Tuberculosis in Spain: An opinion paper

This document is the result of the deliberations of the Committee on Emerging Pathogens and COVID-19 of the Illustrious Official College of Physicians of Madrid (ICOMEM) regarding the current situation of tuberculosis, particularly in Spain. We have reviewed aspects such as the evolution of its incidence, the populations currently most exposed and the health care circuits for the care of these patients in Spain. We have also discussed latent tuberculosis, the reality of extrapulmonary disease in the XXI century and the means available in daily practice for the diagnosis of both latent and active forms. The contribution of molecular biology, which has changed the perspective of this disease, was another topic of discussion. The paper tries to put into perspective both the classical drugs and their resistance figures and the availability and indications of the new ones. In addition, the reality of direct observation in the administration of antituberculosis drugs has been discussed. All this revolution is making it possible to shorten the treatment time for tuberculosis, a subject that has also been reviewed. If everything is done well, the risk of relapse of tuberculosis is small but it exists. On the other hand, many special situations have been discussed in this paper, such as tuberculosis in pediatric age and tuberculosis as a cause for concern in surgery and intensive care. The status of the BCG vaccine and its present indications as well as the future of new vaccines to achieve the old dream of eradicating this disease have been discussed. Finally, the ethical and medicolegal implications of this disease are not a minor issue and our situation in this regard has been reviewed.

Advantages and disadvantages of maintaining the mandatory use of masks in health centers and nursing homes in Spain. How and when is it justified to maintain it?

We address the advantages and disadvantages of maintaining the mandatory use of masks in health centers and nursing homes in the current epidemiological situation in Spain and after the declaration of the World Health Organization on May 5, 2023 of the end of COVID-19 as public health emergency. We advocate for prudence and flexibility, respecting the individual decision to wear a mask and emphasizing the need for its use when symptoms suggestive of a respiratory infection appear, in situations of special vulnerability (such as immunosuppression), or when caring for patients with those infections. At present, given the observed low risk of severe COVID-19 and the low transmission of other respiratory infections, we believe that it is disproportionate to maintain the mandatory use of masks in a general way in health centers and nursing homes. However, this could change depending on the results of epidemiological surveillance and it would be necessary to reconsider returning to the obligation in periods with a high incidence of respiratory infections.

Clinical standards for the management of adverse effects during treatment for TB

BACKGROUND: Adverse effects (AE) to TB treatment cause morbidity, mortality and treatment interruption. The aim of these clinical standards is to encourage best practise for the diagnosis and management of AE.METHODS: 65/81 invited experts participated in a Delphi process using a 5-point Likert scale to score draft standards.RESULTS: We identified eight clinical standards. Each person commencing treatment for TB should: Standard 1, be counselled regarding AE before and during treatment; Standard 2, be evaluated for factors that might increase AE risk with regular review to actively identify and manage these; Standard 3, when AE occur, carefully assessed and possible allergic or hypersensitivity reactions considered; Standard 4, receive appropriate care to minimise morbidity and mortality associated with AE; Standard 5, be restarted on TB drugs after a serious AE according to a standardised protocol that includes active drug safety monitoring. In addition: Standard 6, healthcare workers should be trained on AE including how to counsel people undertaking TB treatment, as well as active AE monitoring and management; Standard 7, there should be active AE monitoring and reporting for all new TB drugs and regimens; and Standard 8, knowledge gaps identified from active AE monitoring should be systematically addressed through clinical research.CONCLUSION: These standards provide a person-centred, consensus-based approach to minimise the impact of AE during TB treatment.

Clinical standards for drug-susceptible pulmonary TB

BACKGROUND: The aim of these clinical standards is to provide guidance on 'best practice´ for diagnosis, treatment and management of drug-susceptible pulmonary TB (PTB).METHODS: A panel of 54 global experts in the field of TB care, public health, microbiology, and pharmacology were identified; 46 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all 46 participants.RESULTS: Seven clinical standards were defined: Standard 1, all patients (adult or child) who have symptoms and signs compatible with PTB should undergo investigations to reach a diagnosis; Standard 2, adequate bacteriological tests should be conducted to exclude drug-resistant TB; Standard 3, an appropriate regimen recommended by WHO and national guidelines for the treatment of PTB should be identified; Standard 4, health education and counselling should be provided for each patient starting treatment; Standard 5, treatment monitoring should be conducted to assess adherence, follow patient progress, identify and manage adverse events, and detect development of resistance; Standard 6, a recommended series of patient examinations should be performed at the end of treatment; Standard 7, necessary public health actions should be conducted for each patient. We also identified priorities for future research into PTB.CONCLUSION: These consensus-based clinical standards will help to improve patient care by guiding clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment for PTB.

Clinical standards for the assessment, management and rehabilitation of post-TB lung disease

BACKGROUND: Increasing evidence suggests that post-TB lung disease (PTLD) causes significant morbidity and mortality. The aim of these clinical standards is to provide guidance on the assessment and management of PTLD and the implementation of pulmonary rehabilitation (PR).METHODS: A panel of global experts in the field of TB care and PR was identified; 62 participated in a Delphi process. A 5-point Likert scale was used to score the initial ideas for standards and after several rounds of revision the document was approved (with 100% agreement).RESULTS: Five clinical standards were defined: Standard 1, to assess patients at the end of TB treatment for PTLD (with adaptation for children and specific settings/situations); Standard 2, to identify patients with PTLD for PR; Standard 3, tailoring the PR programme to patient needs and the local setting; Standard 4, to evaluate the effectiveness of PR; and Standard 5, to conduct education and counselling. Standard 6 addresses public health aspects of PTLD and outcomes due to PR.CONCLUSION: This is the first consensus-based set of Clinical Standards for PTLD. Our aim is to improve patient care and quality of life by guiding clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage PTLD.

Outcome of treatment of MDR-TB or drug-resistant patients treated with bedaquiline and delamanid: Results from a large global cohort

The World Health Organization (WHO) recommends countries introduce new anti-TB drugs in the treatment of multidrug-resistant tuberculosis. The aim of the study is to prospectively evaluate the effectiveness of bedaquiline (and/or delamanid)- containing regimens in a large cohort of consecutive TB patients treated globally. This observational, prospective study is based on data collected and provided by Global Tuberculosis Network (GTN) centres and analysed twice a year. All consecutive patients (including children/adolescents) treated with bedaquiline and/or delamanid were enrolled, and managed according to WHO and national guidelines. Overall, 52 centres from 29 countries/regions in all continents reported 883 patients as of January 31st 2021, 24/29 countries/regions providing data on 100% of their consecutive patients (10-80% in the remaining 5 countries). The drug-resistance pattern of the patients was severe (>30% with extensively drug-resistant -TB; median number of resistant drugs 5 (3-7) in the overall cohort and 6 (4-8) among patients with a final outcome). For the patients with a final outcome (477/883, 54.0%) the median (IQR) number of months of anti-TB treatment was 18 (13-23) (in days 553 (385-678)). The proportion of patients achieving sputum smear and culture conversion ranged from 93.4% and 92.8% respectively (whole cohort) to 89.3% and 88.8% respectively (patients with a final outcome), a median (IQR) time to sputum smear and culture conversion of 58 (30-90) days for the whole cohort and 60 (30-100) for patients with a final outcome and, respectively, of 55 (30-90) and 60 (30-90) days for culture conversion. Of 383 patients treated with bedaquiline but not delamanid, 284 (74.2%) achieved treatment success, while 25 (6.5%) died, 11 (2.9%) failed and 63 (16.5%) were lost to follow-up.

Risk factors for early mortality in patients with pulmonary tuberculosis admitted to the emergency room

BACKGROUND AND OBJECTIVES

Mortality of patients with pulmonary tuberculosis (TB) admitted to emergency departments is high. This study was aimed at analysing the risk factors associated with early mortality and designing a risk score based on simple parameters.

METHODS

This prospective case-control study enrolled patients admitted to the emergency department of a referral TB hospital. Clinical, radiological, biochemical and microbiological risk factors associated with death were compared among patients dying within one week from admission (cases) and those surviving (controls).

RESULTS

Forty-nine of 250 patients (19.6%) experienced early mortality. Multiple logistic regression analysis showed that oxygen saturation (SaO₂) ≤90%, severe malnutrition, tachypnoea, tachycardia, hypotension, advanced disease at chest radiography, severe anaemia, hyponatremia, hypoproteinemia and hypercapnia were independently and significantly associated with early mortality. A clinical scoring system was further designed to stratify the risk of death by selecting five simple parameters (SpO₂ ≤ 90%, tachypnoea, hypotension, advanced disease at chest radiography and tachycardia). This model predicted early mortality with a positive predictive value of 94.88% and a negative predictive value of 19.90%.

CONCLUSIONS

The scoring system based on simple parameters may help to refer severely ill patients early to a higher level to reduce mortality, improve success rates, minimise the need for pulmonary rehabilitation and prevent post-treatment sequelae.

Detection of katG and inhA mutations to guide isoniazid and ethionamide use for drug-resistant tuberculosis

BACKGROUND

Depending on the presence of mutations that determine isoniazid (INH) susceptibility (katG and inhA), Mycobacterium tuberculosis may be susceptible to high doses of INH or ethionamide (ETH).

OBJECTIVE

To describe the INH resistance profile and association of katG mutation with previous INH treatment and level of drug resistance based on rapid molecular drug susceptibility testing (DST) in southern Brazil and central Mozambique.

DESIGN

Descriptive study of 311 isolates from Ribeirão Preto, São Paulo, Brazil (2011-2014) and 155 isolates from Beira, Mozambique (2014-2015). Drug resistance patterns and specific gene mutations were determined using GenoType(®) MTBDRplus.

RESULTS

katG gene mutations were detected in 12/22 (54.5%) Brazilian and 32/38 (84.2%) Mozambican isolates. inhA mutations were observed in 9/22 (40.9%) isolates in Brazil and in 4/38 (10.5%) in Mozambique. Both katG and inhA mutations were detected in respectively 1/22 (5%) and 2/38 (5.2%). The difference in the frequency of katG mutations in Brazil and Mozambique was statistically significant (P = 0.04). katG mutations were present in 68.8% (33/48) of patients previously treated with INH and 31.2% (15/48) of patients without previous INH. This difference was not statistically significant (P = 0.223).

CONCLUSION

INH mutations varied geographically; molecular DST can be used to guide and accelerate decision making in the use of ETH or high doses of INH.

Factors Associated with Fatality during the Intensive Phase of Anti-Tuberculosis Treatment

OBJECTIVE

To determine the case-fatality rate (CFR) at the end of the intensive phase of tuberculosis (TB) treatment, and factors associated with fatality.

METHODS

TB patients diagnosed between 2006 and 2013 were followed-up during treatment. We computed the CFR at the end of the intensive phase of TB treatment, and the incidence of death per 100 person-days (pd) of follow-up. We performed survival analysis using the Kaplan-Meier method and Cox regression, and calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

A total of 5,182 patients were included, of whom 180 (3.5%) died; 87 of these deaths (48.3%) occurred during the intensive phase of treatment, with a CFR of 1.7%. The incidence of death was 0.028/100 pd. The following factors were associated with death during the intensive phase: being >50 years (HR = 36.9;CI:4.8-283.4); being retired (HR = 2.4;CI:1.1-5.1); having visited the emergency department (HR = 3.1;CI:1.2-7.7); HIV infection (HR = 3.4;CI:1.6-7.2); initial standard treatment with 3 drugs (HR = 2.0;CI:1.2-3.3) or non-standard treatments (HR = 2.68;CI:1.36-5.25); comprehension difficulties (HR = 2.8;CI:1.3-6.1); and smear-positive sputum (HR = 2.3-CI:1.0-4.8).

CONCLUSION

There is a non-negligible CFR during the intensive phase of TB, whose reduction should be prioritised. The CFR could be a useful indicator for evaluating TB programs.

Successful management of multidrug-resistant tuberculosis under programme conditions in the Dominican Republic

SETTING

The Dominican Republic is a high-incidence area for multidrug-resistant tuberculosis (MDR-TB; 6.6% of initial cases). Standardised treatment regimens for MDR-TB may be a potential solution.

OBJECTIVE

To present the effectiveness of standard regimens under routine national conditions.

DESIGN

We reviewed all MDR-TB patients treated under routine conditions from 29 August 2006 to 30 June 2010, showing interim and final outcomes. Patients were treated with regimens that were standardised or individualised based on previously received second-line anti-tuberculosis drugs.

RESULTS

Population description and culture conversion data are reported for the 289 MDR-TB patients. The median patient age was 31 years. Most had failed first-line treatment (72.6%). Culture negativity was obtained within 4 months (median 2 months) in 78.6%. Among the 150 patients treated between 2006 and 2008, 74% had favourable results on standardised and 66% on individualised regimens (P = 0.211). The efficacy of the standardised and individualised regimens was respectively 92.8% and 81% (P = 0.056). The relapse rate was approximately 1%. A median of five drug side effects occurred per patient. More than 2 months to culture conversion and bilateral cavitation on chest X-ray were found to be unfavourable outcome risk factors.

CONCLUSIONS

Standardised MDR-TB regimens may be effective at the national level, even in resource-poor settings.

European union standards for tuberculosis care

The European Centre for Disease Prevention and Control (ECDC) and the European Respiratory Society (ERS) jointly developed European Union Standards for Tuberculosis Care (ESTC) aimed at providing European Union (EU)-tailored standards for the diagnosis, treatment and prevention of tuberculosis (TB). The International Standards for TB Care (ISTC) were developed in the global context and are not always adapted to the EU setting and practices. The majority of EU countries have the resources and capacity to implement higher standards to further secure quality TB diagnosis, treatment and prevention. On this basis, the ESTC were developed as standards specifically tailored to the EU setting. A panel of 30 international experts, led by a writing group and the ERS and ECDC, identified and developed the 21 ESTC in the areas of diagnosis, treatment, HIV and comorbid conditions, and public health and prevention. The ISTCs formed the basis for the 21 standards, upon which additional EU adaptations and supplements were developed. These patient-centred standards are targeted to clinicians and public health workers, providing an easy-to-use resource, guiding through all required activities to ensure optimal diagnosis, treatment and prevention of TB. These will support EU health programmes to identify and develop optimal procedures for TB care, control and elimination.

Linezolid: an effective, safe and cheap drug for patients failing multidrug-resistant tuberculosis treatment in India

Linezolid is identified as an effective drug with which to treat patients failing multidrug-resistant (MDR)-tuberculosis (TB) treatment. However, cost and safety are the concerns. In India, the average price of a 600-mg pill of linezolid is less than one US dollar, much cheaper than most of the third-line drugs. A prospective study of 29 MDR-TB treatment failure patients (16 with laboratory-proven extensively drug-resistant (XDR)-TB and the remaining 13 with MDR-TB with resistance to any quinolone but sensitive to injectables) was carried out in Delhi, India. All patients received daily unsupervised therapy with linezolid, one injectable agent, one fluoroquinolone and two or more other drugs. Patients received a median of six anti-mycobacterial agents. Besides linezolid, capreomycin, moxifloxacin, levofloxacin and amoxycillin-clavulanic acid were used in 41.4%, 58.6%, 41.4%, and 79.3% of patients. Out of a total of 29 patients, 89.7% patients achieved sputum smear and culture conversion; 72.4% showed interim favourable outcome; 10.3% died, 6.8% failed and 10.3% patients defaulted. Linezolid had to be stopped in three (10.3%) patients due to adverse reactions. The outcome of treatment of 16 XDR-TB patients was comparable to the other 13 MDR-TB patients. Linezolid is an effective, cheap and relatively safe drug for patients failing MDR-TB treatment, including those with confirmed XDR-TB.

WHO guidelines for the programmatic management of drug-resistant tuberculosis: 2011 update

The production of guidelines for the management of drug-resistant tuberculosis (TB) fits the mandate of the World Health Organization (WHO) to support countries in the reinforcement of patient care. WHO commissioned external reviews to summarise evidence on priority questions regarding case-finding, treatment regimens for multidrug-resistant TB (MDR-TB), monitoring the response to MDR-TB treatment, and models of care. A multidisciplinary expert panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to develop recommendations. The recommendations support the wider use of rapid drug susceptibility testing for isoniazid and rifampicin or rifampicin alone using molecular techniques. Monitoring by sputum culture is important for early detection of failure during treatment. Regimens lasting ≥ 20 months and containing pyrazinamide, a fluoroquinolone, a second-line injectable drug, ethionamide (or prothionamide), and either cycloserine or p-aminosalicylic acid are recommended. The guidelines promote the early use of antiretroviral agents for TB patients with HIV on second-line drug regimens. Systems that primarily employ ambulatory models of care are recommended over others based mainly on hospitalisation. Scientific and medical associations should promote the recommendations among practitioners and public health decision makers involved in MDR-TB care. Controlled trials are needed to improve the quality of existing evidence, particularly on the optimal composition and duration of MDR-TB treatment regimens.

Multidrug-resistant tuberculosis: epidemiology, risk factors and case finding

Although the multidrug-resistant tuberculosis (MDR-TB) epidemic is a very recent problem, many studies have attempted to understand it. We now have good estimates of the current burden (approximately 500 000 MDR-TB cases worldwide), and following the introduction of potential MDR-TB control strategies projections of these figures are being estimated. The projected trends in tuberculosis (TB) and MDR-TB incidence vary. Risk factors for resistance can be divided into two categories: 1) those facilitating the selection of resistance in the community and 2) the specific conditions that appear to increase some patients' vulnerability to resistance. The epidemiological situation varies greatly across countries, principally due to poor treatment practices and poor implementation of control programmes in the past-and even today, to a lesser degree-and recent data have suggested that national TB programmes that use existing drugs efficiently can postpone and even reverse the MDR-TB epidemic. Other factors that have also contributed to this epidemic situation are analysed in this article. The recognition of factors leading to the epidemic in some regions and the identification of populations at risk will assist in focusing case-finding efforts. From an individual perspective, treatment failures with first-line rifampicin-containing regimens and contacts of MDR-TB cases have the highest rates of resistance. Patients previously treated for TB and the other risk factors analysed in this article should be prioritised in case finding.

Isoniazid preventive therapy for people living with HIV: public health challenges and implementation issues

Isoniazid preventive therapy (IPT) is recognised as an important component of collaborative tuberculosis (TB) and human immunodeficiency virus (HIV) activities to reduce the burden of TB in people living with HIV (PLHIV). However, there has been little in the way of IPT implementation at country level. This failure has resulted in a recent call to arms under the banner title of the 'Three I's' (infection control to prevent nosocomial transmission of TB in health care settings, intensified TB case finding and IPT). In this paper, we review the background of IPT. We then discuss the important challenges of IPT in PLHIV, namely responsibility and accountability for the implementation, identification of latent TB infection, exclusion of active TB and prevention of isoniazid resistance, length of treatment and duration of protective efficacy. We also highlight several research questions that currently remain unanswered. We finally offer practical suggestions about how to scale up IPT in the field, including the need to integrate IPT into a package of care for PLHIV, the setting up of operational projects with the philosophy of 'learning while doing', the development of flow charts for eligibility for IPT, the development and implementation of care prior to antiretroviral treatment, and finally issues around procurement, distribution, monitoring and evaluation. We support the implementation of IPT, but only if it is done in a safe and structured way. There is a definite risk that 'sloppy' IPT will be inefficient and, worse, could lead to the development of multidrug-resistant TB, and this must be avoided at all costs.

Evolution in the resistance of Mycobacterium tuberculosis to anti-tuberculosis drugs in Nicaragua

SETTING

Nicaragua, a country where the DOTS strategy has been successfully implemented since 1984.

OBJECTIVE

To estimate the prevalence and trends of Mycobacterium tuberculosis resistance to first-line anti-tuberculosis drugs.

DESIGN

A prospective national survey carried out in 2004 according to the standardised model developed by the World Health Organisation and the International Union Against Tuberculosis and Lung Disease.

RESULTS

A total of 423 M. tuberculosis strains were studied. Among the 320 strains evaluated for initial resistance, 13.1% displayed resistance to any drug, lower than the 1998 figure of 15.6%. Overall initial resistance to isoniazid (INH), rifampicin (RMP) and multidrug resistance (MDR) was respectively 6.6%, 0.9% and 0.6%. Initial resistance was higher in older age groups. Overall acquired resistance was 35.9% (n = 103); resistance to INH was 29.3% and to RMP 8.9%, while MDR was 7.9%. The acquired MDR rate was clearly higher in Category I failures (44.4%) than in relapses (3.8%) and retrieved defaulters (2.7%). All resistance rates found in this study were lower than those detected in 1998.

CONCLUSION

This study shows low rates of resistance and MDR and a downward trend in all rates, undoubtedly related to the proper implementation of the National Tuberculosis Programme.

Likelihood of generating MDR-TB and XDR-TB under adequate National Tuberculosis Control Programme implementation

The most frequent factors associated with selection of resistance at the community level and the generation of multidrug-resistant tuberculosis (MDR-TB) under epidemic conditions have been described in the last decades. These factors are multiple, and it is often a combination of these that has been implicated in the origin of MDR-TB epidemics in specific zones or countries. The analysis of and correct approach to the causes should be the first and most important step in the fight against this critical problem. However, it has never been investigated whether specific circumstances, even under adequate implementation of a National TB Control Programme (NTP), could lead to selection or amplification of resistance. The NTP should consider explanations for when there is no decline in MDR-TB rates even after appropriate control measures have been implemented. Under the special circumstances analysed in this article, the World Health Organization (WHO) Category I regimen can amplify resistance to rifampicin (in initial isoniazid-resistant cases) or ethambutol (EMB) + pyrazinamide (in initial MDR-TB cases). The WHO Category II regimen can also amplify resistance to EMB or streptomycin. The subsequent addition of the only second-line drugs available in many countries (fluoroquinolones and/or injectables) can worsen the situation and generate extensively drug-resistant TB. Strategies for minimising these risks of amplifying resistance are discussed in this article.

Treatment of multidrug-resistant tuberculosis: evidence and controversies

In the last decade, multidrug-resistant tuberculosis (MDR-TB, defined as resistance to at least isoniazid and rifampicin) has become an epidemiological issue of first priority at the global level. Case management needs to be simplified and standardised, as in many countries MDR-TB cases cannot receive individualised attention from specialist physicians. However, before any decision can be made on standardisation, a careful analysis must first be made of the evidence and controversies behind the various published recommendations. Unfortunately, the controversies outweigh the evidence. The difficulties lie not only in the absence of controlled trials to validate specific recommendations, but also in the very different and even contradictory results found in the literature. It is therefore essential to analyse these discrepancies before developing rational, uniform recommendations. The analysis should encompass the most essential and controversial issues regarding the management of MDR-TB patients: 1) confirmation of diagnosis in a suspected MDR-TB patient, and determination of the value of drug susceptibility testing; 2) the number of anti-tuberculosis drugs required to treat MDR-TB; 3) the most rational use of effective drugs against tuberculosis; 4) the advisable length of parenteral drug administration or of the initial phase of treatment; 5) the contribution of surgery to the management of MDR-TB patients; and 6) the optimal regimen for treating MDR-TB: standardised vs. individualised regimens. The evidence and controversies regarding each of the above questions are analysed with the aim of facilitating decision making in the treatment of these complex patients.

[Controversies in the treatment of extrapulmonary tuberculosis]

Tuberculosis (TB) can spread to any tissue or organ of the body by way of hematogenous or lymphatic dissemination or contiguity. However, pulmonary TB is the most common presentation and the only form of the disease of epidemiologic importance. Consequently, the literature on the various forms of extrapulmonary TB (EPTB) is scant, and most of the published authors are specialists in specific extrapulmonary forms. As a result, in most of the major areas of study of EPTB, recommendations similar to those for pulmonary TB or others based on little or no evidence have been accepted. This lack of evidence is of particular concern in the case of treatment guidelines. The present article reviews important work that has given rise to current treatment guidelines. While most of these guidelines reveal the lack of evidence available on this subject, it can, nevertheless, be concluded that a 6-month treatment regimen similar to that used in patients with pulmonary TB may be sufficient to treat all forms of EPTB, including meningeal disease. The role of steroids and surgery in the treatment of TB affecting different sites is also discussed. Other topics dealt with are the considerations that should be taken into account and the treatment modifications necessary in patients infected with the human immunodeficiency virus.

Management of multidrug-resistant tuberculosis and patients in retreatment

Retreatment of tuberculosis involves the management of entities as diverse as relapse, failure, treatment after default, and poor patient adherence to the previous treatment. The emergence of conditions for selection of resistance (failure and partial abandonment) is a matter of great concern. The development of a retreatment regimen for tuberculosis requires consideration of certain basic premises. The importance of a comprehensive and directed history of drugs taken in the past, and the limited reliability of susceptibility tests to many of these drugs, should be kept in mind. Taking this into account, and possessing a thorough knowledge of all anti-tuberculosis medications, it is possible to cure almost all patients with an appropriate retreatment regimen including a minimum of three or four drugs not previously used. Nonetheless, the treatment of these patients is so complex that it should only be carried out by experienced staff. Concern about treating tuberculosis patients with drug resistance varies greatly depending on the available resources. High-income countries should provide individual treatment regimens adapted to each patient; however, in other settings, restricted resources could justify the implementation of standardised therapeutic guidelines with second-line drugs in order to facilitate management and reduce costs.

A 6-month regimen for EPTB with intermittent treatment in the continuation phase: a study of 679 cases

BACKGROUND

No large studies have demonstrated the effectiveness of a 6-month regimen for all forms of extra-pulmonary tuberculosis (EPTB).

METHODS

Retrospective, observational analysis to evaluate the effectiveness of a 6-month treatment regimen (2HRZE/4H3R3) for all patients diagnosed with EPTB in Caracas, Venezuela, from 1 January 1998 to 31 December 2000, using direct observation.

RESULTS

Of 679 patients enrolled, 101 (14.9%) had AIDS. In 83.2% the diagnosis was based on microbiological, histological or genetic amplification information. Of 612 (90.1%) patients who took more than 90% of the doses, treatment had to be altered in six (1%) due to drug side effects. Of the remaining 606 patients who took more than 90% of the doses, 603 (99.5%) were cured and three failed. In the follow-up conducted 2 years after the end of treatment, only 6 relapsed (1%). Cures without relapse were achieved in 24 cases of central nervous system involvement, 27 cases of osteoarticular involvement and in the 42 who had miliary and/or disseminated TB.

CONCLUSION

A 6-month treatment regimen for all forms of EPTB, with treatment three times a week during the continuation phase, was highly effective.

Results of a national study on anti-mycobacterial drug resistance in El Salvador

SETTING

The DOTS strategy was introduced in El Salvador in 1997 and had become fully implemented countrywide by 2001. Previously, many deficiencies were identified in the management of patients with tuberculosis (TB).

OBJECTIVE

To ascertain the prevalence of Mycobacterium tuberculosis resistant to first-line drugs.

DESIGN

A national prospective survey was carried out in 2001 using the standardised World Health Organization/ International Union Against Tuberculosis and Lung Disease model.

RESULTS

A total of 711 cultures were analysed (59% of total smear-positive cases); 611 were never treated and 100 were previously treated patients. The study showed resistance rates to isoniazid and rifampicin, either alone or combined (multidrug resistance, MDR), of 1.3%, 1.1% and 0.3%, respectively, in never treated patients, and 12%, 13% and 7%, respectively, in previously treated patients.

CONCLUSION

The low rates of MDR-TB in El Salvador are puzzling, as out-patient DOTS was introduced only recently and fixed-dose combination tablets have not been used.

Current status of treatment completion and fatality among tuberculosis patients in Spain

OBJECTIVES

To determine treatment completion among patients with tuberculosis (TB), and to analyse factors associated with treatment default and fatality.

METHODS

A prospective cohort study of patients who began treatment between 1 June 1999 and 31 May 2000 in areas where members of the SEPAR Tuberculosis and Respiratory Infections Group work. Factors associated with treatment default and fatality were studied using logistic regression, calculating odds ratios (OR) and their 95% confidence intervals (95%CI).

RESULTS

The study involved 142 physicians from 76 different hospitals who provided information on 1515 cases. Eighty-two per cent of the patients completed treatment correctly, 14% defaulted, 5% died, 0.5% failed, and 8.7% interrupted treatment due to transfer or other reasons. The variables associated with default were intravenous drug use (IVDU) (OR 6.00, 95%CI 2.59-13.89) and immigration (OR 8.57, 95%CI 3.78-19.45); sex, age, homelessness, incarceration, directly observed treatment (DOT) or hospitalisation were not associated with default. Variables found to be predictive of fatality were alcoholism (OR 6.38, 95%CI 2.09-19.48), human immunodeficiency virus (HIV) infection (OR 7.08, 95%CI 2.08-29.15) and age >64 years (OR 10, 95%CI 2.9-34.07), whereas sex, IVDU, homelessness, DOT and hospitalisation were not.

CONCLUSIONS

In industrialised countries, IVDU patients and immigrants should be targeted for DOT, while to reduce fatality rates stricter monitoring is required for patients who are alcoholic, HIV-infected, or aged >64 years.

Impact of a model training course for private and public specialist physicians in El Salvador

BACKGROUND

Private and non-private specialist practitioners are often considered an obstacle to the performance of the National Tuberculosis Control Programme (NTP).

OBJECTIVE

To evaluate the impact of an intensive refresher course directed at specialist physicians in El Salvador, a questionnaire was sent to all course participants on their basic knowledge of tuberculosis (TB) control.

RESULTS

Of 64 participants, 55 were assessed (86%); 33 were chest physicians and 22 belonged to other related specialities. The evaluation showed a considerable improvement in both groups in their ability to suspect the disease, in their tendency to avoid hospitalising patients and instead refer them to out-patient clinics, and in their adherence to the recommendations of the NTP manual (diagnostic procedures, treatment guidelines, case notification and cohort studies). Improvements were more noticeable, in all the parameters evaluated, among the non-chest physicians.

CONCLUSION

The intervention model succeeded in improving the collaboration of private and non-private specialist practitioners with the NTP.

Is the DOTS strategy sufficient to achieve tuberculosis control in low- and middle-income countries? 2. Need for interventions among private physicians, medical specialists and scientific societies

In the first of these two articles it was expressed how, in practically all middle-income and many low-income countries, it is necessary to implement interventions in addition to the DOTS strategy if adequate tuberculosis control is to be achieved. We need to act in two directions: 1) in universities and medical schools, as explained in the first article, and 2) specifically among private physicians and medical specialists, an important obstacle for many National Tuberculosis Programmes (NTPs). These professionals, especially medical specialists (many of whom also work in private practice), are an influential sector that is held in high regard, but which tends not to follow guidelines considered as excessively simplistic or rigid, such as those stipulated by the NTP. Private physicians have practically no access to information or training programmes, which accounts for the surprising disparity in their clinical criteria. All this leads to important distortions that can compromise the NTP's outcome. The present article evaluates the need to intervene among private physicians and medical specialists in order to achieve better tuberculosis control. Special strategies are described to obtain concrete, specific agreements for their participation in the NTP, and for the implementation of specific training programmes for this group. At the end of the article the work performed by the IUATLD in these groups in Latin America is described.

Epidemiology of tuberculosis on Gran Canaria: a 4 year population study using traditional and molecular approaches

BACKGROUND

In recent years several population based studies using restriction fragment length polymorphism (RFLP) analysis have shown a higher rate of recent transmission of tuberculosis than previously thought. This study was undertaken to determine the transmission patterns of tuberculosis and the potential causes of recent transmission on the island of Gran Canaria (Spain).

METHODS

The strains of all patients diagnosed with tuberculosis confirmed by culture between 1 January 1993 and 31 December 1996 were typed by RFLP using the insertion sequence IS6110. A cluster was defined as two or more isolates with an identical RFLP pattern. Epidemiological linkage through contact tracing was investigated.

RESULTS

Of the total of 719 patients, 153 (21.3%) were excluded because there was inadequate bacterial DNA for genotyping (n=129) or the isolates of Mycobacterium tuberculosis had less than five copies of IS6110 (n=24). The isolates from 409 patients (72.3%) were grouped into 78 different clusters with an estimated 58.5% of the cases being due to recent transmission. Young age was the only significant predictor of clustering. Only in 147 (35.9%) of the 409 patients belonging to a cluster could an epidemiological link be found. 111 patients (19.6%) were identified as having had previous contact with a tuberculosis patient and 81 of them (72.9%) belonged to a cluster. The three largest clusters included 75, 49 and 20 patients, respectively.

CONCLUSION

Recent transmission is frequent among patients with tuberculosis on Gran Canaria and could be associated with certain aspects of control measures. Some of the clusters described in the study could be due to the prevalence of particular strains of M tuberculosis on the island.

Is the DOTS strategy sufficient to achieve tuberculosis control in low- and middle-income countries? 1. Need for interventions in universities and medical schools

Now that progress is gradually being made in the implementation of the DOTS strategy in low-income countries, we must take into account the fact that nearly 30% of all tuberculosis (TB) cases worldwide occur in middle-income countries, which usually have an adequate health infrastructure and sufficient economic resources for TB control. These countries nevertheless have other limitations that make it necessary to develop other aspects in addition to the DOTS strategy. These can be summarised in three main themes: 1) adequate coordination of all health structures involved in TB management, ensuring that they follow the basic norms of the National Tuberculosis Programme (NTP), 2) direct intervention in universities and medical schools, which are ubiquitous in such countries, and 3) specific collaboration with specialists and physicians in private practice, an important obstacle to the success of NTPs in several countries. A detailed analysis is presented of strategies that need to be implemented in different countries depending on their economic resources and their TB situation. The need to carry out specific interventions in addition to training in DOTS in universities and medical schools in order to improve TB control is discussed. A specific project in this area developed by the IUATLD in Latin America is described.

Evaluation of tuberculosis trends in Spain, 1991-1999

SETTING

There are no reliable official data available on tuberculosis (TB) in Spain.

OBJECTIVE

To ascertain the epidemiological trends of TB in Spain from 1991-1999.

METHODS

In an annual survey conducted by the Tuberculosis and Respiratory Infections (TRI) Working Group of the Spanish Society of Pneumology and Thoracic Surgery (SEPAR), data on tuberculosis disease and infection were solicited from two information sources: 1) the public health services of the 17 Autonomous Regions (AR), and 2) 60 TRI members in different parts of Spain.

RESULTS

TB incidence declined from 36.4/100,000 in 1991 to 26.7 in 1999 according to the AR (average annual decline 3.3%), and from 45.6 to 26.8 according to TRI members (annual decline 5.1%). A similar observation was made for smear-positive cases (AR annual decline: 3.0%; TRI: 5.6%). Tuberculosis infection at 6 years of age also decreased according to both information sources (AR: 0.87% in 1991 to 0.5% in 1998, annual decline 6%, and TRI members: 1.00% in 1991 and 0.9% in 1997, annual decline 4.2%).

CONCLUSIONS

The observed rates of TB are higher than stated in official figures. In spite of the decreasing trend, observed declines are small and the current rates continue to be among the highest among industrialised countries.

Epidemiological evidence of the spread of a Mycobacterium tuberculosis strain of the Beijing genotype on Gran Canaria Island

Molecular epidemiological studies suggest that particular Mycobacterium tuberculosis strains have an enhanced capacity to spread within a community. One strain, the Beijing genotype, has been associated with outbreaks in a number of communities throughout the world. IS6110 restriction fragment length polymorphism (RFLP) analysis was performed on M. tuberculosis isolates from 566 of the 721 patients (78.5%) diagnosed with tuberculosis (TB) on Gran Canaria Island from 1993 to 1996, as well as 35% of isolates from 1991-1992 (85 strains). RFLP identification of the family of strains of the Beijing genotype was confirmed by spoligotyping. Medical records of all patients were reviewed and epidemiological links were identified. Of 566 M. tuberculosis isolates from 1993 to 1996 with RFLP available, 72% belonged to clusters. The largest contained 75 cases and was caused by a strain of the Beijing genotype that was introduced to the island in 1993. It was found in 10 patients in 1993 (5.5%), 12 in 1994 (8.1%), 18 in 1995 (16.4%), and 35 in 1996 (27.1%). Epidemiological linkage was confirmed for 68% of cases. This study has demonstrated rapid dissemination of this strain of the Beijing genotype. This genotype might play an important role in the future of the worldwide tuberculosis epidemic.

Exogenous reinfection with tuberculosis on a European island with a moderate incidence of disease

The frequency and determinants of exogenous reinfection and of endogenous reactivation of tuberculosis in patients previously treated are poorly understood. In Gran Canaria Island, Spain, between 1991 and 1996, 962 tuberculosis cases were confirmed by culture. Drug susceptibility testing was performed on available bacterial isolates and IS6110-based RFLP genotyping was carried out. Twenty-three patients (2.4%) had two positive cultures separated by at least 12 mo, 18 of whom had bacterial DNA available for genotypic analysis. The initial and final isolates from eight (44%) were different genotypes, indicating exogenous reinfection. Six of them were retreated after cure and two retreated after default. Six were HIV seronegative and two were HIV seropositive. Endogenous reactivation was seen in the remaining 10 patients of whom eight were retreated after default and two after cure. Three of the eight (38%) being retreated after default developed multidrug resistance. One genotype was responsible for a second episode of tuberculosis in five cases, three exogenous reinfections and two endogenous reactivations. In the context of a moderate incidence of tuberculosis, exogenous reinfection is an important cause of TB recurrence, even in HIV-seronegative patients.

Towards elimination of tuberculosis in a low income country: the experience of Cuba, 1962-97

BACKGROUND

This study describes the epidemiological trends of tuberculosis in Cuba and the performance of the tuberculosis control programme. The circumstances that caused an increase in the incidence of new cases of tuberculosis between 1991 and 1994 had been analysed and were corrected in 1995-7.

METHODS

A descriptive study of the incidence rates of new cases of tuberculosis notified from 1962 to 1997 was made, with special emphasis on the total change between 1965 and 1991 and the increase thereafter.

RESULTS

The case notification rate of 14.7 per 100 000 in 1994 was almost three times the rate found in 1991 (4.8 per 100 000) and reversed the mean annual decrease of 5% observed since 1965. This increase was almost twofold in the rate of smear positive new cases (4.4 per 100 000 in 1991 and 8.3 in 1994). From 1971 onwards the programme had achieved a cure rate of 90% throughout the country with only 2% absconding by applying directly observed treatment. The main factors associated with the increasing trends were: (1) a probable underdetection of cases for the 1988-92 period that generated contagious sources in the community; (2) improved case finding from 1993 onwards and the introduction of an expanded case definition in 1994; (3) a considerable increase in the diagnostic delay from initial medical consultation to beginning of antituberculosis treatment (56.9 days in 1993); and (4) operational changes in the tuberculosis control programme due to the economic crisis in Cuba. In 1995, 1996 and 1997 it has been possible to reverse this trend, achieving rates of 14.1, 13.5, and 12.2 per 100 000, respectively (7. 6, 7.6, and 6.9 for smear positive cases) as a result of effective intervention correcting the problems identified. Reducing the diagnostic delay attributable to shortcomings in the health care system and the study of contacts were of particular importance for re-establishing the tuberculosis programme as a priority.

CONCLUSIONS

Cuba represents a good example of how it is possible to fight against tuberculosis effectively, even in a low income country, by applying control strategies advocated by the World Health Organisation and the International Union Against Tuberculosis and Lung Disease and by giving adequate support to the programme through political commitment.

Evaluation of a directly observed six months fully intermittent treatment regimen for tuberculosis in patients suspected of poor compliance

BACKGROUND

Although a priority for tuberculosis control is to achieve the maximum cure rate, compliance with chemotherapy in specific high risk groups (homeless, intravenous drug abusers, chronic alcoholics) is usually poor.

METHODS

From January 1990 to December 1994 102 patients with tuberculosis (96 pulmonary, six extrapulmonary) who were poorly compliant with treatment were treated with a six month fully intermittent (twice weekly) directly observed regimen. They comprised 71 homeless subjects, 50 chronic alcoholics, 23 intravenous drug abusers, nine infected with HIV, and 11 who had previously abandoned a daily antituberculosis regimen; 53 had more than one of these risk factors. Treatment included isoniazid and rifampicin for six months and pyrazinamide during the first two months. Patients who failed to take their medication on two consecutive occasions were actively sought by telephone or by personal search.

RESULTS

After two months of treatment 95 of the 102 patients had taken their medication regularly and 90 of them had negative cultures. Four of the remaining patients had negative cultures after three months. At the end of the six months 87 patients had completed treatment and were considered cured. Only 15 patients abandoned the treatment (13 of whom had more than one risk factor). Only three relapses occurred in the 102 patients at one year follow up and in the 88 patients followed for two years. Two patients required a change of treatment due to major side effects. Although intravenous drug abuse was the only predictor of non-compliance in the multivariate analysis, if the available variables in the second month of treatment were analysed, current poor compliance and abandonment of treatment in the past were found to be significantly associated with non-compliance.

CONCLUSIONS

This study shows the efficacy of this intermittent regimen and the effectiveness of a directly observed treatment programme.

The epidemiology of tuberculosis in Gran Canaria, Canary Islands, 1988-92: effectiveness of control measures

SETTING

Since there is no national programme for tuberculosis control in Spain and the epidemiological situation in this country is unknown, a programme against tuberculosis in Gran Canaria (Canary Islands) was started in 1987.

OBJECTIVE

To analyze the impact of this control programme, particularly the trend of new cases of tuberculosis by age groups and risk factors for 1988-92.

DESIGN

A detailed search of all new cases of tuberculosis was carried out by examining the files of all public and private hospitals and outpatient clinics of the island, the records of the Services of Clinical Microbiology and Pathology of the public hospitals, and the registers of patients with AIDS.

RESULTS

The annual rates of new cases of tuberculosis per 100,000 were 32.2 in 1988 (214 cases), 26.2 in 1990 (174 cases), and 29.4 in 1992 (196 cases), and the rates of sputum-positive cases 13.3 (89 cases), 12 (80 cases) and 15 (100 cases), respectively. The distribution of tuberculosis cases by age peaked in the age groups 40-49 and 30-39 years. Between 1988 and 1992, statistically significant differences were found in the percentage of cured patients (21% [45/214] vs 85.7% [168/196]), patients with a delay in diagnosis > 3 months (40.2% [86/214] vs 21.9% [43/196]), and contacts evaluated (45.3% [97/214] vs 90.3% [177/196]). However, an upward trend in the incidence of tuberculosis for 1990-92 was found in association with an increase of new cases among the homeless, immigrants, and HIV-infected people. When these three population groups were excluded from the analysis, the annual rate for the total population showed a progressive decline from 1988-92.

CONCLUSIONS

The data studied here show that successful priority control measures (cure rate, early diagnosis, study of contacts) have been achieved in this island. It is necessary, however, to develop strategies for combating the tuberculosis problem in specific high risk populations.

Surgical treatment of childhood mediastinal tuberculous lymphadenitis

Between 1985 and 1991, we treated 6 children, aged 2 months to 3 years, who required an invasive procedure for the management of complications caused by enlarged mediastinal lymph nodes secondary to tuberculosis. Radiologic and endoscopic studies revealed bronchial involvement by lymph nodes, with endobronchial granulomas and lobar or pulmonary obstruction in 4 patients and marked tracheal and esophageal stenosis produced by extrinsic compression in the remaining 2. Pathologic study of the lymph node or bronchial samples from the 6 patients disclosed granulomas with caseous necrosis and Langhans' giant cells. All the children were treated with a standard 6-month drug regimen consisting of isoniazid, rifampicin, and pyrazinamide. Five of the patients underwent thoracotomy for the purpose of nodal curettage or excision. In 1, upper right lobectomy and bronchoplasty were necessary. The sixth patient was treated by endoscopic resection of the granulomas. There was no postoperative morbidity, and radiologic and endoscopic evidence of resolution of the lesions was observed in all the patients. In our experience, surgical treatment, when performed as a coadjuvant treatment for tracheobronchial complications stemming from mediastinal tuberculous lymphadenitis, results in the resolution of the lesions and has no related morbidity.

Value of ELISA using A60 antigen in the serodiagnosis of tuberculosis

This study was set in a general, university hospital in the Canary Islands, with the objective to evaluate an enzyme-linked immunosorbent assay (ELISA) using A60 in the serodiagnosis of tuberculosis. IgG antibody to A60 was determined in 205 patients with active disease [149 culture-positive patients with pulmonary tuberculosis (positive sputum smear 94, negative sputum smear 55) and 56 patients with extrapulmonary tuberculosis], 20 patients with inactive disease, 22 patients with lepromatous leprosy, and 51 controls. The mean levels of anti-A60 antibodies were significantly higher in patients with active disease as compared with controls or patients with inactive disease. Differences were also found between tuberculous patients with pulmonary and extrapulmonary disease. In patients with pulmonary disease, significant differences were detected between smear-positive and smear-negative patients. The overall sensitivity of the test (cutoff 240 ELISA units) was 52.2%. The highest sensitivity was found among smear-positive patients with pulmonary tuberculosis (67%) and the lowest among those with extrapulmonary tuberculosis (32.1%). We conclude that ELISA for the measurement of IgG antibody to Mycobacterium tuberculosis antigen A60 could be of interest, specially in smear-negative cases and extrapulmonary tuberculosis.

Diagnosis of pleural tuberculosis by detection of specific IgG anti-antigen 60 in serum and pleural fluid

The objective of this study was the prospective evaluation of the IgG antibody levels to mycobacterial antigen 60 (A60) in serum and pleural fluid and their role in the diagnosis of tuberculous pleuritis. The level of IgG was measured by Elisa in 30 patients with tuberculous pleuritis and 48 control subjects with pleural effusion (24 with carcinoma, 10 with transudative pleural effusion, 11 with empyema or parapneumonic effusion, 1 with pulmonary embolism and 2 due to systemic lupus erythematosus). The median titers of IgG against A60 of both serum and pleural fluid from tuberculous patients [445.6 +/- 133.56 and 263 +/- 72.58 Elisa units (EU) respectively] were significantly higher than those of corresponding median values (97.3 +/- 8.35 and 41.3 +/- 4.93 EU) of the control group (p < 0.01 and p < 0.01, respectively). Considering 240 units as cutoff point for a positive test in serum, the sensitivity was 53.3% and the specificity 100%. In the pleural fluid the cutoff point value was established at 150 units, with a sensitivity of 50% and specificity of 100%. We concluded that Elisa using A60 is a reliable and rapid test with an acceptable sensitivity and magnificent specificity.

[Epidemiology of tuberculosis in the Gran Canary Island]

BACKGROUND

The aim of the present study was to obtain information about tuberculosis (TB) in our area that might contribute to assess the status in Spain.

METHODS

A meticulous case finding was carried out during 1988 in all the hospitals of the Gran Canaria island.

RESULTS

214 cases were found (rate 32.2) and 77% were admitted to hospitals. In 160 (74%) the involvement was pulmonary and in 82 (37%) it was extrapulmonary. Mean age was 34 years (range 1-84) and 62% were younger than 40 years. 69% were males. Complete data were obtained in 183 cases (85%). 56% were smokers, 34% alcoholic abusers, 15% drug abusers (35% parenteral) and 4% homosexuals. 26% had some risk factor for TB; 14 of them had been infected by the HIV (8 had AIDS). In 64% there was a diagnostic delay longer than one month. Out of the 214 cases, the diagnosis was made by direct microscopy and/or culture in 110 (51%), by consistent pathological findings in 41 (19%), with some of these studies but with negative results in 35 (16%) and only with clinical and radiological criteria in 28 (13%). 96 (60%) of the pulmonary cases had cavitation. The most common therapeutic schedule (84%) was the recommended 9-month regimen. In 54% no recommendation for the investigation of contacts was made.

CONCLUSIONS

In the authors' area, the prevalence of TB is higher than in developed countries. It is more common in middle aged individuals, many diagnoses are still made without bacteriologic studies and in a high number of cases investigation of contacts is not carried out.