Extrapulmonary tuberculosis: Mycobacterium tuberculosis strains and host risk factors in a large urban setting in Brazil

Novelty of Physiotherapy Protocols in a Classic Case of Extrapulmonary Tuberculosis in a 35-Year-Old Male Patient: A Case Report

Tuberculosis is the most frequent cause of death, specifically caused by a single infectious agent, Mycobacterium tuberculosis. There are two types of tuberculosis: pulmonary tuberculosis and extrapulmonary tuberculosis. Patients with extrapulmonary tuberculosis often have reduced lung function due to the disease's structural abnormalities, which also significantly impair their quality of life. The suggested standard of care for the treatment of extrapulmonary tuberculosis patients is pulmonary rehabilitation. A 35-year-old male patient who complained of shortness of breath, dry cough, and on-and-off fever diagnose with extrapulmonary tuberculosis was the subject of the case study. The patient had extrapulmonary tuberculosis with a history of pleural effusion, which was managed with proper medications. After increasing symptoms of the disease, the patient was referred for pulmonary rehabilitation. Physiotherapy protocol includes breathing exercises, relaxation techniques, and mobility exercises for the upper limb and lower limb. Effective physical rehabilitation was necessary to minimize complications and allow him to resume daily activities. Several outcome measures, like the dyspnea scale, visual analog scale, six-minute walk test, and World Health Organization-Quality of Life (WHO-QOL) questionnaire, were used to monitor the patient's progress during rehabilitation. The benefits of physiotherapy protocols emphasize the need for tailored approaches to addressing individual patient needs for comprehensive recovery as it significantly enhances clinical, physical, psychosocial, and overall quality of life, making it crucial for patients with extrapulmonary tuberculosis. The protocols are beneficial to improve exercise capacity, muscle force, symptoms such as dyspnea, cough, and health-related quality of life in these patients. In this study, the focus was more on breathing exercises such as segmental breathing exercises for lung expansion and increasing air entry in the lungs followed by improving functional capacity and strength.

Caracterización de la tuberculosis multidrogorresistente y resistente a rifampicina en Colombia

Objetivo Caracterizar la población afectada por tuberculosis multidrogorresistente y resistente a rifampicina (TB-MDR/RR) en Colombia. Métodos Estudio transversal a partir de la información nominal de los pacientes con TB-MDR/RR tratados y reportados en Colombia desde 2009 hasta 2020, usando la totalidad de las fuentes de información oficiales. Se compararon, además, las tasas de TB-MDR/RR de diferentes grupos de riesgo con la de la población general y se evaluaron variables asociadas a la TB-MDR/RR extrapulmonar y a resistencias medicamentosas. Resultados La TB-MDR/RR ha aumentado progresivamente durante la última década y se ha concentrado en hombres (64% vs. 36%, p<0,001), edades medias (mediana: 39,5 años; RIC: 27) y zonas de mayor densidad poblacional (59% de los casos en Antioquia, Valle del Cauca y Santiago de Cali). Además, al compararlas con las poblaciones de referencia que aplicaran, se evidenciaron tasas 2, 10 y 200 veces mayores en población indígena (9,45/1 000 000 vs. 4,31/1 000 000; p=0,02), prisioneros (169/1 000 000 vs. 16,9/1 000 000; p<0,001) y habitantes de calle (21/100000 vs. 0,1/100 000; p<0,001), respectivamente. Conclusiones El aumento en los casos de TB-MDR/RR y sus grupos de riesgo deben tenerse en cuenta para la planeación de políticas, distribución de recursos y atención clínica.

Molecular epidemiology of Mycobacterium tuberculosis in Brazil before the whole genome sequencing era: a literature review

Molecular-typing can help in unraveling epidemiological scenarios and improvement for disease control strategies. A literature review of Mycobacterium tuberculosis transmission in Brazil through genotyping on 56 studies published from 1996-2019 was performed. The clustering rate for mycobacterial interspersed repetitive units - variable tandem repeats (MIRU-VNTR) of 1,613 isolates were: 73%, 33% and 28% based on 12, 15 and 24-loci, respectively; while for RFLP-IS6110 were: 84% among prison population in Rio de Janeiro, 69% among multidrug-resistant isolates in Rio Grande do Sul, and 56.2% in general population in São Paulo. These findings could improve tuberculosis (TB) surveillance and set up a solid basis to build a database of Mycobacterium genomes.

Expression of mycolic acid in response to stress and association with differential clinical manifestations of tuberculosis

Background

Extrapulmonary tuberculosis (EPTB), accounting for 10%-20% of all cases of tuberculosis (TB), is known to be determined by host immunity. However, the contribution of bacterial factors to the development of EPTB has not been studied extensively. Mycolic acids are predominant lipids constituting the cell wall of Mycobacterium tuberculosis, and keto-mycolic acid is involved in the synthesis of foamy macrophages that facilitate persistence of mycobacteria. Hence, the present study was performed to gain an insight into variable expression of mycolic acids in clinical isolates of M. tuberculosis under stress.

Methods

Pansusceptible clinical isolates of M. tuberculosis from patients with lymph node TB (LNTB) (n = 10) and pulmonary TB (PTB) (n = 10) were subjected to sodium dodecyl sulfate (SDS) stress, and the expression of mycolic acid and its biosynthetic genes was compared. Any bias arising due to the genotype of the clinical isolates was ruled out by performing single-nucleotide polymorphism cluster grouping (SCG), wherein no significant difference was observed between the SCG of LNTB or PTB isolates.

Results

The expression of α-mycolic acid during the exposure to SDS was high in 7/10 (70%) LNTB and 6/10 (60%) PTB isolates. Methoxy mycolic acid showed an increased expression in 7/10 (70%) LNTB isolates and 4/10 (40%) PTB isolates. Increased expression of keto-mycolic acid on exposure with SDS was observed in 8/10 (80%) M. tuberculosis LNTB and 3/10 (30%) PTB isolates. Similarly, the mycolic acid synthesis gene, fas, was upregulated more in LNTB isolates than PTB isolates in vitro and ex vivo. SCG 3a was the most common SCG observed in 40% (8/20) of the isolates, followed by SCG 3b in 30% (6/20) of the isolates. There was no significant difference between the SCG of LNTB or PTB isolates.

Conclusion

The higher expression of keto-mycolic acid in LNTB as against PTB isolates may indicate better survival in LNTB isolates in the presence of stress.

Description of demographic and clinical characteristics of extrapulmonary tuberculosis in Shandong, China

BACKGROUND

According to the clinical manifestation, tuberculosis (TB) is divided into pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB). The incidence rate of EPTB has increased in many countries. The demographic and clinical characteristics of EPTB in China remain still unclear.

MATERIALS AND METHODS

We retrospectively analyzed the medical records of 5,624 hospitalized patients with positive M. tuberculosis culture between January 2008 and June 2013 in Shandong province. We investigated the epidemiological, demographic, and clinical characteristics of patients with EPTB.

RESULTS

Among 5,624 hospitalized TB patients with positive M. tuberculosis culture, 4,277 (76.05 %) had PTB, 618 (10.99 %) had EPTB, and 729 (12.96 %) had both PTB and EPTB. The proportion of EPTB increased significantly from 6.97 % in 2008 to 19.98 % in 2012 (p <0.001).  The most frequent sites or foci of EPTB were pleura (63.27 %), followed by bone/joint (13.75 %), and lymph nodes (8.9 %). The mean duration of treatment for pleural TB was eight months and for EPTB in the other foci was more than 15 months.

CONCLUSION

The proportion of EPTB in Shandong province has significantly increased. Clinicians need to be aware of the trend and remain vigilant against EPTB. EPTB requires prolonged treatment, and clinical supervision should be strengthened to prevent drug resistance. HIPPOKRATIA 2020, 24(1): 27-32.

Tuberculosis-Related Hospitalizations in a Low-Incidence Country: A Retrospective Analysis in Two Italian Infectious Diseases Wards

In recent years, a decrease in the incidence of tuberculosis (TB) has been recorded worldwide. However, an increase in TB cases has been reported in foreign people living in low-incidence countries, with an increase in extrapulmonary TB (EPTB) in the western region of the world. In the present work, a retrospective study was conducted in two Italian infectious diseases wards to evaluate the clinical characteristics of TB admission in the time period 2013-2017. A significant increase in TB was shown in the study period: 166 (71% males) patients with TB were enrolled, with ~70% coming from outside Italy (30% from Africa, 25% from Europe, and 13% from Asia and South America). Compared to foreign people, Italians were significantly older (71.5 (interquartile range, IQR: 44.5-80.0) vs. 30 (IQR: 24-40) years; p < 0.0001) more immunocompromised (48% vs. 17%; p < 0.0001), and affected by comorbidities (44% vs. 14%; p < 0.0001). EPTB represented 37% of all forms of the disease, and it was more incident in subjects coming from Africa than in those coming from Europe (39.3% vs. 20%, respectively). In logistic regression analysis, being European was protective (odd ratio, OR (95% CI): 0.2 (0.1-0.6); p = 0.004) against the development of EPTB forms. In conclusion, an increase in the rate of TB diagnosis was documented in two Italian reference centers in the period 2013-2017, with 39% of EPTB diagnosed in patients from outside Europe.

Epidemiology of tuberculous lymphadenitis in Africa: A systematic review and meta-analysis

INTRODUCTION

Tuberculous lymphadenitis is the most frequent form of extra-pulmonary TB (EPTB) and accounts for a considerable proportion of all EPTB cases. We conducted a systematic review of articles that described the epidemiological features of TBLN in Africa.

METHODS

Any article that characterized TBLN cases with respect to demographic, exposure and clinical features were included. Article search was restricted to African countries and those published in English language irrespective of publication year. The articles were retrieved from the electronic database of PubMed, Scopus, Cochrane library and Lens.org. Random effect pooled prevalence with 95% CI was computed based on Dersimonian and Laird method. To stabilize the variance, Freeman-Tukey double arcsine root transformation was done. The data were analyzed using Stata 14.

RESULTS

Of the total 833 articles retrieved, twenty-eight articles from 12 African countries fulfilled the eligibility criteria. A total of 6746 TBLN cases were identified. The majority of the cases, 4762 (70.6%) were from Ethiopia. Over 77% and 88% of identified TBLN were cervical in type and naïve to TB drugs. Among the total number of TBLN cases, 53% were female, 68% were in the age range of 15-44 years, 52% had a history of livestock exposure, 46% had a history of consuming raw milk/meat and 24% had history of BCG vaccination. The proportion of TBLN/HIV co-infection was much lower in Ethiopia (21%) than in other African countries (73%) and the overall African estimate (52%). Fever was recorded in 45%, night sweating in 55%, weight loss in 62% and cough for longer than two weeks in 32% of the TBLN cases.

CONCLUSIONS

TBLN was more common in females than in males. The high prevalence of TBLN in Ethiopia did not show directional correlation with HIV. Population based prospective studies are warranted to better define the risk factors of TBLN in Africa.

Genetic diversity of Mycobacterium tuberculosis isolates causing pulmonary and extrapulmonary tuberculosis in the capital of Iran

OBJECTIVES

Evaluation of the genetic diversity of Mycobacterium tuberculosis (M.tb) and determining if the association between a specific genotype and the site of infection is crucial. Accordingly, the current study aimed at comparing predominant M.tb genotypes in pulmonary (PTB) and extrapulmonary tuberculosis (EPTB) isolates circulating in the capital of Iran.

METHODS

The genetic diversity of culture-confirmed PTB and EPTB isolates were evaluated by Spoligotyping and MIRU-VNTR (mycobacterial interspersed repetitive-unit-variable-number tandem-repeat) typing methods. Genotyping data were analyzed with SITVIT, MIRU-VNTRplus, and TBminer databases. To assess adjusted associations, chi-square/the Fisher exact test and multiple logistic regression model were applied.

RESULTS

URAL2 (NEW-1) (28/88; 31.8%) and CAS1-DELHI (25/84; 29.8%) genotypes were predominant in EPTB and PTB strains, respectively. Based on MIRU-VNTR typing, 158 different MIRU-VNTR patterns were identified. Clustering rate and minimum estimate of the proportion of TB caused by recent transmission was 4.1% and 8.1%, respectively.

CONCLUSIONS

The current study provided new insight into circulating genotypes of M.tb in PTB and EPTB patients in Tehran, Iran. This low percentage of TB transmission rate, demonstrated that mode of TB transmission was mainly associated with reactivation of latent TB rather than recently transmitted infection in this region. There was no significant difference in the association between the genotypes of M.tb strains and the site of the disease.

Risk factors associated with cluster size of Mycobacterium tuberculosis (Mtb) of different RFLP lineages in Brazil

BACKGROUND

Tuberculosis (TB) transmission is influenced by patient-related risk, environment and bacteriological factors. We determined the risk factors associated with cluster size of IS6110 RFLP based genotypes of Mycobacterium tuberculosis (Mtb) isolates from Vitoria, Espirito Santo, Brazil.

METHODS

Cross-sectional study of new TB cases identified in the metropolitan area of Vitoria, Brazil between 2000 and 2010. Mtb isolates were genotyped by the IS6110 RFLP, spoligotyping and RDRio. The isolates were classified according to genotype cluster sizes by three genotyping methods and associated patient epidemiologic characteristics. Regression Model was performed to identify factors associated with cluster size.

RESULTS

Among 959 Mtb isolates, 461 (48%) cases had an isolate that belonged to an RFLP cluster, and six clusters with ten or more isolates were identified. Of the isolates spoligotyped, 448 (52%) were classified as LAM and 412 (48%) as non-LAM. Our regression model found that 6-9 isolates/RFLP cluster were more likely belong to the LAM family, having the RDRio genotype and to be smear-positive (adjusted OR = 1.17, 95% CI 1.08-1.26; adjusted OR = 1.25, 95% CI 1.14-1.37; crude OR = 2.68, 95% IC 1.13-6.34; respectively) and living in a Serra city neighborhood decrease the risk of being in the 6-9 isolates/RFLP cluster (adjusted OR = 0.29, 95% CI, 0.10-0.84), than in the others groups. Individuals aged 21 to 30, 31 to 40 and > 50 years were less likely of belonging the 2-5 isolates/RFLP cluster than unique patterns compared to individuals < 20 years of age (adjusted OR = 0.49, 95% CI 0.28-0.85, OR = 0.43 95% CI 0.24-0.77and OR = 0. 49, 95% CI 0.26-0.91), respectively. The extrapulmonary disease was less likely to occur in those infected with strains in the 2-5 isolates/cluster group (adjustment OR = 0.45, 95% CI 0.24-0.85) than unique patterns.

CONCLUSIONS

We found that a large proportion of new TB infections in Vitoria is caused by prevalent Mtb genotypes belonging to the LAM family and RDRio genotypes. Such information demonstrates that some genotypes are more likely to cause recent transmission. Targeting interventions such as screening in specific areas and social risk groups, should be a priority for reducing transmission.

Association between Mycobacterium tuberculosis lineage and site of disease in Florida, 2009-2015

BACKGROUND

Mycobacterium tuberculosis is characterized into four global lineages with strong geographical restriction. To date one study in the United States has investigated M. tuberculosis lineage association with tuberculosis (TB) disease presentation (extra-pulmonary versus pulmonary). We update this analysis using recent (2009-2015) data from the State of Florida to measure lineage association with pulmonary TB, the infectious form of the disease.

METHODS

M. tuberculosis lineage was assigned based on the spacer oligonucleotide typing (spoligotyping) patterns. TB disease site was defined as exclusively pulmonary or extra-pulmonary. We used ORs to measure the association between M. tuberculosis lineages and pulmonary compared to extra-pulmonary TB. The final multivariable model was adjusted for patient socio-demographics, HIV and diabetes status.

RESULTS

We analyzed 3061 cases, 83.4% were infected with a Euro-American lineage, 8.4% Indo-Oceanic and 8.2% East-Asian lineage. The majority of the cases (86.0%) were exclusively pulmonary. Compared to the Indo-Oceanic lineage, infection with a Euro-American (AOR=1.87, 95% CI: 1.21, 2.91) or an East-Asian (AOR=2.11, 95% CI: 1.27, 3.50) lineage favored pulmonary disease compared to extra-pulmonary. In a sub-analysis among pulmonary cases, strain lineage was not associated with sputum smear positive status, indicating that the observed association with pulmonary disease is independent of host contagiousness.

CONCLUSION

As an obligate pathogen, M. tuberculosis' fitness is directly correlated to its transmission potential. In this analysis, we show that M. tuberculosis lineage is associated with pulmonary disease presentation. This association may explain the predominance in a region of certain lineages compared to others.

Light-emitting diode fluorescent microscopy and Xpert MTB/RIF® assay for diagnosis of pulmonary tuberculosis among patients attending Ambo hospital, west-central Ethiopia

Background

The relatively simple and cheaper light-emitting diode fluorescent microscopy (LED-FM) was recommended by the World Health Organization (WHO) to replace the conventional tuberculosis (TB) microscopy in both high- and low-volume laboratories. More recently the WHO also endorsed one more technique, Xpert MTB/RIF® assay (Xpert), for improved TB diagnosis particularly among human immunodeficiency virus (HIV)-infected cases. However, the relative performance of both of these tools differs from setting to setting in reference to the conventional TB diagnostics. This study thus aimed to evaluate these tools for TB detection in individuals visiting Ambo Hospital, west-central Ethiopia.

Methods

Cross-sectional early-morning sputum samples were collected from presumptive TB patients between January and August 2015. Socio-demographic data were captured using a structured questionnaire. Clinical information was gathered from patients’ medical records. The sputum samples were diagnosed using LED-FM, Xpert, concentrated Ziehl-Neelsen (cZN) staining and Lowenstein-Jensen (LJ) culture as the gold standard. Drug sensitivity test (DST) was also conducted.

Results

Out of 362 sputum samples collected and processed, 36(9.9%) were positive by LED-FM, 42(11.6%) by cZN and 50(13.8%) by Xpert. But, only 340 samples could be declared culture positive or negative for mycobacteria. Of these 340, eight were non-tubercle mycobacteria (NTM). Out of the remaining 332 samples, 45(13.6%) had culture-confirmed TB with 11(24.4%) being HIV co-infected. LED-FM, Xpert and culture detected 54.5% (6/11), 90.9% (10/11) and 100% (11/11) mycobacteria in HIV-positive individuals and 81.3% (26/32), 73.7% (28/38), 78.8% (26/33) and 73.2% (30/41), in HIV negatives respectively. Two samples were rifampicin resistant by both Xpert and DST. The overall sensitivity, specificity, positive and negative predictive values of LED-FM and Xpert were 77.8, 100, 100 and 96; and 93.3, 98, 97.5 and 98.9% respectively.

Conclusion

The data demonstrated the high diagnostic yield of Xpert. LED-FM sensitivity is higher compared to results quoted by recent systematic reviews although it appears to be lower than what was cited in the WHO policy statement (83.6%) during the recommendation of the technology. The high specificity of LED-FM in the study area is encouraging and is expected to boost its reliability and uptake.

A systematic review of East African-Indian family of Mycobacterium tuberculosis in Brazil

Introduction

The Mycobacterium tuberculosis East African-Indian (EAI) spoligotyping family (belonging to lineage 1, Indo-Oceanic, defined by the region of deletion RD239) is distributed worldwide, but is more prevalent in Southeast Asia, India, and East Africa. Studies in Latin America have rarely identified EAI. In this study, we describe the occurrence of the EAI family in Brazil.

Methods

EAI was identified in a systematic literature review of genetic diversity studies pertaining to M. tuberculosis in Brazil, as well as in a survey conducted in Salvador, Bahia, located in the northeastern region of this country.

Results

The EAI6-BGD1 spoligotyping family and the EAI5 Spoligotype International Type (SIT) 1983 clade were the most frequently reported, with wide distribution of this particular clade described in Brazil. The distribution of other EAI spoligotyping patterns with broader worldwide distribution was restricted to the southeastern region of the country.

Conclusions

EAI may be endemic at a low frequency in Brazil, with some clades indicating increased fitness with respect to this population.

Association of HIV infection with extrapulmonary tuberculosis: a systematic review

PURPOSE

HIV/AIDS is a known risk factor for the development of pulmonary tuberculosis (PTB). However, the association is less clear between HIV and extrapulmonary tuberculosis (EPTB). We conducted a systematic review to determine the association between HIV and EPTB.

METHODS

We searched the electronic databases Medline, Embase, and relevant conference literature using defined search terms for EPTB and HIV. Only publications in English and only studies reporting adjusted estimates were included, while our search criteria did not include restriction by age or geographic location of study participants. Qualitative and quantitative analyses (including I 2 test for heterogeneity) were performed.

RESULTS

Sixteen studies (15 cross-sectional and 1 case-control) conducted from 1984 to 2016 were included in the final analyses after screening 5163 articles and conference abstracts. Our qualitative analysis showed heterogeneity in study design and study population characteristics along with a medium/high risk of bias in the majority of studies. While most of the individual studies showed increased odds of EPTB compared with PTB among HIV-infected individuals, we did not provide an overall pooled estimate, as the I 2 value was high at 93% for the cross-sectional studies.

CONCLUSIONS

While an association between HIV and EPTB is observed in most individual studies, the high heterogeneity and risk of bias in these studies highlight the need for further well-designed prospective cohort studies to assess the true risk of EPTB in the HIV-infected patient population.

Difference in Antibody Responses to Mycobacterium tuberculosis Antigens in Japanese Tuberculosis Patients Infected with the Beijing/Non-Beijing Genotype

The Beijing genotype Mycobacterium tuberculosis (MTB), notorious for its virulence and predisposition to relapse, could be identified by spoligotyping based on genetic heterogeneity. The plasma samples from 20 cases of Beijing and 16 cases of non-Beijing MTB infected individuals and 24 healthy controls (HCs) were collected, and antibodies against 11 antigens (Rv0679c142Asn, Rv0679c142Lys, Ag85B, Ag85A, ARC, TDM-M, TDM-K, HBHA, MDP-1, LAM, and TBGL) were measured by ELISA. Compared to the HCs, the MTB infected subjects showed higher titers of anti-Ag85B IgG (positivity 58.2%) and anti-ACR IgG (positivity 48.2%). Of note, anti-ACR IgG showed higher titer in Beijing MTB infected tuberculosis (TB) patients than in HC (Kruskal–Wallis test, p < 0.05), while the levels of anti-Ag85B, anti-TBGL, anti-TDM-K, and anti-TDM-M IgG were higher in non-Beijing TB patients than in HC. Moreover, anti-Ag85B IgG showed higher response in non-Beijing TB patients than in Beijing TB patients (p < 0.05; sensitivity, 76.9% versus 44.4%). The sensitivity and specificity analysis showed that 78.8% Beijing infected individuals were negative in anti-TBGL-IgG or/and anti-Ag85B-IgG, while 75.0% of those were positive in anti-TBGL-IgA or/and anti-ACR-IgG tests. These results indicate the possibility of developing antibody-based test to identify Beijing MTB.

Clinical and epidemiological characteristics associated with unfavorable tuberculosis treatment outcomes in TB-HIV co-infected patients in Brazil: a hierarchical polytomous analysis

Background

TB patients co-infected with HIV have worse treatment outcomes than non-coinfected patients. How clinical characteristics of TB and socioeconomic characteristics influence these outcomes is poorly understood. Here, we use polytomous regression analysis to identify clinical and epidemiological characteristics associated with unfavorable treatment outcomes among TB-HIV co-infected patients in Brazil.

Methods

TB-HIV cases reported in the Brazilian information system (SINAN) between January 1, 2001 and December 31, 2011 were identified and categorized by TB treatment outcome (cure, default, death, and development of MDR TB). We modeled treatment outcome as a function of clinical characteristics of TB and patient socioeconomic characteristics by polytomous regression analysis. For each treatment outcome, we used cure as the reference outcome.

Results

Between 2001 and 2011, 990,017 cases of TB were reported in SINAN, of which 93,147 (9.4%) were HIV co-infected. Patients aged 15–19 (OR = 2.86; 95% CI: 2.09–3.91) and 20–39 years old (OR = 2.30; 95% CI: 1.81–2.92) were more likely to default on TB treatment than those aged 0–14 years old. In contrast, patients aged ≥60 years were more likely to die from TB (OR = 2.22; 95% CI: 1.43–3.44) or other causes (OR = 2.86; 95% CI: 2.14–3.83). Black patients were more likely to default on TB treatment (OR = 1.33; 95% CI: 1.22–1.44) and die from TB (OR = 1.50; 95% CI: 1.29–1.74). Finally, alcoholism was associated with all unfavorable outcomes: default (OR = 1.94; 95% CI: 1.73–2.17), death due to TB (OR = 1.46; 95% CI: 1.25–1.71), death due to other causes (OR = 1.38; 95% CI: 1.21–1.57) and MDR-TB (OR = 2.29; 95% CI: 1.46–3.58).

Conclusions

Socio-economic vulnerability has a significant effect on treatment outcomes among TB-HIV co-infected patients in Brazil. Enhancing social support, incorporation of alcohol abuse screening and counseling into current TB surveillance programs and targeting interventions to specific age groups are interventions that could improve treatment outcomes.

Mycobacterium tuberculosis causing tuberculous lymphadenitis in Maputo, Mozambique

Background

The zoonosis bovine tuberculosis (TB) is known to be responsible for a considerable proportion of extrapulmonary TB. In Mozambique, bovine TB is a recognised problem in cattle, but little has been done to evaluate how Mycobacterium bovis has contributed to human TB. We here explore the public health risk for bovine TB in Maputo, by characterizing the isolates from tuberculous lymphadenitis (TBLN) cases, a common manifestation of bovine TB in humans, in the Pathology Service of Maputo Central Hospital, in Mozambique, during one year.

Results

Among 110 patients suspected of having TBLN, 49 had a positive culture result. Of those, 48 (98 %) were positive for Mycobacterium tuberculosis complex and one for nontuberculous mycobacteria. Of the 45 isolates analysed by spoligotyping and Mycobacterial Interspersed Repetitive Unit – Variable Number Tandem Repeat (MIRU-VNTR), all were M. tuberculosis. No M. bovis was found.

Cervical TBLN, corresponding to 39 (86.7 %) cases, was the main cause of TBLN and 66.7 % of those where from HIV positive patients.

We found that TBLN in Maputo was caused by a variety of M. tuberculosis strains. The most prevalent lineage was the EAI (n = 19; 43.2 %). Particular common spoligotypes were SIT 48 (EAI1_SOM sublineage), SIT 42 (LAM 9), SIT 1 (Beijing) and SIT53 (T1), similar to findings among pulmonary cases.

Conclusions

M. tuberculosis was the main etiological agent of TBLN in Maputo. M. tuberculosis genotypes were similar to the ones causing pulmonary TB, suggesting that in Maputo, cases of TBLN arise from the same source as pulmonary TB, rather than from an external zoonotic source. Further research is needed on other forms of extrapulmonary TB and in rural areas where there is high prevalence of bovine TB in cattle, to evaluate the risk of transmission of M. bovis from cattle to humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-015-0603-5) contains supplementary material, which is available to authorized users.

High Genotypic Discordance of Concurrent Mycobacterium tuberculosis Isolates from Sputum and Blood of HIV-Infected Individuals

Background

Among HIV-infected individuals with CD4 less than 200 cells/mm³, tuberculosis often has an atypical presentation, is more likely to be disseminated and is diagnostically challenging. We sought to understand the genotypic discordance of concurrent sputum and blood M. tuberculosis (MTB) isolates from HIV-infected individuals.

Methods

From a prospective diagnostic accuracy study with 182 HIV-infected culture-positive TB adults, isolates were obtained from 51 of 66 participants who were MTB culture-positive by both sputum and blood. Isolates were subjected to susceptibility testing to 1^st line drugs, spoligotyping and 24 locus- MIRU-VNTR.

Results

The median age of the participants was 31 (IQR; 27–38) years and 51% were male. The median CD4 count was 29 (IQR; 10–84) cells/mm³ with 20% taking ART; 8.0% were previously treated for TB, and 63% were AFB smear-negative. The isolates belonged to two of the main global MTB-lineages; East-African-Indian (L3) 17 (16.7%) and Euro-American (L4) 85 (83.3%). We identified 26 (51.0%) participants with discordant MTB-genotypes between sputum and blood, including two patients with evidence of mixed infection in either compartment. Having discordant MTB-genotypes was not predicted by the MTB-lineage in either blood or sputum, CD4 cell count, or any other clinical characteristic.

Conclusions

There is a high genotypic discordance among M. tuberculosis concurrently isolated from sputum and blood of HIV-infected individuals. These findings suggest that infection with more than one strain of M. tuberculosis occurs in at least half of patients with advanced HIV infection.

Microglia are crucial regulators of neuro-immunity during central nervous system tuberculosis

Mycobacterium tuberculosis (M. tuberculosis) infection of the central nervous system (CNS) is the most devastating manifestation of tuberculosis (TB), with both high mortality and morbidity. Although research has been fueled by the potential therapeutic target microglia offer against neurodegenerative inflammation, their part in TB infection of the CNS has not been fully evaluated nor elucidated. Yet, as both the preferential targets of M. tuberculosis and the immune-effector cells of the CNS, microglia are likely to be key determinants of disease severity and clinical outcomes. Following pathogen recognition, bacilli are internalized and capable of replicating within microglia. Cellular activation ensues, utilizing signaling molecules that may be neurotoxic. Central to initiating, orchestrating and modulating the tuberculous immune response is microglial secretion of cytokines and chemokines. However, the neurological environment is unique in that inflammatory signals, which appear to be damaging in the periphery, could be beneficial by governing neuronal survival, regeneration and differentiation. Furthermore, microglia are important in the recruitment of peripheral immune cells and central to defining the pro-inflammatory milieu of which neurotoxicity may result from many of the participating local or recruited cell types. Microglia are capable of both presenting antigen to infiltrating CD4(+) T-lymphocytes and inducing their differentiation-a possible correlate of protection against M. tuberculosis infection. Clarifying the nature of the immune effector molecules secreted by microglia, and the means by which other CNS-specific cell types govern microglial activation or modulate their responses is critical if improved diagnostic and therapeutic strategies are to be attained. Therefore, this review evaluates the diverse roles microglia play in the neuro-immunity to M. tuberculosis infection of the CNS.

Genetic diversity and dynamic distribution of Mycobacterium tuberculosis isolates causing pulmonary and extrapulmonary tuberculosis in Thailand

This study examined the genetic diversity and dynamicity of circulating Mycobacterium tuberculosis strains in Thailand using nearly neutral molecular markers. The single nucleotide polymorphism (SNP)-based genotypes of 1,414 culture-positive M. tuberculosis isolates from 1,282 pulmonary tuberculosis (PTB) and 132 extrapulmonary TB (EPTB) patients collected from 1995 to 2011 were characterized. Among the eight SNP cluster groups (SCG), SCG2 (44.1%), which included the Beijing (BJ) genotype, and SCG1 (39.4%), an East African Indian genotype, were dominant. Comparisons between the genotypes of M. tuberculosis isolates causing PTB and EPTB in HIV-negative cases revealed similar prevalence trends although genetic diversity was higher in the PTB patients. The identification of 10 reported sequence types (STs) and three novel STs was hypothesized to indicate preferential expansion of the SCG2 genotype, especially the modern BJ ST10 (15.6%) and ancestral BJ ST19 (13.1%). An association between SCG2 and SCG1 genotypes and particular patient age groups implies the existence of different genetic advantages among the bacterial populations. The results revealed that increasing numbers of young patients were infected with M. tuberculosis SCGs 2 and 5, which contrasts with the reduction of the SCG1 genotype. Our results indicate the selection and dissemination of potent M. tuberculosis genotypes in this population. The determination of heterogeneity and dynamic population changes of circulating M. tuberculosis strains in countries using the Mycobacterium bovis BCG (bacillus Calmette-Guérin) vaccine are beneficial for vaccine development and control strategies.

Epidemiology of extrapulmonary tuberculosis in Brazil: a hierarchical model

Background

Although extrapulmonary tuberculosis (EPTB) is less frequent than Pulmonary Tuberculosis (PTB) and is a secondary target for national TB control programs, its significance has increased worldwide during the HIV epidemic. The objective of this study was to examine the epidemiology of EPTB in Brazil between 2007 and 2011.

Methods

Cross-sectional study involving all cases of TB reported to the Brazilian Notifiable Diseases Surveillance System (Sistema de Informações de Agravo de Notificação - SINAN) in Brazil between 2007 and 2011. Sociodemographic and clinical characteristics of patients with exclusively PTB and exclusively EPTB were compared. Following analysis with Pearson’s chi-square test, variables with p < 0.05 were included in a hierarchical regression model. Variables with p < 0.05 in the corresponding level were kept in the model.

Results

A total of 427,548 cases of TB were included. Of these, 356,342 cases (83.35%; 95% confidence interval (CI) 83.23% - 83.45%) were PTB, 57,217 (13.37%; 95% CI 13.28% - 13.48%) were EPTB, 13,989 (3.27%; 95% CI 3.21% - 3.32%) were concurrent pulmonary and extrapulmonary TB. Patients with EPTB were mainly white (16.7%), and most (29.1%) patients had five to eight years of education. Among comorbidities, HIV infection was prominent (OR 2.15; 95% CI 2.09 – 2.21), although the proportion of cases awaiting test results or untested was high (39%). Ethanol use (OR 0.45; 95% CI 0.43 – 0.46), diabetes mellitus (OR 0.54; 95% CI 0.51 – 0.57) and mental illness (OR 0.88; 95% CI 0.82 – 0.95) were associated with PTB.

Conclusions

Thirteen percent of patients diagnosed with TB in Brazil have only EPTB. More effective diagnostic strategies and control measures are needed to reduce the number of cases of extrapulmonary TB in Brazil.