Tuberculosis: Current Status, Diagnosis, Treatment and Development of Novel Vaccines

1. Rosalind S. Abernathy, MD* 1. 2. *Associate Professor of Pediatrics, University of Arkansas for Medical Sciences; Pediatric Consultant, Tuberculosis, Arkansas State Department of Health, Little Rock, AR. 1. The majority of tuberculosis cases in children are from high-risk populations, that is, African-Americans, Hispanics, immigrants, and those living in poverty and in the inner cities. 2. The only acceptable tuberculin skin test is the intradermal Mantoux test with purified protein derivative (PPD), and three levels of positivity now are accepted. Children exposed to active disease who have findings suggestive of tuberculosis or who have human immunodeficiency virus (HIV) infection are positive at 5 to 9 mm; other high-risk groups are positive at 10 mm. 3. Diagnosis of childhood tuberculosis depends on a high index of suspicion coupled with suggestive epidemiologic data, tuberculin skin test results, and chest radiographic findings. Cultures are not routinely positive, and results are available only after treatment must be started. 4. Treatment is a uniform 6-month course of isoniazid, rifampin, and pyrazinamide for 2 months followed by 4 months of isoniazid and rifampin daily or twice weekly. Additional drugs are needed in cases of drug resistance. 5. Chemoprophylaxis for all children who have a positive tuberculin reaction will prevent future disease. Despite the availability of effective antituberculosis drugs since 1952, tuberculosis remains an important cause of morbidity, mortality, and health care cost in the United States. Tuberculosis case rates declined at a rate of 6% annually for more than 20 years until 1985 when they leveled off (Fig. 1⇓). Factors responsible for this include human immunodeficiency virus (HIV) infection; immigration of individuals from countries where tuberculosis rates are 10 to 30 times that of the United States; transmission of disease in hospitals, homeless shelters, and prisons; and poverty, overcrowded living, and poor access to medical care. While all this was occurring, funds for tuberculosis control by public health programs declined. Fortunately, the number of cases reported annually has decreased by 8.7% in the past 2 years, probably …

Mycobacterium tuberculosis Infections in Solid Organ Transplantation

Various strategies have been implemented to prevent tuberculosis. Vaccination with Bacille Calmette Guerin (BCG) vaccine is still used around the world. Generally, most people in have gained BCG vaccine as an infant, but the effectiveness of these vaccines do not survive to adulthood. Therefore, the necessary replacement BCG vaccine more effective to eliminate tuberculosis. Mycobacterium tuberculosis is an intracellular pathogen and it was inside the macrophage, which is considered to be the most important component of the immune system. M. tuberculosis has two sets of genes are highly polymorphic referred to as PE and PPE families. These unique families of proteins account for about 10% of the mycobacterial genome and have attracted great interest from a variety of different studies around the world. One member of the as a vaccine candidate is Rv 2430c. It is known that the sera of all patients infected with TB showed strong antibody responses against Rv 2430c compared to healthy individuals. The existence of these antibodies indicates that this protein is found in vivo during infection and is a native immunogenic molecule. The purpose of this study was to clone the Open Reading Frame (ORF) Rv 2430c M. tuberculosis Indonesian isolates to host cells Esherichia coli JM 109. The method used is by isolating -chromosomal DNA from clinical isolates from Indonesia, amplifying the ORF Rv 2430c with , ligating into cloning vectors pGEM-T and transform to E.coli JM 109. Characterization of clones do with migration analysis, restriction analysis and . The results obtained are recombinant clones that carry insertion was Rv 2430cKeywords: Mycobacterium tuberculosis, Rv 2430c, ORF, , JM 109.

To investigate whether an unrecognised diagnosis of tuberculosis (TB) at the start of antiretroviral therapy (ART) influences subsequent CD4+ T cell (CD4) count recovery in an urban HIV clinic in Uganda. In a retrospective cohort study, a multivariable polynomial mixed effects model was used to estimate CD4 recovery in the first 96 weeks of ART in two groups of patients: prevalent TB (started ART while on TB treatment), unrecognised TB (developed TB within 6 months after start ART). Included were 511 patients with a median baseline CD4 count of 57 cells/mm(3) (interquartile range: 22-130), of whom 368 (72%) had prevalent TB and 143 (28%) had unrecognised TB. Compared with prevalent TB, unrecognised TB was associated with lower CD4 count recovery at 96 weeks: -22.3 cells/mm(3) (95% confidence interval -43.2 to -1.5, P = 0.036). These estimates were adjusted for gender, age, baseline CD4 count and the use of zidovudine-based regimen. Unrecognised TB at the time of ART initiation resulted in impaired CD4 recovery compared with TB treated before ART initiation. More vigilant screening with more sensitive and rapid TB diagnostics prior to ART initiation is needed to decrease the risk of ART-associated TB and sub-optimal immune reconstitution.

Targeting HspX of Mycobacterium tuberculosis: Advances in diagnostics, treatment, and vaccine development.

BACKGROUND AND OBJECTIVES:There are few reports of cutaneous tuberculosis with immunosuppressed states such as HIV, use of immunosuppressants or malignancy. Diagnosis is thus difficult and despite scientific advances such as polymerase chain reaction, it is frequently missed. Although rare, given its worldwide prevalence and the rising incidence of HIV, it is important for clinicians to recognize the variants and promptly treat the patient.DESIGN AND SETTING:Retrospective study of all cases of cutaneous tuberculosis diagnosed from October 2007 to November 2009 at an outpatient clinic of a tertiary-care hospital in northern India.METHODS:We collected information on the clinical form of disease, histopathology and HIV concurrence rates and looked for differences in presentation between mmunocompetent and immunocompromised states. We also looked for differences and HIV concurrence between immunocompetent and immunocomprised patients. Diagnosis was based on clinical, histopathological and microbiological tests for tuberculosis and a test for HIV.RESULTS:The overall incidence of cutaneous tuberculosis was 0.7% (131 of 18720 outpatients). HIV concurrence was 9.1% (12 cases) of all cutaneous tuberculosis cases. Most common variants seen were scrofuloderma (36.5%), lupus vulgaris (31%), tuberculosis verruca cutis (12.9%), lichen scrofulosorum (11.4%), papulonecrotic tuberculids (3.8%), erythema nodosum (2.2%) and erythema induratum of Bazin (1.5%).CONCLUSIONS:Cutaneous tuberculosis rates were slightly higher in our study than in other studies from India. HIV co-infection rates were similar to those in other studies. Many atypical morphological forms and presentations were observed in HIV co-infected patients. Due to the varied clinical presentations, physician awareness and a high index of suspicion are necessary to diagnose cutaneous forms of tuberculosis.

The prevalence of tuberculosis (TBC) in children tends to increase and become a serious public health problem. The higher case of TBC in children requires comprehensive surveillance. Surveillance can be carried out by clustering the cases of TBC in children based on region. One of the clustering methods that can be used is the K-Means method. Furthermore, Geographic Information Systems (GIS) has been successfully used in health fields and have the advantages in the processing and presentation of spatial and non-spatial information. The present research aims to classify the cases of TBC in children using K-Means clustering and identify the distribution patterns using GIS. Based on the analysis, the spatial pattern of the distribution of TBC in children can be categorized into: areas with high prevalence, areas with moderate prevalence, and areas with low prevalence. The result can be used to help decision making in controlling the cases of TBC in children.

BackgroundAlthough the Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis (TB) has been available for more than 75 years, one third of the world's population is still infected with Mycobacterium tuberculosis and approximately 2 million people die of TB every year. To reduce this immense TB burden, a clearer understanding of the functional genes underlying the action of BCG and the development of new vaccines are urgently needed.Methods and FindingsComparative genomic analysis of 19 M. tuberculosis complex strains showed that BCG strains underwent repeated human manipulation, had higher region of deletion rates than those of natural M. tuberculosis strains, and lost several essential components such as T-cell epitopes. A total of 188 BCG strain T-cell epitopes were lost to various degrees. The non-virulent BCG Tokyo strain, which has the largest number of T-cell epitopes (359), lost 124. Here we propose that BCG strain protection variability results from different epitopes. This study is the first to present BCG as a model organism for genetics research. BCG strains have a very well-documented history and now detailed genome information. Genome comparison revealed the selection process of BCG strains under human manipulation (1908–1966).ConclusionsOur results revealed the cause of BCG vaccine strain protection variability at the genome level and supported the hypothesis that the restoration of lost BCG Tokyo epitopes is a useful future vaccine development strategy. Furthermore, these detailed BCG vaccine genome investigation results will be useful in microbial genetics, microbial engineering and other research fields.

IntroductionThe inadequate efficacy of the Bacillus Calmette–Guérin (BCG) vaccine against adult pulmonary tuberculosis (TB) necessitates the development of new and effective vaccines. Human adenovirus serotype 5 (Ad5), which induces T-cell response, is a widely used viral vector. In this study, we aimed to evaluate the efficacy of a multi-antigenic recombinant Ad5 vectored vaccine and determine the optimal immunization route for enhanced immune response against Mycobacterium tuberculosis.MethodsWe constructed a multi-antigenic recombinant Ad5 vectored vaccine expressing four antigens (Ag85B-ESAT6-MPT64-Rv2660c) of M. tuberculosis (rAd-TB4), immunized with rAd-TB4 (5 × 107 infectious virus units/mouse) twice at an interval of 4 weeks starting at 10 weeks after BCG priming, and evaluated its boosting efficacy in a BCG-primed mouse model, and determined the optimal immunization route.ResultsCompared with the BCG-only (2 × 105 colony forming units/mouse), subcutaneous injection of rAd-TB4 (1 × 107 infectious virus units/mL; two doses) elicited a T-cell response and cytokine production in lung lymphocytes and splenocytes. rAd-TB4 immunization significantly reduced bacterial loads and inflamed lung areas compared to BCG immunization (p < 0.01) and protected against the H37Rv challenge performed at 17 weeks of BCG priming. RNA sequencing of the whole blood of rAd-TB4-vaccinated mice collected pre- and, 1 and 4 weeks post-infection, identified differentially expressed genes associated with immune and inflammatory responses, especially those in the Wnt signaling pathway.ConclusionOur results indicate that rAd-TB4 immunization enhances the immune response to the vaccine boosting antigens in BCG-primed mice, making it a potential adult pulmonary TB vaccine candidate.

The tuberculosis control strategy of vaccinating First Nations newborns with BCG (bacille Calmette-Guerin) is currently undergoing re-evaluation in Canada. Review of recent pediatric tuberculosis morbidity could inform this re-evaluation. Potential source cases and pediatric cases of tuberculosis from Alberta First Nations were identified over the 10 years 1991-2000. The distribution of pediatric disease was described. The effect of BCG on tuberculosis morbidity in two large outbreaks was determined. A total of 57 potential source cases and 41 pediatric cases of tuberculosis were reported from 17 (41.5%) and 8 (19.5%) of the 41 on-reserve First Nation Community Health Centres, respectively. Three outbreaks traceable to three source cases accounted for 34 (18, 3, and 13, respectively) of the 41 (82.9%) pediatric cases. Each outbreak was spatially and temporally separate from the other. Each outbreak strain of Mycobacterium tuberculosis had a unique DNA fingerprint. In the largest outbreaks, disease-to-infection ratios (secondary case rates) were higher in newly infected unvaccinated versus vaccinated close pediatric contacts (12/13 [92.3%] versus 7/15 [46.7%], p=0.02), but the infection rate was almost certainly falsely high in the BCG vaccinated. One unvaccinated child had a brain tuberculoma in addition to primary pulmonary tuberculosis. For most Alberta First Nations communities, the spatial and temporal distribution of disease, and the meager impact on morbidity, challenge the rationale for continued use of BCG.

Rationale: Tuberculosis (TB) imposes a significant financial and social burden on people with this disease, their families, society, and the state. Understanding the financial and social burden due to TB makes it possible to justify the need for investment in the TB service. The purpose was to study the average cost of treatment of active and latent TB in children in Belarus. Methods: A database of 774 children with pulmonary TB was used to calculate the average age of a child with TB. The price for medical services of the Republican Scientific and Practical Center of Pulmonology and Tuberculosis of the Ministry of Health of the Republic of Belarus were used. We used the average prices for anti-TB drugs from the International Medical Products Price Guide (2016). Results: The average age of a child with pulmonary TB was 14.2 ± 4.3 years. The average weight of a child with pulmonary TB was 50.8 kilograms. The total cost of inpatient and outpatient treatment of one child with drug-sensitive pulmonary TB amounted $ 8 806, with drug-resistant pulmonary TB - $ 16 025. The cost of different courses of treatment of latent TB is determined. The total cost of treatment of latent TB for one child with latent TB with isoniazid for 6 months was $ 5.8, with isoniazid and rifampicin for 3 months - $ 25.4, with rifampicin for 4 months - $ 30.0. Conclusions: The results show that the cost of treatment of latent TB in children in 293.5 - 346.7 - 1518.2 times lower than the cost of treatment of drug-sensitive TB, in 534.2 - 630.9 - 2763.0 times lower than the cost of treatment drug-resistant TB. The results can be used to determine the cost of medical care for children with active and latent TB.

Tuberculosis (TB) is still a public health problem worldwide. Tuberculosis is an infectious disease caused by the Mycobacterium tuberculosis germ and is one of the 10 leading causes of death worldwide. The methods section should be able to explain the research methods used, including how the procedures were carried out. Tools, materials, media or research instruments must be well described. There is no gold standard for ILTB diagnosis. Tuberculin Skin Test (TST) and Immunoglobulin Release Assay (IGRA) are the WHO recommended ILTB tests. The purpose of TPT is to prevent the occurrence of TB disease so as to reduce the burden of TB. One of the efforts in preventing tuberculosis disease in children is the Bacille Calmette Guerin (BCG) vaccine. BCG vaccine is very effective in preventing tuberculosis in children, where children who do not get BCG vaccine have a 6.87 times higher risk of developing tuberculosis compared to children who get BCG vaccine. The effectiveness of the BCG vaccine in preventing tuberculosis is 85%.

There is an urgent need for effective prophylactic measures against Mycobacterium tuberculosis (Mtb) infection, particularly given the highly variable efficacy of Bacille Calmette-Guerin (BCG), the only licensed vaccine against tuberculosis (TB). Most studies indicate that cell-mediated immune responses involving both CD4+ and CD8+ T cells are necessary for effective immunity against Mtb. Genetic vaccination induces humoral and cellular immune responses, including CD4+ and CD8+ T-cell responses, against a variety of bacterial, viral, parasitic and tumor antigens, and this strategy may therefore hold promise for the development of more effective TB vaccines. Novel formulations and delivery strategies to improve the immunogenicity of DNA-based vaccines have recently been evaluated, and have shown varying degrees of success. In the present study, we evaluated DNA-launched Venezuelan equine encephalitis replicons (Vrep) encoding a novel fusion of the mycobacterial antigens α-crystallin (Acr) and antigen 85B (Ag85B), termed Vrep-Acr/Ag85B, for their immunogenicity and protective efficacy in a murine model of pulmonary TB. Vrep-Acr/Ag85B generated antigen-specific CD4+ and CD8+ T cell responses that persisted for at least 10 wk post-immunization. Interestingly, parenterally administered Vrep-Acr/Ag85B also induced T cell responses in the lung tissues, the primary site of infection, and inhibited bacterial growth in both the lungs and spleens following aerosol challenge with Mtb. DNA-launched Vrep may, therefore, represent an effective approach to the development of gene-based vaccines against TB, particularly as components of heterologous prime-boost strategies or as BCG boosters.

Vaccination is an excellent approach to stimulating the host immune response and reducing human morbidity and mortality against microbial infections, such as tuberculosis (TB). Bacillus Calmette–Guerin (BCG) is the most widely administered vaccine in the world and the only vaccine approved by the World Health Organization (WHO) to protect against TB. Although BCG confers “protective” immunity in children against the progression of Mycobacterium tuberculosis (Mtb) infection into active TB, this vaccine is ineffective in protecting adults with active TB manifestations, such as multiple-, extensive-, and total-drug-resistant (MDR/XDR/TDR) cases and the co-existence of TB with immune-compromising health conditions, such as HIV infection or diabetes. Moreover, BCG can cause disease in individuals with HIV infection or other immune compromises. Due to these limitations of BCG, novel strategies are urgently needed to improve global TB control measures. Since live vaccines elicit a broader immune response and do not require an adjuvant, developing recombinant BCG (rBCG) vaccine candidates have received significant attention as a potential replacement for the currently approved BCG vaccine for TB prevention. In this report, we aim to present the latest findings and outstanding questions that we consider worth investigating regarding novel mycobacteria-based live attenuated TB vaccine candidates. We also specifically discuss the important features of two key animal models, mice and rabbits, that are relevant to TB vaccine testing. Our review emphasizes that the development of vaccines that block the reactivation of latent Mtb infection (LTBI) into active TB would have a significant impact in reducing the spread and transmission of Mtb. The results and ideas discussed here are only based on reports from the last five years to keep the focus on recent developments.

Tuberculosis (TB) and leprosy still represent significant public health challenges, especially in low- and lower middle-income countries. Both poverty-related mycobacterial diseases require better tools to improve disease control. For leprosy, there has been an increased emphasis on developing tools for improved detection of infection and early diagnosis of disease. For TB, there has been a similar emphasis on such diagnostic tests, while increased research efforts have also focused on the development of new vaccines. Bacille Calmette–Guérin (BCG), the only available TB vaccine, provides insufficient and inconsistent protection to pulmonary TB in adults. The impact of BCG on leprosy, however, is significant, and the introduction of new TB vaccines that might replace BCG could, therefore, have serious impact also on leprosy. Given the similarities in antigenic makeup between the pathogens Mycobacterium tuberculosis (Mtb) and M. leprae, it is well possible, however, that new TB vaccines could cross-protect against leprosy. New TB subunit vaccines currently evaluated in human phase I and II studies indeed often contain antigens with homologs in M. leprae. In this review, we discuss pre-clinical studies and clinical trials of subunit or whole mycobacterial vaccines for TB and leprosy and reflect on the development of vaccines that could provide protection against both diseases. Furthermore, we provide the first preclinical evidence of such cross-protection by Mtb antigen 85B (Ag85B)-early secretory antigenic target (ESAT6) fusion recombinant proteins in in vivo mouse models of Mtb and M. leprae infection. We propose that preclinical integration and harmonization of TB and leprosy research should be considered and included in global strategies with respect to cross-protective vaccine research and development.