Latent tuberculosis diagnostics: current scenario and review.

This review presents a comprehensive examination of the contemporary landscape pertaining to latent tuberculosis infection (LTBI) diagnostics, with a particular emphasis on the global ramifications and the intricacies surrounding LTBI diagnosis and treatment. It accentuates the imperative of bolstering diagnostic, preventive, and treatment modalities for tuberculosis (TB) to fulfill the ambitious targets set forth by the World Health Organization aimed at reducing TB-related mortalities and the incidence of new TB cases. The document underscores the significance of addressing LTBI as a means of averting the progression to active TB, particularly in regions burdened with high TB prevalence, such as India. An in-depth analysis of the spectrum delineating latent and active TB disease is provided, elucidating the risk factors predisposing individuals with LTBI to progress towards active TB, including compromised immune functionality, concurrent HIV infection, and other immunosuppressive states. Furthermore, the challenges associated with LTBI diagnosis are elucidated, encompassing the absence of a definitive diagnostic assay, and the merits and demerits of tuberculin skin testing (TST) and interferon-γ release assays (IGRAs) are expounded upon. The document underscores the necessity of confronting these challenges and furnishes a meticulous examination of the advantages and limitations of TST and IGRAs, along with the intricacies involved in interpreting their outcomes across diverse demographics and settings. Additionally, attention is drawn towards the heritability of the interferon-γ response to mycobacterial antigens and the potential utility of antibodies in LTBI diagnosis.

Subtyping of advanced lung cancer based on PD-L1 expression, tumor histopathology and mutation burden (EGFR and KRAS): a study from North India.

Immune checkpoint inhibitor (PD-L1) therapy of advanced non-small-cell lung cancer (NSCLC) has variable outcomes. Tumor subtypes based on PD-L1 expression, histopathology, mutation burden is required for patient stratification and formulation of treatment guidelines. Lung cancers (n=57) diagnosed at Pathology department, VPCI (2018-2021) were retrospectively analyzed. PD-L1(SP263) expressed by tumor cells [low (<1%), medium (1-49%), high (≥50%)] was correlated with histopathology, microenvironment, EGFR, KRAS expression. Patients were categorized into high and low risk based on their: i) gender: males (n=47, 30-89 years), females (n=10, 45-80 years); ii) smoking history: males 26/47 (45.61%), females 1/10 (10%); iii) tumor subtyping: squamous cell carcinoma 15/57 (26.32%), adenocarcinoma 6/57 (17.54%), NSCLC-undifferentiated 24/57 (42.10%), adenosquamous carcinoma 5/57 (8.77 %), carcinosarcoma 4/57 (7.02%), small cell carcinoma 1/57 (1.75%); iv) inflammatory tumor microenvironment/TILs 44/57 (77.1%); iv) PD-L1 positivity-31/57 (54.3%); v) concomitant EGFR/KRAS positivity. PD-L1positive cases showed squamous/undifferentiated histopathology, concomitant EGFR+ (9/20, 45%) and KRAS+ (8/15, 53.3%), smoking+ (21/31,67.74%).PD-L1 negative cases (26/57, 45.6%), were EGFR+ (2/14, 14.28%) and KRAS+ (6/19, 31.5%). The high-risk lung cancer subtypes show squamous/undifferentiated histopathology, inflammatory microenvironment, male preponderance, smoking history, higher concomitant PD-L1, KRAS and EGFR positivity. Lung cancer subtyping can predict clinical response/resistance of patients prior to initiation of PD-L1 inhibitor therapies and can be used to guide therapy.

Air pollution and its effects on emergency room visits in tertiary respiratory care centers in Delhi, India.

Environmental pollution has harmful effects on human health, particularly the respiratory system. We aimed to study the impact of daily ambient air pollution on daily emergency room visits for acute respiratory symptoms. This study was conducted in two tertiary respiratory care centres in Delhi, India. Daily counts of emergency room visits were collected. All patients attending the emergency room were screened for acute onset (less than 2 weeks) of respiratory symptoms and were recruited if they were staying in Delhi continuously for at least 4 weeks and having onset (≤2 weeks) of respiratory symptoms. Daily average air pollution data for the study period was obtained from four continuous ambient air quality monitoring stations. A total of 61,285 patients were screened and 11,424 were enrolled from June 2017 to February 2019. Cough and difficulty in breathing were most common respiratory symptoms. Poor air quality was observed during the months of October to December. Emergency room visits with acute respiratory symptoms significantly increased per standard deviation increase in PM10 from lag days 2-7. Increase in wheezing was primarily seen with increase in NO2. Pollutant levels have effect on acute respiratory symptoms and thus influence emergency room visits. *************************************************************** *Appendix Authors list Kamal Singhal,1 Kana Ram Jat,2 Karan Madan,3 Mohan P. George,4 Kalaivani Mani,5 Randeep Guleria,3 Ravindra Mohan Pandey,5 Rupinder Singh Dhaliwal,6 Rakesh Lodha,2 Varinder Singh1 1Department of Paediatrics, Lady Hardinge Medical College and associated Kalawati Saran Children's Hospital, New Delhi, India 2Department of Paediatrics, All India Institute of Medical Sciences, New Delhi, India 3Department of Pulmonary Medicine, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India 4Department of Environment, Delhi Pollution Control Committee, Kashmere Gate, New Delhi, India 5Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India 6Department of Non-communicable Diseases, Indian Council of Medical Research, New Delhi, India.

Uncontrolled Diabetes Mellitus Predicts Post-COVID-19 Fibrosis.

INTRODUCTION: Post-coronavirus 2019 (COVID-19) complications are now well-recognized and may involve multiple organs. Post-COVID-19 pulmonary fibrosis is one of the serious long-term consequences of COVID-19 infection, and the risk factors for its development largely remain unidentified. AIMS AND OBJECTIVES: The study aimed to evaluate the clinical and radiological profile of post COVID-19 patients with diagnosed diabetes mellitus (DM). MATERIALS AND METHODS: All the patients attending the post-COVID-19 respiratory care center over a period of 1 year who were diagnosed with cases of DM were evaluated for residual clinical symptoms and radiological changes and glycosylated hemoglobin (HbA1c) levels were measured from their blood samples. RESULTS: A total of 50 patients were enrolled in this observational cross-sectional study. Most patients were males in the age group of 45-60 years. Approximately 74% of patients had uncontrolled DM. Patients with uncontrolled DM had a higher probability of having a severe disease with an odds ratio (OR) of 7.30 (0.85, 62.42, and confidence interval (CI) 95%) and were more likely to have fibrotic abnormalities on computed tomography (CT) chest with OR of 3.38 (0.87, 16.86, and CI 95%). CONCLUSION: Uncontrolled diabetes predisposes to the development of post-COVID-19 fibrosis, so physicians should be more vigilant while managing these patients.

Geographic information system-based mapping of air pollution & emergency room visits of patients for acute respiratory symptoms in Delhi, India (March 2018-February 2019).

Background & objectives: Studies assessing the spatial and temporal association of ambient air pollution with emergency room visits of patients having acute respiratory symptoms in Delhi are lacking. Therefore, the present study explored the relationship between spatio-temporal variation of particulate matter (PM)2.5 concentrations and air quality index (AQI) with emergency room (ER) visits of patients having acute respiratory symptoms in Delhi using the geographic information system (GIS) approach. Methods: The daily number of ER visits of patients having acute respiratory symptoms (less than or equal to two weeks) was recorded from the ER of four hospitals of Delhi from March 2018 to February 2019. Daily outdoor PM2.5 concentrations and air quality index (AQI) were obtained from the Delhi Pollution Control Committee. Spatial distribution of patients with acute respiratory symptoms visiting ER, PM2.5 concentrations and AQI were mapped for three seasons of Delhi using ArcGIS software. Results: Of the 70,594 patients screened from ER, 18,063 eligible patients were enrolled in the study. Winter days had poor AQI compared to moderate and satisfactory AQI during summer and monsoon days, respectively. None of the days reported good AQI (<50). During winters, an increase in acute respiratory ER visits of patients was associated with higher PM2.5 concentrations in the highly polluted northwest region of Delhi. In contrast, a lower number of acute respiratory ER visits of patients were seen from the 'moderately polluted' south-west region of Delhi with relatively lower PM2.5 concentrations. Interpretation & conclusions: Acute respiratory ER visits of patients were related to regional PM2.5 concentrations and AQI that differed during the three seasons of Delhi. The present study provides support for identifying the hotspots and implementation of focused, intensive decentralized strategies to control ambient air pollution in worst-affected areas, in addition to the general city-wise strategies.

Role of IP-10 during follow up of pulmonary tuberculosis patients.

Pulmonary tuberculosis (PTB) is an infectious disease caused by Mycobacterium tuberculosis (MTB) and is associated with significant mortality and morbidity. There has been a number of advances in the diagnosis of PTB but there is a need for simple blood based diagnostic test. A follow up of the patients on treatment remains challenging. This study was planned to evaluate the role of IP-10 in the follow up of PTB patients. A total of 60 subjects were enrolled in the study, 40 patients with confirmed diagnosis of PTB and 20 healthy controls. The value of interferon (IFN)γ inducible protein 10 (IP10) was measured in all the subjects at the start of the treatment and at a follow up of two months. Mean age of the study subjects was 40.96 years. Mean duration of symptoms at presentation was 1 month and 17 days. The induration on Tuberculin skin test (TST) was between 10-20mm in most (62.5%) of the study subjects. Majority (45%) showed moderately advanced disease on chest x-ray. There was no association of IP-10 with TST diameter and gene x-pert. Similarly, no significant difference in IP-10 levels was found in relation to sputum grading and x-ray score at diagnosis and after 2 months of treatment. IP-10 has very limited role in diagnosis of active TB in especially in high TB burden countries. The role of IP-10 in follow up of PTB patients could not be ascertained by our study. However, more studies are needed in this pretext with larger sample size and extended duration of follow up.

One-year continuous abstinence rate for smoking cessation via telephonic counselling: The Indian scenario.

Tobacco control methods differ by country, with telephonic counseling being one of them. The effectiveness of telephone counseling in smoking cessation has been discussed on several occasions. India's tobacco problem is more complex than that of any other country in the world. To begin with, tobacco is consumed in a variety of ways, and India is a large multilingual country with remarkable cultural diversity. In India, the National Tobacco Quitline Service (NTQLS) is a government-run program. Its data from May 2016 to May 2021 were analyzed retrospectively in this cross-sectional study to determine the prevalence and pattern of tobacco use in India, as well as the abstinence rate for smoking cessation. A total of 4,611,866 calls were received by the Interactive Voice Response system (IVR). The number of calls increased from 600 to 5400 per day after the toll-free number was printed on all tobacco products. Smokeless tobacco use was discovered to be more prevalent, with males significantly more likely to use both smoking and smokeless tobacco. At one month and one year after quitting, 33.42% and 21.9%, respectively, remained tobacco-free. The study emphasizes the efficacy of behavioral counseling in increasing abstinence rates. The printing of a toll-free number on tobacco products is an effective strategy for expanding the operation of quit lines. Despite the challenges of cultural diversity and complex tobacco use, India's quit line service has been able to provide counseling to callers with prolonged abstinence and quit rates comparable to the various quit lines around the world.

Pulmonary sarcoidosis presenting as hoarseness and mass lesion.

A 46-year male, ex-smoker presented with cough and hoarseness for 2-3 months. The CECT chest revealed a left upper lobe mass. BAL was negative for AFB, GeneXpert, and malignant cells. The bronchial biopsy showed granuloma with no caseation and infiltration of lymphoid cells. The ultrasound abdomen was normal. The patient was started on prednisolone 0.5 mg/kg. He improved clinic-radiologically. Ex-smoker, middle-aged man with hoarseness and mass lesion on CECT chest is highly suspicious of lung malignancy. Pulmonary sarcoidosis should be kept in the differential diagnosis of unexplained hoarseness and mass lesion as the disease has diverse presentations.

Uncontrolled diabetes mellitus: A risk factor for post COVID fibrosis.

Dear Editor, The Corona virus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in the Wuhan province of china in December 2019. COVID-19 spread to the world in a short time and was declared as public health emergency of international concern by World Health Organization...

Characteristics of COVID-19 at a non-COVID tertiary pulmonary care centre in Delhi, India.

The pandemic of COVID-19 has emerged as a serious health crisis globally and India too has been extensively affected with 604,641 active cases reported, till date. The present study focuses on the demographic, clinical and laboratory profile of such patients from a tertiary level non-COVID respiratory care hospital. This is a retrospective observational study. Seventy-seven sick patients fulfilling COVID suspect criteria were admitted to the isolation area. Their RT-PCR test was done from the designated laboratory and 35 of them  were confirmed to be COVID-19 patients. The detailed demographic, clinical and laboratory profile of these COVID-19 patients was studied. The mean age was 46±17 years with male predominance (57%). Majority  of the cases (83%) were symptomatic. The most common symptom was cough (66%) followed by breathlessness and fever. Nineteen (54.3%) patients had one or the other co-morbidity and 16 (45.7%) had chronic lung diseases as one of the comorbidities. Nearly half of the patients (51%) required supplementary oxygen on presentation. Two patients were put on invasive mechanical ventilation while 4 patients required non-invasive ventilation before being shifted to the COVID hospital. Hence, it can be concluded that COVID-19 in patients of chronic respiratory diseases  manifests with higher prevalence of symptoms and also higher severity of disease. Further, the  symptomatology of COVID-19 closely mimics the acute exacerbation of chronic lung diseases, so cautious screening and testing should be done, especially at the pulmonary department.

Pulmonary Function and Diffusing Capacity of Carbon Monoxide in Hypersensitivity Pneumonitis: An Observational Study of 152 Patients.

OBJECTIVE: Hypersensitivity pneumonitis (HP) is an inflammatory and/or fibrotic lung disease. The restrictive lung function with low diffusing capacity of carbon monoxide (DLCO) is common in interstitial lung diseases (ILD). There are limited data on pulmonary function test (PFT) in HP and its role for diagnosis is questionable. We analyzed the data of 152 HP patients for type of defect, lung volume, and DLCO. MATERIAL AND METHODS: The present study is a retrospective analysis of 152 patients at one of the tertiary chest institutes in India. All diagnosed cases with at least spirometry were included. PFT findings were classified and graded as obstructive, restrictive, and mixed patterns. The correlation of PFT was calculated with disease duration and 6MWT distance. RESULTS: The majority were female [106 (70%)], with a mean age of 47.8 ± 12.3 years. Spirometry with lung volume data were available for 97% patients. PFT was abnormal in 118 (80%) cases. Among the patterns of abnormality, the most common type was restrictive (74%) followed by mixed (15%) and obstructive (11%) with the majority in the severe to very severe grade. The mean total lung capacity (TLC) and residual volume (RV) were reduced, with the grade more severe when the pattern of abnormality was restrictive while the RV/ TLC was higher suggestive of air tapping. DLCO data were available for 132 (87%) cases, with levels decreased in 67%. The severity of DLCO was highest when the pattern of abnormality was restrictive. One of the PFT parameters was abnormal in 137 (90%) cases, with isolated decreased DLCO levels seen in 16 (10%) cases. Forced vital capacity (FVC), TLC, and DLCO showed positive correlation with 6MWT distance (FVC r = .22, P = .02; TLC r = .28, P = .003; DLCO r = .30, P = .002). CONCLUSION: The PFT abnormality is seen in >80% of HP patients. All types of abnormality were seen, with the restrictive pattern being the most common. Isolated decreased DLCO levels were seen in 10% of cases. We advised to do full PFT for diagnosis and followup of HP.

Role of Single Port Rigid Thoracoscopy in Undiagnosed Pleural Effusion.

BACKGROUND: In recent years, medical thoracoscopy has been well established to play an important role in undiagnosed pleural effusion; however, this procedure is underutilized due to limited availability of the instruments it requires. This study analysed the outcome of single port rigid thoracoscopy in patients with undiagnosed pleural effusions. METHODS: This study retrospectively analysed the outcomes of all patients with undiagnosed pleural effusion presenting to our centre between 2016 to 2020 who underwent single port rigid medical thoracoscopy as a diagnostic procedure. RESULTS: In total, 92 patients underwent single port rigid medical thoracoscopy. The most common presenting symptom was shortness of breath. A majority of the patients had lymphocytic exudative pleural effusion. The average biopsy sample size was 18 mm, and no major complication was reported in any of the patients. CONCLUSION: Single port rigid thoracoscopy is a safe and well-tolerated procedure that yields a biopsy of a larger size with high diagnostic yield. Moreover, the low cost of the instruments required by this procedure makes it particularly suited for use in developing countries.

Initial COVID-19 Severity and Long-COVID Manifestations: An Observational Analysis.

OBJECTIVE: New-onset or persistent symptoms beyond after 4 weeks from COVID-19 are termed "long-COVID." Whether the initial severity of COVID-19 has a bearing on the clinicoradiological manifestations of long COVID is an area of interest. MATERIAL AND METHODS: We did an observational analysis of the long-COVID patients after categorizing them based on their course of COVID-19 illness into mild, moderate, and severe groups. The clinical and radiological profile was compared across these groups. RESULTS: Out of 150 long-COVID patients recruited in the study, about 79% (118), 14% (22), and 7% (10) had a history of mild, moderate, and severe COVID-19, respectively. Fatigue (P = .001), breathlessness (P = .001), tachycardia (P = .002), tachypnea (P < .001), raised blood pressure (P < .001), crepitations (P = .04), hypoxia at rest (P < .001), significant desaturation in 6-minute walk test (P = .27), type 1 respiratory failure (P = .001), and type 2 respiratory failure (P = .001) were found to be significantly higher in the long-COVID patients with a history of severe COVID-19. These patients also had the highest prevalence of abnormal chest X-ray (60%) and honeycombing in computed tomography scan thorax (25%, P = .027). CONCLUSION: The course of long COVID bears a relationship with initial COVID-19 severity. Patients with severe COVID-19 are prone to develop more serious long-COVID manifestations.

Pre-conference workshop on pulmonary rehabilitation and smoking cessation - NATCON 2022.

The 77th National Conference of Tuberculosis and Chest Diseases was held on 27th February 2023. The workshop on Pulmonary rehabilitation and smoking cessation was conducted as a part of the various pre-conference workshops being conducted on the occasion. It helped the participants to know regarding the role, efficacy and benefits of pulmonary rehabilitation and smoking cessation for the management of Chronic respiratory diseases.

Indian Guidelines on Nebulization Therapy.

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

Isolated Pulmonary Cysticercosis Presenting as Mass Lesion.

We report a case of pulmonary cysticercosis manifesting as a mass lesion. Cysticercosis confined to lungs is a rare manifestation of human cysticercosis. The disease mainly affects the central nervous system, skeletal muscles, and eyes. Pulmonary involvement is rare and usually presents as bilateral pulmonary nodules. The diagnosis was made based on positive enzyme-linked immunosorbent assay (ELISA) for anticysticercal antibodies, and the patient was started on antiparasitic therapy along with steroids. Symptomatic and radiological improvement was seen. There is no previous case report of isolated pulmonary cysticercosis presenting as mass lesion.

Tobacco use, tuberculosis and Covid-19: A lethal triad.

Smoking, TB and Covid-19 are high prevalence entities with public health consequences. All three of them have a possible complex interaction at cellular level. Smoking behavior makes it difficult to maintain infection control measures. Smoking is known to increase TB infection and also adversely affect treatment outcomes in TB. There is also upcoming evidence which suggests that smoking and TB increase the risk of severe Covid-19 symptoms. Simple infection control measures like, social distancing, cough etiquette, isolation, hand hygiene, quarantine, use of masks etc. play a pivotal role in prevention of these diseases. There is need of strengthening of the public health policies and incorporation of the Covid-19 safety awareness measures into the various national programmes.

Untangling the KRAS mutated lung cancer subsets and its therapeutic implications.

The Kirsten rat sarcoma virus transforming protein (KRAS) mutations (predominate in codons 12, 13, and 61) and genomically drive nearly one-third of lung carcinomas. These mutations have complex functions in tumorigenesis, and influence the tumor response to chemotherapy and tyrosine kinase inhibitors resulting in a poorer patient prognosis. Recent attempts using targeted therapies against KRAS alone have met with little success. The existence of specific subsets of lung cancer based on KRAS mutations and coexisting mutations are suggested. Their interactions need further elaboration before newer promising targeted therapies for KRAS mutant lung cancers can be used as earlier lines of therapy. We summarize the existing knowledge of KRAS mutations and their coexisting mutations that is relevant to lung cancer treatment, in this review. We elaborate on the prognostic impact of clinical and pathologic characteristics of lung cancer patients associated with KRAS mutations. We briefly review the currently available techniques for KRAS mutation detection on biopsy and cytology samples. Finally, we discuss the new therapeutic strategies for targeting KRAS-mutant non-small cell lung cancer (NSCLC). These may herald a new era in the treatment of KRASG12Cmutated NSCLC as well as be helpful to develop demographic subsets to predict targeted therapies and prognosis of lung cancer patients.

Effects of ambient air pollution on emergency room visits of children for acute respiratory symptoms in Delhi, India.

The present study explored the association between daily ambient air pollution and daily emergency room (ER) visits due to acute respiratory symptoms in children of Delhi. The daily counts of ER visits (ERV) of children (≤15 years) having acute respiratory symptoms were obtained from two hospitals of Delhi for 21 months. Simultaneously, data on daily concentrations of particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and ozone (O3) and weather variables were provided by the Delhi Pollution Control Committee. K-means clustering with time-series approach and multi-pollutant generalized additive models with Poisson link function was used to estimate the 0-6-day lagged change in daily ER visits with the change in multiple pollutants levels. Out of 1,32,029 children screened, 19,120 eligible children having acute respiratory symptoms for ≤2 weeks and residing in Delhi for the past 4 weeks were enrolled. There was a 29% and 21% increase in ERVs among children on high and moderate level pollution cluster days, respectively, compared to low pollution cluster days on the same day and previous 1-6 days of exposure to air pollutants. There was percentage increase (95% CI) 1.50% (0.76, 2.25) in ERVs for acute respiratory symptoms for 10 µg/m3 increase of NO2 on previous day 1, 46.78% (21.01, 78.05) for 10 µg/m3 of CO on previous day 3, and 13.15% (9.95, 16.45) for 10 µg/m3 of SO2 on same day of exposure. An increase in the daily ER visits of children for acute respiratory symptoms was observed after increase in daily ambient air pollution levels in Delhi.