Changing approaches to the diagnosis of tuberculosis

Primary Laryngeal Tuberculosis: A Series of 15 Cases

Tuberculosis usually involves the lungs, but can also involve various other organs. Extra pulmonary tuberculosis is very rarely confined to the larynx in the absence of an associated pulmonary lesion. In this retrospective study, clinicopathological characteristics of patients with final diagnosis of laryngeal tuberculosis (LTB) were reviewed. The diagnosis of LTB was based on: (1) the existence of chronic granulomatous inflammation with caseous necrosis in the histopathology of laryngeal lesions or (2) the presence of laryngeal lesions with atypical histopathology (chronic granulomatous inflammation) which had a complete response to anti-tuberculosis therapy. Fifteen cases with a diagnosis of LTB were collected. The patients' age ranged between 24 and 75 years with a mean of 49 years. On laryngoscopy, 66.6% of cases (10/15) had an ulceroproliferative lesion while the remaining 33.3% of cases (5/15) had an exophytic growth. The pathology of laryngeal lesions revealed chronic granulomatous inflammation with caseous necrosis in nine cases and chronic granulomatous inflammation without necrosis in six cases. Nine out of 15 cases (60%) showed presence of acid-fast bacilli on Ziehl-Neelsen stain. Any evidence of pulmonary tuberculosis was ruled out by chest X-ray findings. The response to anti-tuberculosis therapy was desirable in all patients. Since the introduction of anti-tuberculous therapy, the incidence of LTB has declined. However, with the incidence of TB increasing, the overall incidence of laryngeal involvement may be on the rise. This study highlights the importance to consider the rare possibility of LTB in the presence of non-specific clinical and laryngoscopic signs and to confirm this by histological examination.

Association of MBL2 gene polymorphisms with pulmonary tuberculosis susceptibility: trial sequence meta-analysis as evidence

Background

Mannose-binding lectin (MBL) or mannose-binding protein (MBP), encoded by MBL2 gene and secreted by the liver, activates complement system through lectin pathway in innate immunity against the host’s infection. Conflictingly, a number of MBL2 variants, rs1800450 (A>B), rs1800451 (A>C), rs5030737 (A>D), rs7096206 (Y>X), rs11003125 (H>L), and rs7095891 (P>Q) allele, have been found to be associated with compromised serum levels and pulmonary tuberculosis (PTB) susceptibility. The present meta-analysis study was performed to evaluate the potential association of these MBL2 gene variants with PTB susceptibility.

Materials and methods

A quantitative synthesis was performed on PubMed (Medline), EMBASE, and Google Scholar web database searches. A meta-analysis was performed to calculate the pooled odds ratios and 95% CIs for all the genetic models.

Results

A total of 14 eligible studies were included to analyze their pooled data for associations between alleles, genotypes, and minor allele carriers. The statistical analysis revealed the significant reduced PTB risk with homozygous variant genotype of rs1800451 polymorphism (CC vs AA: P=0.043; OR =0.828, 95% CI =0.689–0.994). Contrary to this, the variant allele of rs5030737 polymorphism showed association with increased PTB risk (D vs A: P=0.026; OR =1.563, 95% CI =1.054–2.317). However, the other genetic models of rs1800450 (A>B), rs7096206 (Y>X), and rs11003125 (H>L) MBL2 gene polymorphisms did not divulge any association with PTB susceptibility.

Conclusion

The current meta-analysis concludes that rs1800451 (A>C) and rs5030737 (A>D) polymorphisms of MBL2 gene play a significant role in PTB susceptibility. Further, well-designed epidemiological studies with larger sample size including consideration of environmental factors are warranted for the future.

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

Rapid detection of Mycobacterium tuberculosis cultures by direct ambient corona discharge ionization mass spectrometry of volatile metabolites

High-throughput TB screening with high chemical specificity is achieved using direct ambient corona discharge ionization MS analysis of volatile metabolites.

Primary tuberculosis of the larynx

INTRODUCTION

Tuberculosis is a chronic bacterial infection caused by Mycobacterium tuberculosis, usually affecting the lung, but very rare cases of isolated laryngeal tuberculosis have been reported.

PURPOSE

To demonstrate the importance of considering the diagnosis of this disease, which presents with very variable and sometimes misleading clinical and endoscopic features, but for which medical treatment is very effective.

MATERIAL AND METHODS

This retrospective study was based on ten cases of laryngeal tuberculosis managed between January 2004 and December 2009. The objective of this study was to describe the epidemiology, clinical and complementary investigation findings and treatment of primary tuberculosis of the larynx in a context of endemic tuberculosis based on a review of the literature.

RESULT

In this series, primary tuberculosis of the larynx essentially affected male smokers and drinkers. Clinical and endoscopic signs were totally non-specific and similar to those of laryngeal cancer. Only bacteriological and histological examinations were able to establish the diagnosis. Once the diagnosis was confirmed, antituberculosis chemotherapy was administered for a minimum duration of 6 months with excellent short-term and long-term results.

CONCLUSION

Globally, the characteristics of this series are closely correlated with those reported in the literature. Due to the non-specific laryngeal signs observed on clinical examination, clinicians must consider the possibility of laryngeal tuberculosis and must not hesitate to confirm this diagnosis by bacteriological and histological examination

Immunocytochemistry versus nucleic acid amplification in fine needle aspirates and tissues of extrapulmonary tuberculosis

Background:

Immunocytochemistry (ICC) is an established routine diagnostic adjunct to cytology and histology for tumor diagnosis but has received little attention for diagnosis of tuberculosis.

Aims:

To have an objective method of direct visualization of mycobacteria or their products in clinical extrapulmonary tuberculosis (EPTB) specimens, immunocytochemical localization of M. tuberculosis antigen by staining with species specific monoclonal antibody to 38-kDa antigen of Mycobacterium tuberculosis complex.

Materials and Methods:

Immunostaining with specific monoclonal antibody to 38-kDa antigen of Mycobacterium tuberculosis complex was done in fresh and archival fine needle aspirates and tissue granulomata of 302 cases of extrapulmonary tuberculosis and was compared with the molecular diagnostic i.e., nucleic amplification and conventional [Cytomorphology, Ziehl Neelsen (ZN) staining and culture] tests and 386 controls.

Results:

Diagnostic indices by Bayesian analysis for all types of archival and fresh material varied from 64 to 76% in nucleic acid amplification (NAA) and 96 to 98% in ICC. There was no significant difference in the diagnostic indices of ZN staining and/ or ICC in fresh or archival material whereas the sensitivity of NAA differed significantly in fresh versus archival material both in cytology (71.4% vs 52.1%) and histology (51.1% vs 38.8%). ICC can be easily used on archival smears and formalin-fixed paraffin-embedded tissue sections with almost equal sensitivity and specificity as with fresh material, in contrast to NAA which showed significant difference in test results on archival and fresh material.

Conclusions:

Low detection sensitivity of MTB DNA in archival material from known tuberculous cases showed the limitation of in-house NAA-based molecular diagnosis. ICC was found to be sensitive, specific and a better technique than NAA and can be used as an adjunct to conventional morphology and ZN staining for the diagnosis of EPTB in tissue granulomas.

Classification and regression tree (CART) model to predict pulmonary tuberculosis in hospitalized patients

Background

Tuberculosis (TB) remains a public health issue worldwide. The lack of specific clinical symptoms to diagnose TB makes the correct decision to admit patients to respiratory isolation a difficult task for the clinician. Isolation of patients without the disease is common and increases health costs. Decision models for the diagnosis of TB in patients attending hospitals can increase the quality of care and decrease costs, without the risk of hospital transmission. We present a predictive model for predicting pulmonary TB in hospitalized patients in a high prevalence area in order to contribute to a more rational use of isolation rooms without increasing the risk of transmission.

Methods

Cross sectional study of patients admitted to CFFH from March 2003 to December 2004. A classification and regression tree (CART) model was generated and validated. The area under the ROC curve (AUC), sensitivity, specificity, positive and negative predictive values were used to evaluate the performance of model. Validation of the model was performed with a different sample of patients admitted to the same hospital from January to December 2005.

Results

We studied 290 patients admitted with clinical suspicion of TB. Diagnosis was confirmed in 26.5% of them. Pulmonary TB was present in 83.7% of the patients with TB (62.3% with positive sputum smear) and HIV/AIDS was present in 56.9% of patients. The validated CART model showed sensitivity, specificity, positive predictive value and negative predictive value of 60.00%, 76.16%, 33.33%, and 90.55%, respectively. The AUC was 79.70%.

Conclusions

The CART model developed for these hospitalized patients with clinical suspicion of TB had fair to good predictive performance for pulmonary TB. The most important variable for prediction of TB diagnosis was chest radiograph results. Prospective validation is still necessary, but our model offer an alternative for decision making in whether to isolate patients with clinical suspicion of TB in tertiary health facilities in countries with limited resources.

Les nouveaux tests immunologiques dans le diagnostic de la tuberculose (TB or not TB)

INTRODUCTION

Targeted testing and treatment of individuals with latent tuberculosis infection (LTBI), at high risk of progression to active tuberculosis (ATB), are key elements in the battle against tuberculosis, both in France and in many parts of the world. Though the finding of tubercle bacilli is the essential examination for the diagnosis of ATB, there is no indisputable test for LTBI.

BACKGROUND

The help currently given to the diagnosis of LTBI by the degree of positivity of the tuberculin skin test (TST) is limited, both operationally and logistically, in populations vaccinated with BCG or sensitised by atypical mycobacteria, and by its low sensitivity in those immuno-suppressed persons who are at greatest risk of progression. Moreover the TST has other operational limitations linked to return visits, repeat testing causing a boosting effect and subjective interpretation. A new approach follows the availability of two biological tests for the diagnosis of LTBI (QuantiFERON-TB and T-SPOT-TB) that measure the in-vitro production of interferon gamma (IFN-gamma) by the blood mononuclear cells in response to M. tuberculosis specific antigens (ESAT-6 and CFP10). This revue analyses the published studies, undertaken with varying numbers of patients, that evaluate the diagnostic accuracy of these two tests in comparison with TST. However, validation is handicapped by the lack of a "gold standard" for the diagnosis of LTBI. These studies demonstrate similar levels of specificity for the two biological tests. They are statistically higher than those for TST, particularly in populations vaccinated by BCG. On the other hand, their sensitivity was at least equivalent to that of TST and, in certain studies, superior with T-SPOT-TB. Finally, several studies in contacts have been undertaken with the aim of measuring the concordance between these biological tests and TST. The essential finding is of a very good correlation between positivity of the biological tests and the degree of exposure of the contacts. These tests have additional operational advantages over TST: completed in one visit, results available in 24 hours, absence of inter and intra observer divergence, detection of potential immuno-depression and avoidance of boosting by repeat testing.

VIEWPOINT

Currently, however, these biological tests present several operational limits: lower sensitivity in severe disease, incomplete data in immuno-suppressed subjects and in children, lack of predictive value for future development of ATB, lack of distinction between LTBI and ATB. Numerous clinical studies are under way, in France and elsewhere, in order to reduce these limitations and to allow the appropriate incorporation of these tests into protocols for the diagnosis of tuberculosis.

CONCLUSIONS

These two biological tests should, in the near future, replace or complement TST in the diagnosis of recent LTBI, leading to their optimal incorporation into the decision making processes of the national plans for the control of tuberculosis.

T-cell-based diagnosis of neonatal multidrug-resistant latent tuberculosis infection

Young children exposed to tuberculosis have a high risk of progression to severe tuberculosis disease, but diagnosis of recent infection is hindered by the poor sensitivity of the tuberculin skin test. Whether new blood tests can detect latent infection in this vulnerable group is unknown because there is no gold standard. We monitored a tuberculin skin test-negative infant whose mother had infectious multidrug-resistant tuberculosis with enzyme-linked immunospot, a blood test that enumerates Mycobacterium tuberculosis-specific T cells. The enzyme-linked immunospot test became persistently positive by 6 months, and 18 months later the child developed active tuberculosis despite appropriate chemoprophylaxis. At this point, the magnitude of the enzyme-linked immunospot response increased >10-fold. Our findings demonstrate that this blood test detected latent infection with dormant, yet viable, bacilli and illustrate how enzyme-linked immunospot could improve diagnosis of childhood tuberculosis infection.

Evaluation of the TB-Biochip oligonucleotide microarray system for rapid detection of rifampin resistance in Mycobacterium tuberculosis

The TB-Biochip oligonucleotide microarray system is a rapid system to detect mutations associated with rifampin (RIF) resistance in mycobacteria. After optimizing the system with 29 laboratory-generated rifampin-resistant mutants of Mycobacterium tuberculosis, we evaluated the performance of this test using 75 clinical isolates of Mycobacterium tuberculosis. With this small sample set, the TB-Biochip system displayed a sensitivity of 80% and a specificity of 100% relative to conventional drug susceptibility testing results for RIF resistance. For these samples (approximately 50% tested positive), the positive predictive value was 100% and the negative predictive value was 85%. Four of the seven observed discrepancies were attributed to rare and new mutations not represented in the microarray, while three of the strains with discrepant results did not carry mutations in the RIF resistance-determining region. The results of this study confirm the utility of the system for rapid detection of RIF resistance and suggest approaches to increasing its sensitivity.

Effect of nucleic acid amplification for Mycobacterium tuberculosis on clinical decision making in suspected extrapulmonary tuberculosis

BACKGROUND

Laboratory-based studies have suggested the nucleic acid amplification test (NAAT) for Mycobacterium tuberculosis may be useful in diagnosing extrapulmonary tuberculosis. We sought to determine how clinicians in one hospital used results of the NAAT in clinical decision making in cases of suspected extrapulmonary tuberculosis.

METHODS

We performed a retrospective analysis of all patients who underwent the NAAT on at least one nonsputum sample, excluding cerebrospinal fluid, from 1999 to 2001 in one large urban hospital. For these patients, we reviewed the hospital course, with particular attention to date of the NAAT and its influence on days treated with antituberculous medications and days to final diagnosis.

RESULTS

Thirty-five patients with suspected tuberculosis who had undergone the NAAT on extrapulmonary specimens were identified. From three patients, NAAT results were nondiagnostic because of inhibitors, and they were excluded from the analysis, leaving 32 patients. Tuberculosis was ultimately diagnosed in 14 of these 32 patients. NAAT findings were positive in specimens from 12 of 14 patients with extrapulmonary tuberculosis and in 0 of 18 cases in which tuberculosis was excluded (sensitivity, 86%; specificity, 100%; positive predictive value, 100%; negative predictive value, 90%). In only 2 of 19 patients treated with antituberculous medications was the NAAT result used to determine the onset or discontinuation of therapy. In no instance was a negative NAAT result used by clinicians as definitive evidence that a patient did not have extrapulmonary tuberculosis; in all but one case, patients were continued on antituberculous therapy until final culture results were available.

CONCLUSIONS

The NAAT proved to be a sensitive and specific test for detection of M tuberculosis in extrapulmonary specimens but did not weigh heavily in clinical decision making at our hospital. Judicious use of these tests may improve the accuracy and speed of diagnosis of extrapulmonary tuberculosis, while helping to eliminate unnecessary antituberculous treatment in patients without tuberculosis.

Comparison of the COBAS AMPLICOR MTB and BDProbeTec ET assays for detection of Mycobacterium tuberculosis in respiratory specimens

The performances of the BDProbeTec ET (Becton Dickinson) and COBAS AMPLICOR MTB (Roche) were retrospectively evaluated for detecting Mycobacterium tuberculosis complex in various respiratory specimens. The BACTEC and MGIT liquid culture system (Becton Dickinson) was used as a reference method. A total of 824 respiratory specimens, comprised of sputa, bronchoalveolar lavage fluid, and bronchial and tracheal aspirates from 580 patients, were evaluated. Out of 824 clinical specimens, 109 specimens from 43 patients were culture positive for M. tuberculosis. Of these 109 specimens, 67 were smear positive, 85 were positive by the COBAS AMPLICOR MTB test, and 94 were positive by the BDProbeTec ET. Of the 715 culture-negative specimens, 17 were positive by the auramine staining, 11 were positive by the COBAS AMPLICOR MTB test, and 12 were positive by the BDProbeTec ET. After discrepancy analysis and review of the patients' clinical data, 130 specimens from 50 patients were considered "true-positive" specimens. This resulted in the following sensitivities: microscopy, 61.5%; COBAS AMPLICOR MTB test, 78.0%; and BDProbeTec ET, 86.2%. The specificities of each system, based on the clinical diagnosis, were 99.7% for microscopy, 99.9% for the COBAS AMPLICOR MTB test, and 99.9% for the BDProbeTec ET. The data presented represent a considerable number of specimens evaluated with a considerable number of culture- and auramine-positive and culture-positive and auramine-negative results and therefore give a realistic view of how the data should be interpreted in a daily routine situation. Specifically, the data with regard to the culture-positive and auramine-negative specimens are useful, because in a routine situation, auramine-negative specimens are sometimes accepted, on clinical indications, to be analyzed by an amplification method.

Mycobacterium tuberculosis Infection in Recipients of Solid Organ Transplants

Tuberculosis is a serious opportunistic infection that may affect transplant recipients. The incidence of tuberculosis among such persons is 20-74 times higher than that for the general population, with a mortality rate of up to 30%. The most common form of acquisition of tuberculosis after transplantation is the reactivation of latent tuberculosis in patients with previous exposure. Clinical presentation is frequently atypical and diverse, with unsuspected and elusive sites of affection. Manifestations include fever of unknown origin and allograft dysfunction. Coinfection with other pathogens is not uncommon. New techniques, such as PCR and quantification of interferon- gamma , have been developed to achieve more-rapid and -accurate diagnoses. Treatment requires control of interactions between antituberculous drugs and immunosuppressive therapy. Prophylaxis against latent tuberculosis is the main approach to treatment, but many issues remain unsolved, because of the difficulty in identifying patients at risk (such as those with nonreactive purified protein derivative test results) and the toxicity of therapy.

Rapid detection of isoniazid and rifampin resistance mutations in Mycobacterium tuberculosis complex from cultures or smear-positive sputa by use of molecular beacons

The slow-growing nature of Mycobacterium tuberculosis complex hinders the improvement of turnaround time for phenotypic drug susceptibility testing. We designed a set of molecular beacons for the detection of isoniazid and rifampin resistance mutations in M. tuberculosis complex organisms from cultures or from N-acetyl-l-cysteine-NaOH-treated, smear-positive specimens. The performance of the molecular beacons was characterized by studying a total of 196 clinical isolates (127 drug-resistant isolates and 69 drug-susceptible isolates). For detection of isoniazid resistance, the sensitivity and specificity of the assay were 82.7 and 100%, and the positive predictive value (PPV) and negative predictive value (NPV) at a resistance prevalence of 10% were 100 and 98.11%, respectively. For detection of rifampin resistance, the sensitivity and specificity of the assay were 97.5 and 100%, and the PPV and NPV at a resistance prevalence of 2.0% were 100 and 99.95%, respectively.

Molecular genetic methods for diagnosis and antibiotic resistance detection of mycobacteria from clinical specimens

Mycobacteria comprise a diverse group of bacteria that are widespread in nature, some of which cause significant disease in humans. Members of the Mycobacterium tuberculosis complex (MTBC) are the most important human pathogens of the genus Mycobacterium. Traditional methods for detection and identification of mycobacteria include microscopy, culture and phenotypic tests. These methods either lack sensitivity, specificity, or are time consuming. Advances in the field of molecular biology have provided rapid diagnostic tools that have reduced the turnaround times for detecting MTBC and drug resistance in cultures and directly in clinical specimens from weeks to days. This review discusses the molecular genetic techniques for detecting and identifying MTBC as well as drug resistance of mycobacteria in clinical specimens.

Evaluation of the BDProbeTec strand displacement amplification assay in comparison with the AMTD II direct test for rapid diagnosis of tuberculosis

The BDProbeTec MTB assay for direct detection of Mycobacterium tuberculosis was evaluated in comparison with the AMTD-II assay on 94 samples from different patients with clinical suspicion of tuberculosis. Using a combination of culture on Lowenstein-Jensen medium (with or without preculture in BACTEC 9000) and clinical diagnosis as the standard, BDProbeTec MTB showed high sensitivity and specificity (96.1% and 100%, respectively), similar to AMTD-II (96.1% and 97.1%, respectively), with significantly higher sensitivity than the Ziehl-Neelsen stain for acid-fast bacilli (73%, p < 0.05).

Role of clinical judgment in the application of a nucleic acid amplification test for the rapid diagnosis of pulmonary tuberculosis

BACKGROUND

Several nucleic acid amplification (NAA) tests for Mycobacterium tuberculosis (MTB) have been licensed for the rapid diagnosis of active pulmonary tuberculosis (PTB) in respiratory secretions. There is uncertainty however regarding the practical application of these tests in clinical decision making.

OBJECTIVE

To evaluate the utility of the COBAS AMPLICOR assay (Roche Diagnostics; Singapore) for MTB as applied by specialists for the rapid diagnosis of PTB in the routine clinical setting.

DESIGN

A prospective study of consecutive patients suspected of PTB and tested with the AMPLICOR assay under the care of respiratory physicians. The final diagnosis was based on all relevant clinical information after at least 3 months of follow-up. Accuracy of the NAA test was compared with that of the initial expectant treatment. Expectant treatment was based on an integrated approach that incorporated clinical evaluation with results of direct smear and NAA tests.

RESULTS

The incidence of PTB in 168 patients was 32%. The basis for expectant treatment of PTB was positive smear result in 47%, clinical suspicion in 26%, and positive AMPLICOR result in 23%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the AMPLICOR test were 77%, 100%, 99%, 90%, and 93%, respectively. In comparison, they were 96%, 97%, 94%, 98%, and 97%, respectively, for the integrated clinical approach.

CONCLUSIONS

In the rapid diagnosis of PTB, the clinical judgment of specialists augmented the utility of the NAA test: (1) specialists selected patients with high-to-moderate pretest probabilities, (2) they commenced treatment promptly on a positive NAA test result, and (3) they were willing to start treatment in some patients on the basis of high clinical suspicion despite negative smear and negative NAA test results.

Tuberculosis

Approximately one-third of the world population is infected with Mycobacterium tuberculosis, the organism that causes tuberculosis (TB). After a brief resurgence beginning in the mid-1980s, the incidence of TB is once again declining in the United States. Health care workers, including dentists and their staff, however, remain at risk for occupational acquisition of the disease. This risk can be managed by educating dental health care workers about the oral and systemic manifestations of TB and the mechanisms by which it is spread so that appropriate measures may be taken in the office to minimize the opportunity for disease transmission.

Comparison of the BDProbeTec ET system with the Cobas Amplicor PCR for direct detection of Mycobacterium tuberculosis in respiratory samples

In the study presented here, the performance of the BDProbeTec ET system (Becton Dickinson, USA) was compared with the Roche Cobas Amplicor-PCR (Roche, Switzerland) to detect Mycobacterium tuberculosis complex (MTB) in clinical respiratory samples. The Bactec MGIT 960 liquid culture system (Becton Dickinson) was used as a reference method. A total of 411 samples were tested. Of the 93 culture-positive samples, both the BDProbeTec ET system and the Cobas Amplicor-PCR detected 87 (sensitivity, 93.5%). When only smear-negative samples were considered, the BDProbeTec ET exhibited a sensitivity of 50% and the Cobas Amplicor-PCR 60%. Specificity was 99.7% for the BDProbeTec ET system and 100% for the Cobas Amplicor-PCR. Percent agreement between the two nucleic amplification methods was 98.7%. Inhibition occurred in three (0.7%) samples in the BDProbeTec ET system. The high sensitivity and specificity of the BDProbeTec ET system suggest it is a useful method for the rapid and direct detection of MTB in smear-positive respiratory samples.

What is the optimal approach for using a direct amplification test in the routine diagnosis of pulmonary tuberculosis? A preliminary assessment

OBJECTIVE

The aim of this study was to determine the most appropriate strategy for the rapid diagnosis of pulmonary tuberculosis (PTB) using a nucleic acid amplification (NAA) test.

METHODOLOGY

This was a prospective study of 128 adult patients in whom respiratory secretions were tested for Mycobacterium tuberculosis by the AMPLICOR assay. The basis for starting PTB treatment was noted for each patient. The optimal approach was determined by using Bayes' theorem to compare different combinations of pretest probability, smear results with the AMPLICOR test.

RESULTS

The incidence of PTB was 15.6%. In only one patient was treatment for PTB commenced because of a positive AMPLICOR result. The rest were managed according to the conventional approach which relied upon clinical judgment and direct smear. The optimal approach was to treat patients with high or intermediate pretest risk for PTB who returned positive AMPLICOR tests. The overall accuracies of the conventional approach, AMPLICOR test and optimal approach were 89.8, 95.3 and 96.1%, respectively.

CONCLUSION

This small study suggests that NAA testing be limited to patients with high or intermediate pretest risk of PTB. In this group, positive results demand treatment while the management of those with negative results still relies on clinical judgment.

Congenital tuberculosis: a rare manifestation of a common infection

The epidemiology of tuberculosis has changed dramatically over the past 5 years with significant shifts in at-risk populations, resulting in increased disease among young adults and children, especially among those from developing countries. Congenital tuberculosis is rare, and the clinical presentation of tuberculosis during pregnancy and infancy is often non-specific, making recognition difficult. Advances have been made with diagnostic tools, in public health practices, and with treatment recommendations. Controversy and debate continue regarding the safety and use of isoniazid for latent tuberculosis infection during pregnancy. New vaccine development may be promising for the future, but much work is needed to understand the complicated immune response to tuberculosis.