Molecular characterization of de novo ring chromosome 21 in a child with seizures, growth retardation, and multiple congenital anomalies.

The ring chromosome 21[r(21)] syndrome is a rare disorder, and mainly occurs as a de novo event. However, a wide variation of the phenotype has been reported in r(21) cases depending on breakpoints, loss of genetic material, and mosaicism of cells with r(21) and monosomy 21, causing copy number alterations. A 29-month-old female was referred to the centre for seizures, developmental delay, microcephaly, hypotonia, deafness, and other congenital abnormalities. Physical examination revealed short stature and multiple facial dysmorphism. She was unable to sit, walk or stand by herself. Cytogenetic study with GTG banding revealed a karyotype of mos 46,XX,r(21)(p11.1q22.12)[70]/45,XX,-21[10]/47,XX,r(21),+r(21)[1]/46,XX[10]. Additionally, molecular cytogenetics refined the breakpoints and characterized the deleted region (RP11-410P24/CHR21: 32849565-33019511) in the clone with the r(21) as ~12-14 Mb contiguous region at 21q22.12 to 21qter. The present study has accurately detected copy number alterations caused by ring chromosome formation. The basis of the UCSC Genome Browser on Human (GRCh38/hg38) analysis suggests hemizygous expression of a deleted critical region of chromosome 21 in ring chromosome cell lines. This is likely to be the underlying cause of the present phenotypes in the patient. Overall, the genotype-phenotypic correlation in r(21) cases remains widely diverse, most likely due to tissue-specific mosaicism of the 45, XX,-21 cell line.

The association of testis-specific hTAF7L gene variants with idiopathic azoospermic and severe oligozoospermic male infertility.

Spermatogenesis is regulated by complex tissue specific gene expression in the testis to achieve normal male fertility. X-chromosome specific TATA binding protein (TBP)-associated factor 7L (hTAF7L) is one of the transcriptional regulator genes considered essential for spermatogenesis. The aim of this study was to evaluate the role of variants/mutations in the testis-specific hTAF7L gene in non-obstructive azoospermia and severe oligozoospermia male infertility. We studied 156 idiopathic non-obstructive azoospermic, severe oligozoospermic infertile males and 50 fertile proven controls. Infertile males and control subjects were genotyped for variants of the hTAF7L gene using polymerase chain reaction and a direct Sanger sequencing approach. The odds ratio evaluated the association of hTAF7L gene variants with idiopathic male infertility. The variants found in the hTAF7L gene were subjected to an in-silico analysis study. In infertile study subjects, we observed 11 single base pair nucleotide changes at various exons and three frameshift variants at exon 10 in the hTAF7L gene. We also found more than one variant in some non-obstructive azoospermia and severe oligozoospermia infertile males along with control subjects. All these variants changed the amino acid sequences in the hTAF7L gene. However, similar changes were also seen in fertile subjects, and the differences were not statistically significant. In-silico tools also predicted that the variants were likely to be benign. The variants in cDNA of the hTAF7L gene were typical SNPs. It is found that the hTAF7L gene is highly polymorphic and these missense variants are not directly associated with male infertility. However, we feel that more studies are needed to elucidate the role of multiple variants of the hTAF7L gene in the process of normal spermatogenesis.

A missense mutation (c.226C>A) in HMG box SRY gene affects nNLS function in 46,XY sex reversal female.

The SRY initiates cascade of gene expression that transforms the undifferentiated gonad, genital ridge into testis. Mutations of the SRY gene is associated with complete gonadal dysgenesis in females with 46,XY karyotype. Primary amenorrhea is one of the clinical findings to express the genetic cause in 46,XY sex reversal. Here, we report a 26-year-old married woman presenting with primary amenorhea and complete gonadal dysgenesis. The clinical phenotypes were hypoplastic uterus with streak gonad and underdeveloped secondary sexual characters. The cytogenetic analysis confirmed 46,XY sex reversal karyotype of a female. Using molecular approach, we screened open reading frame of the SRY gene by PCR and targeted DNA Sanger sequencing. The patient was confirmed with nucleotide substitution (c.226C>A; p.Arg76Ser) at in HMG box domain of SRY gene that causes 46,XY sex reversal female. Mutation prediction algorithms suggest that alteration might be disease causing mutation and mutated (p.Arg76Ser) amino acid deleteriously affects HMG box nNLS region of SRY protein. Clinical phenotypes and in silico analysis confirmed that missense substitution (p.Arg76Ser) impaired nNLS binding Calmodulin-mediated nuclear transport of SRY from cytoplasm to nucleus. The mutation affects down regulation of male sex differentiation pathway and is responsible for 46,XY sex reversal female with gonadal dysgenesis.

Assessment of Oxidative Stress Biomarkers and Body Mass Index in Pulmonary Tuberculosis Patients: A Case-Control Study.

Background: Pulmonary tuberculosis (PTB) is a major public health concern in most underdeveloped and developing countries. PTB affects the nutritional status of the patients and influences the body mass index (BMI). There is tissue inflammation and free radical burst from activated phagocytes resulting in oxidative stress. The present study was designed to assess the relationship between oxidative stress and body mass index in newly detected pulmonary tuberculosis patients. Method: This was a case-control study designed to assess oxidative stress parameters such as nitric oxide (NO) and malondialdehyde (MDA) in 40 consecutives newly diagnosed PTB patients and compared with 40 age-matched healthy controls. The nutritional status of the study subjects was measured by calculating the BMI. Results: The mean BMI was 21.61±3.52 Kg/m2 in controls and 17.47±1.56 Kg/m2 in PTB patients and the difference was statistically significant (p <0.0001). The mean levels of MDA (7.65±0.65 nmol/ml) and NO (36.12±1.07 µmol/l) were significantly higher in PTB patients compared to controls (MDA 3.56±0.41 nmol/ml and NO 14.48±0.93 µmol/l). Conclusions: Increased levels of malondialdehyde and nitric oxide were observed in newly diagnosed PTB patients when compared to controls indicating oxidative stress in PTB. The BMI of these patients was significantly lower than the controls. Thus, it is concluded that there is an inverse relationship between oxidative stress and BMI in PTB patients and antioxidant supplementation in addition to nutritional intervention under the National Tuberculosis Elimination Program may help to improve the BMI and promote better recovery in these patients.

Oxidative stress and its impact on mitochondrial DNA in pulmonary tuberculosis patients- a pilot study.

BACKGROUND: Pulmonary tuberculosis (PTB) remains a major cause of morbidity and mortality all around the world. Recent studies have pointed out increased oxidative stress and also DNA damage in peripheral blood in PTB. Till date, to the best of our knowledge, no study has so far been conducted to show the mitochondrial DNA (mtDNA) deletions mapping in PTB patients. Therefore we performed the present study with the aim to investigate oxidative stress parameters along with mtDNA damage in newly diagnosed untreated PTB patients. MATERIAL AND METHODS: This is a prospective study carried out in Mahatma Gandhi Institute of Medical Sciences, Sevagram,Wardha, Maharashtra during september 2017 to september 2018.Thirty newly diagnosed untreated PTB patients and thirty age matched healthy controls were enrolled in the present study. Analysis of Oxidative stress parameters such as nitric oxide (NO) and malondialdehyde (MDA) were done by calorimetric methods. Assessment of mitochondrial DNA damage was carried out by mtDNA deletions mapping using primer shift long range polymerase chain reaction technique. RESULTS: There was significant increase in levels of oxidative stress parameters, nitric oxide and malondialdehyde, in PTB patients compared to controls (p < 0.01). Generally there are two common deletion sites of "13 bp direct repeats" (ACCTCCCTCACCA) in mtDNA. One at the junction sites from bp 8470 to 8482 bp and another from bp 13447 to 13460 bp which make mtDNA more prone for 4977bp deletion. Out of thirty cases of PTB, two cases showed mtDNA damage in the form of mtDNA deletion of 4977bp. There was no mtDNA deletion in any control which can be attributed to continuous generation of oxidative stress. CONCLUSION: This pilot study has been able to demonstrate that compared to controls, in newly diagnosed pulmonary tuberculosis patients some mtDNA damage did occur and was probably due to continuous generation of oxidative stress in tuberculous patients. However, sample size is too small to draw any conclusions but definitely a more comprehensive study, by recruiting more number of pulmonary tuberculosis patients is warranted to establish correlation between oxidative stress and mtDNA damage in PTB.

Recurrence of tuberculosis among newly diagnosed sputum positive pulmonary tuberculosis patients treated under the Revised National Tuberculosis Control Programme, India: A multi-centric prospective study.

INTRODUCTION: There is lack of information on the proportion of new smear-positive pulmonary tuberculosis (PTB) patients treated with a 6-month thrice-weekly regimen under Revised National Tuberculosis Control Programme (RNTCP) who develop recurrent TB after successful treatment outcome. OBJECTIVE: To estimate TB recurrence among newly diagnosed PTB patients who have successfully completed treatment and to document endogenous reactivation or re-infection. Risk factors for unfavourable outcomes to treatment and TB recurrence were determined. METHODOLOGY: Adult (aged ≥ 18 yrs) new smear positive PTB patients initiated on treatment under RNTCP were enrolled from sites in Tamil Nadu, Karnataka, Delhi, Maharashtra, Madhya Pradesh and Kerala. Those declared "treatment success" at the end of treatment were followed up with 2 sputum examinations each at 3, 6 and 12 months after treatment completion. MIRU-VNTR genotyping was done to identify endogenous re-activation or exogenous re-infection at TB recurrence. TB recurrence was expressed as rate per 100 person-years (with 95% confidence interval [95%CI]). Regression models were used to identify the risk factors for unfavourable response to treatment and TB recurrence. RESULTS: Of the1577 new smear positive PTB patients enrolled, 1565 were analysed. The overall cure rate was 77% (1207/1565) and treatment success was 77% (1210 /1565). The cure rate varied from 65% to 86%. There were 158 of 1210 patients who had TB recurrence after treatment success. The pooled TB recurrence estimate was 10.9% [95%CI: 0.2-21.6] and TB recurrence rate per 100 person-years was 12.7 [95% CI: 0.4-25]. TB recurrence per 100 person-years varied from 5.4 to 30.5. Endogenous reactivation was observed in 56 (93%) of 60 patients for whom genotyping was done. Male gender was associated with TB recurrence. CONCLUSION: A substantial proportion of new smear positive PTB patients successfully treated with 6 -month thrice-weekly regimen have TB recurrence under program settings.

Spatio-temporal study of environmental nontuberculous mycobacteria isolated from Wardha district in Central India.

During the last two decades, nontuberculous mycobacteria (NTM) have gained in importance but there is still a paucity of data, particularly for environmental isolates. We studied, over a period of two years, the spatio-temporal features of NTM isolates obtained from different environmental sources in Wardha district, India. A total of 1398 samples (699 each of soil and water) were tested and 170 (12.2%) yielded NTM isolates, including 123 from soil and 47 from water samples. Out of 170 NTM isolates, 107 (63%) belonged to potentially pathogenic mycobacteria (PPM) and 63 (37%) to the less pathogenic mycobacterial (LPM) group. Overall, maximum isolation was obtained in rainy season (20.3%) followed by winter (13.5%), post rainy (8.7%) and summer seasons (5.8%). Mycobacterium fortuitum, Mycobacterium gordonae and Mycobacterium avium complex (MAC) were common isolates followed by Mycobacterium flavescens, Mycobacterium scrofulaceum, Mycobacterium simiae and Mycobacterium marinum. From soil, isolation of NTM was highest from grounds used for community gatherings (42.8%) followed by soil from residential premises (27.7%) and near the wells (26.0%). From drinking water sources, highest NTM isolation was obtained from wells (15.4%) followed by treated water tanks (6.9%), household receptacles (6.3%), hand pumps (5.6%) and tap water supply (3.5%). Isolation from natural canal water was 6.6%, while from drainage and waste water ponds isolation was 8.3%. The results of the study revealed that in Wardha district, NTM are present both in the soil and drinking water. As NTM can be pathogenic, particularly in immune-compromised individuals, these can be of potential risk to the human population.

Diagnostic efficacy of microscopy, rapid diagnostic test and polymerase chain reaction for malaria using bayesian latent class analysis.

INTRODUCTION: The diagnostic techniques for malaria are undergoing a change depending on the availability of newer diagnostics and annual parasite index of infection in a particular area. At the country level, guidelines are available for selection of diagnostic tests; however, at the local level, this decision is made based on malaria situation in the area. The tests are evaluated against the gold standard, and if that standard has limitations, it becomes difficult to compare other available tests. Bayesian latent class analysis computes its internal standard rather than using the conventional gold standard and helps comparison of various tests including the conventional gold standard. MATERIALS AND METHODS: In a cross-sectional study conducted in a tertiary care hospital setting, we have evaluated smear microscopy, rapid diagnostic test (RDT), and polymerase chain reaction (PCR) for diagnosis of malaria using Bayesian latent class analysis. RESULTS: We found the magnitude of malaria to be 17.7% (95% confidence interval: 12.5%-23.9%) among the study subjects. In the present study, the sensitivity of microscopy was 63%, but it had very high specificity (99.4%). Sensitivity and specificity of RDT and PCR were high with RDT having a marginally higher sensitivity (94% vs. 90%) and specificity (99% vs. 95%). On comparison of likelihood ratios (LRs), RDT had the highest LR for positive test result (175) and the lowest LR for negative test result (0.058) among the three tests. CONCLUSION: In settings like ours conventional smear microscopy may be replaced with RDT and as we move toward elimination and facilities become available PCR may be roped into detect cases with lower parasitaemia.

Feasibility and Operational Performance of Tuberculosis Detection by Loop-Mediated Isothermal Amplification Platform in Decentralized Settings: Results from a Multicenter Study.

Currently available nucleic acid amplification platforms for tuberculosis (TB) detection are not designed to be simple or inexpensive enough to implement in decentralized settings in countries with a high burden of disease. The loop-mediated isothermal amplification platform (LAMP) may change this. We conducted a study in adults with symptoms suggestive of TB in India, Uganda, and Peru to establish the feasibility of using TB-LAMP (Eiken Chemical Co.) in microscopy laboratories compared with using smear microscopy against a reference standard of solid and liquid cultures. Operational characteristics were evaluated as well. A total of 1,777 participants met the eligibility criteria and were included for analysis. Overall, TB-LAMP sensitivities among culture-positive samples were 97.2% (243/250; 95% confidence interval [CI], 94.3% to 98.2%) and 62.0% (88/142; 95% CI, 53.5% to 70.0%) for smear-positive and smear-negative TB, respectively, but varied widely by country and operator. Specificities ranged from 94.5% (446/472; 95% CI, 92.0% to 96.4%) to 98.0% (350/357; 95% CI, 96.0% to 99.2%) by country. A root cause analysis identified high temperatures, high humidity, and/or low reaction volumes as possible causes for false-positive results, as they may result in nonspecific amplification. The study was repeated in India with training focused on vulnerable steps and an updated protocol; 580 participants were included for analysis. Specificity in the repeat trial was 96.6% (515/533; 95% CI, 94.7% to 97.9%). To achieve acceptable performance of LAMP at the microscopy center level, significant training and infrastructure requirements are necessary.

Prevalence of pulmonary tuberculosis in Wardha district of Maharashtra, Central India.

A house based survey was conducted during 2007-2009 in a representative sample of population in Wardha district implementing Directly Observed Treatment Short Course strategy for tuberculosis (TB) control since 2001. The objective was to estimate prevalence of bacillary pulmonary TB (PTB) in individuals aged 15 years or above, and to estimate trends in prevalence when compared to a previous survey carried out in mid 1980's. Two sputum samples (one spot, one early morning) collected from individuals having symptoms suggestive of PTB, history of previous anti-TB treatment (ATT) or abnormal pulmonary shadow on Mass Miniature Radiography (MMR) consistent with possibly or probably active tuberculosis were subjected to Ziehl-Neelsen microscopy and culture on Lowenstein-Jensen medium. Of 55,096 individuals registered into the survey, 50,332 (91.4%) were screened by interview for symptoms and history of ATT and/or by MMR. Of them, 4805 were eligible for sputum collection; both specimens were collected in 4285 (89.2%) and only one specimen in 27 (0.6%). A total of 86 bacillary cases were detected during the survey. Prevalence of bacillary PTB was estimated at 188.7 (140.3-236.9) per 100,000 populations. There was a decline of 61% in the prevalence of PTB over a period of 22 years.

SXT constin among Vibrio cholerae isolates from a tertiary care hospital.

BACKGROUND & OBJECTIVES: The SXT element, also known as 'constin' (conjugable, self transmissible, integrating element) is an integrating conjugative element (ICE) in Vibrio cholerae discovered in the chromosome of epidemic V. cholerae O139 strain MO10 (SXT MO10 ) which arose in late 1992 in Chennai, India. SXT related ICEs have become widespread and currently, most if not all Asian V. cholerae clinical isolates contain SXT related ICEs. The present study attempts to determine the presence of SXT Int gene in V. cholerae recovered between 2005 to 2007 in a tertiary care hospital, demonstrate its conjugal nature and also detect co-presence and co-transfer of plasmids in representative isolates. METHODS: This prospective study was done on 116 V. cholerae isolates [114- O1 (107 ogawa and 7 inaba) and 2 - Non O1 Non O139 V. cholerae] from watery stools between 2005 to 2007 recovered from equal number of patients. PCR was carried out using SXT Int specific primers that produced a 592 bp internal fragment of SXT element, and rifampicin resistant strain of E.coli K-12 was used as recipient in conjugation experiments to study transfer of SXT, as also co-transfer of resistance to tetracycline, erythromycin, and nalidixic acid. Antibiotic susceptibility was performed against various antibiotics. RESULTS: Of the 116 isolates, 110 (94.8%) were positive for SXT element by PCR. It was demonstrated in 94.7 per cent of the O1, and 100 per cent of non O1 non O139 V. cholerae. All 2005 isolates, 25 per cent of 2006 isolates and 96.6 per cent of 2007 isolates were positive for SXT. Thirty two drug resistance patterns were observed and the 2007 isolates showed resistance to as many as eight antibiotics. The resistance of SXT positive isolates was higher than those of SXT negative and the typical drug resistance pattern corresponding to SXT ET and SXT MO10 was shown by only one V. cholerae O1 isolate. Successful conjugal transfer of SXT was seen in 31 (88.6%) of the 35 isolates studied without any co-transfer while, presence of plasmids was observed in two of the 31 donor V. cholerae studied. INTERPRETATION & CONCLUSIONS: The demonstration of SXT element and its successful horizontal transfer in V. cholerae isolates studied emphasizes the need for its detection to monitor antibiotic resistance and dissemination in V. cholerae.

Mycobacterium avium bacteremia and dual infection with mycobacterium avium and Mycobacterium wolinskyi in the gut of an AIDS patient--first case report.

An AIDS patient was admitted to a tertiary care hospital in central India with fever, weight loss, breathlessness, night sweats, diarrhoea, BMI 14 kg/m2, Hemoglobin 8 gm% and CD4 counts 120 cells/cumm. His blood culture by BACTEC 460 TB system revealed Mycobacterium avium bacteremia and stool culture grew Mycobacterium avium and mycobacterium wolinskyi.

Acrophialophora fusispora: an emerging agent of human mycoses. A report of 3 new clinical cases.

Acrophialophora fusispora is a soil-borne fungus, which is emerging as a human pathogen. Only four cases of human infection had been described previously. We describe three more cases, two from Europe and one from India. Since this fungus has been misidentified in several other cases, it is probably more frequent than first thought.

Evaluation of diagnostic accuracy, feasibility and client preference for rapid oral fluid-based diagnosis of HIV infection in rural India.

BACKGROUND: Oral fluid-based rapid tests are promising for improving HIV diagnosis and screening. However, recent reports from the United States of false-positive results with the oral OraQuick ADVANCE HIV1/2 test have raised concerns about their performance in routine practice. We report a field evaluation of the diagnostic accuracy, client preference, and feasibility for the oral fluid-based OraQuick Rapid HIV1/2 test in a rural hospital in India. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional, hospital-based study was conducted in 450 consenting participants with suspected HIV infection in rural India. The objectives were to evaluate performance, client preference and feasibility of the OraQuick Rapid HIV-1/2 tests. Two Oraquick Rapid HIV1/2 tests (oral fluid and finger stick) were administered in parallel with confirmatory ELISA/Western Blot (reference standard). Pre- and post-test counseling and face to face interviews were conducted to determine client preference. Of the 450 participants, 146 were deemed to be HIV sero-positive using the reference standard (seropositivity rate of 32% (95% confidence interval [CI] 28%, 37%)). The OraQuick test on oral fluid specimens had better performance with a sensitivity of 100% (95% CI 98, 100) and a specificity of 100% (95% CI 99, 100), as compared to the OraQuick test on finger stick specimens with a sensitivity of 100% (95% CI 98, 100), and a specificity of 99.7% (95% CI 98.4, 99.9). The OraQuick oral fluid-based test was preferred by 87% of the participants for first time testing and 60% of the participants for repeat testing. CONCLUSION/SIGNIFICANCE: In a rural Indian hospital setting, the OraQuick Rapid- HIV1/2 test was found to be highly accurate. The oral fluid-based test performed marginally better than the finger stick test. The oral OraQuick test was highly preferred by participants. In the context of global efforts to scale-up HIV testing, our data suggest that oral fluid-based rapid HIV testing may work well in rural, resource-limited settings.

Comparison of a whole blood interferon-gamma assay with tuberculin skin testing for the detection of tuberculosis infection in hospitalized children in rural India.

OBJECTIVE: In vitro interferon-gamma (IFN-gamma) assays have emerged as novel alternatives to the tuberculin skin test (TST) for the diagnosis of latent tuberculosis (TB) infection. These assays have been evaluated in low incidence countries, mainly in adults, and have been shown to be more specific than TST. Because few studies have been done in high incidence countries, and because paediatric data are limited, we compared a whole-blood IFN-gamma assay with TST among hospitalized Indian children. METHODS: Between July 2004 and June 2005, a total of 105 consecutively admitted children (median age 6 years; 82% had BCG scars) in whom TB was suspected or had history of contact with an index case were recruited at a rural hospital in India. All children underwent TST, and the QuantiFERON-TB-Gold In Tube (QFT) assay. RESULTS: The overall prevalence of TB infection was similar with both tests. With a TST cut-off point of > or =10mm, 10 of 105 (9.5%; 95% CI 3.8, 15.2) children were TST positive. With a cut-off point of IFN-gamma> or =0.35IU/ml, 11 of 105 (10.5%; 95% CI 4.5, 16.4) were QFT positive. The concordance between TST and QFT was substantial (agreement 95.2%; kappa [kappa] 0.73; 95% CI for kappa 0.53, 0.92). Agreement between TST and QFT results was 100% (kappa 1.0) in BCG scar-negative children as compared to 94% (kappa 0.63) in scar-positive children. BCG was not associated with the results of either TST or QFT (P>0.05 for both tests). The number of children with bacteriologically confirmed active TB was too small to permit the estimation of sensitivity of the tests. CONCLUSIONS: In a rural, predominantly BCG-vaccinated paediatric population in India, the TST and QFT assay produced comparable results. BCG vaccination did not significantly affect either TST or QFT results. Larger studies are needed to compare the sensitivity of the IFN-gamma assay with that of the TST in children with bacteriologically and/or clinically confirmed TB.

Persistently elevated T cell interferon-gamma responses after treatment for latent tuberculosis infection among health care workers in India: a preliminary report.

BACKGROUND: T cell-based interferon-gamma (IFN-gamma) release assays (IGRAs) are novel tests for latent tuberculosis infection (LTBI). It has been suggested that T cell responses may be correlated with bacterial burden and, therefore, IGRAs may have a role in monitoring treatment response. We investigated IFN-gamma responses to specific TB antigens among Indian health care workers (HCWs) before, and after LTBI preventive therapy. METHODS: In 2004, we established a cohort of HCWs who underwent tuberculin skin testing (TST) and a whole-blood IGRA (QuantiFERON-TB-Gold In-Tube [QFT-G], Cellestis Ltd, Victoria, Australia) at a rural hospital in India. HCWs positive by either test were offered 6 months of isoniazid (INH) preventive therapy. Among the HCWs who underwent therapy, we prospectively followed-up 10 nursing students who were positive by both tests at baseline. The QFT-G assay was repeated 4 and 10 months after INH treatment completion (i.e. approximately 12 months and 18 months after the initial testing). IFN-gamma responses to ESAT-6, CFP-10 and TB7.7 peptides were measured using ELISA, and IFN-gamma >/=0.35 IU/mL was used to define a positive QFT-G test result. RESULTS: All participants (N = 10) reported direct contact with smear-positive TB patients at baseline, during and after LTBI treatment. All participants except one started treatment with high baseline IFN-gamma responses (median 10.0 IU/mL). The second QFT-G was positive in 9 of 10 participants, but IFN-gamma responses had declined (median 5.0 IU/mL); however, this difference was not significant (P = 0.10). The third QFT-G assay continued to be positive in 9 of 10 participants, with persistently elevated IFN-gamma responses (median 7.9 IU/mL; P = 0.32 for difference against baseline average). CONCLUSION: In an environment with ongoing, intensive nosocomial exposure, HCWs had strong IFN-gamma responses at baseline, and continued to have persistently elevated responses, despite LTBI treatment. It is plausible that persistence of infection and/or re-infection might account for this phenomenon. Our preliminary findings need confirmation in larger studies in high transmission settings. Specifically, research is needed to study T cell kinetics during LTBI treatment, and determine the effect of recurrent exposures on host cellular immune responses.