded in 2019, representing 27.6% of the cases. During the COVID-19 era, logistic regression analysis identified significant associations with higher education levels (P = 0.032; OR = 1.380; 95% CI: 1.028-1.851), a decrease in symptoms such as sputum production (P = 0.004; OR = 0.342; 95% CI: 0.166-0.705) and chills (P = 0.036; OR = 0.282; 95% CI: 0.087-0.919), and an increase in symptoms of fatigue (P = 0.006; OR = 2.856; 95% CI: 1.358-6.005).

CONCLUSION

The COVID-19 pandemic has had a prolonged impact on TB cases in our country, resulting in a reduction in reported cases due to challenges in quarantine and screening. However, it has also led to a shift in TB patterns and a potential increase in latent TB cases and future mortality rates. Addressing the repercussions requires enhanced control strategies, prioritized service delivery, and secured funding for intensified case finding, expanded contact-tracing, community engagement, digital health tools, and uninterrupted access to medications.

Spatial Distribution of Smear-Positive Pulmonary Tuberculosis Incidence Rates in Iran: A Registry-Based Study (2018-2022)

Background

Smear-positive pulmonary tuberculosis (SPPTB) is a significant public health concern in Iran. This registry-based study aimed to investigate the incidence rates of SPPTB in Iran from 2018 to 2022.

Methods

The study analyzed SPPTB cases using the Spatial Lag Model to investigate the spatial distribution of SPPTB incidence rates, income inequality, and delayed diagnosis across the provinces of Iran and mapped the results using GIS maps.

Results

The study found that SPPTB is prevalent among older individuals and males. The analysis identified significant spatial variation in the distribution of SPPTB incidence rates, income inequality, and delayed diagnosis across the provinces. The highest incidence rate of SPPTB was found in Sistan and Baluchestan Province and Golestan provinces. The study found a positive association between income inequalities, measured by the Gini index, and SPPTB incidence rates, indicating that provinces with higher income inequality may have higher incidence rates of SPPTB. The negative correlation with delayed diagnosis implies that predominantly, SPPTB cases are identified in the early months.

Conclusions

The study highlights the need to address socioeconomic disparities in health outcomes and implement targeted interventions in areas with higher income inequality to reduce the burden of SPPTB in Iran. Despite decreased SPPTB incidence rates in Iran over the past decade, some regions, such as Sistan and Baluchestan, still have high incidence rates. The Iranian government has implemented policies and programs to reduce income inequality and delayed diagnosis within the country, which can contribute to reducing the burden of SPPTB.

First Molecular Evidence of Emerging Lophomonas Pathogen Among Patients Suspected of Having Pulmonary Tuberculosis in Mazandaran Province, Northern Iran

PURPOSE

Lophomoniasis is a chronic protozoan respiratory disease in humans with main clinical symptoms such as chronic cough, productive sputum, breath shortness, and occasionally hemoptysis. Differentiation diagnosis of lophomoniasis from tuberculosis (TB) and asthma is crucial.

METHODS

In this study, 210 participants with suspected TB referred to tuberculosis laboratories in Mazandaran province, northeastern Iran, were enrolled during 2021. All patients showed low grade fever, chronic cough or sputum on referral. Sputum specimens were collected from the participants, and Lophomonas DNA was detected through a conventional genus-specific polymerase chain reaction (PCR).

RESULTS

Out of 210 participants, 67 (31.9%) had Lophomonas spp., infection, 38 (18.1%) had TB (Smear and culture-positive), and 20 (9.5%) had both TB and Lophomonas co-infection.

CONCLUSION

Based on our results, a relatively high occurrence of Lophomonas infection was found among patients suspected of having TB. Accordingly, due to the high similarity of clinical symptoms between both pulmonary diseases, it is highly recommended to accurately and early diagnose the parasite in the sputum specimen.

Prevalence of Tuberculosis among People Who Use Drugs in Iran: A Systematic Review and Meta-analysis

Background

Drug use, especially injecting drug use, is associated with a higher risk of tuberculosis (TB). This study aimed to systematically review the prevalence of TB among people who use drugs (PWUD) in Iran.

Methods

A systematic search was conducted in international and national databases. All studies that provided data on the prevalence of TB among PWUD based on screening tests and diagnosis from 1990 up to August 2019 were assessed. Meta-analysis was performed on the prevalence of active TB among people who inject drugs (PWID).

Findings

Overall, nine studies were included. The studies were carried out from 1994 to 2012 in seven out of the 31 provinces of Iran. Seven studies provided data on the prevalence of TB diagnosis among 1087 PWID. The pooled prevalence of TB diagnosis was 10.1% (95% CI: 4.5, 15.8) in studies carried out in hospitals and 0.54% (95% CI: 0.04, 1.04) in other settings.

Conclusion

The present review suggests an approximately 40 times higher prevalence of TB among PWID compared to the general population. However, most of the included studies were conducted on a subpopulation of drug users, and caution should be exercised when generalizing the findings.

Investigating the intensity of social contacts associated with tuberculosis: a weighted networks model

BACKGROUND

Tuberculosis is known as one of the principal health problems, especially in developing countries. This study aimed to visualize, statistically model, and describe the weighted networks to investigate the intensity of social contacts associated with tuberculosis.

METHODS

In this case-control study, we applied weighted network analysis to assess the network of person-time spent in stores, workplaces, restaurants, mosques, Police bases, homes, hospitals, colleges, hairdressers, schools, contact homes, health centers, cinemas, parks, and markets. Modules will be determined based on the similarities between the variables in a topology overlap matrix. The most important variables will be found considering the association between each variable and module eigenvalues.

RESULTS

The result shows the extracted modules of locations based on the connectivity followed by the person-time at each place. The correlation (p-value) between TB and the turquoise, blue, and brown modules was 0.058 (0.351), 0.004 (0.943), and 0.117 (0.039), respectively. The brown module is the most important one, demonstrating a significant connection between homes, contact homes, health centers, and hospitals. Therefore, an association was found between person-time in four places and the occurrence of TB.

CONCLUSION

The finding of this study showed that most transmission of tuberculosis infection occurs in homes, contact homes, health centers, and hospitals. These place evaluations allow the identification of people with more contact and in need of screening, so critically leading to the identification of more patients with active TB.

High Occurrence of Emerged Lophomonas Infection among Patients Suspected of Having Pulmonary Tuberculosis: In-House PCR-Based Evidence

Objectives

Lophomonas infection is a respiratory disease in humans that is associated with symptoms of cough, sputum, dyspnea, and sometimes hemoptysis, which shows the importance of differentiating this disease from tuberculosis and asthma.

Methods

This study was performed on 216 participants suspected of having tuberculosis who had symptoms of fever, chronic cough, or sputum and were referred to tuberculosis laboratories in three cities in Golestan Province, northeastern Iran, during 2019-2020. A sputum sample was taken from the suspected patients. DNA was extracted from the frozen samples, and an in-house polymerase chain reaction was performed to detect the Lophomonas DNA.

Results

Out of 216 subjects, 47 (21.75%) were infected with Lophomonas spp. Moreover, 9 patients (4.2%) were infected with tuberculosis. Also, 2 patients had a comorbidity of tuberculosis and Lophomonas infection (P=0.63). There was no significant difference in the comparison of symptoms and the rate of Lophomonas infection (P=0.84), but in the comparison of the set of symptoms of cough, sputum, and fever with those of cough and sputum, cough with fever, sputum with fever, and the rate of Lophomonas infection, there was a significant difference (P=0.012).

Conclusions

Lophomonas infection was relatively high in patients suspected of having tuberculosis and due to the similar clinical symptoms of Lophomonas infection and tuberculosis; it is recommended that the sputum samples of subjects suspected of having tuberculosis be examined for this parasite in order to make a correct diagnosis and the patients receive timely treatment and the appropriate medication.

The probability of diagnostic delays for tuberculosis and its associated risk factors in northwest Iran from 2005 to 2016: a survival analysis using tuberculosis surveillance data

OBJECTIVES

Early diagnosis is essential for effective tuberculosis (TB) control programs. Therefore, this study examined the risk of delays in TB diagnosis and associated factors in Ardabil Province in northwest Iran from 2005 to 2016.

METHODS

This longitudinal retrospective cohort study was conducted using data obtained from the Iranian National Tuberculosis Control Program at the provincial level between 2005 and 2016. The total delay in diagnosis was defined as the time interval (days) between the onset of symptoms and TB diagnosis. Survival analysis was conducted to analyze the delay in diagnosis. Associated factors were identified using a Cox proportional hazards model.

RESULTS

A total of 1,367 new TB cases were identified. The 12-year median diagnostic delay was 45 days (interquartile range [IQR], 30-87). The annual median diagnostic delay decreased from 68 days (IQR, 33-131) in 2005 to 31 days (IQR, 30-62) in 2016. The probability of a delay in TB diagnosis decreased by 5.0% each year (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.04 to 1.07). Residence in a non-capital county (HR, 0.83; 95% CI, 0.74 to 0.92) and referral from the private health system (HR, 0.74%; 95% CI, 0.65 to 0.84) were significantly associated with an increased risk of delay in TB diagnosis over the 12-year study period.

CONCLUSIONS

The median delay decreased during the study period. We identified factors associated with a longer delay in TB diagnosis. These findings may be useful for further TB control plans and policies in Iran.

Genetic diversity of drug-resistant Mycobacterium tuberculosis clinical isolates from Khuzestan province, Iran

The emergence of drug-resistant strains of the Mycobacterium tuberculosis (MTB) has challenged tuberculosis control programs. So far, few studies using the 24-locus mycobacterial interspersed repetitive unit variable number tandem repeats (MIRU-VNTR) have investigated the genetic diversity of MTB in Iran. This study aimed to determine the genetic diversity of MTB isolates resistant to first-line anti-tuberculosis drugs using 24-locus MIRU-VNTR in southwestern Iran. Out of 6620 MTB clinical isolates, 29 resistant isolates to one or more isoniazid, rifampin, and ethambutol were detected using drug susceptibility testing by the proportional method. The manual 24-locus MIRU-VNTR was used to determine the MTB resistant isolates’ phylogenetic relationship. MIRU-VNTRplus web application tools were applied to analyze the associated data. Using 24-locus MIRU-VNTR, 13.8% of isolates (n = 4) were distributed in two clusters, and the remaining 86.2% (n = 25) showed a unique pattern. Four clonal complexes were observed in the minimum spanning tree based on the double-locus variant. Most isolates belonged to Delhi/CAS (34.5%, 10/29) and NEW-1 (24.1%, 7/29) sub-lineages, followed by EAI and LAM with a frequency of 6.9% (2/29) and 3.5% (1/29), respectively. Eight isolates (27.6%) did not match any genotype in the database. The 24-locus MIRU-VNTR showed a high discriminatory power; however, the 15-locus and 12-locus set analyses were more discriminative. Our study revealed a high degree of genetic diversity among drug-resistant MTB isolates, which could be interpreted as the low rate of person-to-person transmission in this region. The 15-locus MIRU-VNTR would be recommended for preliminary genotyping of drug-resistant MTB.

A Saudi Arabian Public Health Perspective of Tuberculosis

Tuberculosis is a global health challenge due to its spreading potential. The Kingdom of Saudi Arabia (KSA) faces a challenge in the spread of tuberculosis from migrant workers, but the foremost threat is the huge number of pilgrims who travel to visit sacred sites of the Islamic world located in the holy cities of Makkah and Al Madina. Pilgrims visit throughout the year but especially in the months of Ramadan and Zul-Hijah. The rise of resistance in Mycobacterium tuberculosis is an established global phenomenon that makes such large congregations likely hotspots in the dissemination and spread of disease at a global level. Although very stringent and effective measures exist, the threat remains due to the ever-changing dynamics of this highly pathogenic disease. This overview primarily highlights the current public health challenges posed by this disease to the Saudi health system, which needs to be highlighted not only to the concerned authorities of KSA, but also to the concerned global quarters since the pilgrims and migrants come from all parts of the world with a majority coming from high tuberculosis-burdened countries.

Spatio-temporal epidemiology of the tuberculosis incidence rate in Iran 2008 to 2018

BACKGROUND

Effective reduction of tuberculosis (TB) requires information on the distribution of TB incidence rate across time and location. This study aims to identify the spatio-temporal pattern of TB incidence rate in Iran between 2008 and 2018.

METHODS

This cross-sectional study was conducted on aggregated TB data (50,500 patients) at the provincial level provided by the Ministry of Health in Iran between 2008 and 2018. The Anselin Local Moran's I and Getis-Ord Gi* were performed to identify the spatial variations of the disease. Furthermore, spatial scan statistic was employed for purely temporal and spatio-temporal analyses. In all instances, the null hypothesis of no clusters was rejected at p ≤ 0.05.

RESULTS

The overall incidence rate of TB decreased from 13.46 per 100,000 (95% CI: 13.19-13.73) in 2008 to 10.88 per 100,000 (95% CI: 10.65-11.11) in 2018. The highest incidence rate of TB was observed in southeast and northeast of Iran for the whole study period. Additionally, spatial cluster analysis discovered Khuzestan Province, in the West of the country, having significantly higher rates than neighbouring provinces in terms of both total TB and smear-positive pulmonary TB (SPPTB). Purely temporal analysis showed that high-rate and low-rate clusters were predominantly distributed in the time periods 2010-2014 and 2017-2018. Spatio-temporal results showed that the statistically significant clusters were mainly distributed from centre to the east during the study period. Some high-trend TB and SPPTB statistically significant clusters were found.

CONCLUSION

The results provided an overview of the latest TB spatio-temporal status In Iran and identified decreasing trends of TB in the 2008-2018 period. Despite the decreasing incidence rate, there is still need for screening, and targeting of preventive interventions, especially in high-risk areas. Knowledge of the spatio-temporal pattern of TB can be useful for policy development as the information regarding the high-risk areas would contribute to the selection of areas needed to be targeted for the expansion of health facilities.

The economic burden of tuberculosis in Sistan: a high-risk region in Iran

INTRODUCTION

To estimate the economic burden of tuberculosis treatment in Sistan, the region with the highest number of tuberculosis cases in Iran.

METHODS

All patients with smear-positive pulmonary tuberculosis who had contracted tuberculosis in 2018 and successfully completed their treatment were interviewed.

RESULTS

Ninety patients with a mean age of 57 ± 18 years were interviewed. Most of them were women (58%), housewives (57%) and resided in rural areas (84%). The mean cost of treatment for tuberculosis was estimated as 6800 USD per patient. Direct costs were 87% of the total cost. Twenty-two patients lost an average income of 530 USD (8514590 rials) during treatment. The results showed the significant correlation of direct and indirect costs with sex, age, place of residence and education (P < 0.05).

CONCLUSION

It appears essential to improve social protection and implement interventions to promote knowledge in rural areas.

Bayesian Spatial Survival Analysis of Duration to Cure among New Smear-Positive Pulmonary Tuberculosis (PTB) Patients in Iran, during 2011-2018

Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), and pulmonary TB is the most prevalent form of the disease worldwide. One of the most concrete actions to ensure an effective TB control program is monitoring TB treatment outcomes, particularly duration to cure; but, there is no strong evidence in this respect. Thus, the primary aim of this study was to examine the possible spatial variations of duration to cure and its associated factors in Iran using the Bayesian spatial survival model. All new smear-positive PTB patients have diagnosed from March 2011 to March 2018 were included in the study. Out of 34,744 patients, 27,752 (79.90%) patients cured and 6992 (20.10%) cases were censored. For inferential purposes, the Markov chain Monte Carlo algorithms are applied in a Bayesian framework. According to the Bayesian estimates of the regression parameters in the proposed model, a Bayesian spatial log-logistic model, the variables gender (male vs. female, TR = 1.09), altitude (>750 m vs. ≤750 m, TR = 1.05), bacilli density in initial smear (3+ and 2+ vs. 1–9 Basil & 1+, TR = 1.09 and TR = 1.02, respectively), delayed diagnosis (>3 months vs. <1 month, TR = 1.02), nationality (Iranian vs. other, TR = 1.02), and location (urban vs. rural, TR = 1.02) had a significant influence on prolonging the duration to cure. Indeed, pretreatment weight (TR = 0.99) was substantially associated with shorter duration to cure. In summary, the spatial log-logistic model with convolution prior represented a better performance to analyze the duration to cure of PTB patients. Also, our results provide valuable information on critical determinants of duration to cure. Prolonged duration to cure was observed in provinces with low TB incidence and high average altitude as well. Accordingly, it is essential to pay a special attention to such provinces and monitor them carefully to reduce the duration to cure while maintaining a focus on high-risk provinces in terms of TB prevalence.

Genotypic and phenotypic characterization of Mycobacterium tuberculosis resistance against fluoroquinolones in the northeast of Iran

BACKGROUND

Fluoroquinolones are broad-spectrum antibiotics that are recommended, and increasingly important, for the treatment of multidrug-resistant tuberculosis (MDR-TB). Resistance to fluoroquinolones is caused by mutations in the Quinolone Resistance Determining Region (QRDR) of gyrA and gyrB genes of Mycobacterium tuberculosis. In this study, we characterized the phenotypic and genotypic resistance to fluoroquinolones for the first time in northeast Iran.

METHODS

A total of 123 Mycobacterium tuberculosis isolates, including 111 clinical and 12 collected multidrug-resistant isolates were studied. Also, 19 WHO quality control strains were included in the study. The phenotypic susceptibility was determined by the proportion method on Löwenstein-Jensen medium. The molecular cause of resistance to the fluoroquinolone drugs ofloxacin and levofloxacin was investigated by sequencing of the QRDR region of the gyrA and gyrB genes.

RESULTS

Among 123 isolates, six (4.8%) were fluoroquinolone-resistant according to phenotypic methods, and genotypically three of them had a mutation at codon 94 of the gyrA gene (Asp→ Gly) which was earlier reported to cause resistance. All three remaining phenotypically resistant isolates had a nucleotide change in codon 95. No mutations were found in the gyrB gene. Five of the 19 WHO quality control strains, were phenotypically fluoroquinolone-resistant, four of them were genotypically resistant with mutations at codon 90, 91 of the gyrA gene and one resistant strain had no detected mutation.

CONCLUSIONS

Mutation at codon 94 of the gyrA gene, was the main cause of fluoroquinolone resistance among M. tuberculosis isolates in our region. In 3/6 fluoroquinolone-resistant isolates, no mutations were found in either gyrA or gyrB. Therefore, it can be concluded that various other factors may lead to fluoroquinolone resistance, such as active efflux pumps, decreased cell wall permeability, and drug inactivation.

Molecular identification of mutations conferring resistance to rifampin, isoniazid and pyrazinamide among Mycobacterium tuberculosis isolates from Iran

Here, we aimed to determine the susceptibility of 70 Mycobacterium tuberculosis isolates obtained from different regions of the country to 8 anti-tuberculosis (anti-TB) drugs and possible underlying mechanisms causing resistance to rifampin, isoniazid, and pyrazinamide. The susceptibility of 70 isolates of M. tuberculosis to anti-TB drugs was tested using proportion method. Strains showing resistance to the first line anti-TB drugs were subjected to PCR amplification and sequencing of the rpoB, katG, ahpC, pncA genes, inhA promoter and oxyR-ahpC intergenic regions to detect resistance conferring mutations. Overall, 77.1% and 77.1% of isolates were resistant to at least one of the tested first- and second-line drugs, respectively. Within the rpoB gene the highest rate of mutation was found in codons 531(450) (56.3%), and 533(452) (12.5%). Also, codons 315 (42.4%) of katG, positions -48, -72 and -77 of oxyR-ahpC (total= 3, 9.1%) and -15 of inhA promoter region (33.3%) were the most altered positions in isoniazid resistant isolates. Only a single mutation was detected for pncA among resistant isolates. High prevalence of resistance to essential anti-TB drugs among M. tuberculosis strains isolated from retreated tuberculosis cases is alarming issue necessitating immediate action to prevent the spread of drug resistant isolates in the country.

Survival analysis of patients with tuberculosis in Erbil, Iraqi Kurdistan region

BACKGROUND

Tuberculosis is an important health concern in Iraq, but limited research has examined the quality of tuberculosis care and the survival of the patients. This study aimed to assess the 12-month survival of tuberculosis patients and evaluate the effect of the associated risk factors on patients' survival.

METHODS

We reviewed the records of 728 patients with tuberculosis who were registered and treated at the Chest and Respiratory Disease Center in Erbil, Iraqi Kurdistan Region, from January 2012 to December 2017. Demographic data, the site of the disease, and treatment outcomes were retrieved from patients' records. Data analysis included the use of the Kaplan-Meier method and the log-rank test to calculate the estimates of the survival and assess the differences in the survival among the patients. The Cox regression model was used for univariate and multivariate analysis.

RESULTS

The mean period of the follow-up of the patients was 7.6 months. Of 728 patients with tuberculosis, 50 (6.9%) had died. The 12-month survival rate of our study was 93.1%. A statistically significant difference was detected in the survival curves of different age groups (P < 0.001) and the site of the disease (P = 0.012). In multivariate analysis, lower survival rates were only observed among patients aged ≥65 years (hazard ratio = 9.36, 95% CI 2.14-40.95) and patients with extrapulmonary disease (hazard ratio = 2.61, 95% CI 1.30-5.27).

CONCLUSION

The 12-month survival rate of tuberculosis patients managed at the Chest and Respiratory Disease Center in Erbil was similar to the international rates. The high rates of extrapulmonary tuberculosis and the low survival rate necessitate further studies and action with a possible revision to the tuberculosis management strategy.

Coprevalence of type 2 diabetes mellitus and tuberculosis in low-income and middle-income countries: A systematic review

Increasing coprevalence of diabetes mellitus (DM) and tuberculosis (TB) in low-income and middle-income countries (LMICs) indicates a rising threat to the decades of progress made against TB and requires global attention. This systematic review provides a summary of type 2 diabetes and tuberculosis coprevalence in various LMICs. We searched PubMed, Ovid Medline, Embase, and PsychINFO databases for studies that provided estimates of TB-DM coprevalence in LMICs published between 1990 and 2016. Studies that were non-English and exclusively conducted in multidrug resistant-tuberculosis or type 1 diabetes and inpatient settings were excluded. We reviewed 84 studies from 31 countries. There were huge diversity of study designs and diagnostic methods used to estimate coprevalence, and this precluded pooling of the results. Most studies (n = 78) were from small, localized settings. The DM prevalence among TB patients in various LMICs varied from 1.8% to 45%, with the majority (n = 44) between 10% and 30%. The TB prevalence among people with DM ranged from 0.1% to 6.0% with most studies (n = 9) reporting prevalences less than 2%. Coprevalence of TB-DM was higher than general population prevalence of either diseases in these countries. This study underscores the need for intervention and more focused research on TB DM bidirectional screening programs in low-income and middle-income countries as well as integrated chronic disease management.