Concurrent pulmonary tuberculosis and lepromatous leprosy in a newly diagnosed HIV positive patient: a case report.

BACKGROUND: The leprosy-tuberculosis (TB) co-infection is rarely reported in recent times. However, this dual comorbidity is associated with high mortality and major morbidity. Unrecognised leprosy-TB co-infection may predispose affected patients to rifampicin monotherapy and subsequent drug resistance. CASE PRESENTATION: A 35 year old migrant, human immunodeficiency virus (HIV) positive male worker presented with 6 month history of symmetric infiltrative nodular plaques of the face and distal, upper extremities. A few days after initial dermatology presentation, a sputum positive pulmonary tuberculosis diagnosis was made at his base hospital. Subsequent dermatology investigations revealed histology confirmed lepromatous leprosy and a weakly reactive rapid plasma reagin test. The presenting clinical features and laboratory results were suggestive of lepromatous leprosy coexisting with pulmonary tuberculosis in an HIV positive patient. CONCLUSIONS: This case illustrates the occurrence of leprosy with pulmonary tuberculosis in an HIV infected patient and the difficulties in interpreting non-treponemal syphilis tests in these patients. This case also highlights the need for a high index of suspicion for co-infection and the need to exclude PTB prior to initiation of rifampicin containing multi-drug therapy (MDT). Interdisciplinary management and social support are crucial in these patients.

Genetic diversity and drug resistance pattern of Mycobacterium tuberculosis strains isolated from pulmonary tuberculosis patients in the Benishangul Gumuz region and its surroundings, Northwest Ethiopia.

INTRODUCTION: Tuberculosis (TB) remains a major global public health problem and is the leading cause of death from a single bacterium, Mycobacterium tuberculosis (MTB) complex. The emergence and spread of drug-resistant strains aggravate the problem, especially in tuberculosis high burden countries such as Ethiopia. The supposedly high initial cost of laboratory diagnosis coupled with scarce financial resources has limited collection of information about drug resistance patterns and circulating strains in peripheral and emerging regions of Ethiopia. Here, we investigated drug susceptibility and genetic diversity of mycobacterial isolates among pulmonary tuberculosis patients in the Benishangul Gumuz region and its surroundings in northwest Ethiopia. METHODS AND MATERIAL: In a cross-sectional study, 107 consecutive sputum smear-positive pulmonary tuberculosis (PTB) patients diagnosed at two hospitals and seven health centers were enrolled between October 2013 and June 2014. Sputum samples were cultured at Armauer Hansen Research Institute (AHRI) TB laboratory, and drug susceptibility testing (DST) was performed against Isoniazid, Rifampicin, Ethambutol, and Streptomycin using the indirect proportion method. Isolates were characterized using polymerase chain reaction (PCR)based Region of Difference 9 (RD9) testing and spoligotyping. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) for Windows version 24.0. RESULTS: Of 107 acid-fast-bacilli (AFB) smear-positive sputum samples collected, 81.3% (87/107) were culture positive. A PCR based RD9 testing revealed that all the 87 isolates were M. tuberculosis. Of these isolates, 16.1% (14/87) resistance to one or more drugs was observed. Isoniazid monoresistance occurred in 6.9% (6/87). Multidrug resistance (MDR) was observed in two isolates (2.3%), one of which was resistant to all the four drugs tested. Spoligotyping revealed that the majority, 61.3% (46/75) of strains could be grouped into ten spoligotype patterns containing two to 11 isolates each while the remaining 38.7% (29/75) were unique. SIT289 (11 isolates) and SIT53 (nine isolates) constituted 43.5% (20/46) among clustered isolates while 29.3% (22/75) were ''New" to the database. The dominant families were T, 37% (28/75), CAS, 16.0% (12/75), and H, 8% (6/75), adding up to 51.3% (46/75) of all isolates identified. CONCLUSION AND RECOMMENDATIONS: The current study indicates a moderate prevalence of MDR TB. However, the observed high monoresistance to Isoniazid, one of the two proxy drugs for MDR-TB, reveals the hidden potential threat fora sudden increase in MDR-TB if resistance to Rifampicin would increase. Clustered spoligotype patterns suggest ongoing active tuberculosis transmission in the area. The results underscore the need for enhanced monitoring of TB drug resistance and epidemiological studies in this and other peripheral regions of the country using robust molecular tools with high discriminatory power such as the Mycobacterial Interspersed Repetitive Units -Variable Number of Tandem Repeats (MIRU-VNTR) typing and whole-genome sequencing (WGS).

The National Tuberculosis Control Programme of Liberia Laboratory Programme Performance.

Background: Tuberculosis (TB) is a major public health problem in Liberia. Little is known about the TB laboratory performance of Liberia and the challenges after the 14 years of civil war which ended in 2003. The purpose of the study was to evaluate the TB laboratory performance of Liberia. Methods: A cross-sectional study was conducted from 2014 to 2015. The study was conducted using quantitative data of TB case findings, sputum microscopy proficiency testing, and on-site assessment of sputum microscopy laboratories in Liberia. 80 laboratories participated in the proficiency testing. Besides, four years' (2012-2015) TB case finding data obtained from the National Leprosy and Tuberculosis Control Programme (NLTCP) were used to complement the study. The data were analysed using descriptive statistics. Results: From the 80 TB sputum microscopy testing laboratories participating in proficiency testing, only 20 (25%) scored acceptable performance. 46 (58%) TB microscopy laboratories reported quantification errors for the proficiency panel slide 6 which was 3+. The national TB smear-positive cases notified were 4342 in 2012 but decreased to 3820 and 2448 in 2013 and 2014, respectively. The TB smear case detection rate showed an increase from 68% in 2010 to 78% in 2011 and a decrease to 60%, 57%, and 42% in 2012, 2013, and 2014, respectively. Conclusion: Between 2010 and 2013, the NLTCP succeeded in increasing the number of TB sputum microscopy laboratories. At most of the TB microscopy sites, the TB laboratory quality system was not implemented. The NLTCP of Liberia should develop strategies to overcome its challenges in TB laboratory testing.

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing.

OBJECTIVE: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. METHODS: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). RESULTS: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. CONCLUSIONS: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing / Desempenho de testes para o diagnóstico de tuberculose pulmonar em populações indígenas no Brasil: a contribuição do Teste Rápido Molecular

ABSTRACT Objective: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. Methods: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). Results: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. Conclusions: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

RESUMO Objetivo: Avaliar a acurácia do teste rápido molecular como ferramenta diagnóstica e estimar a incidência de casos pulmonares positivos entre a população indígena. Métodos: Estudo epidemiológico baseado em dados secundários. Foi calculada a incidência de casos de tuberculose pulmonar positiva entre 1° de janeiro de 2011 e 31 de dezembro de 2016, e o desempenho da baciloscopia e do teste rápido molecular no diagnóstico de tuberculose pulmonar, em comparação à cultura de escarro (teste padrão). Resultados: Foram incluídos 4.048 casos de indígenas considerados sintomáticos respiratórios, que forneceram amostras de escarro para análise. Destes, 3,7%, 6,7% e 3,7% apresentaram resultados positivos para baciloscopia, cultura e teste rápido molecular, respectivamente. A incidência média de tuberculose pulmonar foi de 269,3/100 mil habitantes. A sensibilidade do teste rápido molecular, em relação à cultura, foi 93,1% e a especificidade foi 98,2%. A baciloscopia apresentou sensibilidade 55,1% e especificidade 99,6%. Conclusões: O teste rápido molecular pode ser útil em áreas remotas, com recursos limitados e incidência de tuberculose elevada, como as aldeias indígenas nas áreas rurais do país. Ademais, o teste rápido molecular apresenta como principais vantagens o fácil manuseio, os resultados rápidos e a possibilidade de identificar a resistência à rifampicina. Em conjunto, esses atributos facilitam o início do tratamento precoce, contribuindo para reduzir a transmissão em comunidades reconhecidamente vulneráveis à infecção e à doença.

Under-reporting of tuberculosis in Praia, Cape Verde, from 2006 to 2012.

SETTING: According to World Health Organization (WHO) estimates, the under-reporting rate for tuberculosis (TB) in Cape Verde between 2006 and 2012 was 49%. However, the WHO recognises the challenges associated with this estimation process and recommends implementing other methods, such as record linkage, to combat TB under-reporting. OBJECTIVES: To estimate and analyse under-reporting of cases by TB surveillance health units and to evaluate TB cases retrieved from other TB diagnostic sources in Praia, Cape Verde, from 2006 to 2012. DESIGN: This cross-sectional study evaluated under-reporting using the following data: 1) the under-reporting index from TB reporting health units (RHUs), where the number of validated TB cases from RHUs was compared with data from the National Programme for the Fight against Tuberculosis and Leprosy (NPFTL); and 2) the under-reporting index among overall data sources, or a comparison of the number of all validated TB cases from all sources with NPFTL data. RESULTS: The TB under-reporting rate was 40% in Praia during the study period, and results were influenced by laboratory findings. CONCLUSION: The TB under-reporting rate was very similar to the rate estimated by the WHO. TB surveillance must be improved to reduce under-reporting.

Characterization of non-tuberculous mycobacterium from humans and water in an Agropastoral area in Zambia.

BACKGROUND: The non-tuberculous mycobacteria include those mycobacterium species that are not members of the Mycobacterium tuberculosis complex, the causative agent of pulmonary tuberculosis and Mycobacterium leprae. In Zambia, Non-tuberculous Mycobacteria are gaining recognition as pathogens of public health significance. However, there is scanty information on the isolation and speciation of these organisms for better patient management, consequently reducing the burden of these infections. Given the above information, the thrust of this study was to isolate and characterize NTM from humans and water in Namwala district of Zambia. METHOD: This was a cross-sectional study were 153 individuals with suspected TB were sampled from four health facilities in Namwala district, sputum samples were also collected. Additionally, 149 water samples were collected from different water drinking sources such as Tap water, Borehole water, rivers, wells and streams. Standard TB culture methods were employed to isolate Non-tuberculous Mycobacteria and later 16S-23S internal transcribed spacer region Sequencing was employed to characterize NTM. RESULTS: Seven (7, 4.6%) NTM species were identified from humans with M. arupense (3, 42.9%) being the most common organism, while twenty three (23, 15.4%) NTM were identified from water with the common species being Mycobacterium gordonae (5, 21.7%). Mycobacterium avium and Mycobacterium fortuitum were both identified from human and water samples. CONCLUSION: This study has shown the isolation of NTM species from humans and water. The isolation of NTM from drinking water sources could signify a public health risk to humans.

A cross-sectional study to assess the stigma associated with tuberculosis among tuberculosis patients in Udupi district, Karnataka.

BACKGROUND: For decades, tuberculosis and other communicable diseases like human immunodeficiency virus/acquired immune deficiency syndrome, leprosy, etc., have been associated with stigma and discrimination by the society; this can interfere with the lifestyle and disease management among these patients. OBJECTIVE: To assess the stigma experienced by tuberculosis patients and to find the factors associated with stigma. METHODS: A cross-sectional study was conducted among 209 sputum-positive and sputum-negative tuberculosis patients. Convenient sampling was used to identify the patients. A predesigned, pretested proforma from Explanatory Model Interview Catalogue developed by World Health Organization was used for data collection. RESULTS: The study revealed that out of 209 respondents, 51.2% of the respondents experienced some form of stigma. Majority of the patients have received only primary education and 71.3% of the respondents were males. Most of the patients were under category 1 of Directly Observed Treatment Short course. Age, education, and smear status of the patient were found to be associated with stigmatization (P<0.05), whereas factors like gender, income, occupation, family history, and marital status were found to be not significantly associated with stigmatization. CONCLUSION: Effective counseling measures are recommended for tuberculosis patients with advancing age and education which can help reduce stigmatization and thereby improve quality of life.

[Importance of quality control of baciloscopy in laboratories that perform diagnosis of tuberculosis]. / Importancia del control de la calidad de la baciloscopia en los laboratorios de diagnóstico de tuberculosis.

BACKGROUND: Baciloscopy is the primary tool for pulmonary tuberculosis diagnosis, being this technique the most used internationally in the search for infectious cases. Quality control is the process of the rechecking smears by a highly qualified observer. AIM: To evaluate and highlight the importance of quality control of smear microscopy in the Provincial Laboratories diagnosticians of Tuberculosis in Cuba. METHODS: This study was conducted at the National Reference Laboratory and Research in Tuberculosis, Leprosy and Mycobacteria in the Institute of Tropical Medicine "Pedro Kouri", Havana, Cuba, Were evaluated 2676 smears received from January 2013 to December 2014, from Provincial Centers of Hygiene, Epidemiology and Microbiology of Cuba, including the special municipality Isla de la Juventud. RESULTS: 2,664 (99.5%) were concordant smears, the correlation obtained for the positive smears were 96.5% and 99.8% for negative. Were identified12 reading errors: 7 (3.5%) false positive and 5 (0.2%) false negatives. Slides were classified with adequate quality of smears in 2039 (76.2%), showed difficulties in realizing the extension in 1464 (54.7%) and staining were adequate in 2343 (87.6%). The kappa index was 0.9674. CONCLUSION: Although there was good agreement between observations it is recommended to improve the quality of extended, maintain staff training program that performs this activity, like regular supervision by specialists, to further improve the quality of diagnosis.

Importancia del control de la calidad de la baciloscopia en los laboratorios de diagnóstico de tuberculosis / Importance of quality control of baciloscopy in laboratories that perform diagnosis of tuberculosis

Introducción: La baciloscopia es la herramienta primaria en el diagnóstico de la tuberculosis (TBC) pulmonar activa, siendo esta la técnica más utilizada internacionalmente en la búsqueda de casos infecciosos. El control de calidad consiste en la relectura de las láminas por un observador altamente calificado. Objetivo: Evaluar y destacar la importancia del control de la calidad de la baciloscopia en los laboratorios provinciales encargados del diagnóstico de TBC en Cuba. Material y Métodos: Este estudio fue realizado en el Laboratorio Nacional de Referencia e Investigaciones de Tuberculosis, Lepra y Micobacterias del Instituto de Medicina Tropical "Pedro Kourí", La Habana, Cuba. Fueron evaluadas 2.676 láminas recibidas en el período de enero de 2013-diciembre de 2014, procedentes de los diferentes Centros Provinciales de Higiene, Epidemiología y Microbiología de Cuba, incluido el Municipio Especial Isla de la Juventud. Resultados: Hubo 2.664 (99,5%) láminas concordantes, la concordancia obtenida para las láminas positivas fue 96,5% y las negativas 99,8%. Se identificaron 12 errores de lectura: 7 (3,5%) falsos positivos, 5 (0,2%) falsos negativos. Se calificaron láminas con calidad de la muestra adecuada en 2.039 (76,2%), presentaron deficiencias en la realización de la extensión 1.464 (54,7%), y la tinción fue adecuada en 2.343 (87,6%). El índice de kappa fue de 0.9674. Conclusión: Aunque hubo una adecuada concordancia entre las observaciones realizadas, se recomienda mejorar la calidad del extendido, mantener programa de entrenamiento al personal que realiza esta actividad, al igual que las supervisiones periódicas por parte de especialistas, para continuar mejorando la calidad del diagnóstico.

Background: Baciloscopy is the primary tool for pulmonary tuberculosis diagnosis, being this technique the most used internationally in the search for infectious cases. Quality control is the process of the rechecking smears by a highly qualified observer. Aim: To evaluate and highlight the importance of quality control of smear microscopy in the Provincial Laboratories diagnosticians of Tuberculosis in Cuba. Methods: This study was conducted at the National Reference Laboratory and Research in Tuberculosis, Leprosy and Mycobacteria in the Institute of Tropical Medicine "Pedro Kouri", Havana, Cuba, Were evaluated 2676 smears received from January 2013 to December 2014, from Provincial Centers of Hygiene, Epidemiology and Microbiology of Cuba, including the special municipality Isla de la Juventud. Results: 2,664 (99.5%) were concordant smears, the correlation obtained for the positive smears were 96.5% and 99.8% for negative. Were identified12 reading errors: 7 (3.5%) false positive and 5 (0.2%) false negatives. Slides were classified with adequate quality of smears in 2039 (76.2%), showed difficulties in realizing the extension in 1464 (54.7%) and staining were adequate in 2343 (87.6%). The kappa index was 0.9674. Conclusion: Although there was good agreement between observations it is recommended to improve the quality of extended, maintain staff training program that performs this activity, like regular supervision by specialists, to further improve the quality of diagnosis.

M. tuberculosis DNA detection in nasopharyngeal mucosa can precede tuberculosis development in contacts.

BACKGROUND: The nasopharynx is a known gateway for some mycobacterial species such as Mycobacterium bovis and M. leprae. M. tuberculosis can cross lymphoepithelial barriers in vitro, but its ability to colonise the nasopharyngeal mucosa in vivo has not been established. OBJECTIVE: To determine if M. tuberculosis can be transiently detected in nasopharyngeal mucosa of tuberculosis (TB) contacts as a preliminary step in the development of tuberculous infection. DESIGN: Exploratory study conducted among asymptomatic household contacts of pulmonary TB cases. A chest X-ray, QuantiFERON(®) TB-Gold or tuberculin skin test and a bilateral nasopharyngeal swab for Xpert(®) MTB/RIF and mycobacterial culture were performed at baseline and repeated 8-12 weeks later. RESULTS: Eighty-nine contacts were enrolled a median of 9 days after the diagnosis of the index case. At baseline, 29.9% were positive for latent tuberculous infection and one subject (1.1%) had a positive Xpert in the nasopharyngeal swab with a normal chest X-ray, negative QuantiFERON and negative induced sputum. After 12 weeks' follow-up, this subject developed a new cough and upper lobe infiltrates and M. tuberculosis grew in sputum. No other cases of active TB were detected at follow-up. CONCLUSION: The detection of M. tuberculosis DNA in the nasopharyngeal mucosa of contacts is an infrequent event that in this instance preceded the development of pulmonary TB. Its pathogenic role requires further investigation.

Treatment Outcomes of Childhood TB in Lagos, Nigeria.

BACKGROUND: : Treatment outcomes of tuberculosis (TB) in children are rarely evaluated by most national TB programmes in sub-Saharan Africa. This study evaluated the treatment outcomes of children treated for TB in Lagos State, Nigeria. METHODS: A retrospective review of programme data of the Lagos state TB and the Leprosy control programme in Nigeria from 1 January 2012 to 31 December 2012. Treatment outcomes were categorized according to the national TB guidelines. RESULTS: A total of 535 cases of childhood TB were notified in 2012, representing 6.3% of the total TB cases notified in Lagos state in 2012. The prevalence of TB/HIV co-infection was 29%. The treatment success rate was 79.2% in TB/HIV-negative children compared with 73.4% in TB/HIV-positive children (p = 0.1268). Children <1 year had the worst treatment outcomes (p < 0.001). CONCLUSION: There is a need to intensify effort at improving notification and treatment outcomes in children.

Trend of childhood TB case notification in Lagos, Nigeria, 2011-2014.

BACKGROUND: Childhood tuberculosis (TB) has been neglected by national TB programs in sub-Saharan Africa because of the emphasis on adult smear-positive TB cases. About 80,000 HIV children die from TB, and over 550,000 childhood TB cases occur annually, representing 6% of the global TB burden, making TB an important cause of morbidity and mortality in children. Thus, this study assessed the trend of childhood TB cases notified in Lagos, Nigeria from 2011 to 2014. METHODS: Retrospective data review of childhood TB cases notified to the Lagos State TB and Leprosy Control Programme (LSTBLCP) between January 1, 2011 and December 31, 2014. RESULTS: A total of 2396 children were treated for all forms of TB representing 6.8% of the total 35,305 TB cases notified during the study period. This constituted 1102 (46%) males and 1294 (54%) females. There was a progressive increase in the proportion of children treated for TB from 495 (5.9%) in 2011, 539 (6.4%) in 2012, 682 (7.2%) in 2013 and 680 (7.6%) in 2014. Of the total childhood TB cases notified, 16.3-20% were new sputum pulmonary smear positive; 68.2-74.6% were new sputum pulmonary smear negative; while extra-pulmonary TB accounted for 6.7-10.6%. The case notification rate (CNR) of childhood TB per 100,000 increased from 13.4 in 2011, 14.3 in 2012, 17.7 in 2013 and 17.2 in 2014. CONCLUSION: There was an increase in the case notification rate of TB among children between 2011 and 2014. Efforts should be made to sustain this increasing trend.

Detection of Mycobacterium leprae by PCR testing of sputa from a patient with pulmonary cryptococcus coinfection in northern Australia.

A case of fever, sepsis, and chest lesions evident on a computed tomography scan of an indigenous man in northern Australia following burns to the feet is described. Sputum PCR testing revealed Mycobacterium leprae, and a fine-needle aspirate of the chest lesions demonstrated Cryptococcus coinfection.

Protein-coding housekeeping gene Rv2461c can be used as an amplification target in loop-mediated isothermal amplification assay for the detection of Mycobacterium tuberculosis in sputum samples.

The study is to explore the potential of the conserved Rv2461c gene as a biomarker for Tuberculosis (TB) diagnosis. The conservation of the hypothetical genes was evaluated in this study using multiple sequence alignment and phylogenetic analysis. The conservation of Rv2461c coding gene was evaluated by polymerase chain reaction using six reference strains of M. tuberculosis complex (MTC), 156 M. tuberculosis clinical isolates, 25 species of non-tuberculosis mycobacteria (NTM), and 10 non-mycobacterial species. A total of 126 clinical sputum specimens were collected from patients with respiratory symptoms, including 79 specimens from suspected TB patients, and 47 specimens from patients with respiratory diseases other than TB. Genomic DNAs were extracted and subject to polymerase chain reaction for nucleic acid amplification test. In addition, we successfully developed loop-mediated isothermal amplification (LAMP) technology for rapid detection of M. tuberculosis in sputum specimens. The sensitivity and specificity of LAMP assay were evaluated for the detection of M. tuberculosis. Phylogenetic analysis of the clpP sequences revealed that the Mycobacterium strains were split into two major clusters: i) MTC; ii) NTM strains and M. leprae. During the evaluation of the conservation of Rv2461c coding gene, all MTC strains yielded positive results, and no false-positive results were observed in NTM or other bacterial species. LAMP analysis showed high sensitivity and specificity (84.8% and 95.7%, respectively) for the detection of M. tuberculosis from sputum. Our result indicated that Rv2461c coding gene was an efficient and promising alternative nucleic acid amplification test target for the detection of M. tuberculosis.

Selection and application of ssDNA aptamers to detect active TB from sputum samples.

BACKGROUND: Despite the enormous global burden of tuberculosis (TB), conventional approaches to diagnosis continue to rely on tests that have major drawbacks. The improvement of TB diagnostics relies, not only on good biomarkers, but also upon accurate detection methodologies. The 10-kDa culture filtrate protein (CFP-10) and the 6-kDa early secreted antigen target (ESAT-6) are potent T-cell antigens that are recognised by over 70% of TB patients. Aptamers, a novel sensitive and specific class of detection molecules, has hitherto, not been raised to these relatively TB-specific antigens. METHODS: DNA aptamers that bind to the CFP-10.ESAT-6 heterodimer were isolated. To assess their affinity and specificity to the heterodimer, aptamers were screened using an enzyme-linked oligonucleotide assay (ELONA). One suitable aptamer was evaluated by ELONA using sputum samples obtained from 20 TB patients and 48 control patients (those with latent TB infection, symptomatic non TB patients, and healthy laboratory volunteers). Culture positivity for Mycobacterium tuberculosis (Mtb) served as the reference standard. Accuracy and cut-points were evaluated using ROC curve analysis. RESULTS: Twenty-four out of the 66 aptamers that were isolated bound significantly (p<0.05) to the CFP-10.ESAT-6 heterodimer and six were further evaluated. Their dissociation constant (K(D)) values were in the nanomolar range. One aptamer, designated CSIR 2.11, was evaluated using sputum samples. CSIR 2.11 had sensitivity and specificity of 100% and 68.75% using Youden's index and 35% and 95%, respectively, using a rule-in cut-point. CONCLUSION: This preliminary proof-of-concept study suggests that a diagnosis of active TB using anti-CFP-10.ESAT-6 aptamers applied to human sputum samples is feasible.

Delay in tuberculosis case detection in Pwani region, Tanzania. A cross sectional study.

BACKGROUND: Delay in Tuberculosis (TB) case detection may worsen the disease and increase TB transmission. It is also a challenge to the National TB and Leprosy control Program (NTLP). METHODS: We conducted a cross sectional study in four out of six districts in Pwani region to estimate the extent and factors responsible for delay in TB case detection in Pwani region. Delays were divided into patient, health facility and total delay. RESULTS: We enrolled a total of 226 smear positive TB patients. Out of 226 patient's results were available for 206. The majority (66.5%) of the patients were males. Mean age for males and females were 37.3 and 33.7 years respectively. Mean (SD) total delay was 125.5 (98.5) days (median 90). Out of 206 patients, 79 (38.35%) delayed to seek TB health care. Health facility delay was observed among 121 (58.7%) patients.Risk factors for delay was poor knowledge that chest pain may be a TB symptom (OR = 2.9; 95%CI 1.20- 7.03) and the belief that TB is always associated with HIV/AIDS (OR = 2.7; 95%CI 1.39-5.23). Risk for delay was low among patients who first presented to a government health facility (OR = 0.3; 95%CI 0.12- 0.71) and those presenting with chest pain (OR = 0.2; 95%CI 0.10-0.61). CONCLUSION: There is a considerable delay in TB case detection in Pwani mainly contributed by patients. Risk factors for delay include misconception about TB/HIV and poor knowledge of TB symptoms.

Corynebacterium sputi sp. nov., isolated from the sputum of a patient with pneumonia.

A coryneform bacterium isolated from the sputum of a patient with pneumonia was characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short chain mycolic acids consistent with the genus Corynebacterium. Comparative 16S rRNA gene sequencing studies confirmed this assignment, with the organism forming a hitherto unknown subline within the genus associated with a subcluster containing Corynebacterium hansenii, Corynebacterium freneyi, Corynebacterium xerosis, Corynebacterium amycolatum and Corynebacterium sphenisci. Sequence divergence values of >2.7 % from established corynebacterial species suggested that the new isolate represented a novel species. This was also supported by the results of the biochemical tests. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown bacterium be classified as a novel species of the genus Corynebacterium, Corynebacterium sputi sp. nov. (type strain IMMIB L-999(T)=DSM 45148(T)=CCUG 55795(T)).

Potential of Mw as a prophylactic vaccine against pulmonary tuberculosis.

Mycobacterium w (Mw), is a cultivable, non-pathogenic mycobacterium and has been tried extensively as an immunomodulator in leprosy. This has been found to be safe and has shown beneficial immunoprophylactic effect in population based, double blind placebo controlled trials in North India. These effects were also observed in the vaccine trials in South India. Keeping in view these beneficial effects and its earlier reported protective effect against tuberculosis in animals, its protective efficacy was evaluated in a rural population of about 28,948 people belonging to 272 villages in Ghatampur, Kanpur (India). The population was vaccinated with two doses (1st dose of 1x10(9) heat killed organisms followed 6 months later with a 2nd dose of 5x10(8) organisms) of Mw 10-13 years ago originally to investigate its effect against leprosy. The vaccine/placebo was given to healthy contacts of leprosy patients who had no evidence of suffering from tuberculosis. Incidence and prevalence of pulmonary tuberculosis in the present study was assessed in a blind manner by an active field survey and also retrospectively by history of anti tuberculosis treatment received by the patient in the intervening period (since vaccination), which was also corroborated by scrutinizing the medical records. Diagnosis was confirmed by standard clinical and bacteriological criteria. A total of 69 patients were diagnosed to be suffering from pulmonary tuberculosis during the survey which included 17 new sputum smear positive cases and 52 previously partially treated but still active pulmonary tuberculosis cases. The difference in the new sputum positive cases between the vaccinated (5/17) and placebo groups (12/17) was significant at 5% level of significance for 1 tailed test (Z>1.64). As 75% (52/69) of the cases had been diagnosed as suffering from pulmonary tuberculosis but had not taken adequate therapy all the cases diagnosed during the intervening period were recorded and re-analysis done. The differences are more significant at 1% level of significance for 1 tail test (Z>2.59) when all cases were analysed as a group. A small proportion 12.85% (total number=3036) of the contacts in the study population had BCG scars. On analysis of results on protection against tuberculosis in this group, BCG did provide protection against tuberculosis (p<0.01). In the placebo group the prevalence of tuberculosis was 1.11% which reduced to 0.70% for those who received Mw vaccine (p<0.01) which further decreased to 0.53% in those who had BCG scars and received Mw. These results thus provide evidence suggesting protective efficacy of Mw against pulmonary tuberculosis and that Mw merits investigation in future prospective immunoprophylactic trials along with other candidates for protection against pulmonary tuberculosis.

Rapid differentiation of Mycobacterium tuberculosis and Mycobacterium leprae from sputum by polymerase chain reaction.

Differentiation of M tuberculosis and M leprae by polymerase chain reaction (PCR), when acid-fast bacilli (AFB) were present in sputum from patients at Anandaban hospital, was carried out. Thirty sputum samples microscopy positive for AFB were collected and were subjected to culture. Bacterial DNA was extracted and PCR was performed using primers specific for Mycobacterium tuberculosis and Mycobacterium leprae DNA. Twenty samples were from patients with clinical TB and 10 from patients with clinical leprosy. Fifteen of the TB samples were positive in both TB PCR and culture, among the reminders four were TB PCR negative and one was positive for TB PCR. All TB samples were negative for leprosy PCR. Of the leprosy samples, five were TB PCR and culture positive, and negative for leprosy PCR. The remaining five samples were negative for both TB PCR and culture but positive in leprosy PCR. Five often clinical leprosy samples were positive for tuberculosis. This indicates that AFB in the sputum of leprosy patients might be M. tuberculosis or M. leprae. Thus PCR can be used for rapid differentiation of M. tuberculosis and M. leprae present in sputum where AFB microscopy is inconclusive.