Impact of the COVID-19 pandemic on pediatric tuberculosis diagnosis: a ten-year retrospective study from Türkiye

Authors

Abstract

AimThis study aimed to investigate the impact of the COVID-19 pandemic on the epidemiology and clinical presentation of pediatric tuberculosis (TB) over a ten-year period.
MethodsA retrospective review was conducted on pediatric patients aged 0–18 years diagnosed with TB at a tertiary care hospital between March 2013 and March 2023. Cases were categorized into two groups: the pre-COVID-19 period (2013–2019) and the COVID-19 era (2020–2023). Demographic data,TB classification (pulmonary vs. extrapulmonary), bacteriological confirmation, and contact history were analyzed. Diagnosis was based on clinical assessment, radiological evaluation, and microbiological investigations, including tuberculin skin testing (TST), acid-fast bacilli (AFB) smear microscopy, and mycobacterial culture.
ResultsA total of 57 pediatric TB cases were identified, including 34 cases diagnosed in the pre-COVID-19 period and 23 cases during the COVID-19 period. The proportion of pulmonary TB remained similar between periods (47.8% vs. 47.1%, p=0.925). Comparable rates of TST positivity (31.6%, p=0.987) and culture confirmation (52%, p=0.752) were observed. Although no statistically significant differences in clinical characteristics were detected, a relative increase in TB diagnoses was noted in 2022–2023, coinciding with the normalization of healthcare services. No TB-related mortality was reported.
ConclusionWhile clinical and microbiological features of pediatric TB remained stable, post-pandemic temporal shifts in diagnosis rates likely reflect delayed case detection during the early pandemic, underscoring the need to maintain uninterrupted TB diagnostic and surveillance services during public health emergencies.

Keywords

Introduction

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains one of the most important infectious causes of morbidity and mortality in children worldwide, particularly in low- and middle-income countries.^1,2 Despite sustained global efforts aimed at TB elimination, children continue to represent a vulnerable population in whom TB remains a significant and often underrecognized public health problem.^3,4 In the decade preceding the COVID-19 pandemic, measurable progress was achieved in TB control through strengthened surveillance systems, expanded access to diagnostic tools, and improved treatment strategies. However, these gains proved fragile. With the onset of the COVID-19 pandemic, routine TB services were substantially disrupted, resulting in reduced case detection, delayed diagnoses, and a reversal of declining TB mortality trends for the first time in more than ten years.^5,6 Although the direct clinical impact of COVID-19 has been more pronounced in adults, its indirect effects on pediatric TB have raised serious concern. Public health measures such as school closures, lockdowns, and restrictions in healthcare access altered transmission dynamics and reduced opportunities for timely diagnosis in children.^7,8 hese disruptions occurred in a population already challenged by underreporting and limited access to age-appropriate TB diagnostic services.Diagnosing TB in children is inherently difficult because of non-specific clinical presentations and the paucibacillary nature of the disease, which frequently precludes microbiological confirmation.^9,10 Consequently, pediatric TB diagnosis often relies on clinical judgment supported by epidemiological and radiological findings rather than definitive laboratory evidence. This study aimed to evaluate the demographic, clinical, and laboratory features of pediatric TB cases managed at a tertiary care center between 2013 and 2023, with a particular focus on comparing the pre-COVID-19 and COVID-19 periods.
By examining potential shifts in disease presentation, diagnostic approaches, and bacteriological findings, this study seeks to provide insight into the indirect consequences of global health crises on pediatric TB care.

Materials and Methods

Study Design and SettingThis retrospective study was conducted at a tertiary care center and included pediatric patients aged 0–18 years who were diagnosed with tuberculosis between March 2013 and March 2023. Patients were followed at the Pediatric Infectious Diseases Clinic and Polyclinic of the Faculty of Medicine, Mersin University. Tuberculosis diagnosis was established based on a combination of clinical evaluation, radiological findings, and microbiological investigations, including tuberculin skin testing, acid-fast bacilli smear, and mycobacterial culture. Demographic characteristics, tuberculosis classification (pulmonary or extrapulmonary), bacteriological confirmation, and history of contact with an infectious tuberculosis case were recorded. Risk factors were defined as a history of close contact with an infectious tuberculosis case and the presence of underlying conditions known to increase susceptibility to tuberculosis. Immunosuppressive conditions were defined as chronic diseases or treatments associated with impaired immune function. Children under five years of age were considered a high-risk group for tuberculosis but were not classified as immunosuppressed solely based on age. Patients with malignancies, including lymphoma, and those receiving immunosuppressive therapy were classified as immunosuppressed. For temporal analysis, patients were categorized into two groups according to the year of diagnosis: the pre-COVID-19 period (2013–2019) and the COVID-19 period (2020–2023).
Data Collection and VariablesDemographic data, including age and sex, were recorded for all patients. Clinical variables included the anatomical classification of tuberculosis as pulmonary or extrapulmonary, diagnostic methods applied, bacteriological findings, and mycobacterial culture results. Information on contact history with an infectious tuberculosis case was also collected from medical records. Microbiological evaluation comprised tuberculin skin testing, acid-fast bacilli smear examination, and mycobacterial culture, when available. Variables were selected to allow comparison of demographic characteristics, disease classification, and microbiological confirmation rates between the pre-COVID-19 and COVID-19 periods.The primary objective of the analysis was to compare demographic, clinical, and microbiological characteristics of pediatric tuberculosis cases across the two defined time periods.
Tuberculin Skin Testing ProcedureThe Mantoux tuberculin skin test (TST) was administered intradermally. The transverse diameter of induration was measured 72 hours after administration.
TST positivity thresholds were defined according to Bacillus Calmette–Guérin (BCG) vaccination status. An induration size of ≥10 mm was considered positive in unvaccinated children, ≥15 mm in children vaccinated with one dose of BCG, and ≥17.5 mm in those who had received two doses of BCG. In immunocompromised patients, an induration of ≥5 mm was accepted as positive.¹¹
Diagnostic Criteria for TB SubtypesFor patients with suspected pulmonary tuberculosis, fasting gastric aspirate or sputum samples were obtained on three consecutive mornings for microbiological evaluation. In younger children who were unable to expectorate sputum, fasting gastric aspirates were obtained, whereas sputum samples were collected from older children when possible. Induced sputum and bronchoalveolar lavage were not performed in any patient in this study. In cases presenting with lymphadenitis or abscess formation, appropriate specimens, including lymph node aspirates or abscess material, were collected and submitted for acid-fast bacilli (AFB) smear microscopy and mycobacterial culture.Diagnostic evaluation for tuberculosis was based on clinical assessment, radiological findings, and microbiological investigations. Clinical diagnosis relied on compatible symptoms and physical examination findings, supported by radiological evidence consistent with tuberculosis. Microbiological diagnosis was based on acid-fast bacilli smear microscopy and/or mycobacterial culture positivity.Tuberculosis diagnosis was categorized as microbiologically confirmed or clinically diagnosed. Microbiologically confirmed tuberculosis was defined by the detection of Mycobacterium tuberculosis through acid-fast bacilli smear and/or mycobacterial culture positivity. Clinically diagnosed tuberculosis was defined by the presence of compatible clinical findings and radiological features consistent with tuberculosis, with or without supportive laboratory findings, in the absence of microbiological confirmation. Standard microbiological methods were used for the diagnosis of tuberculosis. Acid-fast bacilli smear microscopy and mycobacterial culture were performed according to routine laboratory protocols.
Definitions of Pulmonary and Extrapulmonary TuberculosisPulmonary tuberculosis was defined as tuberculosis involving the lung parenchyma, tracheobronchial tree, or intrathoracic lymph nodes, including cases complicated by pleural effusion or empyema. Extrapulmonary tuberculosis was defined as tuberculosis affecting organs other than the lungs, including peripheral lymph nodes, bone and joint structures, central nervous system, gastrointestinal system, or other extrapulmonary sites.
Ethical ApprovalEthical approval for the study was obtained
Statistical AnalysisData normality was assessed using the Kolmogorov-Smirnov test. Descriptive statistics were calculated for all variables: categorical data were expressed as frequencies and percentages, while continuous variables were presented as minimum, maximum, mean, and standard deviation values. Categorical variables, such as gender, diagnosis type, treatment method, and culture results, were compared between pre-COVID-19 and COVID-19 periods using the Chi-square test. Differences in age between the two groups were evaluated using the Mann-Whitney U test due to non-normal distribution. All statistical analyses were performed with IBM SPSS Statistics version 26, and a p-value of <0.05 was considered statistically significant.
Reporting GuidelinesThis study was reported in accordance with the STROBE guideline.

Results

Patients were divided into two groups according to the study period: the pre-COVID-19 period (2013–2019) and the COVID-19 period (2020–2023). Over the ten-year study period, a total of 57 pediatric TB cases were identified, including 34 cases diagnosed during the pre-COVID-19 period and 23 cases diagnosed during the COVID-19 period. Among 11,941 pediatric patients evaluated between 2013 and 2019, 0.28% (n = 34) were diagnosed with tuberculosis, whereas this proportion increased to 1.1% (n = 23) among 2,061 pediatric patients evaluated between 2020 and 2023.
The mean age of children diagnosed during the pre-COVID-19 period was comparable to that of children diagnosed during the COVID-19 period, with no statistically significant difference identified (p=0.666). When TB localization was evaluated, pulmonary TB accounted for 47.8% (n = 16) and extrapulmonary TB for 52.9% (n = 18) of cases in the pre-COVID-19 period. Similarly, during the COVID-19 period, pulmonary TB was observed in 47.1% (n = 11) and extrapulmonary TB in 52.2% (n = 12) of cases. The distribution of pulmonary and extrapulmonary TB did not differ significantly between the two periods (p=0.925). A history of contact with an infectious TB case was documented in 17.5% (n = 10) of all pediatric TB cases.Regarding diagnostic findings, tuberculin skin test positivity was detected in 31.6% (n = 18) of patients, with no statistically significant difference observed between the pre-COVID-19 and COVID-19 periods (p=0.987). Acid-fast bacilli smear positivity was identified in 53.6% (n = 30) of tested cases, while mycobacterial culture positivity was observed in 52% (n = 21) of cases. Culture positivity rates were similar between the two study periods (p=0.752). Throughout the study period, no TB-related mortality was recorded. The demographic, clinical, and microbiological characteristics of the study population are summarized in Table 1.A more detailed temporal analysis of cases diagnosed during the COVID-19 period revealed variability according to the month of admission. For the 2020–2021 period, the mean age of children diagnosed between January and June was 11.50 ± 5.75 years, compared with 4.71 ± 5.55 years between July and December, although this difference did not reach statistical significance (p=0.103). Gender distribution did not differ significantly between the two intervals (p=0.137). All cases diagnosed between January and June presented with pulmonary TB, whereas during the July–December period, 42.9% of cases had pulmonary TB and 51.7% had extrapulmonary TB; this difference was not statistically significant (p=0.058).For the 2022–2023 period, the mean age of children diagnosed between January and June was 10 ± 4.29 years, while it was 11.25 ± 7.93 years between July and December, with no statistically significant difference observed (p=0.592). A statistically significant difference in gender distribution by month was identified (p=0.010). However, no statistically significant differences were found with respect to TB localization or histopathological and bacteriological findings between the January–June and July–December periods (p>0.05). These findings are presented in Table 2.

Discussion

The COVID-19 pandemic profoundly affected healthcare systems worldwide and raised concerns regarding delayed diagnosis and management of pediatric tuberculosis.^12,13 It is extremely important to diagnose TB early in childhood. TB in children may present with different symptoms than in adults, and the diagnostic process may be more complex. Therefore, national tuberculosis control program clinics, general child health clinics, and hospitals play an important role in childhood TB diagnosis. Early recognition and treatment remain essential for preventing disease progression and complications in children. One concerning aspect of the pandemic worldwide is that the diagnostic processes of children with tuberculosis (TB) may be overlooked due to the increased workload and sometimes closure of health institutions. Additionally, since COVID-19 is milder in children and causes more serious consequences in adults, there was concern that pediatric intensive care units could serve adult patients, which could delay the treatment process of children.¹⁴ Modeling studies have suggested that disruptions in TB services during the pandemic may increase TB-related mortality.^15,16
We planned to analyze the data of tuberculosis patients diagnosed in our clinic in Turkey before and during the pandemic period. Pediatric patients usually acquire the infection from adults. Therefore, childhood tuberculosis is evidence of inadequate TB control in society. When a contagious adult TB patient is detected, their close contact with children should be screened, and after the disease is ruled out, preventive treatment should be started for these children as soon as possible.¹⁷ This study found the following findings: There was a serious increase in tuberculosis cases during and after Covid 19. It was also observed that most patients had no significant differences in the demographic and microbiological characteristics of TB. In recent years, the incidence of tuberculosis in Turkey and our province has decreased by an average of 3-5% every year in the last five years.⁴ Despite being a curable and preventable illness, tuberculosis (TB) remains a significant burden on pediatric patients. Research on pediatric TB underscores the challenges in diagnosis and the limitations of existing precautions and screening methods, even before the pandemic. Bacteriological confirmation of pediatric TB diagnosis is particularly challenging, with less than 15% of cases resulting in sputum that can be analyzed for TB bacteria. Additionally, only 30-40% of pediatric TB cases yield positive results in mycobacterial cultures.^9,10 In countries where TB is not endemic, childhood TB is primarily diagnosed in symptomatic children. Historically, household transmission has been a major factor in the spread of pediatric TB, making contact tracing an effective method for monitoring transmission patterns. However, the efficacy of contact tracing may vary depending on the local epidemiological context and healthcare infrastructure.⁷ Before the pandemic, a systematic review by Martinez et al. highlighted that household transmission was the primary driver of TB transmission in high burden-bearing areas rather than transmission from the household of a person with TB. This underscores the importance of understanding local transmission dynamics and implementing effective control measures within communities. The high burden and poor outcomes of childhood TB are largely attributed to challenges in diagnosing and verifying pediatric TB cases, leading to delays in treatment initiation.¹⁸ A significant proportion of children, more than 90%, experience delays in receiving treatment due to either lack of diagnosis or misdiagnosis . Additionally, in 2019, more than 40% of households with child contacts had not been screened for tuberculosis disease or infection, underscoring the need for expanded screening efforts to effectively identify and treat TB cases among children.¹⁹ Expanding access to TB contact tracing and implementing inhibitor treatment are crucial to improving TB control efforts. Additionally, as the COVID-19 pandemic evolves, further examination of TB screening is warranted, considering the added complications and obstacles. Unfortunately, despite efforts to increase TB contact tracing, case identification has significantly declined, particularly among the pediatric population. This trend could have significant implications for the global TB pandemic, as TB diagnoses have typically been decreasing by 1% to 2% annually.¹⁹ According to the CDC, reported TB cases in the US decreased by 20% in 2020, with a further 13% decrease in 2021 following the COVID-19 outbreak.¹⁴ In addition to these challenges, families are advised to stay together to prevent TB transmission in their homes, potentially leading to delays in diagnosis and treatment initiation.²⁰ As more data becomes available, the link between pediatric TB and the effects of COVID-19 may become more apparent. There is concern that pediatric patients may be more susceptible to the disease due to various risk factors associated with staying at home during pandemic measures ^21,22(22,23). Despite being a preventable and treatable disease, TB infection can lead to worse outcomes when compounded by COVID-19 infection.²² In a compilation by Ryckman and colleagues titled "COVID-19 post-pandemic tuberculosis worldwide," it is suggested that an intervention focused on targeting individuals and promoting equality is key to addressing health inequalities exacerbated by the pandemic.⁶
This study demonstrates a marked rise in pediatric tuberculosis (TB) cases during and after the COVID-19 pandemic, suggesting a potential shift in the disease's epidemiology. Beyond the increased incidence, the pandemic also disrupted the timely admission and management of TB cases in children. These results emphasize the ongoing need for early detection and effective treatment strategies in pediatric populations.

Limitations

The main limitations of this study are its retrospective single-center design and the relatively small sample size. In addition, the findings may not be generalizable to other populations, and some clinical data may have been affected by incomplete medical records.

Conclusion

In conclusion, this study highlights the impact of the COVID-19 pandemic on the diagnosis and clinical characteristics of pediatric tuberculosis cases. While the number of cases decreased during the pandemic, no significant differences were observed in demographic data, clinical findings, or treatment outcomes between the pre-pandemic and pandemic periods. These findings suggest that, despite healthcare disruptions, tuberculosis diagnosis and management in our clinic remained consistent. Continued TB surveillance is essential during public health emergencies.

Declarations

Abbreviations

AFB: Acid-fast bacilli
BCG: Bacillus Calmette-Guérin
COVID-19: Coronavirus disease 2019
TB: Tuberculosis
TST: Tuberculin skin test

References

1. John CA. Realizing the World Health Organization’s End TB Strategy, 2016-2035: how can social approaches to tuberculosis elimination contribute to progress in Asia and the Pacific? Trop Med Infect Dis. 2019;4(1):28. doi:10.3390/tropicalmed4010028
   Article PubMed Google Scholar
2. Liu L, Johnson HL, Cousens S. Erratum: global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000. Lancet. 2012;380(9850):1308.
   PubMed Google Scholar
3. Dodd PJ, Yuen CM, Sismanidis C, Seddon JA, Jenkins HE. The global burden of tuberculosis mortality in children: a mathematical modelling study. Lancet Glob Health. 2017;5(9). doi:10.1016/s2214-109x(17)30289-9
   Article PubMed Google Scholar
4. Swaminathan S, Rekha B. Pediatric tuberculosis: global overview and challenges. Clin Infect Dis. 2010;50(suppl 3). doi:10.1086/651490
   Article PubMed Google Scholar
5. Pai M, Kasaeva T, Swaminathan S. Covid-19’s devastating effect on tuberculosis care: a path to recovery. N Engl J Med. 2022;386(16):1490-1493. doi:10.1056/nejmp2118145
   Article PubMed Google Scholar
6. Ryckman T, Robsky K, Cilloni L, et al. Ending tuberculosis in a post-COVID-19 world: a person-centred, equity-oriented approach. Lancet Infect Dis. 2023;23(2). doi:10.1016/s1473-3099(22)00500-x
   Article PubMed Google Scholar
7. Martinez L, Lo NC, Cords O, et al. Paediatric tuberculosis transmission outside the household: challenging historical paradigms to inform future public health strategies. Lancet Respir Med. 2019;7(6):544-552. doi:10.1016/s2213-2600(19)30137-7
   Article PubMed Google Scholar
8. Rajput S, Gupta S, Chaturvedi T. Impact of the COVID-19 pandemic on tuberculosis management in India: a brief overview. J Exp Biol Agric Sci. 2023;11(3):534-541. doi:10.18006/2023.11(3).534.541
   Article PubMed Google Scholar
9. Cruz AT, Starke JR. Clinical manifestations of tuberculosis in children. Paediatr Respir Rev. 2007;8(2):107-117. doi:10.1016/j.prrv.2007.04.008
   Article PubMed Google Scholar
10. Eamranond P, Jaramillo E. Tuberculosis in children: reassessing the need for improved diagnosis in global control strategies. Int J Tuberc Lung Dis. 2001;5(7):594-603.
    PubMed Google Scholar
11. Ildirim I, Hacimustafaogu M, Ediz B. Correlation of tuberculin induration with the number of bacillus Calmette-Guérin vaccines. Pediatr Infect Dis J. 1995;14(12):1060-1063. doi:10.1097/00006454-199512000-00006
    Article PubMed Google Scholar
12. Dong Y, Dong Y, Mo X, et al. Epidemiology of COVID-19 among children in China. Pediatrics. 2020;145(6). doi:10.1542/peds.2020-0702
    Article PubMed Google Scholar
13. Roper LE, Godfrey M, Link-Gelles R, et al. Use of additional doses of 2024-2025 COVID-19 vaccine for adults aged 65 years or older and persons aged 6 months or older with moderate or severe immunocompromise: recommendations of the Advisory Committee on Immunization Practices—United States, 2024. MMWR Morb Mortal Wkly Rep. 2024;73(49):1118-1123. doi:10.15585/mmwr.mm7349a2
    Article PubMed Google Scholar
14. Togun T, Kampmann B, Stoker NG, Lipman M. Anticipating the impact of the COVID-19 pandemic on TB patients and TB control programmes. Ann Clin Microbiol Antimicrob. 2020;19(1):21. doi:10.1186/s12941-020-00363-1
    Article PubMed Google Scholar
15. Glaziou P. Predicted impact of the COVID-19 pandemic on global tuberculosis deaths in 2020. medRxiv. Published online May 4, 2020. doi:10.1101/2020.04.28.20079582
    Article PubMed Google Scholar
16. World Health Organization. Coronavirus disease (COVID-19): tuberculosis. World Health Organization; 2020.
    PubMed Google Scholar
17. Tatar D, ed. Göğüs Hastalıkları: Bölüm 15, Akciğer Enfeksiyonları.
    PubMed Google Scholar
18. Nkereuwem E, Kampmann B, Togun T. The need to prioritise childhood tuberculosis case detection. Lancet. 2021;397(10281):1248-1249. doi:10.1016/s0140-6736(21)00672-3
    Article PubMed Google Scholar
19. World Health Organization. Roadmap Towards Ending TB in Children and Adolescents. World Health Organization; 2023:1-40.
    PubMed Google Scholar
20. Mohr-Holland E, Douglas-Jones B, Apolisi I, et al. Tuberculosis preventive therapy for children and adolescents: an emergency response to the COVID-19 pandemic. Lancet Child Adolesc Health. 2021;5(3):159-161. doi:10.1016/s2352-4642(21)00003-1
    Article PubMed Google Scholar
21. Rangchaikul P, Ahn P, Nguyen M, Zhong V, Venketaraman V. Review of pediatric tuberculosis in the aftermath of COVID-19. Clin Pract. 2022;12(5):738-754. doi:10.3390/clinpract12050077
    Article PubMed Google Scholar
22. Mathur SB, Saxena R, Pallavi P, Jain R, Mishra D, Jhamb U. Effect of concomitant tuberculosis infection on COVID-19 disease in children: a matched, retrospective cohort study. J Trop Pediatr. 2022;68(4). doi:10.1093/tropej/fmac056
    Article PubMed Google Scholar

Additional Information

Publisher’s Note
Bayrakol MP remains neutral with regard to jurisdictional and institutional claims.

Rights and Permissions

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). To view a copy of the license, visit https://creativecommons.org/licenses/by-nc/4.0/

View full license details →

About This Article

Received:

April 16, 2026

Accepted:

June 3, 2026

Published Online:

June 21, 2026