Association of indicators of extensive disease and rifampin-resistant tuberculosis treatment outcomes: an individual participant data meta-analysis.

BACKGROUND: Indicators of extensive disease-acid fast bacilli (AFB) smear positivity and lung cavitation-have been inconsistently associated with clinical rifampin-resistant/multidrug-resistant tuberculosis (RR/MDR-TB) outcomes. We evaluated the association of these indicators with end-of-treatment outcomes. METHODS: We did an individual participant data meta-analysis of people treated for RR/MDR-TB with longer regimens with documented AFB smear and chest radiography findings. We compared people AFB smear-negative without cavities to people: (1) smear-negative with lung cavities; (2) smear-positive without lung cavities and (3) AFB smear-positive with lung cavities. Using multivariable logistic regression accounting for demographic, treatment and clinical factors, we calculated adjusted ORs (aOR) for any unfavourable outcome (death, lost to follow-up, failure/recurrence), and mortality and treatment failure/recurrence alone. RESULTS: We included 5596 participants; included participants significantly differed from excluded participants. Overall, 774 (13.8%) were AFB smear-negative without cavities, 647 (11.6%) only had cavities, 1424 (25.4%) were AFB smear-positive alone and 2751 (49.2%) were AFB smear-positive with cavities. The median age was 37 years (IQR: 28-47), 3580 (64%) were male and 686 (12.5%) had HIV. Compared with participants AFB smear-negative without cavities, aOR (95% CI) for any unfavourable outcome was 1.0 (0.8 to 1.4) for participants smear-negative with lung cavities, 1.2 (0.9 to 1.5) if smear-positive without cavities and 1.6 (1.3 to 2.0) if AFB smear-positive with lung cavities. Odds were only significantly increased for mortality (1.5, 95% CI 1.1 to 2.1) and failure/recurrence (2.2, 95% CI 1.5 to 3.3) among participants AFB smear-positive with lung cavities. CONCLUSION: Only the combination of AFB smear-positivity and lung cavitation was associated with unfavourable outcomes, suggesting they may benefit from stronger regimens.

SLCO1B1 and SLC10A1 polymorphism and plasma rifampin concentrations in patients with co-morbidity tuberculosis-diabetes mellitus in Baja California, Mexico.

Rifampicin is one of the most important drugs for the treatment of tuberculosis (TB). Polymorphisms in SLCO1B1 and SLC10A1 genes are associated with impaired transporter function of drug compounds such as rifampicin. The relationship between genetic variation, clinical comorbidities, and rifampicin exposures in TB patients has not been completely elucidated. The aim of this study was to investigate the prevalence of SLCO1A1 and SLCO1B1 polymorphisms in TB and TB-DM patients and to determine their relationship with rifampicin pharmacokinetics on patients from México. Blood samples were collected in two hospitals in Baja California, Mexico from February through December 2017. Sampling included 19 patients with TB, 11 with T2DM and 17 healthy individuals. Polymorphisms genotype rs2306283, rs11045818, rs11045819, rs4149056, rs4149057, rs72559746,rs2291075 and rs4603354 of SLCO1B1 and rs4646285 and rs138880008 of SLC10A1 were analyzed by Sanger's sequencing. None of the SLCO1B1 and SLC10A1 variants were significantly associated with rifampicin Cmax. TB and T2DM patients with suboptimal Cmax rifampicin levels showed wild alleles in rs11045819 and rs2291075 in SLCO1B1 SLC10A1 and SLC10A1. This is the first study to analyze SLC10A1 and SLCO1B1 polymorphisms in TB and TB-T2DM patients and healthy individuals in Mexico. Further research to confirm and extend these findings is necessary.

Drug-associated adverse events in the treatment of multidrug-resistant tuberculosis: an individual patient data meta-analysis.

BACKGROUND: Treatment of multidrug-resistant tuberculosis requires long-term therapy with a combination of multiple second-line drugs. These drugs are associated with numerous adverse events that can cause severe morbidity, such as deafness, and in some instances can lead to death. Our aim was to estimate the absolute and relative frequency of adverse events associated with different tuberculosis drugs to provide useful information for clinicians and tuberculosis programmes in selecting optimal treatment regimens. METHODS: We did a meta-analysis using individual-level patient data that were obtained from studies that reported adverse events that resulted in permanent discontinuation of anti-tuberculosis medications. We used a database created for our previous meta-analysis of multidrug-resistant tuberculosis treatment and outcomes, for which we did a systematic review of literature published between Jan 1, 2009, and Aug 31, 2015 (updated April 15, 2016), and requested individual patient-level information from authors. We also considered for this analysis studies contributing patient-level data in response to a public call made by WHO in 2018. Meta-analysis for proportions and arm-based network meta-analysis were done to estimate the incidence of adverse events for each tuberculosis drug. FINDINGS: 58 studies were identified, including 50 studies from the updated individual patient data meta-analysis for multidrug-resistant tuberculosis treatment. 35 of these studies, with 9178 patients, were included in our analysis. Using meta-analysis of proportions, drugs with low risks of adverse event occurrence leading to permanent discontinuation included levofloxacin (1·3% [95% CI 0·3-5·0]), moxifloxacin (2·9% [1·6-5·0]), bedaquiline (1·7% [0·7-4·2]), and clofazimine (1·6% [0·5-5·3]). Relatively high incidence of adverse events leading to permanent discontinuation was seen with three second-line injectable drugs (amikacin: 10·2% [6·3-16·0]; kanamycin: 7·5% [4·6-11·9]; capreomycin: 8·2% [6·3-10·7]), aminosalicylic acid (11·6% [7·1-18·3]), and linezolid (14·1% [9·9-19·6]). Risk of bias in selection of studies was judged to be low because there were no important differences between included and excluded studies. Variability between studies was significant for most outcomes analysed. INTERPRETATION: Fluoroquinolones, clofazimine, and bedaquiline had the lowest incidence of adverse events leading to permanent drug discontinuation, whereas second-line injectable drugs, aminosalicylic acid, and linezolid had the highest incidence. These results suggest that close monitoring of adverse events is important for patients being treated for multidrug-resistant tuberculosis. Our results also underscore the urgent need for safer and better-tolerated drugs to reduce morbidity from treatment itself for patients with multidrug-resistant tuberculosis. FUNDING: Canadian Institutes of Health Research, Centers for Disease Control and Prevention (USA), American Thoracic Society, European Respiratory Society, and Infectious Diseases Society of America.

Design, synthesis and evaluation of the antibacterial activity of new Linezolid dipeptide-type analogues.

Worldwide studies towards development of new drugs with a lower rate in emergence of bacterial resistance have been conducted. The molecular docking analysis gives a possibility to predict the activity of new compounds before to perform their synthesis. In this work, the molecular docking analysis of 64 Linezolid dipeptide-type analogues was performed to predict their activity. The most negative scores correspond to six Fmoc-protected analogues (9as, 9bs, 9bu, 10as, 10ax and 10ay) where Fmoc group interacts in PTC for Linezolid. Twenty-six different Fmoc-protected Linezolid dipeptide-type analogues 9(as-bz) and 10(as-bz) were synthesized and tested in antimicrobial experiments. Compounds 9as, 9ay, 9ax, 10as, 10ay and 9bu show significant activity against group A Streptococcus clinical isolated. Analogue 10ay also display high activity against ATCC 25923 Staphylococcus aureus strain and MRSA-3, MRSA-4 and MRSA-5 clinical isolates, with MIC values lower than Linezolid. The highest activity against multidrug-resistant clinical isolates of Mycobacterium tuberculosis was exhibited by 9bu. Finally, a cytotoxicity assay with ARPE-19 human cells revealed a non-cytotoxic effect of 9bu and 10ay at 50 and 25 µM, respectively.

Surveillance of adverse events in the treatment of drug-resistant tuberculosis: first global report.

The World Health Organization (WHO) recommends that countries implement pharmacovigilance and collect information on active drug safety monitoring (aDSM) and management of adverse events.The aim of this prospective study was to evaluate the frequency and severity of adverse events to anti-tuberculosis (TB) drugs in a cohort of consecutive TB patients treated with new (i.e. bedaquiline, delamanid) and repurposed (i.e. clofazimine, linezolid) drugs, based on the WHO aDSM project. Adverse events were collected prospectively after attribution to a specific drug together with demographic, bacteriological, radiological and clinical information at diagnosis and during therapy. This interim analysis included patients who completed or were still on treatment at time of data collection.Globally, 45 centres from 26 countries/regions reported 658 patients (68.7% male, 4.4% HIV co-infected) treated as follows: 87.7% with bedaquiline, 18.4% with delamanid (6.1% with both), 81.5% with linezolid and 32.4% with clofazimine. Overall, 504 adverse event episodes were reported: 447 (88.7%) were classified as minor (grade 1-2) and 57 (11.3%) as serious (grade 3-5). The majority of the 57 serious adverse events reported by 55 patients (51 out of 57, 89.5%) ultimately resolved. Among patients reporting serious adverse events, some drugs held responsible were discontinued: bedaquiline in 0.35% (two out of 577), delamanid in 0.8% (one out of 121), linezolid in 1.9% (10 out of 536) and clofazimine in 1.4% (three out of 213) of patients. Serious adverse events were reported in 6.9% (nine out of 131) of patients treated with amikacin, 0.4% (one out of 221) with ethionamide/prothionamide, 2.8% (15 out of 536) with linezolid and 1.8% (eight out of 498) with cycloserine/terizidone.The aDSM study provided valuable information, but implementation needs scaling-up to support patient-centred care.

Inyectables de segunda línea para el tratamiento de la tuberculosis multidrogorresistente: ¿Porque los seguimos utilizando? / Second-Line Injectable Drugs for the Treatment of Multidrug-Resistant Tuberculosis. Why do We Keep Using Them?

Los inyectables de segunda línea (kanamicina, amikacina y capreomicina) han sido una parte integral del régimen de tratamiento de la tuberculosis multirresistente (MDR-TB) durante décadas, a pesar de su conocida toxicidad auditiva y renal. Desafortunadamente, muchos países no han incluido medicamentos nuevos o reutilizados en sus regímenes de tratamiento para la MDR-TB y aún dependen de los inyectables de segunda línea (ISL) para incluir suficientes medicamentos eficaces en sus regímenes. Nuestro objetivo es presentar la frecuencia y la gravedad de la ototoxicidad asociada con el uso de ISL que solo se detectó inicialmente mediante audiometría. Se realizó un análisis retrospectivo que incluyó a todos los pacientes que recibieron regímenes de tratamiento con ISL durante el período 2010-2017 en una clínica de tuberculosis en México. Se incluyeron 47 pacientes que recibieron ISL (amikacina, kanamicina o capreomicina). Su edad media fue de 40,3 ± 16,4 años. Treinta y un pacientes (63.3%) habían recibido tratamiento para la tuberculosis en el pasado. El ISL más utilizado fue la amikacina en 33 casos (67.3%), seguido de capreomicina en 14 casos (28.6%). Veintisiete pacientes (55.1%) desarrollaron una pérdida auditiva significativa (> 40 dB); 13 pacientes (26.5%) desarrollaron pérdida auditiva grave o profunda (> 70 dB). La pérdida de audición grave es una complicación frecuente, irreversible y ahora innecesaria del tratamiento de MDR / RR-TB, ya que el ISL puede y debe ser sustituido por medicamentos nuevos y reutilizados más efectivos y mucho menos tóxicos.

Second-Line Injectable Drugs for the Treatment of Multidrug-Resistant Tuberculosis: Why do We Keep Using Them?

Second-line injectable drugs (kanamycin, amikacin and capreomycin) have been an integral part of the multidrug-resistant tuberculosis (MDR-TB) treatment regimen for decades, despite their known association with renal failure and ototoxicity. Unfortunately, there are many countries that haven't included new or reused drugs in their treatment regimens for MDR-TB and still depend on second-line injectable drugs (SLIDs) in order to have a sufficient amount of effective drugs in their regimens. Our purpose is to show the frequency and severity of the ototoxicity associated with the use of SLIDs only detected initially by means of an audiometry. We conducted a retrospective analysis including all the patients who received treatment regimens with SLIDs from 2010 to 2017 in a tuberculosis clinic in Mexico. 47 patients who received SLIDs (amikacin, kanamycin, capreomycin) were included in the analysis. The mean age was 40.3 ± 16.4 years. Thirty one patients (63.3%) had previously received TB treatment in the past. The most commonly used SLID was amikacin in 33 cases (67.3%), followed by capreomycin in 14 cases (28.6%). Twenty seven patients (55.1%) developed significant hearing loss (> 40 dB), and 13 patients (26.5%) developed severe or profound hearing loss (> 70 dB). Severe hearing loss is a common, irreversible and now unnecessary complication of the MDR/RR-TB (multidrug- and rifampicin-resistant tuberculosis) treatment, since the SLIDs may and shall be substituted by new and reused, more effective and far less toxic drugs.

Surveillance of adverse events in the treatment of drug-resistant tuberculosis: A global feasibility study.

The World Health Organization launched a global initiative, known as aDSM (active TB drug safety monitoring and management) to better describe the safety profile of new treatment regimens for drug-resistant tuberculosis (TB) in real-world settings. However, comprehensive surveillance is difficult to implement in several countries. The aim of the aDSM project is to demonstrate the feasibility of implementing national aDSM registers and to describe the type and the frequency of adverse events (AEs) associated with exposure to the new anti-TB drugs. Following a pilot study carried out in 2016, official involvement of TB reference centres/countries into the project was sought and cases treated with bedaquiline- and/or delamanid-containing regimens were consecutively recruited. AEs were prospectively collected ensuring potential attribution of the AE to a specific drug based on its known safety profile. A total of 309 cases were fully reported from 41 centres in 27 countries (65% males; 268 treated with bedaquiline, 20 with delamanid, and 21 with both drugs) out of an estimated 781 cases the participating countries had committed to report by the first quarter of 2019.

Coccidioidomycosis in Latin America.

Coccidioidomycosis is a highly prevalent systemic mycosis in Latin America and has been reported (human and zoonotic cases) in México, Guatemala, Honduras, Colombia, Venezuela, Brazil, Paraguay, Bolivia, and Argentina. The incidence of coccidioidomycosis in Latin America is unknown due to lack of clinical awareness and limited access to laboratory diagnosis. Coccidioidomycosis is as prevalent in Mexico as in the endemic regions of the United States. The number of cases reported in Brazil and Argentina has progressively increased during the last decade, including areas that were not considered as endemic. Genetic studies have shown that the prevalent species in Latin America is Coccidioides posadasii. Coccidioides immitis has been reported sporadically in indigenous cases from Mexico and Colombia. Coccidioidomycosis and tuberculosis share some risk factors such as immunosuppression and residing in areas endemic for these conditions, so their coexistence in the same patient is not uncommon in Latin America. In most regions, clinical diagnosis of coccidioidomycosis is based on direct sputum examination and histopathology results from biopsies or autopsies. This would explain why primary coccidioidomycosis is rarely diagnosed, and most cases published are about chronic pulmonary or disseminated disease.

Unexpected Pregnancy during Treatment of Multidrug-resistant Tuberculosis.

Several drugs used in the treatment of multidrug-resistant tuberculosis (MDR-TB) have been reported as teratogenic. Treatment of such cases during gestation is disputable. Some experts favor the termination of pregnancy, whereas others suggest reducing the dose of teratogenic drugs or even suspending the regimen during pregnancy. There have been no clinical trials on the subject, but case reports and case series show excellent outcomes for children exposed during pregnancy to second-line agents, indicating that aggressive management of gestational MDR-TB may benefit not only the mother but also the fetus. We present a case of pregnancy in a teenager while she was under treatment for MDR-TB and continued with full treatment and nevertheless delivered a healthy child.

Clinical challenges in the era of multiple and extensively drugresistant tuberculosis

In 2014, there were 480 000 new cases of multidrug-resistant tuberculosis (MDR-TB) around the world, but only 25% of them were diagnosed and reported. Drug resistance in TB is necessarily a laboratory diagnosis. An urgent priority in everyday practice is to diagnose tuberculosis and rule out drug resistance as quickly and as accurately as possible. However, worldwide, only 12% of new bacteriologically confirmed TB cases and 58% of previously treated TB cases were tested for drug resistance in 2014. New tools for diagnosis of TB and drug-resistant TB have been introduced for clinical practice during the past decade. Those new tools can detect and identify drug resistance to antituberculosis drugs in less than 24 hours, and they should be urgently integrated into clinical practice, especially in high-burden regions. Ongoing transmission of TB generates new infections, and this infected population is the inexhaustible source of new TB cases. If we are really determined to stop the global TB epidemic, we need to treat active cases and also halt the transmission of the infection. The only strategy for preventing the development of active disease in individuals with subclinical infection is to give treatment for this latent infection. Global control of TB requires a huge investment of funds to address current detection and treatment gaps. We must reconsider our current strategy and combine social components with biomedical interventions. This will require the development of alliances between government and civil society, as well as leadership and true political commitment at the highest level of government.

En el 2014 se presentaron 480 000 nuevos casos de tuberculosis multirresistente, pero solo se diagnosticó y notificó 25% de ellos. La farmacorresistencia en la tuberculosis se diagnostica necesariamente por medio de pruebas de laboratorio. En la práctica clínica diaria resulta urgente y prioritario poder diagnosticar la tuberculosis y descartar la farmacorresistencia con la mayor rapidez y exactitud posibles. Sin embargo, en todo el mundo, apenas 12% de los nuevos casos de tuberculosis bacteriológicamente confirmados y 58% de los casos ya tratados se sometieron a prueba de farmacorresistencia en el 2014. En los diez últimos años se han dado a conocer nuevas herramientas para el diagnóstico de la tuberculosis y la tuberculosis farmacorresistente en la práctica clínica. Esas herramientas nuevas permiten detectar e identificar la resistencia a medicamentos antituberculosos en menos de 24 horas, por lo que deberían integrarse urgentemente a la práctica clínica, especialmente en las regiones con una carga de enfermedad alta. La persistencia de la transmisión de la tuberculosis genera nuevas infecciones, y la población infectada es una fuente inagotable de nuevos casos de esta enfermedad. Si estamos realmente decididos a poner fin a la epidemia mundial de la tuberculosis, tenemos que tratar los casos activos y también detener la transmisión de la infección. La única estrategia para prevenir la aparición de la enfermedad activa en personas con infección subclínica es administrar tratamiento contra esta infección latente. El control mundial de la tuberculosis requiere una enorme inversión de fondos para cerrar las brechas existentes en la detección y el tratamiento. Debemos reconsiderar nuestra estrategia actual y combinar los componentes sociales con las intervenciones biomédicas. Esto obliga a conformar alianzas entre el gobierno y la sociedad civil, y requiere del liderazgo y de un verdadero compromiso político de las más altas instancias gubernamentales.

Em 2014, houve 480 mil novos casos de tuberculose (TB) resistente a múltiplos medicamentos, porém apenas 25% foram diagnosticados e notificados. A resistência aos medicamentos na TB requer necessariamente que seja feito um diagnóstico laboratorial. É prioridade na prática clínica diária diagnosticar a TB e descartar a resistência aos medicamentos o mais rápido e com maior precisão possível. Porém, em 2014, o teste da resistência aos medicamentos foi realizado mundialmente em apenas 12% dos novos casos de TB com confirmação bacteriológica e em 58% dos casos de TB com tratamento anterior. Novas ferramentas para o diagnóstico de TB e TB resistente a múltiplos a medicamentos foram introduzidas na prática clínica na última década. São ferramentas com capacidade de detectar e identificar a resistência aos medicamentos antituberculose em menos de 24 horas e, portanto, é imprescindível que sejam integradas à prática clínica, sobretudo em regiões de elevada carga da doença. A transmissão contínua da TB causa novas infecções, sendo a população infectada uma fonte inesgotável de novos casos da doença. Se estivermos realmente determinados a conter a epidemia global de TB, é preciso tratar os casos ativos e interromper a transmissão da infecção. A única estratégia para prevenir o surgimento de doença ativa em indivíduos com infecção subclínica é o tratamento da infecção latente. O controle global da TB requer um enorme investimento financeiro para sanar as falhas atuais de detecção e tratamento da doença. A estratégia atual deve ser reexaminada e combinar componentes sociais e intervenções biomédicas. Faz-se necessário forjar alianças entre o governo e a sociedade civil bem como assumir a liderança e o firme compromisso no mais alto nível político.

Whole genome sequencing of Mycobacterium bovis to obtain molecular fingerprints in human and cattle isolates from Baja California, Mexico.

OBJECTIVES: To determine genetic diversity by comparing the whole genome sequences of cattle and human Mycobacterium bovis isolates from Baja California. METHODS: A whole genome sequencing strategy was used to obtain the molecular fingerprints of 172 isolates of M. bovis obtained from Baja California, Mexico; 155 isolates were from cattle and 17 isolates were from humans. Spoligotypes were characterized in silico and single nucleotide polymorphism (SNP) differences between the isolates were evaluated. RESULTS: A total of 12 M. bovis spoligotype patterns were identified in cattle and humans. Two predominant spoligotypes patterns were seen in both cattle and humans: SB0145 and SB1040. The SB0145 spoligotype represented 59% of cattle isolates (n=91) and 65% of human isolates (n=11), while the SB1040 spoligotype represented 30% of cattle isolates (n=47) and 30% of human isolates (n=5). When evaluating SNP differences, the human isolates were intimately intertwined with the cattle isolates. CONCLUSIONS: All isolates from humans had spoligotype patterns that matched those observed in the cattle isolates, and all human isolates shared common ancestors with cattle in Baja California based on SNP analysis. This suggests that most human tuberculosis caused by M. bovis in Baja California is derived from M. bovis circulating in Baja California cattle. These results reinforce the importance of bovine tuberculosis surveillance and control in this region.

Molecular epidemiology of Mycobacterium tuberculosis in Baja California, Mexico: A result of human migration?

The State of Baja California (BC) exhibits the highest incidence and prevalence rates of tuberculosis (TB), and multidrug-resistant TB (MDR-TB) in Mexico. However information about the circulation of M. tuberculosis lineages in BC and Mexico as a whole is limited. Here, we describe the genetic relationship and genetic diversity among M. tuberculosis clinical isolates (n=140) collected in BC between October 2009 and April 2011 with other regions of Mexico, the United States, and Latin America. All specimens were genotyped based on 24 mycobacterial interspersed repetitive units (MIRU)-variable number of tandem repeats (VNTR) loci. Population structure and minimum spanning tree (MST) analyses were used to assess the genetic diversity and distribution of BC isolates in comparison to USA and South America strains. Among the nine lineages observed, LAM, Haarlem and S were the most frequent identified in BC. Population structure analysis clustered most BC isolates (41%) into three distinctive groups that included strains from San Diego and South America, whereas other BC strains (22%) clustered with other Mexican strains. A subset of isolates (12%) seemed to be autochthonous of BC, while 25% were cosmopolitan and grouped into multiple clusters. It is highly likely that the TB genetic structure observed in BC is due to human migration. Additional studies are required to determine the mechanism involved in the phylogeographic distribution of M. tuberculosis in Mexico. Implementation of domestic molecular TB surveillance programs is required to better understand the molecular epidemiology of TB not only in the region but at the national level.

Clinical challenges in the era of multiple and extensively drug-resistant tuberculosis.

In 2014, there were 480 000 new cases of multidrug-resistant tuberculosis (MDR-TB) around the world, but only 25% of them were diagnosed and reported. Drug resistance in TB is necessarily a laboratory diagnosis. An urgent priority in everyday practice is to diagnose tuberculosis and rule out drug resistance as quickly and as accurately as possible. However, worldwide, only 12% of new bacteriologically confirmed TB cases and 58% of previously treated TB cases were tested for drug resistance in 2014. New tools for diagnosis of TB and drug-resistant TB have been introduced for clinical practice during the past decade. Those new tools can detect and identify drug resistance to antituberculosis drugs in less than 24 hours, and they should be urgently integrated into clinical practice, especially in high-burden regions. Ongoing transmission of TB generates new infections, and this infected population is the inexhaustible source of new TB cases. If we are really determined to stop the global TB epidemic, we need to treat active cases and also halt the transmission of the infection. The only strategy for preventing the development of active disease in individuals with subclinical infection is to give treatment for this latent infection. Global control of TB requires a huge investment of funds to address current detection and treatment gaps. We must reconsider our current strategy and combine social components with biomedical interventions. This will require the development of alliances between government and civil society, as well as leadership and true political commitment at the highest level of government.

En el 2014 se presentaron 480 000 nuevos casos de tuberculosis multirresistente, pero solo se diagnosticó y notificó 25% de ellos. La farmacorresistencia en la tuberculosis se diagnostica necesariamente por medio de pruebas de laboratorio. En la práctica clínica diaria resulta urgente y prioritario poder diagnosticar la tuberculosis y descartar la farmacorresistencia con la mayor rapidez y exactitud posibles. Sin embargo, en todo el mundo, apenas 12% de los nuevos casos de tuberculosis bacteriológicamente confirmados y 58% de los casos ya tratados se sometieron a prueba de farmacorresistencia en el 2014.En los diez últimos años se han dado a conocer nuevas herramientas para el diagnóstico de la tuberculosis y la tuberculosis farmacorresistente en la práctica clínica. Esas herramientas nuevas permiten detectar e identificar la resistencia a medicamentos antituberculosos en menos de 24 horas, por lo que deberían integrarse urgentemente a la práctica clínica, especialmente en las regiones con una carga de enfermedad alta.La persistencia de la transmisión de la tuberculosis genera nuevas infecciones, y la población infectada es una fuente inagotable de nuevos casos de esta enfermedad. Si estamos realmente decididos a poner fin a la epidemia mundial de la tuberculosis, tenemos que tratar los casos activos y también detener la transmisión de la infección. La única estrategia para prevenir la aparición de la enfermedad activa en personas con infección subclínica es administrar tratamiento contra esta infección latente.El control mundial de la tuberculosis requiere una enorme inversión de fondos para cerrar las brechas existentes en la detección y el tratamiento. Debemos reconsiderar nuestra estrategia actual y combinar los componentes sociales con las intervenciones biomédicas. Esto obliga a conformar alianzas entre el gobierno y la sociedad civil, y requiere del liderazgo y de un verdadero compromiso político de las más altas instancias gubernamentales.

Em 2014, houve 480 mil novos casos de tuberculose (TB) resistente a múltiplos medicamentos, porém apenas 25% foram diagnosticados e notificados. A resistência aos medicamentos na TB requer necessariamente que seja feito um diagnóstico laboratorial. É prioridade na prática clínica diária diagnosticar a TB e descartar a resistência aos medicamentos o mais rápido e com maior precisão possível. Porém, em 2014, o teste da resistência aos medicamentos foi realizado mundialmente em apenas 12% dos novos casos de TB com confirmação bacteriológica e em 58% dos casos de TB com tratamento anterior.Novas ferramentas para o diagnóstico de TB e TB resistente a múltiplos a medicamentos foram introduzidas na prática clínica na última década. São ferramentas com capacidade de detectar e identificar a resistênciaaos medicamentos antituberculose em menos de 24 horas e, portanto, é imprescindível que sejam integradas à prática clínica, sobretudo em regiões de elevada carga da doença.A transmissão contínua da TB causa novas infecções, sendo a população infectada uma fonte inesgotável de novos casos da doença. Se estivermos realmente determinados a conter a epidemia global de TB, é preciso tratar os casos ativos e interromper a transmissão da infecção. A única estratégia para prevenir o surgimento de doença ativa em indivíduos com infecção subclínica é o tratamento da infecção latente.O controle global da TB requer um enorme investimento financeiro para sanar as falhas atuais de detecção e tratamento da doença. A estratégia atual deve ser reexaminada e combinar componentes sociais e intervenções biomédicas. Faz-se necessário forjar alianças entre o governo e a sociedade civil bem como assumir a liderança e o firme compromisso no mais alto nível político.

Molecular characterization of multidrug-resistant Mycobacterium tuberculosis isolates from high prevalence tuberculosis states in Mexico.

Mexico is one of the most important contributors of multidrug resistance tuberculosis (MDR-TB) in Latin-America, however little is known about the molecular characteristics of these strains. For this reason, the objective of this work was to determine the genotype and characterize polymorphisms in genes associated with resistance to rifampicin, isoniazid, and second-line drugs in isolates from two regions of Mexico with high prevalence of drug resistant tuberculosis. Clinical isolates from individuals with confirmed MDR-TB were genotyped using MIRU-VNTR 12 loci. To characterize the polymorphisms in genes associated with resistance to rifampicin, isoniazid and second-line drugs; rpoB, katG, inhA, rrs, eis, gyrA, gyrB and tlyA were sequenced. 22 (41%) of the 54 MDR-TB isolates recovered were from the state of Baja California, while 32 (59%) were from Veracruz. The results show the katGS315T mutation was observed in 20% (11/54) of the isolates, while rpoBS315L was present in 33% (18/54). rrs had three polymorphisms (T1239C, ntA1401C and ntA1401G), gyrB presented no modifications, whereas gyrA showed five (S95T, F60Y, A90V, S91P and P124A), eis two (G-10A and A431G) and tlyA one (insertion at codon 67). Only 20% (11/54) of isolates were confirmed as MDR-TB by sequencing, and no mutations at any of the genes sequenced were observed in 43% (23/54) of the strains. Two isolates were recognized with the proper set of mutations like pre-XDR and one was XDR-TB. Eighteen isolates were classified as orphans and the remaining thirty-six were distributed in fourteen lineages, the most frequent were S (11%), Haarlem (9%), Ghana (9%) and LAM (7%). Out of the fourteen clusters identified, seven included unknown genotypes and nine had lineages. This is one of the most detailed analyses of genotypic characteristics and mutations associated with drug resistance to first and second-line drugs in MDR-TB isolates from Mexico. An important genetic variability and significant discrepancy between phenotypic tests and polymorphisms was observed. Our results set the need to screen additional loci as well as implement a molecular epidemiological surveillance system of MDR-TB in the country.

Clinical challenges in the era of multiple and extensively drug-resistant tuberculosis / Retos clínicos en la era de la tuberculosis multirresistente y extensamente resistente / Desafios clínicos na era da tuberculose com resistência ampla a múltiplos medicamentos

ABSTRACT In 2014, there were 480 000 new cases of multidrug-resistant tuberculosis (MDR-TB) around the world, but only 25% of them were diagnosed and reported. Drug resistance in TB is necessarily a laboratory diagnosis. An urgent priority in everyday practice is to diagnose tuberculosis and rule out drug resistance as quickly and as accurately as possible. However, worldwide, only 12% of new bacteriologically confirmed TB cases and 58% of previously treated TB cases were tested for drug resistance in 2014. New tools for diagnosis of TB and drug-resistant TB have been introduced for clinical practice during the past decade. Those new tools can detect and identify drug resistance to antituberculosis drugs in less than 24 hours, and they should be urgently integrated into clinical practice, especially in high-burden regions. Ongoing transmission of TB generates new infections, and this infected population is the inexhaustible source of new TB cases. If we are really determined to stop the global TB epidemic, we need to treat active cases and also halt the transmission of the infection. The only strategy for preventing the development of active disease in individuals with subclinical infection is to give treatment for this latent infection. Global control of TB requires a huge investment of funds to address current detection and treatment gaps. We must reconsider our current strategy and combine social components with biomedical interventions. This will require the development of alliances between government and civil society, as well as leadership and true political commitment at the highest level of government.

RESUMEN En el 2014 se presentaron 480 000 nuevos casos de tuberculosis multirresistente, pero solo se diagnosticó y notificó 25% de ellos. La farmacorresistencia en la tuberculosis se diagnostica necesariamente por medio de pruebas de laboratorio. En la práctica clínica diaria resulta urgente y prioritario poder diagnosticar la tuberculosis y descartar la farmacorresistencia con la mayor rapidez y exactitud posibles. Sin embargo, en todo el mundo, apenas 12% de los nuevos casos de tuberculosis bacteriológicamente confirmados y 58% de los casos ya tratados se sometieron a prueba de farmacorresistencia en el 2014. En los diez últimos años se han dado a conocer nuevas herramientas para el diagnóstico de la tuberculosis y la tuberculosis farmacorresistente en la práctica clínica. Esas herramientas nuevas permiten detectar e identificar la resistencia a medicamentos antituberculosos en menos de 24 horas, por lo que deberían integrarse urgentemente a la práctica clínica, especialmente en las regiones con una carga de enfermedad alta. La persistencia de la transmisión de la tuberculosis genera nuevas infecciones, y la población infectada es una fuente inagotable de nuevos casos de esta enfermedad. Si estamos realmente decididos a poner fin a la epidemia mundial de la tuberculosis, tenemos que tratar los casos activos y también detener la transmisión de la infección. La única estrategia para prevenir la aparición de la enfermedad activa en personas con infección subclínica es administrar tratamiento contra esta infección latente. El control mundial de la tuberculosis requiere una enorme inversión de fondos para cerrar las brechas existentes en la detección y el tratamiento. Debemos reconsiderar nuestra estrategia actual y combinar los componentes sociales con las intervenciones biomédicas. Esto obliga a conformar alianzas entre el gobierno y la sociedad civil, y requiere del liderazgo y de un verdadero compromiso político de las más altas instancias gubernamentales.

RESUMO Em 2014, houve 480 mil novos casos de tuberculose (TB) resistente a múltiplos medicamentos, porém apenas 25% foram diagnosticados e notificados. A resistência aos medicamentos na TB requer necessariamente que seja feito um diagnóstico laboratorial. É prioridade na prática clínica diária diagnosticar a TB e descartar a resistência aos medicamentos o mais rápido e com maior precisão possível. Porém, em 2014, o teste da resistência aos medicamentos foi realizado mundialmente em apenas 12% dos novos casos de TB com confirmação bacteriológica e em 58% dos casos de TB com tratamento anterior. Novas ferramentas para o diagnóstico de TB e TB resistente a múltiplos a medicamentos foram introduzidas na prática clínica na última década. São ferramentas com capacidade de detectar e identificar a resistência aos medicamentos antituberculose em menos de 24 horas e, portanto, é imprescindível que sejam integradas à prática clínica, sobretudo em regiões de elevada carga da doença. A transmissão contínua da TB causa novas infecções, sendo a população infectada uma fonte inesgotável de novos casos da doença. Se estivermos realmente determinados a conter a epidemia global de TB, é preciso tratar os casos ativos e interromper a transmissão da infecção. A única estratégia para prevenir o surgimento de doença ativa em indivíduos com infecção subclínica é o tratamento da infecção latente. O controle global da TB requer um enorme investimento financeiro para sanar as falhas atuais de detecção e tratamento da doença. A estratégia atual deve ser reexaminada e combinar componentes sociais e intervenções biomédicas. Faz-se necessário forjar alianças entre o governo e a sociedade civil bem como assumir a liderança e o firme compromisso no mais alto nível político.

Performance of the G4 Xpert® MTB/RIF assay for the detection of Mycobacterium tuberculosis and rifampin resistance: a retrospective case-control study of analytical and clinical samples from high- and low-tuberculosis prevalence settings.

BACKGROUND: The Xpert® MTB/RIF (Xpert) assay is a rapid PCR-based assay for the detection of Mycobacterium tuberculosis complex DNA (MTBc) and mutations associated with rifampin resistance (RIF). An updated version introduced in 2011, the G4 Xpert, included modifications to probe B and updated analytic software. METHODS: An analytical study was performed to assess Xpert detection of mutations associated with rifampin resistance in rifampin-susceptible and -resistant isolates. A clinical study was performed in which specimens from US and non-US persons suspected of tuberculosis (TB) were tested to determine Xpert performance characteristics. All specimens underwent smear microscopy, mycobacterial culture, conventional drug-susceptibility testing and Xpert testing; DNA from isolates with discordant rifampin resistance results was sequenced. RESULTS: Among 191 laboratory-prepared isolates in the analytical study, Xpert sensitivity for detection of rifampin resistance associated mutations was 97.7% and specificity was 90.8%, which increased to 99.0% after DNA sequencing analysis of the discordant samples. Of the 1,096 subjects in the four clinical studies, 49% were from the US. Overall, Xpert detected MTBc in 439 of 468 culture-positive specimens for a sensitivity of 93.8% (95% confidence interval [CI]: 91.2%-95.7%) and did not detect MTBc in 620 of 628 culture-negative specimens for a specificity of 98.7% (95% CI: 97.5%-99.4%). Sensitivity was 99.7% among smear-positive cases, and 76.1% among smear-negative cases. Non-determinate MTBc detection and false-positive RIF resistance results were low (1.2 and 0.9%, respectively). CONCLUSIONS: The updated Xpert assay retained the high sensitivity and specificity of the previous assay versions and demonstrated low rates of non-determinate and RIF resistance false positive results.

Alternativas actuales para la confirmación diagnóstica de la tuberculosis en pacientes pediátricos / Current alternatives for diagnostic confirmation of pediatric tuberculosis

Every year, more than half a million of children develop tuberculosis worldwide, representing 7 percent of all tuberculosis cases. The biggest diagnostic obstacle in pediatric tuberculosis is microbiology confirmation. Clinical diagnosis in children is unreliable because signs and symptoms lack specificity. Several diagnostic alternatives have been developed in the past two decades, including light-emitting diodes (LED) microscopy which is more sensitive and faster than conventional microscopy, automated liquid culture methods that have increased the yield and shorten turn around report times, and finally the molecular biology assays, like the Xpert MTB/RIF, a fully automated polymerase chain reaction system that can identify M. tuberculosis complex and resistance to rifampicin in about 2 hours, and the GenoType assay that can identify M. tuberculosis complex and detect resistance to rifampicin and isoniazid in less than 24 hours.

Anualmente más de medio millón de niños desarrolla tuberculosis, representando el 7 por ciento de todos los casos a nivel mundial. La dificultad en la confirmación diagnóstica constituye el principal reto en el paciente pediátrico. El diagnóstico clínico en niños es complejo, ya que los signos y síntomas son poco sensibles y específicos. En la últimas dos décadas se han desarrollado alternativas para diagnóstico, entre las que se incluyen la microscopía LED, más sensible que la microscopía convencional, los sistemas de cultivo líquido automatizados que han mejorado el rendimiento y reducido los tiempos para reporte y los métodos moleculares, en donde destacan el Xpert MTB/RIF, sistema automatizado de reacción en cadena de la polimerasa que puede detectar el Mycobacterium tuberculosis y simultáneamente la resistencia a rifampicina en solo dos horas, así como el ensayo GenoType, que permite la identificación y detección de resistencia a isoniacida y rifampicina en menos de un día.

Primary drug resistance in a region with high burden of tuberculosis. A critical problem.

OBJECTIVE: To determine rates of drug resistance in new cases of pulmonary tuberculosis in a region with a high burden of the disease. MATERIALS AND METHODS: New case suspects were referred for drug susceptibility testing. RESULTS: 28.9% of new cases were resistant to at least one first line drug; 3.9% had a multidrug-resistant strain, 15.6% a monoresistant strain and 9.4% a polyresistant strain. CONCLUSION: Our rate of drug resistant tuberculosis in new cases is very high; this has important clinical implications, since even monoresistance can have a negative impact on the outcome of new cases treated empirically with a six month regimen.

Mutation at embB codon 306, a potential marker for the identification of multidrug resistance associated with ethambutol in Mycobacterium tuberculosis.

Ethambutol inhibits arabinogalactan and lipoarabinomannan biosynthesis in mycobacteria. The occurrence of mutations in embB codon 306 in ethambutol-susceptible isolates and their absence in resistant isolates has raised questions regarding the utility of this codon as a potential marker for resistance against ethambutol. The characterization of mutations on embB 306 will contribute to a better understanding of the mechanisms of resistance to this drug; therefore, the purpose of this study was to investigate the association between embB 306 mutations and first-line drug resistance profiles in tuberculosis isolates. We sequenced the region surrounding the embB 306 codon in 175 tuberculosis clinical isolates, divided according to drug sensitivity, in three groups: 110 were resistant to at least one first-line drug, of which 61 were resistant to ethambutol (EMB(r)), 49 were sensitive to ethambutol (EMB(s)) but were resistant to another drug, and 65 were pansensitive isolates (P(s)). The associations between embB 306 mutations and phenotypic resistance to all first-line drugs were determined, and their validity and safety as a diagnostic marker were assessed. One of the P(s) isolates (1/65), one of the EMB(s) isolates (1/49), and 20 of the EMB(r) isolates (20/61) presented with an embB 306 mutation. Four different single-nucleotide polymorphisms (SNPs) at embB 306 were associated with simultaneous resistance to ethambutol, isoniazid, and rifampin (odds ratio [OR], 17.7; confidence interval [CI], 5.6 to 56.1) and showed a positive predictive value of 82%, with a specificity of 97% for diagnosing multidrug resistance associated with ethambutol, indicating its potential as a molecular marker for several drugs.