Prevalence of Latent Tuberculosis Infection in the Middle East and North Africa: A Systematic Review

Prevalence of opportunistic infections in Syrian inflammatory bowel disease patients on biologic therapy: a multi-center retrospective cross-sectional study

BACKGROUND

Hepatitis B, hepatitis C, cytomegalovirus (CMV), and tuberculosis (TB) pose significant risks to patients with inflammatory bowel disease (IBD) receiving biological therapy. However, data on the prevalence of these infections in Syria are scarce.

METHODS

We conducted a retrospective chart review of IBD patients receiving biologic therapy at Damascus Hospital and Ibn Al-Nafees Hospital, two major public institutions in Syria, between January 2021 and November 2024. A minimum sample size of 130 was estimated; however, all available records were reviewed.

RESULTS

Among 185 IBD patients (104 from Damascus and 81 from Ibn Al-Nafees), 51.4% had ulcerative colitis and 47.6% had Crohn's disease. The smoking prevalence was 9.2%, which was higher in Crohn's disease (5.9%) than in ulcerative colitis (3.2%). TST performed in 61.1% of patients, with 4.3% positivity, and interferon-gamma release assay (IGRA) in 8.7% (1.1% positive). Hepatitis B surface antigen (HBsAg) and anti-HBc antibodies were found in 2.7% and 5.4% of the patients, respectively, while hepatitis C seroprevalence was low (0.5%). CMV seropositivity was high in Damascus (50.8%), with two cases (1.1%) of CMV colitis. Biologic therapies included infliximab (42.7%), ustekinumab (24.3%), golimumab (10.8%), and adalimumab (6.5%). Data gaps, particularly in viral serology and TB screening, are notable.

CONCLUSION

This study identifies deficiencies in TB/hepatitis B screening (notably anti-HBs Ab) and elevated CMV seroprevalence among Syrian IBD patients receiving biologics, extending to immunosuppressed cohorts (rheumatology, dermatology, oncology). Insufficient screening heightens occult infection/reactivation risks, necessitating standardized pretreatment protocols to reduce morbidity in high-risk populations.

CLINICAL TRIAL NUMBER

Not applicable.

Identification of immune phenotypes and diagnostic biomarkers in active and latent tuberculosis infections

The diagnosis and treatment of tuberculosis rely on a deep understanding of the pathobiology and immune responses. This study aimed to identify potential immune response mechanisms by integrating gene expression analysis with immune cell distribution profiling to characterize the immune phenotypes of active tuberculosis (ATB) and latent tuberculosis infection (LTB). Differentially expressed genes (DEGs) between ATB or LTB and controls were identified using the GSE19491 and GSE107994 datasets. A total of 273 and 105 immune-related DEGs were identified in ATB and LTB through ImmProt database, respectively. Immune-related DEGs specific to LTB were mainly enriched in the MAPK signaling pathway, Ras signaling pathway. Furthermore, random forest analysis identified HLA-DRB5 and IRF1 as showing diagnostic potential in ATB, LCN10, SHC1, IKBKG, RETN, and SOS1 showed importance in LTB. Flow cytometry detected significantly higher levels of macrophages M0 in ATB compared to LTB and controls, while other types of immune cells showed significant increases in LTB. The levels of marker genes were validated by RT-qPCR and Western blot, as well as single-cell data in ATB and LTB. The findings of this study provide potential biomarkers for the diagnosis of tuberculosis and may facilitate the development of more effective treatment strategies.

Sarcoidosis in first- and second-generation immigrants: a cohort study of all adults 18 years of age and older in Sweden

BACKGROUND

There is a lack of studies on sarcoidosis among immigrants, which is of interest as there may be genetic and environmental characteristics affecting immigrants from certain countries. We aimed to study hazard ratios (HRs) of sarcoidosis in first- and second-generation immigrants, comparing them with native Swedes in the total adult Swedish population.

METHODS

We conducted a nationwide study of individuals ≥18 y of age. Sarcoidosis was defined as at least two registered diagnoses in the National Patient Register between 1 January 1998 and 31 December 2018. Cox regression analysis was used to estimate HRs with 99% confidence intervals (CIs) of first registration of sarcoidosis in first- and second-generation immigrants compared with native Swedes. The Cox regression models were stratified by sex and adjusted for age, comorbidities and sociodemographic characteristics.

RESULTS

In total, 6 175 251 were included in the first-generation study, with 12 617 cases of sarcoidosis, and 4 585 529 in the second-generation study, with 12 126 cases. The overall sarcoidosis risk was lower in foreign-born men (fully adjusted HR 0.63 [99% CI 0.57 to 0.69]) but not in foreign-born women (fully adjusted HR 0.98 [99% CI 0.90 to 1.06]). The overall risk was slightly lower in second-generation immigrants (HR 0.82 [99% CI 0.78 to 0.88]). Women from Asia exhibited a higher risk (HR 1.25 [99% CI 1.02 to 1.53)], while a potential trend was observed among women from Africa (HR 1.47 [99% CI 0.99 to 2.19]).

CONCLUSIONS

Sarcoidosis risk was lower in foreign-born men but not in women and also lower in second-generation immigrants.

Intestinal Helminth Infections and Their Association with QuantiFERON-TB Gold Plus Test Performance in an Endemic Setting, Northwest Ethiopia

Background

Timely detection and treatment of latent TB infection (LTBI) is part of WHO's strategy against tuberculosis (TB). Helminth infections can modulate immune responses, potentially impacting the performance of interferon-gamma release assays (IGRAs) such as the QuantiFERON-TB Gold Plus (QFT-Plus). This study evaluated the association between helminth infections and QFT-Plus results among participants from a TB-endemic region.

Methods

A cross-sectional study was conducted from October 2022 to March 2023 in Bahir Dar, Ethiopia. Stool samples of 314 potential participants were examined for helminths using wet mount and Kato-Katz techniques. LTBI was assessed by QFT-Plus from a total of 100 gender-matched helminth-positive and -negative participants. The association between helminth infection status, egg count, and QFT-Plus positivity was analyzed, and p values <0.05 were considered significant.

Results

Overall, 53 of 314 screened participants were infected with helminths (16.9%), with A. lumbricoides (47.2%) and hookworm (30.2%) as most prevalent species. The overall QFT-Plus positivity rate was 30.0%, with similar rates observed between helminth-positive and helminth-negative participants. Although QFT-Plus positivity was slightly lower in hookworm carriers (25%) compared to those with A. lumbricoides (32%), a higher-than-median hookworm egg burden was significantly associated with reduced QFT-Plus positivity (P = 0.029). QFT-Plus positivity was significantly higher among male participants than females (P = 0.032).

Conclusion

While overall helminth infection status did not significantly affect QFT-Plus positivity, higher hookworm burden was associated with reduced QFT-Plus reactivity. These findings suggest that the type of helminth and infection intensity, rather than its mere presence, may influence IGRA performance. Further studies with larger sample sizes are warranted to understand the species-specific effect of helminth infection on immune modulation of the host.

Magnitude and Determinants of Latent Tuberculosis Among Inmates of Saudi Correctional Facilities: A Cross-Sectional Study

Purpose

To estimate the prevalence and determinants of latent tuberculosis (LTBI) among inmates of four correctional facilities in Saudi Arabia.

Methods

This is a retrospective review of health records. All inmates of four correctional facilities in Saudi Arabia were screened for tuberculosis in 2022. Their LTBI status was defined as more than 10mm Mantoux test result and negative X-ray chest result. The prevalence of LTBI and their determinants like age, gender, country of origin, location of the prison, and human immunodeficiency viruses (HIV) status were studied.

Results

We reviewed screening data of 10,042 inmates in four Saudi prisons. The prevalence of LTBI was 7.4%. The risk difference of LTBI was significantly higher in males compared to female inmates (P < 0.001). The highest prevalence of LTBI was noticed among males (7.7%), those older than 60 years old (26.9%), and African expatriates (12.1%). None of the female inmates or those with HIV had LTBI. The binomial regression analysis revealed a highly significant effect of older age on the risk of having LTBI.

Conclusion

The prevalence of LTBI was low among inmates at Saudi correctional facilities. The males, old age, and persons from African and Asian countries had a higher risk of LTBI. The prevalence of LTBI among inmates of Saudi prisons could be predicted by knowing their age group.

Prior COVID-19 infection among newly diagnosed tuberculosis patients in a tertiary care center in Tehran: A case-control study

OBJECTIVE

To assess the risk of developing pulmonary tuberculosis (TB) in accordance with prior history of COVID-19 infection.

BACKGROUND

Since the advent of the COVID-19 pandemic much discussion has been had on the possible role it might play on global efforts to combat TB; most, focusing on the pandemic's impact on health care systems' capabilities to manage TB cases. Mechanisms have also been proposed by which the COVID-19 infection may directly affect individuals' chance of developing TB infection. Cases have been reported with a history of COVID-19 infection preceding a diagnosis of TB, evidencing its possible role as a risk factor for the disease.

METHODS

A case-control study was conducted enrolling patients diagnosed with pulmonary TB in the absence of major risk factors previous history of TB, (HIV) human immunodeficiency virus infection), end-stage renal disease, organ transplants, and use of immunosuppressive agents) for developing TB. Each patient was age and sex matched with one healthy control. Data regarding prior COVID-19 infection, diabetes, and smoking status as well as the use of corticosteroids and Tocilizumab for the treatment of COVID-19 infection was obtained. Bivariate analysis was conducted and variables with a likely association with TB status were entered in a multivariate model.

RESULTS

Bivariate analysis demonstrated a significant relationship between prior COVID-19 infection and TB (95% confidence interval = 1.1-22.8, odds ratio [OR] = 5). Among other variables the severity of COVID-19 infection was found to have a likely association with TB status (p = .125). In a multivariate model, prior COVID-19 infection per se, was not found to be significantly associated with TB (p = .12, OR = 4.5).

CONCLUSIONS

There seems to be an association between prior history of COVID-19 and a future diagnosis of TB partially linked to the severity of disease. The findings of the current study may serve as a basis for further studies to determine the need for and efficacy of measures to follow-up COVID-19 patients at an increased risk for developing TB.

Mycobacterium tuberculosis latent infection in healthcare students: systematic review of prevalence

OBJECTIVE

The aim of this study was to synthesize the evidence on the prevalence of latent Mycobacterium tuberculosis infection (LTBI) among undergraduate health care students.

METHODS

A systematic review of prevalence with meta-analysis was conducted. Prospective and retrospective cohorts and cross-sectional studies involving probable exposure to M. tuberculosis during undergraduate education, along with the tuberculin skin test (TST) or interferon-γ release assay (IGRA) for investigation of latent tuberculosis were searched. Searches were conducted in MEDLINE, CINAHL, EMBASE, LILACS, Scopus, and Web of Science databases. Independent reviewers were responsible for the selection and inclusion of studies. Data were extracted, critically appraised, and synthesized using the JBI approach. PRISMA was used to report the study.

RESULTS

Twenty-two studies were analyzed. The overall prevalence in healthcare undergraduate students was 12.53%.

CONCLUSION

The prevalence of LTBI in undergraduate health students was high for such a highly educated population. Screening with TST and/or IGRA and chemoprophylaxis, when necessary, should be provided to undergraduate health students when in contact with respiratory symptomatic patients.

Tuberculosis in Sudan: systematic review and meta analysis

Every year, 10 million people fall ill with tuberculosis (TB). Despite being a preventable and curable disease, 1.5 million people die from TB each year -making it the world's top infectious disease. TB is the leading cause of death of people with HIV and also a major contributor to antimicrobial resistance. Its presumed that TB was the cause of 1% of the total deaths among inpatients in Sudan in 2017. The current study is aimed to provide pooled prevalence of Mycobacterium tuberculosis among Sudanese as well as to determine any socio-cultural risk factors associated. A systematic review of the literature was conducted and regulated in accordance with the PRISMA Statement. After abstract and full text screening only twenty-six articles met our inclusion criteria and passed the quality assessment procedure. Pulmonary tuberculosis prevalence was assessed in sixteen included studies among participants from Khartoum, Gezira, Kassala, Blue Nile, River Nile, White Nile, Gadarif, Red sea, North Kordofan, Northern State, Sennar and West Darfur States, representing a total sample size of 11,253 participants of suspected individuals such as febrile outpatients, TB patients' contacts and other groups such as HIV/AIDS patients, hemodialysis patients, School adolescents as well as pregnant women. The pooled prevalence was 30.72% [CI: 30.64, 30.81]. Moreover, Khartoum State recorded the highest pooled prevalence as 41.86% [CI: 14.69, 69.02] based on a total sample size of 2,737 participants. Furthermore, male gender and rural residence were found to be significantly associated with TB infection. Further research with larger sample sizes targeting prevalence and risk factors of TB among Sudanese population is needed to be conducted.

Prevalence of Latent Tuberculosis Infection Among Rheumatology Patients and Management Practices in the United Arab Emirates: A Single-Center Retrospective Cohort Study

Introduction Prior to immunosuppression, rheumatology patients are routinely screened for latent tuberculosis (TB) infection using interferon-gamma release assays (IGRAs). Variability in the management of latent and indeterminate IGRA results across institutions limited long-term outcome data. A retrospective study was conducted at Tawam Hospital, United Arab Emirates, to investigate the incidence and management protocols associated with positive and indeterminate IGRA results, as well as TB infection, among patients with rheumatic conditions. Methods A single-center retrospective observational study was performed at Tawam Hospital, Abu Dhabi, UAE. Ethical approval for this study was obtained from the Tawam Human Research Ethics Committee. Laboratory records and the hospital's electronic medical system were used to obtain information about IGRA results over a 12-year period (April 2010-April 2022). The hospital's electronic medical system was used to obtain patient information and subsequent management approaches of positive and indeterminate IGRAs. Moreover, long-term follow-up data were collected to determine the risk of TB reactivation in the cohort. Results We found a total of 1,012 positive and 223 indeterminate IGRA test results within the 12-year period. Within the rheumatology department, 123 positive and 39 indeterminate IGRA results were identified. In the indeterminate IGRA group, the majority were women (n = 24, 61.5%) and UAE nationals (n = 22, 56.4%), and their mean age was 38.6 years. Systemic lupus erythematosus was the most prevalent rheumatologic condition (n = 21, 53.8%). Thirteen (33.3%) were on disease-modifying anti-rheumatic drugs (DMARDs) and 26 (66.7%) were on corticosteroids during IGRA testing. A total of eight patients (20.5%) received anti-TB medications. In the positive IGRA group, the mean age was 55.7 years and the female-to-male ratio was 3:1. The most common rheumatologic condition was rheumatoid arthritis (n = 69, 56%). Sixty-five (52.8%) patients were on conventional DMARDs, 43 (34.9%) were on corticosteroids during IGRA testing, and 74 (60%) received anti-TB medications. Two cases (1.6%) of active TB infections were detected among patients with positive IGRA tests, both of whom were receiving anti-tumor necrosis factor alpha inhibitor treatment in combination with methotrexate. No cases of active TB infection were observed in the indeterminate IGRA group. Conclusion Long-term data on the risk of TB activation in positive and indeterminate IGRA results for rheumatological conditions are low. It is recommended to reassess the choice of using anti-TNF-α, with a positive IGRA result if no other feasible alternatives can be offered. Our findings stress the importance of age, underlying diseases, and immunosuppressive treatments in interpreting IGRA results and guiding patient management. A large multicenter study is needed to understand the differences and outcomes of such patients in TB endemic and nonendemic geographical areas.

High prevalence of current tobacco smoking among patients with tuberculosis and people living with HIV in Jordan: A cross-sectional survey

INTRODUCTION

Continued smoking by patients with tuberculosis (TB) and people living with HIV (PLHIV) leads to adverse treatment outcomes. Estimates of tobacco use among the population are scarce in the Eastern Mediterranean region, where the burden of TB and HIV is also low but highly variable. This study determined the prevalence of current smoking and assessed factors associated with current smoking among patients with TB and PLHIV in Jordan.

METHODS

We analyzed data from the Jordan Knowledge, Attitude, and Practices survey in 2021. Information on current tobacco use, including products and frequency of smoking, was collected from 452 patients with TB and 152 PLHIV. We performed multivariable logistic regression to assess the sociodemographic characteristics independently associated with current smoking.

RESULTS

Prevalence of current smoking was 43.8% among TB patients and 67.8 % among PLHIV, and conventional cigarettes were the most used tobacco products. The prevalence of current smoking among patients with TB was higher among males (AOR=8.20; 95% CI: 5.05-13.32), Jordanians (AOR=5.37; 95% CI: 2.66-10.86) and Syrians (AOR=4.13; 95% CI: 1.60-10.67), and those experiencing financial difficulties (AOR=2.83; 95% CI: 1.69-4.74). The prevalence of current smoking among PLHIV was higher in those with financial difficulties (AOR=3.13; 95% CI: 1.19-8.27).

CONCLUSIONS

Nearly half of the patients with TB and PLHIV were current tobacco smokers, higher than the general population. There is an urgent need to investigate the reasons for such a high smoking prevalence and introduce and strengthen smoking cessation services under the TB and HIV control programs.

Changes in the rate of bacillus tuberculosis infection in health workers in the first year of the COVID-19 epidemic in Kashan- Iran

Objective

This cohort study aimed to determine the prevalence and risk factors of latent tuberculosis infection among healthcare workers during the COVID-19 pandemic.

Methods

A one-year cohort study was conducted in a referral hospital in Kashan, involving 176 medical, educational, and cleaning personnel. Initial evaluations and tuberculin skin tests were performed, followed by a one-year follow-up period. Data were analyzed using SPSS version 26 software.

Results

Among the participants, 26.1% (46 individuals) tested positive for latent tuberculosis infection. Age was a significant risk factor, with a 3.6% increase in latent tuberculosis infection risk with each advancing year. Men had 2.19 times (1.10-4.35) the chance of having a latent infection compared to women. Hospital staff were 3.7 times more at risk of tuberculosis infection than students. Among the hospital job categories, nursing assistants had the highest chance of tuberculosis infection, 6.77 times higher than medical students, followed by cleaning staff and nurses. The ICU, General, and Obstetrics and Gynecology departments had an infection chance of 2.46 (1.11-5.46) compared to other departments. No new positive cases were detected during the follow-up period.

Conclusion

This study contributes to the understanding of latent tuberculosis infection prevalence and its risk factors among healthcare workers during the COVID-19 pandemic. The findings highlight the importance of infection control measures and targeted interventions to protect healthcare workers from occupational tuberculosis exposure.

Genetic and hormonal mechanisms underlying sex-specific immune responses in tuberculosis

Tuberculosis (TB), the world's deadliest bacterial infection, afflicts more human males than females, with a male/female (M/F) ratio of 1.7. Sex disparities in TB prevalence, pathophysiology, and clinical manifestations are widely reported, but the underlying biological mechanisms remain largely undefined. This review assesses epidemiological data on sex disparity in TB, as well as possible underlying hormonal and genetic mechanisms that might differentially modulate innate and adaptive immune responses in males and females, leading to sex differences in disease susceptibility. We consider whether this sex disparity can be extended to the efficacy of vaccines and discuss novel animal models which may offer mechanistic insights. A better understanding of the biological factors underpinning sex-related immune responses in TB may enable sex-specific personalized therapies for TB.

Prevalence trends of latent tuberculosis infection at the global, regional, and country levels from 1990-2019

OBJECTIVES

To track the prevalence trends of latent tuberculosis infection (LTBI) at the global, regional, and national levels.

METHODS

Data on the prevalence of LTBI were extracted from the Global Burden of Disease database. The average annual percent change (AAPC) was estimated by joinpoint regression and was used to evaluate the epidemic of the disease.

RESULTS

Globally, the prevalence rate of LTBI decreased from 30.66% in 1990 to 23.67% in 2019, with an AAPC of -0.9%. The prevalence rate of LTBI varied from 5.02% (Jordan) to 48.35% (Uganda) in 1990 and from 2.51% (Jordan) to 43.75% (Vietnam) in 2019 at the country level. The prevalence decreased in all the six World Health Organization (WHO) regions and in most countries, with the AAPC ranging from -0.5% in the Western Pacific Region to -2.1% in the European Region and from -4.3% (Bhutan) to -0.1% (Malaysia, Myanmar, South Africa, Tokelau, and Vietnam), respectively. Disparities were also observed among different sex and age groups.

CONCLUSION

The prevalence of LTBI decreased slightly worldwide in the last three decades, but the decrease is slow and not sufficient to meet the targets of WHO tuberculosis elimination. Much more effort and progress should be made in order to decrease the prevalence of LTBI.

Latent Tuberculosis Infection Status of Pregnant Women in Uganda Determined Using QuantiFERON TB Gold-Plus

Background

The risk of progression of latent tuberculosis infection (LTBI) to active disease increases with pregnancy. This study determined the prevalence and risk factors associated with LTBI among pregnant women in Uganda.

Methods

We enrolled 261 pregnant women, irrespective of gestational age. Participants who had known or suspected active tuberculosis (TB) on the basis of clinical evaluation or who had recently received treatment for TB were excluded. LTBI was defined as an interferon-γ concentration ≥0.35 IU/mL (calculated as either TB1 [eliciting CD4⁺ T-cell responses] or TB2 [eliciting CD8⁺ T-cell responses] antigen minus nil) using QuantiFERON TB Gold-Plus (QFT-plus) assay.

Results

LTBI prevalence was 37.9% (n = 99) (95% confidence interval [CI], 32.3–44.0). However, 24 (9.2%) subjects had indeterminate QFT-plus results. Among participants with LTBI, TB1 and TB2 alone were positive in 11 (11.1%) and 18 (18.2%) participants, respectively. In multivariable analysis, human immunodeficiency virus (HIV) infection (adjusted odds ratio [aOR], 4.4 [95% confidence interval {CI}, 1.1–18.0]; P = .04) and age 30–39 years (aOR, 4.0 [95% CI, 1.2–12.7]; P = .02) were independently associated with LTBI. Meanwhile, smoking status, alcohol use, nature of residence, crowding index, and TB contact were not associated with LTBI.

Conclusions

Our findings are in keeping with the evidence that HIV infection and advancing age are important risk factors for LTBI in pregnancy. In our setting, we recommend routine screening for LTBI and TB preventive therapy among eligible pregnant women.