Clinical presentations of nontuberculous mycobacteria as suspected and drug-resistant tuberculosis: Experience from a tertiary care center in Eastern India.

Background: Nontuberculous mycobacteria (NTM) are on the rise worldwide. The diagnosis and treatment of NTM disease create a dilemma for physicians as their clinical features often overlap with that of tuberculosis (TB). The present study aims to report a series of NTM infections presenting as suspected TB. Methods: It was a prospective observational study starting from December 2018 to January 2022. A total of 1850 suspected TB patients (pulmonary = 522 and extrapulmonary = 1328) were included in this study. Clinical features, radiological findings, microbiological diagnosis, treatment, and outcome were recorded. Clinical specimens were processed for Ziehl-Neelsen staining, GeneXpert MTB/Rif assay by cartridge-based nucleic acid amplification test, and culture. The culture-positive isolates were categorized as Mycobacterium tuberculosis complex or NTM depending on the detection of MPT64 antigen by immunochromatographic test. The NTM isolates were speciated by line probe assay using GenoType® Mycobacterium common mycobacteria kit. The criteria of the American Thoracic Society/Infectious Diseases Society of America were applied to confirm NTM disease. Results: Of 1850 suspected TB patients, NTM disease was diagnosed in 20 patients (pulmonary = 9, nonpulmonary = 11). Eight NTM cases presented as suspected drug-resistant-TB with a history of antitubercular therapy. Among pulmonary NTM cases, Mycobacterium scrofulaceum (n = 7) was the most common species followed by Mycobacterium kansasii (n = 1) and Mycobacterium intracellulare (n = 1). In nonpulmonary cases, Mycobacterium abscessus (n = 8) was involved in majority of cases followed by Mycobacterium fortuitum (n = 3). Cavitary lung disease and laparoscopic port site infections were most frequent pulmonary and non-pulmonary manifestations respectively. Conclusion: Hence, there is an urgent need for better diagnostic and drug susceptibility testing facility along with standardized treatment protocol for NTM disease.

Comparison of Cycle Threshold and Clinical Status Among Different Age Groups of COVID-19 Cases.

Introduction The COVID-19 pandemic has shaken the entire world ever since its emergence in March 2020. The disease manifestation of COVID-19 has been more severe, with a high degree of mortality in the elderly than in the young population. The cycle threshold (Ct ) value obtained in the real-time polymerase chain reaction (RT-PCR) has been used as the surrogate marker of viral load. Therefore, assessing Ct value and clinical status among different age groups with SARS-CoV-2 infection is required to understand the viral kinetics and to assess the transmission potential of that particular age group. Purpose The aim of this study was to compare the viral load and clinical status among different age groups with COVID-19 infection. Methods and materials A retrospective cross-sectional study was carried out to analyze the Ct values of SARS-CoV-2 positive samples reported from April 2020 till May 2021. The results of 13,820 RT-PCR (reverse transcriptase-polymerase chain reaction) positive samples were included for analysis of Ct values. Ct values of confirmatory genes were taken into consideration, and Ct values below 25, >25 to 30, and >30 were categorized as high, moderate, and low viral load, respectively. Age group was stratified into ≤18 years (young), 18-60 years (adult), and >60 years (elderly). The data were analyzed using SPSS Windows Version 25.0. Results The mean Ct values were 27.9, 26, and 26.2 in the young, adult, and elderly age groups, respectively. The mean Ct values of young patients were significantly higher as compared to adult and elderly patients (p<0.05). The percentage of high viral load (Ct<25) was found to be significantly higher in adults and elderly (44.6% & 43.7%) as compared to young (32.2%) (p<0.001). Majority of the COVID-19 positive cases younger than 18 years (75.9%) were asymptomatic as compared to 64.5% and 59.7% in the adult and elderly age groups, respectively. Conclusion This study observed a significantly high proportion of viral load in the adult and elderly population, which plays a substantial contribution to SARS-CoV-2 transmission, whereas the majority of the young population being asymptomatic plays a major role as silent transmitters. The study reemphasizes the need for strict adherence to COVID-appropriate behaviors.

High proportion of low cycle threshold value as an early indicator of COVID-19 surge.

Many countries in the world are experiencing a recent surge in COVID-19 cases. This is mainly attributed to the emergence of new SARS-CoV-2 variants. Genome sequencing is the only means to detect the evolving virus mutants and emerging variants. Cycle threshold values have an inverse relationship with viral load and lower Ct values are also found to be associated with increased infectivity. In this study, we propose to use Ct values as an early indicator for upcoming COVID-19 waves. A retrospective cross-sectional study was carried out to analyze the Ct values of positive samples reported during the first wave and second wave (April 2020-May 2021). Median Ct values of confirmatory genes were taken into consideration for comparison. Ct values below 25, >25-30, and >30 were categorized as high, moderate, and low viral load respectively. Our study found a significantly higher proportion of positive samples with a low Ct value (<25) across age groups and gender during the second wave of the COVID-19 pandemic. A higher proportion of positive samples with a low Ct value (high viral load) may act as an early indicator of an upcoming surge.

Comparison of Clinical Presentation and Vaccine Effectiveness Among Omicron and Non-omicron SARS Coronavirus-2 Patients.

Introduction The rapidly mutating Omicron SARS-CoV-2 variant has replaced the previous dominant SARS-CoV-2 variants like alpha, and delta resulting in the amplification of coronavirus disease 2019 (COVID-19) cases. The present study was conducted to compare the clinical profile and vaccination status in patients infected with Omicron and non-Omicron SARS-CoV-2 variants. Methods All patients who tested positive for coronavirus disease 2019 (COVID-19) during the study period (January 2022 to February 2022) were further tested for detection of SARS-CoV-2 Omicron variant by using Omisure kit (TATA MD CHECK RT-PCR, TATA MEDICAL AND DIAGNOSTICS LIMITED, Tamil Nadu, INDIA). Clinico-demographic factors and vaccination status were compared between both Omicron and non-Omicron groups. Results A total of 1,722 patients who tested positive for COVID-19 were included in the study, of which 656 (38.1%) were Omicron and 1,066 (61.9%) were non-Omicron SARS-CoV-2 variants. Blood group and vaccination status were the major predictors for Omicron. The proportion of male patients was 58.4% in the Omicron group and 57.9% in the non-Omicron group. Maximum cases (86.2%) belonged to >18-60 years age group, 7.3% to >60 years age group, and least to 0-18 years (6.5%). The average age of the study participants was 35.4 ± 14.5 years. Vaccinated participants had less chance of having Omicron than the unvaccinated participants (p-value - 0.003). Fever and loss of smell were found to be significantly associated with the non-Omicron SARS-CoV-2 variant. (p-value < 0.05). Conclusion The present study reflects that the clinical course of the disease is milder in Omicron as compared to the non-Omicron variant. However rapid rise in cases can badly affect the healthcare system demanding good preparedness to tackle all the predicaments. Good Vaccination coverage should be of utmost priority irrespective of the variant type.