Current concepts in the management of tuberculosis

Negative latent tuberculosis at time of incarceration: identifying a very high-risk group for infection

The main aim was to measure the incidence of latent tuberculosis infection (LTBI) and identify risk factors associated with infection. In addition, we determined the number needed to screen (NNS) to identify LTBI and active tuberculosis. We followed 129 prisoners for 2 years following a negative two-step tuberculin skin test (TST). The cumulative incidence of TST conversion over 2 years was 29·5% (38/129), among the new TST converters, nine developed active TB. Among persons with no evidence of LTBI, the NNS to identify a LTBI case was 3·4 and an active TB case was 14·3. The adjusted risk factors for LTBI conversion were incarceration in prison number 1, being formerly incarcerated, and overweight. In conclusion, prisoners have higher risk of LTBI acquisition compared with high-risk groups, such as HIV-infected individuals and children for whom LTBI testing should be performed according to World Health Organization guidance. The high conversion rate is associated with high incidence of active TB disease, and therefore we recommend mandatory LTBI screening at the time of prison entry. Individuals with a negative TST at the time of entry to prison are at high risk of acquiring infection, and should therefore be followed in order to detect convertors and offer LTBI treatment. This approach has a very low NNS for each identified case, and it can be utilized to decrease development of active TB disease and transmission.

Tuberculosis: Still an emerging threat

Primary care providers must be aggressive in their assessment and screening of tuberculosis (TB) infection, which is still a major cause of mortality and morbidity worldwide. This article highlights the overall management of TB infection including the appropriate screening, diagnosis, and treatment of both latent and active infection.

Unique Chemokine Profiles of Lung Tissues Distinguish Post-chemotherapeutic Persistent and Chronic Tuberculosis in a Mouse Model

There is a substantial need for biomarkers to distinguish latent stage from active Mycobacterium tuberculosis infections, for predicting disease progression. To induce the reactivation of tuberculosis, we present a new experimental animal model modified based on the previous model established by our group. In the new model, the reactivation of tuberculosis is induced without administration of immunosuppressive agents, which might disturb immune responses. To identify the immunological status of the persistent and chronic stages, we analyzed immunological genes in lung tissues from mice infected with M. tuberculosis. Gene expression was screened using cDNA microarray analysis and confirmed by quantitative RT-PCR. Based on the cDNA microarray results, 11 candidate cytokines genes, which were obviously up-regulated during the chronic stage compared with those during the persistent stage, were selected and clustered into three groups: (1) chemokine genes, except those of monocyte chemoattractant proteins (MCPs; CXCL9, CXCL10, CXCL11, CCL5, CCL19); (2) MCP genes (CCL2, CCL7, CCL8, CCL12); and (3) TNF and IFN-γ genes. Results from the cDNA microarray and quantitative RT-PCR analyses revealed that the mRNA expression of the selected cytokine genes was significantly higher in lung tissues of the chronic stage than of the persistent stage. Three chemokines (CCL5, CCL19, and CXCL9) and three MCPs (CCL7, CCL2, and CCL12) were noticeably increased in the chronic stage compared with the persistent stage by cDNA microarray (p < 0.01, except CCL12) or RT-PCR (p < 0.01). Therefore, these six significantly increased cytokines in lung tissue from the mouse tuberculosis model might be candidates for biomarkers to distinguish the two disease stages. This information can be combined with already reported potential biomarkers to construct a network of more efficient tuberculosis markers.

Review of Organism Density and Bacteriologic Conversion of Sputum among Tuberculosis Patients

OBJECTIVE

This study sought to describe the trend of sputum organism density and the rate of bacteriological conversion among smear positive TB patients assessing care at the Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana.

METHODS

We conducted a retrospective patient folder review from January 2013 to March 2016 at the KATH, a tertiary hospital in Ghana. The data was entered into Microsoft Access database and exported into STATA for analysis. We applied basic descriptive statistics to study variables. Sputum conversion rate (SCR) was estimated using the number of negative tests recorded over a period (numerator) and the number of patients reported in the same period (denominator) and expressed as a percentage.

RESULTS

A total of 278 patient records with sputum smear positive at onset were studied. Before treatment sputum density detected in smear microscopy was as follows: 1 acid-fast bacillus (+) (n = 114), scanty (n = 19), ++ (n = 67), and +++ (n = 78). We recorded sputum conversion rate of 80.90%, 94.56%, and 98.31% in the intensive, continuation, and completion phases, respectively.

CONCLUSION

This study has shown an increasing trend in sputum conversion of smear positive pulmonary tuberculosis and an increasing trend in loss to follow-ups among tuberculosis patients on treatment.

Low Yield of Chest Radiography in General Inpatients and Outpatients with "Positive PPD" Results in a Country with Low Prevalence of TB

RATIONALE AND OBJECTIVES

The purpose of this study was to assess the frequency and spectrum of abnormalities on routine screening chest radiographs among inpatients and outpatients with "positive purified protein derivative (PPD)" in a large tertiary care academic medical center in a country with low prevalence of tuberculosis (TB).

MATERIALS AND METHODS

The reports of all chest radiographs of general inpatients and outpatients referred for positive PPD (2010-2014) were evaluated for the frequency of evidence of active or latent TB and the spectrum of imaging findings. The results of additional chest radiographs and computed tomography scans were recorded, as were additional relevant clinical histories and symptoms.

RESULTS

Of the 2518 patients who underwent chest radiography for positive PPD, the radiographs were normal in 91.3%. The vast majority of the abnormal radiographs demonstrated findings consistent with old tuberculous disease. There were three cases (0.1%) of active TB, all of which were either recent immigrants from an endemic area or had other relevant histories or clinical symptoms suggestive of the disease.

CONCLUSIONS

Universal chest radiography in general inpatient and outpatient populations referred for positive PPD is of low yield for detecting active disease in a country with low prevalence of TB.

The risk factor of false-negative and false-positive for T-SPOT.TB in active tuberculosis

OBJECTIVES

T-SPOT.TB is a promising diagnosis tool to identify both pulmonary tuberculosis and extrapulmonary tuberculosis, as well as latent tuberculosis; however, the factors that affect the results of T-SPOT.TB remains unclear. In this study, we aim to figure out the risk factor of T-SPOT.TB for active TB.

METHODS

A total of 349 patients were recruited between January 1st, 2016 and January 22st, 2017 at Renmin Hospital of Wuhan University, including 98 subjects with TB and 251 subjects with non-TB disease, and received T-SPOT.TB (Oxford Immunotec Ltd). Statistics were analyzed by SPSS 19.0 using logistic regression.

RESULTS

The overall specificity and sensitivity of the T-SPOT.TB was 92.83% (233/251; 95%CI 0.8872-0.9557) and 83.67% (82/98; 95%CI 0.7454-0.9010), respectively. Patients with tuberculous meningitis were more likely to have false-negative results (OR 17.4, 95%CI 3.068-98.671; P<.001) while patients with cured TB tended to induce false-positive results (OR 30.297; 95%CI 7.069-129.849; P<.001). The results were not affected by sex, age, onset time, smoke, alcohol, treatment, allergic history, co-morbidity, TB (exclude tuberculous meningitis) (P>.05).

CONCLUSION

Tuberculous meningitis was a risk factor of false-negative for T-SPOT.TB, while cured TB was a risk factor of false-positive.

Prevalence and risk factors for latent tuberculosis infection among healthcare workers in Nampula Central Hospital, Mozambique

BACKGROUND

Healthcare workers in high tuberculosis burdened countries are occupationally exposed to the tuberculosis disease with uncomplicated and complicated tuberculosis on the increase among them. Most of them acquire Mycobacterium tuberculosis but do not progress to the active disease - latent tuberculosis infection. The objective of this study was to assess the prevalence and risk factors associated with latent tuberculosis infection among healthcare workers in Nampula Central Hospital, Mozambique.

METHODS

This cross-sectional study of healthcare workers was conducted between 2014 and 2015. Participants (n = 209) were administered a questionnaire on demographics and occupational tuberculosis exposure and had a tuberculin skin test administered. Multivariate linear and logistic regression tested for associations between independent variables and dependent outcomes (tuberculin skin test induration and latent tuberculosis infection status).

RESULTS

The prevalence of latent tuberculosis infection was 34.4%. Latent tuberculosis infection was highest in those working for more than eight years (39.3%), those who had no BCG vaccination (39.6%) and were immunocompromised (78.1%). Being immunocompromised was significantly associated with latent tuberculosis infection (OR 5.97 [95% CI 1.89; 18.87]). Positive but non-significant associations occurred with working in the medical domain (OR 1.02 [95% CI 0.17; 6.37]), length of employment > eight years (OR 1.97 [95% CI 0.70; 5.53]) and occupational contact with tuberculosis patients (OR 1.24 [95% CI 0.47; 3.27]).

CONCLUSIONS

Personal and occupational factors were positively associated with latent tuberculosis infection among healthcare workers in Mozambique.

Delayed tuberculosis diagnosis and costs of contact investigations for hospital exposure: New York City, 2010-2014

BACKGROUND

A delayed diagnosis of tuberculosis (TB) in the hospital may lead to nosocomial exposure, placing employees and other patients at risk. A lack of prompt infection control measures for suspected cases at the time of admission may require complicated and expensive contact investigations. The purpose of this study was to estimate the person-hour costs required by infection control staff to investigate a single hospital-based TB exposure.

METHODS

Electronic data were extracted from 2 tertiary hospitals and 1 community hospital in a large health care system in metropolitan New York City to identify pulmonary TB cases unsuspected at admission. All cases were reviewed by infection prevention and control (IPC) staff to identify exposures.

RESULTS

From 2010-2014, 34 pulmonary TB cases which necessitated a contact investigation were identified. IPC staff calculated an average of 15-20 hours of work per exposure plus 30 minutes of follow-up for each exposed staff member. For exposures, time from admission to isolation averaged 3.3 days, with a mean of 41 staff exposed per patient and an approximate resource usage of 38 person-hours.

CONCLUSIONS

Contact investigations are costly to the health care system. In a low-prevalence country, such as the United States, it is still important that health care providers are trained to think TB.

Meningeal TB in a 39-Year-Old Male Presenting with Headache

Meningeal tuberculosis is rare in the developed world, with only 92 cases of meningeal TB reported in the United States in 2014 according to the CDC (CDC, 2015). We describe the case of a 39-year-old male with a history of alcohol abuse, whose cerebral spinal fluid acid fast smears confirmed TB only weeks after his death. His only initial presenting symptom was headache, and his condition declined rapidly during his hospitalization.

In vitro and In vivo antimycobacterial, hepatoprotective and immunomodulatory activity of Euclea natalensis and its mode of action

ETHNOPHARMACOLOGICAL RELEVANCE

The Natal gwarri or Natal ebony (Euclea natalensis A.DC.) is a deciduous tree found widespread throughout southern Africa, especially in Kwazulu-Natal and the southern cost. It has been widely used by indigenous communities such as the Zulus, Tsongas and Vendas for symptoms related to tuberculosis (TB). The decoctions made from the plant parts are administered for chest diseases to treat complications such as chest pains, bronchitis, pleurisy and asthma. TB is prevalent in immune-compromised patients and it is evident that TB-drugs cause hepatotoxicity. The objective of the present study was therefore to evaluate the antimycobacterial activity of the ethanolic extract of E. natalensis against TB and its hepatoprotective and immunomodulatory activities.

MATERIALS AND METHODS

The antimycobacterial, antioxidant, hepatoprotective, immunomodulatory activity and cytotoxicity of the ethanolic extract of the shoots of E. natalensis were determined in vitro. The mechanism of action of the antituberculosis activity was determined by investigating the inhibitory effect on mycothiol disulfide reductase enzyme. Furthermore, the acute, sub-acute toxicity (50-2000mg/kg) and antimycobacterial effect (300mg/kg) of E. natalensis shoot extract were investigated in Balb/c mice. Hepatoprotective activity of the extract (50-150mg/kg) was evaluated on isoniazid and rifampicin (50mg/kg; i.p.) induced hepatic damage in a rat model.

RESULTS

The minimum inhibitory concentration of the extract was found to be 125µg/ml against Mycobacterium tuberculosis. The extracts 50% inhibitory concentration (IC₅₀) against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical was found to be 22.55µg/ml. The plant showed a hepatoprotective effect (50% at 12.5µg/ml) and the ability to increase T-helper 1 cell cytokines; Interleukin 12, Interleukin 2 and Interferon α by up to 12 fold and the ability to decrease the T-helper 2 cell cytokine Interleukin 10 4 fold when compared to baseline cytokine production. No cellular toxicity was observed in primary peripheral blood mononuclear cells (PBMC's) and two secondary cell lines; U937 monocytes and Chang liver cells (a derivative of the HepG2 cell line). During mechanistic studies, the extract showed a 50% inhibition of mycothiol reductase activity at 38.62µg/ml. During the acute and sub-acute studies, E. natalensis exhibited no toxic effect and the 50% lethal dose (LD₅₀) was established to be above 2000mg/kg. The extract was able to reduce the mycobacterial load (1.5-fold reduction) in infected mice. Isoniazid and rifampicin caused significant hepatic damage in rats, and the extract was able to reduce the toxicity by 15% and 40% at 50 and 150mg/kg respectively.

CONCLUSION

The present study supports the traditional usage of the plant against tuberculosis symptoms. The study showed the ability of E. natalensis shoot extract to inhibit mycobacterial growth, stimulate an appropriate immune response and have a hepatic protective effect. Due to the extract's significant results for hepatoprotective, immunomodulatory effects and antimycobacterial activity, it may prove to be effective to serve as an adjuvant for TB-patients.

Trends in Testing for Mycobacterium tuberculosis Complex From US Public Health Laboratories, 2009-2013

OBJECTIVE

We investigated data from US public health laboratories funded through the Centers for Disease Control and Prevention's Tuberculosis Elimination and Laboratory Cooperative Agreement to document trends and challenges in meeting national objectives in tuberculosis (TB) laboratory diagnoses.

METHODS

We examined data on workload and turnaround time from public health laboratories' progress reports during 2009-2013. We reviewed methodologies, laboratory roles, and progress toward rapid detection of Mycobacterium tuberculosis complex through nucleic acid amplification (NAA) testing. We compared selected data with TB surveillance reports to estimate public health laboratories' contribution to national diagnostic services.

RESULTS

During the study period, culture and drug susceptibility tests decreased, but NAA testing increased. Public health laboratories achieved turnaround time benchmarks for drug susceptibility tests at lower levels than for acid-fast bacilli smear and identification from culture. NAA positivity in laboratories among surveillance-reported culture-positive TB cases increased from 26.6% (2355 of 8876) in 2009 to 40.0% (2948 of 7358) in 2013. Public health laboratories provided an estimated 50.9% (4285 of 8413 in 2010) to 57.2% (4210 of 7358 in 2013) of culture testing and 88.3% (6822 of 7727 in 2011) to 94.4% (6845 of 7250 in 2012) of drug susceptibility tests for all US TB cases.

CONCLUSIONS

Public health laboratories contribute substantially to TB diagnoses in the United States. Although testing volumes mostly decreased, the increase in NAA testing indicates continued progress in rapid M tuberculosis complex detection.

Gallbladder tuberculosis camouflaging as gallbladder cancer - case series and review focussing on treatment

INTRODUCTION

Gallbladder tuberculosis, in an endemic region, is a common infectious etiology affecting a rare organ. The high prevalence of carcinoma gallbladder in the endemic regions of tuberculosis, like India, poses diagnostic dilemma.

CASE SERIES

We are reporting three cases of gallbladder tuberculosis mimicking carcinoma gallbladder of which the first two cases were operated with a presumptive diagnosis of malignancy. The third case presented to us after laparoscopic cholecystectomy elsewhere and on evaluation was found to have disseminated tuberculosis.

DISCUSSION

The lack of pathognomonic clinical and radiological characters results in histological surprise of gallbladder tuberculosis following surgery performed for other indications like malignancy. In preoperatively diagnosed patients medical management plays pivotal role in management. Surgery is required in symptomatic patients. On the other hand, histologically proven cases following surgical resection require antitubercular therapy.

CONCLUSION

Previous history of tuberculosis or concomitant tuberculosis at other sites may provide clue to the diagnosis of biliary tuberculosis. Antitubercular treatment after surgery plays an important role in preventing further dissemination.

Biomarkers for discrimination between latent tuberculosis infection and active tuberculosis disease

OBJECTIVE

We aimed to determine whether combinations of multiplex cytokine responses could differentiate Mycobacterium tuberculosis (Mtb) infection states.

METHODS

Mtb-specific antigen-induced and unstimulated cytokines were measured by Luminex assay in supernatants of QuantiFERON^® Gold In-Tube assay (QFT) in 48 active pulmonary TB patients (TB), 15 latent TB infection subjects (LTBI), and 13 healthy controls (HCs).

RESULTS

Among the 29 cytokines, eight Mtb antigen-specific biomarkers (GM-CSF, IFN-γ, IL-1RA, IL-2, IL-3, IL-13, IP-10, and MIP-1β) in the Mtb-infected group were significantly different from those of the HCs. Five Mtb-specific biomarkers (EGF, GM-CSF, IL-5, IL-10, and VEGF), two unstimulated biomarkers (TNF-α_[Nil] and VEGF_[Nil]), and one Mtb-specific biomarker ratio (IL-2/IFN-γ) showed significant differences between active TB and LTBI. Three unstimulated biomarkers (IL-8_[Nil], IL-13_[Nil], and VEGF_[Nil]) and 5 Mtb-specific biomarkers (IFN-γ, IL-2, IL-3, IP-10, and VEGF) were significantly different between active TB and non-active TB groups. Combinations of three cytokine biomarkers resulted in the accurate prediction of 92.1-93.7% of Mtb-infected cases and 92.3-100% of HCs, respectively. Moreover, combinations of five biomarkers accurately predicted 90.9-100% of active TB cases and 80-100% of LTBI subjects, respectively. In discriminating between active TB and non-active TB regardless of QFT results, combinations of six biomarkers predicted 79.2-95.8% of active TB cases and 67.9-89.3% of non-active TB subjects.

CONCLUSIONS

Taken together, our data suggest that combinations of whole blood Mtb antigen-dependent cytokines could serve as biomarkers to determine TB disease states. Especially, VEGF is highlighted as a key biomarker for reflecting active TB, irrespective of stimulation.

The assessment of host and bacterial proteins in sputum from active pulmonary tuberculosis

Pulmonary tuberculosis (TB) is caused by Mycobacterium tuberculosis. The protein composition of sputum may reflect the immune status of the lung. This study aimed to evaluate the protein profiles in spontaneous sputum samples from patients with active pulmonary TB. Sputum samples were collected from patients with pulmonary TB and healthy controls. Western blotting was used to analyze the amount of interleukin 10 (IL-10), interferon-gamma (IFN-γ), IL-25, IL-17, perforin-1, urease, albumin, transferrin, lactoferrin, adenosine deaminase (also known as adenosine aminohydrolase, or ADA), ADA-2, granzyme B, granulysin, and caspase-1 in sputum. Results of detection of IL-10, IFN-γ, perforin-1, urease, ADA2, and caspase-1, showed relatively high specificity in distinguishing patients with TB from healthy controls, although sensitivities varied from 13.3% to 66.1%. By defining a positive result as the detection of any two proteins in sputum samples, combined use of transferrin and urease as markers increased sensitivity to 73.2% and specificity to 71.1%. Furthermore, we observed that the concentration of transferrin was proportional to the number of acid-fast bacilli detected in sputum specimens. Detection of sputum transferrin and urease was highly associated with pulmonary TB infection. In addition, a high concentration of transferrin detected in sputum might correlate with active TB infection. This data on sputum proteins in patients with TB may aid in the development of biomarkers to assess the severity of pulmonary TB.

Transcriptomic Biomarkers for Tuberculosis: Evaluation of DOCK9. EPHA4, and NPC2 mRNA Expression in Peripheral Blood

Lately, much effort has been made to find mRNA biomarkers for tuberculosis (TB) disease/infection with microarray-based approaches. In a pilot investigation, through RNA sequencing technology, we observed a prominent modulation of DOCK9, EPHA4, and NPC2 mRNA abundance in the blood of TB patients. To corroborate these findings, independent validations were performed in cohorts from different areas. Gene expression levels in blood were evaluated by quantitative real-time PCR (Brazil, n = 129) or reanalysis of public microarray data (UK: n = 96; South Africa: n = 51; Germany: n = 26; and UK/France: n = 63). In the Brazilian cohort, significant modulation of all target-genes was observed comparing TB vs. healthy recent close TB contacts (rCt). With a 92% specificity, NPC2 mRNA high expression (NPC2^high) showed the highest sensitivity (85%, 95% CI 65%–96%; area under the ROC curve [AUROC] = 0.88), followed by EPHA4 (53%, 95% CI 33%–73%, AUROC = 0.73) and DOCK9 (19%, 95% CI 7%–40%; AUROC = 0.66). All the other reanalyzed cohorts corroborated the potential of NPC2^high as a biomarker for TB (sensitivity: 82–100%; specificity: 94–97%). An NPC2^high profile was also observed in 60% (29/48) of the tuberculin skin test positive rCt, and additional follow-up evaluation revealed changes in the expression levels of NPC2 during the different stages of Mycobacterium tuberculosis infection, suggesting that further studies are needed to evaluate modulation of this gene during latent TB and/or progression to active disease. Considering its high specificity, our data indicate, for the first time, that NPC2^high might serve as an accurate single-gene biomarker for TB.

Prevalence of Drug Resistance Mycobacterium Tuberculosis among Patients Seen in Coast Provincial General Hospital, Mombasa, Kenya

Background

Although prevention and control of spread of multi-drug resistant tuberculosis strains is a global challenge, there is paucity of data on the prevalence of DR-TB in patients diagnosed with TB in referral hospitals in Kenya. The present study assessed patients’ characteristics and prevalence of drug resistant TB in sputa smear positive TB patients presenting to Coast Provincial General Hospital (CPGH) in Mombasa, Kenya.

Methods

Drug resistance was evaluated in 258 randomly selected sputa smear TB positive cases between the periods of November 2011 to February 2012 at the CPGH-Mombasa. Basic demographic data was obtained using administered questionnaires, and clinical history extracted from the files. For laboratory analyses, 2mls of sputum was obtained, decontaminated and subjected to mycobacteria DNA analyses. Detection of first line drug resistance genes was done using MDRTDR plus kit. This was followed with random selection of 83 cases for second line drug resistance genes testing using Genotype MDRTBsl probe assay kit (HAINS Lifesciences, GmbH, Germany), in which ethambutol mutation probes were included. The data was then analyzed using SPSS statistical package version 19.0.

Results

Male to female ratio was 1:2. Age range was 9 to 75 years, with median of 30 years. New treatment cases constituted 253(98%), among which seven turned out to be PTB negative, and further grouped as 4 (1.6%) PTB negative and 3(1.1%) NTM. 237(91.7%) new cases were fully susceptible to INH and RIF. The remaining, 8 (3.1%) and 1(0.4%) had mono- resistance to INH and RIF, respectively. All the retreatment cases were fully susceptible to the first line drugs. HIV positivity was found in 48 (18.6%) cases, of which 46(17.8%) were co-infected with TB. Of these, 44 (17.1%) showed full susceptibility to TB drugs, while 2 (0.8%) were INH resistant. For the second line drugs, one case each showed mono resistance to both and FQ. Also, one case each showed drug cross poly resistance to both ETH and FQ, with second line injectable antibiotics. However, no significant statistical correlation was established between TB and resistance to the second line drugs p = 0.855.

Conclusion

The findings of this study showed the existence of resistance to both first and second line anti-tubercular drugs, but no MDR-TB and XDR-TB was detected among patients attending TB clinic at CPGH using molecular techniques.

Isoniazid metabolism and hepatotoxicity

Isoniazid (INH) is highly effective for the management of tuberculosis. However, it can cause liver injury and even liver failure. INH metabolism has been thought to be associated with INH-induced liver injury. This review summarized the metabolic pathways of INH and discussed their associations with INH-induced liver injury.

The formulation of nanomedicines for treating tuberculosis

Recent estimates indicate that tuberculosis (TB) is the leading cause of death worldwide, alongside the human immunodeficiency virus (HIV) infection. The current treatment is effective, but is associated with severe adverse-effects and noncompliance to prescribed regimens. An alternative route of drug delivery may improve the performance of existing drugs, which may have a key importance in TB control and eradication. Recent advances and emerging technologies in nanoscale systems, particularly nanoparticles (NPs), have the potential to transform such approach to human health and disease. Until now, several nanodelivery systems for the pulmonary administration of anti-TB drugs have been intensively studied and their utility as an alternative to the classical TB treatment has been suggested. In this context, this review provides a comprehensive analysis of recent progress in nanodelivery systems for pulmonary administration of anti-TB drugs. Additionally, more convenient and cost-effective alternatives for the lung delivery, different types of NPs for oral and topical are also being considered, and summarized in this review. Lastly, the future of this growing field and its potential impact will be discussed.

Optimizing treatment outcome of first-line anti-tuberculosis drugs: the role of therapeutic drug monitoring

INTRODUCTION

Tuberculosis (TB) remains one of the world's deadliest communicable diseases. Although cure rates of the standard four-drug (rifampicin, isoniazid, pyrazinamide, ethambutol) treatment schedule can be as high as 95-98 % under clinical trial conditions, success rates may be much lower in less well resourced countries. Unsuccessful treatment with these first-line anti-TB drugs may lead to the development of multidrug resistant and extensively drug resistant TB. The intrinsic interindividual variability in the pharmacokinetics (PK) of the first-line anti-TB drugs is further exacerbated by co-morbidities such as HIV infection and diabetes.

METHODS

Therapeutic drug monitoring has been proposed in an attempt to optimize treatment outcome and reduce the development of drug resistance. Several studies have shown that maximum plasma concentrations (C max), especially of rifampicin and isoniazid, are well below the proposed target C max concentrations in a substantial fraction of patients being treated with the standard four-drug treatment schedule, even though treatment's success rate in these studies was typically at least 85 %.

DISCUSSION

The proposed target C max concentrations are based on the concentrations of these agents achieved in healthy volunteers and patients receiving the standard doses. Estimation of C max based on one or two sampling times may not have the necessary accuracy since absorption rate, especially for rifampicin, may be highly variable. In addition, minimum inhibitory concentration (MIC) variability should be taken into account to set clinically meaningful susceptibility breakpoints. Clearly, there is a need to better define the key target PK and pharmacodynamic (PD) parameters for therapeutic drug monitoring (TDM) of the first-line anti-TB drugs to be efficacious, C max (or area under the curve (AUC)) and C max/MIC (or AUC/MIC).

CONCLUSION

Although TDM of first-line anti-TB drugs has been successfully used in a limited number of specialized centers to improve treatment outcome in slow responders, a better characterization of the target PK and/or PK/PD parameters is in our opinion necessary to make it cost-effective.

Temporal Expression of Peripheral Blood Leukocyte Biomarkers in a Macaca fascicularis Infection Model of Tuberculosis; Comparison with Human Datasets and Analysis with Parametric/Non-parametric Tools for Improved Diagnostic Biomarker Identification

A temporal study of gene expression in peripheral blood leukocytes (PBLs) from a Mycobacterium tuberculosis primary, pulmonary challenge model Macaca fascicularis has been conducted. PBL samples were taken prior to challenge and at one, two, four and six weeks post-challenge and labelled, purified RNAs hybridised to Operon Human Genome AROS V4.0 slides. Data analyses revealed a large number of differentially regulated gene entities, which exhibited temporal profiles of expression across the time course study. Further data refinements identified groups of key markers showing group-specific expression patterns, with a substantial reprogramming event evident at the four to six week interval. Selected statistically-significant gene entities from this study and other immune and apoptotic markers were validated using qPCR, which confirmed many of the results obtained using microarray hybridisation. These showed evidence of a step-change in gene expression from an ‘early’ FOS-associated response, to a ‘late’ predominantly type I interferon-driven response, with coincident reduction of expression of other markers. Loss of T-cell-associate marker expression was observed in responsive animals, with concordant elevation of markers which may be associated with a myeloid suppressor cell phenotype e.g. CD163. The animals in the study were of different lineages and these Chinese and Mauritian cynomolgous macaque lines showed clear evidence of differing susceptibilities to Tuberculosis challenge. We determined a number of key differences in response profiles between the groups, particularly in expression of T-cell and apoptotic makers, amongst others. These have provided interesting insights into innate susceptibility related to different host `phenotypes. Using a combination of parametric and non-parametric artificial neural network analyses we have identified key genes and regulatory pathways which may be important in early and adaptive responses to TB. Using comparisons between data outputs of each analytical pipeline and comparisons with previously published Human TB datasets, we have delineated a subset of gene entities which may be of use for biomarker diagnostic test development.

Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis

OBJECTIVE/BACKGROUND

The present investigation was undertaken to synthesize zinc oxide nanoparticles using Limonia acidissima L. and to test their efficacy against the growth of Mycobacterium tuberculosis.

METHODS

The formation of zinc oxide nanoparticles was confirmed with UV-visible spectrophotometry. Fourier transform infrared spectroscopy shows the presence of bio-molecules involved in the stabilization of zinc oxide nanoparticles. The shape and size was confirmed with atomic force microscope, X-ray diffraction, and high resolution transmission electron microscope. These nanoparticles were tested for their effect on the growth of M. tuberculosis through the microplate alamar blue assay technique.

RESULTS

The UV-visible data reveal that an absorbance peak at 374nm confirms formation of zinc oxide nanoparticles and they are spherical in shape with sizes between 12nm and 53nm. These nanoparticles control the growth of M. tuberculosis at 12.5μg/mL.

CONCLUSION

Phytosynthesis of zinc oxide nanoparticles is a green, eco-friendly technology because it is inexpensive and pollution free. In the present investigation, based on our results we conclude that the aqueous extract of leaves of L. acidissima can be used for the synthesis of zinc oxide nanoparticles. These nanoparticles control the growth of M. tuberculosis and this was confirmed with the microplate alamar blue method. The potential of biogenic zinc oxide nanoparticles may be harnessed as a novel medicine ingredient to combat tuberculosis disease.

A Novel Sample Processing Method for Rapid Detection of Tuberculosis in the Stool of Pediatric Patients Using the Xpert MTB/RIF Assay

BACKGROUND

Tuberculosis (TB) is difficult to diagnose in children using molecular tests, because children have difficulty providing respiratory samples. Stool could replace sputum for diagnostic TB testing if adequate sample processing techniques were available.

METHODS

We developed a rapid method to process large volumes of stool for downstream testing by the Xpert MTB/RIF (Xpert) TB-detection assay. The method was tested and optimized on stool samples spiked with known numbers of M. tuberculosis colony forming units (CFU), and stools from M. tuberculosis-infected cynomolgus macaques (Macaca fascicularis). Performance was scored on number of positive Xpert tests, the cycle thresholds (Cts) of the Xpert sample-processing control (SPC), and the Cts of the M. tuberculosis-specific rpoB probes. The method was then validated on 20 confirmed TB cases and 20 controls in Durban, South Africa.

RESULTS

The assay's analytical limit of detection was 1,000 CFU/g of stool. As much as one gram of spiked stool could be tested without showing increased PCR inhibition. In analytical spiking experiments using human stool, 1g samples provided the best sensitivity compared to smaller amounts of sample. However, in Macaques with TB, 0.6g stool samples performed better than either 0.2g or 1.2g samples. Testing the stool of pediatric TB suspects and controls suggested an assay sensitivity of 85% (95% CI 0.6-0.9) and 84% (95% CI 0.6-0.96) for 0.6g and 1.2g stool samples, respectively, and a specificity of 100% (95% CI 0.77-1) and 94% (95% CI 0.7-0.99), respectively.

CONCLUSION

This novel approach may permit simple and rapid detection of TB using pediatric stool samples.

PET/CT imaging of Mycobacterium tuberculosis infection

Tuberculosis has a high morbidity and mortality worldwide. Mycobacterium tuberculosis (Mtb) has a complex pathophysiology; it is an aerobic bacillus capable of surviving in anaerobic conditions in a latent state for a very long time before reactivation to active disease. In the latent tuberculosis infection, the individual has no clinical evidence of active disease, but exhibits a hypersensitive response to proteins of Mtb. Only some 5–10 % of latently infected individuals appear to have reactivation of tuberculosis at any one time point after infection, and neither imaging nor immune tests have been shown to predict tuberculosis reactivation reliably. The complex pathology of the organism provides multiple molecular targets for imaging the infection and targeting therapy. Positron emission tomography (PET) integrated with computer tomography (CT) provides a unique opportunity to noninvasively image the whole body for diagnosing, staging and assessing therapy response in many infectious and inflammatory diseases. PET/CT is a powerful noninvasive tool that can rapidly provide three-dimensional views of disease deep within the body and conduct longitudinal assessment over time in one particular patient. Some PET tracers, such as ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG), have been found to be useful in various infectious diseases for detection, assessing disease activity, staging and monitoring response to therapy. This tracer has also been used for imaging tuberculosis. ¹⁸F-FDG PET relies on the glucose uptake of inflammatory cells as a result of the respiratory burst that occurs with infection. Other PET tracers have also been used to image different aspects of the pathology or microbiology of Mtb. The synthesis of the complex cell membrane of the bacilli for example can be imaged with ¹¹C-choline or ¹⁸F-fluoroethylcholine PET/CT while the uptake of amino acids during cell growth can be imaged by 3′-deoxy-3′-[¹⁸F]fluoro-l-thymidine. PET/CT provides a noninvasive and sensitive method of assessing histopathological information on different aspects of tuberculosis and is already playing a role in the management of tuberculosis. As our understanding of the pathophysiology of tuberculosis increases, the role of PET/CT in the management of this disease would become more important. In this review, we highlight the various tracers that have been used in tuberculosis and explain the underlying mechanisms for their use.

Tolerability and Healthcare Utilization in Maintenance Hemodialysis Patients Undergoing Treatment for Tuberculosis-Related Conditions

BACKGROUND

The incidence of tuberculosis (TB) in end-stage renal disease is significantly higher than that in the general population. Among those with kidney dysfunction, anti-TB treatment is associated with increased side effects, but the effect on healthcare utilization is unknown. Methods/Aim: To assess patient-reported symptoms, adverse effects and describe changes in healthcare utilization patterns during treatment for TB, we conducted a case series (n = 12) of patients receiving maintenance hemodialysis (HD) from Mayo Clinic Dialysis Services and concurrent drug therapy for TB from January 2002 through May 2014. Healthcare utilization (hospitalizations and emergency department (ED) visits independent of hospital admission) was compared before and during treatment.

RESULTS

Patients were treated for latent (n = 7) or active (n = 5) TB. The majority of patients with latent disease were treated with isoniazid (n = 5, 71%), while active-disease patients received a 4-drug regimen. Adverse effects were reported in 83% of patients. Compared to measurements prior to drug initiation, serum albumin and dialysis weights were similar at 3 months. Commonly reported anti-TB drug toxicities were described. More than half (58%) of the patients were hospitalized at least once. No ED or hospital admissions occurred in the period prior to drug therapy, but healthcare utilization increased during treatment in the latent disease group (hospitalization rate per person-month: pre 0 vs. post 1).

CONCLUSIONS

Among HD patients, anti-TB therapy is associated with frequently reported symptoms and increased healthcare utilization. Among this subset, patients receiving treatment for latent disease may be those with greatest increase in healthcare use. Careful monitoring and early complication detection may help optimize medication adherence and minimize hospitalizations.

Circulating Interferon-Gamma Levels Are Associated with Low Body Weight in Newly Diagnosed Kenyan Non-Substance Using Tuberculosis Individuals

Although interferon-gamma, interleukin-10, and adiponectin are key immunopathogenesis mediators of tuberculosis, their association with clinical manifestations of early stage disease is inconclusive. We determined interferon-gamma, interleukin-10, and adiponectin levels in clinically and phenotypically well-characterised non-substance using new pulmonary tuberculosis patients (n = 13) and controls (n = 14) from Kenya. Interferon-gamma levels (P < 0.0001) and interferon-gamma to interleukin-10 (P < 0.001) and interferon-gamma to adiponectin (P = 0.027) ratios were elevated in tuberculosis cases. Correlation analyses in tuberculosis cases showed associations of interferon-gamma levels with body weight (ρ = -0.849; P < 0.0001), body mass index (ρ = 0.664; P = 0.013), hip girth (ρ = -0.579; P = 0.038), and plateletcrit (ρ = 0.605; P = 0.028); interferon-gamma to interleukin-10 ratio with diastolic pressure (ρ = -0.729; P = 0.005); and interferon-gamma to adiponectin ratio with body weight (ρ = -0.560; P = 0.047), body mass index (ρ = -0.604; P = 0.029), and plateletcrit (ρ = 0.793; P = 0.001). Taken together, our results suggest mild-inflammation in early stage infection characterised by upregulation of circulating interferon-gamma production in newly infected TB patients.

Diagnosis of smear-negative pulmonary tuberculosis based on clinical signs in the Republic of Congo

BACKGROUND

The diagnosis of pulmonary tuberculosis (PTB) and smear-negative pulmonary tuberculosis (SNPT) in resource-limited countries is often solely based on clinical signs, chest X-ray radiography and sputum smear microscopy. We investigated currently used methods for the routine diagnosis of SNPT in the Republic of Congo (RoC) among TB suspected patients. The specific case of HIV positive patients was also studied.

METHODS

A cross-sectional study was conducted at the anti-tuberculosis center (CAT) of Brazzaville, RoC. Tuberculosis suspects were examined for physical signs of TB. Clinical signs, results from sputum smear microscopy, tuberculin skin test (TST) and chest X-ray were recorded.

RESULTS

Of the 772 enrolled participants, 372 were diagnosed PTB. Cough was a common symptom for PTB and no PTB patients. Pale skin, positive TST, weight loss and chest X-ray with abnormalities compatible with PTB (PTB-CXR) were significant indicators of PTB. Thirty-six percent of PTB patients were diagnosed SNPT. This category of patients presented less persistent cough and less PTB-CXR. Anorexia and asthenia were significant indicators of SNPT. In the case of HIV+ patients, 57% were SNPT with anorexia, asthenia and shorter cough being strong indicators of SNPT.

CONCLUSION

Chest X-ray abnormalities, weight loss, pale skin and positive TST were significant indicators of PTB. Anorexia and asthenia showed good diagnostic performance for SNPT, which deserve to be recommended as index indicators of SNPT diagnosis. Duration of cough is also a relevant indicator, especially for HIV+ patients.

Effusive-constrictive tuberculous pericarditis in the setting of penetrating abdominal trauma

Tuberculous pericarditis is rare in developed nations and is most commonly associated with effusive-constrictive pericarditis. We present the case of a 33-year-old man with a self-inflicted mid-abdominal stab wound. The patient underwent an exploratory laparotomy, revealing a grade IV pancreatic transection and injuries to the portal vein, right renal vein, inferior vena cava and the superior mesenteric vein. Repair of the vessels was performed and a pancreaticojejunostomy with a gastrojejunostomy was created for the pancreatic injury. The patient's hospital course was complicated by tuberculous effusive-constrictive pericarditis requiring emergent median sternotomy with opening of the pericardial sac and eventual expiration. The final cultures from the pericardial fluid demonstrated tuberculosis.

Contact Investigations Around Mycobacterium tuberculosis Patients Without Positive Respiratory Culture

OBJECTIVE

To evaluate the yield and effectiveness of contact investigations conducted around potentially infectious tuberculosis (TB) patients with no positive respiratory culture for Mycobacterium tuberculosis in New York City (NYC).

DESIGN

All TB patients without a positive respiratory culture from 2003 to 2012 were extracted from the NYC TB registry, and all patients eligible for contact investigation and their contacts were evaluated. Patients without a positive respiratory culture were defined as eligible for contact investigation if they had a respiratory nucleic acid amplification result positive for M tuberculosis, a cavitary chest radiograph, or a positive respiratory acid-fast bacilli smear.

SETTING

NYC, New York.

MAIN OUTCOME MEASURES

To evaluate the yield of the investigations, the number of contacts identified and the outcome of testing was quantified. Potential transmission was defined on the basis of whether active TB patients were detected among the contacts and if a contact had a TB test conversion.

RESULTS

From 2003 to 2012, there were 2191 TB patients without a positive respiratory culture in NYC, 374 (17%) of which were considered eligible for contact investigation. A total of 11 096 contacts were identified around 300 (80%) eligible patients, 136 of whom had a diagnosis of TB infection; of those with TB infection who initiated preventive treatment, 66% completed treatment. Potential transmission was identified around 14 patients, with the identification of 2 additional cases of active TB and 15 contacts with TB infection test conversion.

CONCLUSIONS

Conducting contact investigations around patients without a positive respiratory culture yielded evidence of possible transmission and led to the identification and treatment of new TB cases and those with TB infection. These findings suggest that these investigations should be conducted in settings where resources permit.

Latent tuberculosis infection: myths, models, and molecular mechanisms

The aim of this review is to present the current state of knowledge on human latent tuberculosis infection (LTBI) based on clinical studies and observations, as well as experimental in vitro and animal models. Several key terms are defined, including "latency," "persistence," "dormancy," and "antibiotic tolerance." Dogmas prevalent in the field are critically examined based on available clinical and experimental data, including the long-held beliefs that infection is either latent or active, that LTBI represents a small population of nonreplicating, "dormant" bacilli, and that caseous granulomas are the haven for LTBI. The role of host factors, such as CD4(+) and CD8(+) T cells, T regulatory cells, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ), in controlling TB infection is discussed. We also highlight microbial regulatory and metabolic pathways implicated in bacillary growth restriction and antibiotic tolerance under various physiologically relevant conditions. Finally, we pose several clinically important questions, which remain unanswered and will serve to stimulate future research on LTBI.

The assessment of cytokines in Quantiferon supernatants for the diagnosis of latent TB infection in a tribal population of Melghat, India

The tuberculin skin test (TST) and interferon-gamma release assays (IGRA), namely, the QuantiFERON-TB Gold test (QFT), remain the standard immunological diagnostic tools for latent tuberculosis (TB) infection (LTBI). However, the sub-optimal detection rates of both of these tests are major impediments in recognizing the population at risk. This study was aimed at evaluating additional cytokines besides interferon-gamma (IFN-γ) as biomarkers for improving LTBI diagnosis in the tribal population of Melghat, India. Seventy-four close TB contacts were stratified by QFT and TST results into: (i) QFT+/TST+ (n = 26), (ii) QFT+/TST- (n = 12), (iii) QFT-/TST- (n = 35) and (iv) QFT-/TST+ (n = 1) groups. A panel of cytokines (IL-6, IL-10, TNF-α and IL-2R) was then evaluated in antigen-stimulated QFT cell-free culture supernatants using IMMULITE-1000, an automated immunoassay analyzer. Cytokine estimation showed significantly higher levels of IL-6 in the QFT+/TST+ group, while significantly higher levels of IL-10 were found in the QFT-/TST- group. Correlation analysis identified a positive correlation between IL-6 and the QFT response (r = 0.6723, P < 0.0001), while a negative correlation was seen between QFT and IL-10 expression (r = -0.3271, P = 0.0044). Similarly, IL-6 was positively correlated with TST levels (r = 0.6631, P <0 .0001), and conversely, a negative correlation was found between TST and IL-10 expression (r = -0.5698, P < 0.0001). The positive and negative predictive values of IL-6 were found to be 92.59 and 93.33%, respectively, and the positive and negative predictive values of IL-10 were 96.55 and 91.18%, respectively. No significant impact of the demographic characteristics on cytokine positivity was observed. Our preliminary results suggest that the evaluation of additional cytokines in QFT cell-free culture supernatants may be valuable for the identification of LTBI. Combining IL-6 and IL-10 with QFT and/or TST could markedly improve the detection accuracy of LTBI. Our observations require investigation in larger well-characterized cohorts along with follow-up studies to further confirm the study outcome.

Treatment of chest wall tuberculosis with transdermal ultrasound-mediated drug delivery

Chest wall tuberculosis (TB) is an endemic disease with a large number of variants. The condition affects numerous parts of the body and can penetrate the skin to form chronic open ulcers. Current treatment methods include oral anti-TB drugs and surgery. However, conventional drug treatments are not effective due to the difficulty in achieving an effective local concentration, and certain patients are unable to tolerate surgery. The recurrence rate for chest wall TB is high following surgery, and may result in the prolonged healing of wounds in certain patients, as well as chronic sinusitis and fistula formation. To identify a safe, simple, less invasive and more clinically effective treatment method, the present study investigated transdermal ultrasound-mediated anti-TB drug delivery. A total of 186 patients were selected and randomly divided into transdermal ultrasound, surgery and oral anti-TB drug only groups. Rifampicin was the drug delivered by transdermal ultrasound. The cure and efficiency rates were shown to be 87.10 and 93.55%, respectively, in the ultrasound treatment group. No statistically significant difference was observed in the cure rates between the transdermal ultrasound and surgery groups; however, a statistically significant difference was identified in the cure rates between the transdermal ultrasound and oral anti-TB drug only groups. Therefore, transdermal ultrasound technology was shown to deliver anti-TB drugs quickly and directly, which resulted in a high local concentration of the drug, overcoming the problem of obtaining an effective local drug concentration. The observations demonstrated that transdermal ultrasound-mediated drug delivery is an effective method by which to control TB, particularly when compared with traditional oral anti-TB therapy and surgery.

Tuberculosis-related stigma leading to an incomplete contact investigation in a low-incidence country

A contact investigation following a case of infectious tuberculosis (TB) reported in a call centre in Milan (Italy) led to the identification of three additional cases that had occurred in employees of the same workplace during the previous 5 years, one of whom was the probable source case. Thirty-three latent infections were also identified. At the time of diagnosis, the source case, because of fear of stigma related to TB, claimed to be unemployed and a contact investigation was not performed in the workplace. Cases were linked through genotyping of Mycobacterium tuberculosis. TB stigma has been described frequently, mainly in high-incidence settings, and is known to influence health-seeking behaviours and treatment adherence. The findings in this report highlight that TB-associated stigma may also lead to incomplete contact investigations. Little is known about the causes and impact of TB-related stigma in low-incidence countries and this warrants further exploration. Research is also needed to evaluate the effectiveness of specific interviewing techniques and training interventions for staff in reducing feelings of stigma in TB patients. Finally, the outbreak emphasizes the importance of integrating routine contact investigations with genotyping.

Infectious Diseases

Infectious disease agents include viruses, bacteria, fungi, protozoa, parasites, and proteins called prions. Some patients are asymptomatic from their infection, whereas in other patients, clinical or subclinical illness affects the patient during the perioperative period. Transmission of the agents can occur through airborne inhalation, through contact with contaminated body fluids, via food, through physical contact, or through vector organisms. Additionally, patient-patient and patient-healthcare worker (HCW) transmission of infectious diseases remain a high concern. The perioperative period represents a unique challenge in the prevention of transmission. While diligent hand washing remains a staple in the standard of care, other measures must be implemented with certain infectious agents. Several of the major infectious diseases will be reviewed in this section, and universal precautions will be examined. Careful perioperative planning and situational awareness should be practiced by the healthcare worker taking care of patients with transmissible diseases.

Allele-specific induction of IL-1β expression by C/EBPβ and PU.1 contributes to increased tuberculosis susceptibility

Mycobacterium tuberculosis infection is associated with a spectrum of clinical outcomes, from long-term latent infection to different manifestations of progressive disease. Pro-inflammatory pathways, such as those controlled by IL-1β, have the contrasting potential both to prevent disease by restricting bacterial replication, and to promote disease by inflicting tissue damage. Thus, the ultimate contribution of individual inflammatory pathways to the outcome of M. tuberculosis infection remains ambiguous. In this study, we identified a naturally-occurring polymorphism in the human IL1B promoter region, which alters the association of the C/EBPβ and PU.1 transcription factors and controls Mtb-induced IL-1β production. The high-IL-1β expressing genotype was associated with the development of active tuberculosis, the severity of pulmonary disease and poor treatment outcome in TB patients. Higher IL-1β expression did not suppress the activity of IFN-γ-producing T cells, but instead correlated with neutrophil accumulation in the lung. These observations support a specific role for IL-1β and granulocytic inflammation as a driver of TB disease progression in humans, and suggest novel strategies for the prevention and treatment of tuberculosis.

IL-1β is important for the initial establishment of antimicrobial adaptive immunity, but prolonged IL-1β expression can also cause progressive immunopathology during M. tuberculosis infection. The paradoxical activities of IL-1β in promoting both antimycobacterial immunity and chronic tissue damage have left the ultimate contribution of this cytokine to TB progression in human populations unclear. In this work, we address the role of IL-1β-mediated inflammation using a combination of human genetics and molecular biology, and suggest that exuberant IL-1β responses are causatively associated with TB progression and poor treatment outcome in humans. This work furthers our understanding of the immunological factors that underlie TB disease and provide a strong rationale for the development of specific anti-inflammatory adjunctive therapies that could improve the long-term outcome of TB treatment. In addition, these insights inform the design of future TB control efforts that include the rational design of disease-preventing vaccines and genotype-targeted delivery of TB chemotherapy.

Spatial clustering of tuberculosis incidence in the North of Iran

Background and Purpose:

Tuberculosis (TB) poses a serious threat to public health throughout the world but disproportionately afflicts low-income nations. The aim of this study is to identify the high-risk areas in Mazandaran province (North of Iran) in helping the heath programmer for the best intervention.

Materials and Methods:

This is an ecological study conducted from 1999 through 2008. The sample included 2444 Tuberculosis (TB) patients. The variables were age, gender, type of disease and residential location, analyzed by descriptive statistical methods and spatial analysis to identify cluster of disease incidence. Geographical information system software applied to map of smooth rate of TB.

Results:

Of 2444 registered patients, 1283 (52.5%) were male. The data showed 61% urban and 96.4% of them with the Iranian nationality. There was insignificant difference between genders, but the main difference was observed between locations that are the incidence rate in the Tonekabon and Behshahr cities were 30% higher than mean incidence rate of Mazandaran province (P-value<0.05). The comprising chance of acquiring infection between urban and rural was 1.46 with confidence interval of 95% (1.35, 1.59).

Conclusion:

Geostatistical method showed spatial variability of TB incidence rate in all districts and identifying high-risk area (core areas). The most important core of TB incidence has been noticed in the eastern boundary of Mazandaran in the city of Behshahr which is due to proximity to Golestan Province. The incidence rate of TB in Behshahr city is about two times more than the number observed in Mazandaran province. Lower TB incidence rate has been observed in Golestan province is because there is usually a delay in the diagnosis of the disease especially in the positive smear patients.

Tuberculosis infection following anti-TNF therapy in inflammatory bowel disease, despite negative screening

We present two patients with inflammatory bowel disease who, despite negative tuberculosis screening, developed a de novo tuberculosis infection after the start of anti tumor necrosis factor alpha treatment. We discuss current screening methods and their limitations, the approach after positive screening and the timing to resume anti-TNFα treatment after TB infection. We shortly mention the immune reconstitution inflammatory syndrome (IRIS), described in a few cases after the stop of anti-TNFalpha while treating the tuberculosis infection. We conclude with some remaining questions concerning tuberculosis in IBD patients.

Prevalence of Extensively Drug Resistant Tuberculosis among Archived Multidrug Resistant Tuberculosis Isolates in Zimbabwe

We conducted a cross-sectional study of second line drug resistance patterns and genetic diversity of MDR-TB isolates archived at the BRTI-TB Laboratory, Harare, between January 2007 and December 2011. DSTs were performed for second line antituberculosis drugs. XDR-TB strains were defined as MDR-TB strains with resistance to either kanamycin and ofloxacin or capreomycin and ofloxacin. Strain types were identified by spoligotyping. No resistance to any second line drugs was shown in 73% of the isolates, with 23% resistant to one or two drugs but not meeting the definition of XDR-TB. A total of 26 shared types were identified, and 18 (69%) matched preexisting shared types in the current published spoligotype databases. Of the 11 out of 18 clustered SITs, 4 predominant (>6 isolates per shared type) were identified. The most and least abundant types were SIT 1468 (LAM 11-ZWE) with 12 (18%) isolates and SIT 53 (T1) with 6 (9%) isolates, respectively. XDR-TB strains are rare in Zimbabwe, but the high proportion of “pre-XDR-TB” strains and treatment failure cases is of concern. The genetic diversity of the MDR-TB strains showed no significant association between SITs and drug resistance.

Tuberculous pyomyositis: a re-emerging entity of many faces

Tuberculosis (TB) has become a global concern due to its increasing incidence, particularly in immunocompromised patients, closely following the migratory patterns of populations. TB pyomyositis is a rare extrapulmonary manifestation of TB. Its clinical presentation varies and requires a high degree of suspicion for early diagnosis. We present three patients diagnosed with TB pyomyositis: a 46-year-old man with dermatomyositis (DM) and hepatitis B who presented with fever, muscle weakness, and an abscess at the right proximal arm; a 71-year-old immunocompetent male, with a past medical history of tuberculous lymphadenopathy in childhood, who presented with a 2-month history of fever and pain at the right thigh, and a 44-year-old woman with systemic lupus erythematosus (SLE) on prednisone and methotrexate who presented with skin eruption at her thighs mimicking lupus panniculitis. In all three patients, Mycobacterium tuberculosis was identified as the causative agent. The lack of specific signs, the false negative tuberculin skin test in some cases, and the unfamiliarity of many clinicians with this entity can cause diagnostic delays. Prompt diagnosis requires a high index of suspicion especially in immunocompromised patients with fever.

Tuberculous peritonitis in pregnancy: a case report

Introduction

Tuberculous peritonitis is one of the least common forms of extrapulmonary tuberculosis. In the literature, few cases in pregnancy have been previously published. Tuberculous peritonitis in pregnancy is a diagnostic challenge, especially in the absence of lung involvement. It mimics other diseases and clinical presentation is usually non-specific, which may lead to diagnostic delay and development of complications.

Case presentation

We report here a new case of tuberculous peritonitis that occurred in a 31-year-old Caucasian pregnant woman at 22 weeks' gestation. She was complaining of abdominal pain, nausea and vomiting. These symptoms appeared 6 months prior to presentation. Initially, they were attributed to pregnancy, but they progressively became more severe during subsequent weeks. A laparoscopy showed the presence of yellow-white nodules on the peritoneal surface and a biopsy demonstrated caseous necrotic granuloma. She made a good physical recovery after being placed on antituberculous chemotherapy and gave birth to a healthy male neonate of 3100g at 37 weeks' gestation by vaginal delivery.

Conclusions

Extreme vigilance should be used when dealing with unexplained abdominal symptoms to ensure timely diagnosis of tuberculous peritonitis. Diagnosis often requires a histopathological examination. In these patients early diagnosis with early antituberculous therapy are essential to prevent obstetrical and neonatal morbidity.

Immune response to mycobacterial infection: lessons from flow cytometry

Detecting and treating active and latent tuberculosis are pivotal elements for effective infection control; yet, due to their significant inherent limitations, the diagnostic means for these two stages of tuberculosis (TB) to date remain suboptimal. This paper reviews the current diagnostic tools for mycobacterial infection and focuses on the application of flow cytometry as a promising method for rapid and reliable diagnosis of mycobacterial infection as well as discrimination between active and latent TB: it summarizes diagnostic biomarkers distinguishing the two states of infection and also features of the distinct immune response against Mycobacterium tuberculosis (Mtb) at certain stages of infection as revealed by flow cytometry to date.

Drug resistance profiles of Mycobacterium tuberculosis complex and factors associated with drug resistance in the Northwest and Southwest Regions of Cameroon

BACKGROUND

Anti-tuberculosis drug resistance continues to be a major obstacle to tuberculosis (TB) control programmes with HIV being a major risk factor in developing TB. We investigated anti-TB drug resistance profiles and the impact of socioeconomic as well as behavioural factors on the prevalence of TB and drug resistance in two regions of Cameroon with such data paucity.

METHODS

This was a hospital-based study in which 1706 participants, comprising 1133 females and 573 males consecutively enrolled from selected TB and HIV treatment centres of the Northwest and Southwest regions. Demographic, clinical and self-reported risk behaviours and socioeconomic data were obtained with the consent of participants using questionnaires. Culture and drug resistance testing were performed according to standard procedures.

RESULTS

The prevalence of resistance to at least one anti-TB drug was 27.7% and multi-drug resistance was 5.9%. Smoking, concurrent alcohol consumption and smoking, being on antiretroviral therapy for ≤ 12 months and previous household contact with TB patient were independently associated with tuberculosis prevalence, while only previous tuberculosis infection was associated with drug resistance in a univariate analysis.

CONCLUSION

The study showed a high prevalence of drug resistance TB in the study population with only previous TB infection associated with drug resistance in a univariate analysis. It also provides evidence in our context, of the role of alcohol and smoking in increasing the risk of developing TB, which is more likely in people living with HIV/AIDS. Therefore, it is important for public health authorities to integrate and intensify alcohol/smoking abstention interventions in TB and HIV control programs in Cameroon.

Clinical analysis of 21 cases of cervical tuberculous lymphadenitis without active pulmonary lesion

CONCLUSION

The necessity of considering cervical tuberculous lymphadenitis (CTL) should be emphasized even today for the differential diagnosis of cervical lymphadenopathy, particularly when it is located in the posterior triangle and supraclavicular regions even in patients without active pulmonary tuberculosis (PTB).

OBJECTIVE

This study was conducted to highlight the characteristics of patients with CTL without active PTB who were treated in our department.

METHODS

Between 2004 and 2011, 21 cases of CTL without active PTB were included in this retrospective study. Histological examination after excisional biopsy of the affected lymph node was performed in 18 patients using hematoxylin and eosin staining and Ziehl-Neelsen (Z-N) staining for acid-fast bacilli (AFB) identification. Growth of Mycobacterium tuberculosis was detected by culturing and/or nucleic acid amplification tests including polymerase chain reaction (PCR) and transcription-mediated amplification (Mycobacterium Tuberculosis Direct: MTD).

RESULTS

The male to female ratio was 1:1.3. Patient ages ranged from 22 to 89 years. Eighteen patients (85.7%) complained of indolent unilateral cervical lymphadenopathy in the posterior triangle (26.5%), internal jugular (24.5%), or supraclavicular nodes (18.4%). Positive rates of AFB according to Z-N staining and culturing of M. tuberculosis and/or PCR or MTD were 33.3% (6/18) and 72.2% (13/18), respectively.

Association between gallium-67 uptake by lung foci and sputum smear status in patients with pulmonary tuberculosis

OBJECTIVES

Rapid determination of the inflammatory and sputum smear status in patients with pulmonary tuberculosis (PTB) is crucial for clinical decision making. The purpose of this study was to assess the relationship between gallium-67 (Ga-67) uptake by lung foci and sputum smear status in patients with PTB. We also attempted to predict the patients with acid-fast bacilli (AFB) smear-positive PTB by means of a semiquantitative measurement of Ga-67 uptake ratio using single-photon emission computed tomography images.

PATIENTS AND METHODS

Ninety-five patients with PTB were enrolled in this retrospective study. A volume-of-interest method was used to quantify Ga-67 uptake in single-photon emission computed tomography images. The Ga-67 uptake ratio was defined as the maximum voxel value of the pulmonary lesion divided by the maximum voxel value of normal lung tissue.

RESULTS

The Ga-67 uptake ratio was higher in patients with active PTB than in those with inactive PTB (3.11 ± 1.52 vs. 1.42 ± 0.14, P<0.01). In active PTB, the Ga-67 uptake ratio was higher in smear-positive patients than in smear-negative patients (3.41 ± 1.60 vs. 2.16 ± 0.61, P<0.01). In patients with AFB smear grades 1+, 2+, and 3+, the Ga-67 uptake ratios were 2.51 ± 0.81, 3.30 ± 1.57, and 4.23 ± 1.73, respectively. The correlation between Ga-67 uptake ratio and AFB smear grading was statistically significant (Spearman's ρ=0.60, P<0.01). In receiver operating characteristic curve analyses, the area under the curve for the Ga-67 uptake ratio was 0.95 ± 0.02 (P<0.01) for predicting active PTB and 0.87 ± 0.04 (P<0.01) for predicting smear-positive active PTB.

CONCLUSION

In patients with active PTB, more-intense Ga-67 uptake was associated with more AFB load in the sputum - that is a greater potential to transmit PTB. This finding might facilitate clinical decision making for immediate isolation and treatment to reduce transmission of PTB.