'One Health´ approach to end zoonotic TB.

Mycobacterium bovis has a wide host range causing TB in animals, both in wildlife and cattle (bovine TB bTB), and in humans (zoonotic TB zTB). The real burden of bovine and zoonotic TB (b/zTB) remains unknown due to diagnostic challenges. Although progress has been made to reduce the burden of TB, b/zTB has been neglected in low- and middle-income countries (LMICs) with little improvement in prevention, diagnosis or treatment. Using Tanzania as a case study, because of its high TB burden, large wildlife diversity and wide reliance on livestock, we developed an approach to comprehensively estimate the burden and implement multidisciplinary actions against b/zTB. We performed a review of the literature on b/zTB, but there is a lack of available data on the b/zTB burden in Tanzania and, notably, on epidemiological indicators other than incidence. We propose a five-action programme to address b/zTB in Tanzania, and we believe our proposed approach could benefit other LMICs as it operates by implementing and strengthening surveillance and health delivery. The resulting knowledge and system organisation could further prevent and mitigate the effects of such conditions on human and animal health, livestock production, population livelihood and the economy.

Isoniazid preventive treatment: predictors of adverse events and treatment completion.

SETTING: Villa Marelli Institute (VMI), Niguarda Ca'Granda Hospital, Milan, Italy. BACKGROUND: A recent report on the fatal side effects of isoniazid preventive therapy (IPT) from the United States has re-ignited discussion on the safety of this intervention. OBJECTIVE: To evaluate IPT feasibility, treatment completion and adverse events (AE) and their determinants under field conditions. METHODS: Data from consecutive subjects undergoing IPT at the VMI were recorded in an electronic database from 1992 to 2009. Logistic regression analysis was performed to detect completion and AE determinants. RESULTS: A total of 11,963 patients were included in the study. AE (odds ratio [OR] 2.70, 95%CI 2.22-3.28) and human immunodeficiency virus positive status (OR 5.20, 95%CI 2.10-12.93) were the main determinants of treatment interruption among Italians, while social weakness (no housing/job; OR 2.88, 95%CI 2.43-3.42), AEs (OR 1.33, 95%CI 1.15-1.53, 2.22-3.28) and screening in undocumented subjects (OR 1.20, 95%CI 1.01-1.44) prevailed among foreigners. Age was the main determinant of transaminase increase (OR 1.03, 95%CI 1.03-1.04), as were AEs of the gastrointestinal (OR 1.02, 95%CI 1.02-1.03), central nervous (OR 1.02, 95%CI 1.02-1.05) and peripheral nervous systems (OR 1.04, 95%CI 1.02-1.05). CONCLUSION: This analysis demonstrates the feasibility and safety of IPT, with determinants of interruption and AEs being predictable and addressable.

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.

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.

Informed patient consent for defaulter tracing: should we obtain it?

Active default tracing is an integral part of tuberculosis (TB) programmatic control. It can be differentiated into the tracing of defaulters (patients not seen at the clinic for > or =2 months) and 'late patients' (late for their scheduled appointments). Tracing is carried out to obtain reliable information about who has truly died, transferred out or stopped treatment, and, if possible, to persuade those who have stopped treatment to resume. This is important because, unlike routine care for non-communicable diseases, TB has the potential for transmission to other members of the community, and therefore presents the issue of the rights of the individual over the rights of the community. For this reason, default or 'late patient' tracing (defined together as default tracing in this article) has been incorporated into standard practice in most TB programmes and, in many industrialised countries, it is also a part of public health legislation. In resource-poor countries with limited access to phones or e-mails, default tracing involves active home visits. In this Unresolved Issues article, we discuss the need for patient consent within both the programmatic and the research context; we describe how this subject arose during operational research training at the Research Institute of Tuberculosis in Japan; we provide comments from individuals who are experienced and skilled at international and national TB control; and finally we offer some conclusions about the way forward. This is not an easy subject, and we welcome open debate on the issue.

Clinical and operational value of the extensively drug-resistant tuberculosis definition.

Currently, no information is available on the effect of resistance/susceptibility to first-line drugs different from isoniazid and rifampicin in determining the outcome of extensively drug-resistant tuberculosis (XDR-TB) patients, and whether being XDR-TB is a more accurate indicator of poor clinical outcome than being resistant to all first-line anti-tuberculosis (TB) drugs. To investigate this issue, a large series of multidrug-resistant TB (MDR-TB) and XDR-TB cases diagnosed in Estonia, Germany, Italy and the Russian Federation during the period 1999-2006 were analysed. Drug-susceptibility testing for first- and second-line anti-TB drugs, quality assurance and treatment delivery was performed according to World Health Organization recommendations in all study sites. Out of 4,583 culture-positive TB cases analysed, 361 (7.9%) were MDR and 64 (1.4%) were XDR. XDR-TB cases had a relative risk (RR) of 1.58 to have an unfavourable outcome compared with MDR-TB cases resistant to all first-line drugs (isoniazid, rifampicin ethambutol, streptomycin and, when tested, pyrazinamide), and an RR of 2.61 compared with "other" MDR-TB cases (those susceptible to at least one first-line anti-TB drug among ethambutol, pyrazinamide and streptomycin, regardless of resistance to the second-line drugs not defining XDR-TB). The emergence of extensively drug-resistant tuberculosis confirms that problems in tuberculosis management are still present in Europe. While waiting for new tools which will facilitate management of extensively drug-resistant tuberculosis, accessibility to quality diagnostic and treatment services should be urgently ensured and adequate public health policies should be rapidly implemented to prevent further development of drug resistance.

Tuberculosis in HIV-infected persons in the context of wide availability of highly active antiretroviral therapy.

Highly active antiretroviral therapy (HAART) greatly reduces the risk of developing tuberculosis for HIV-infected persons. Nonetheless, HIV-associated tuberculosis continues to occur in countries where HAART is widely used. To identify the characteristics of HIV-infected persons who develop tuberculosis in the context of the availability of HAART, the current authors analysed data taken from 271 patients diagnosed, in Italy, during 1999-2000. These patients represent 0.7% of the 40,413 HIV-infected patients cared for in the clinical units participating in this current study. From the data it was observed that 20 patients (7.4%) had a previous episode of tuberculosis whose treatment was not completed. Eighty-one patients (29.9%) were diagnosed with HIV at tuberculosis diagnosis, 108 (39.8%) were aware of their HIV status but were not on antiretroviral treatment and 82 (30.3%) were on antiretroviral treatment. Patients on antiretroviral treatment were significantly less immunosuppressed than patients with HIV diagnosed concurrently with tuberculosis, or other patients not on antiretrovirals (median CD4 lymphocytes count: 220 cells x mm(-3) versus 100 cells x mm(-3), and 109 cells x mm(-3), respectively). No significant differences in clinical presentation of tuberculosis according to antiretroviral therapy status were recorded. Failure of tuberculosis control interventions (e.g. noncompletion of treatment) and of HIV care (delayed diagnosis of HIV infection and suboptimal uptake of therapy) may contribute to continuing occurrence of HIV-associated tuberculosis in a country where highly active antiretroviral therapy is largely available. However, a significant proportion of cases occur in patients who are on antiretroviral treatment.

DOTS expansion: will we reach the 2005 targets?

The global targets for tuberculosis control consist of detecting 70% of estimated infectious cases and curing 85% of these by 2005. Since the introduction of the DOTS strategy, DOTS geographical coverage has increased substantially and treatment success rates under DOTS are approaching the targets, standing at 82% in 2000. However, DOTS case detection, albeit increasing, is still relatively low, at 32% in 2001. This target may not be reached by 2005. The low case detection is unlikely to stem from overestimating the global number of TB cases which has been estimated on several occasions, but from TB cases not being detected or notified for various reasons. The population may have poor access to TB services, cases may not be suspected or correctly diagnosed, cases may not be notified, and/or public health programmes or the private sector may not be adequately linked to the National Tuberculosis Programmes. Since the global TB targets were set, progress has been made. Political commitment has increased, additional financial resources mobilised, access to anti-tuberculosis drugs augmented and planning and coordination improved. Constraints still remain, the most important related to human resource capacity. Although the issue is being tackled, many countries still suffer from a lack of trained health care professionals. Finally, new strategies have been developed to face the current challenges such as public-private mix, community TB care, social mobilisation, TB/HIV collaborative interventions and Practical Approach to Lung Health. The current efforts should be maintained and strengthened in order to approach these targets.

Frequency of recurrence among MDR-tB cases 'successfully' treated with standardised short-course chemotherapy.

SETTING: Ivanovo Oblast, Russian Federation, 300 km north-east of Moscow, where a pilot DOTS TB control programme was implemented in October 1995. OBJECTIVE: To determine the frequency of TB recurrence among MDR (multidrug-resistant) patients who achieved treatment 'success' on standard short-course chemotherapy. METHODS: All patients with MDR tuberculosis, defined as resistance to at least isoniazid and rifampicin, who were declared 'cured' or 'treatment completed', were identified using the district register and traced whenever possible. Eligible patients underwent medical examination and, if necessary, chest radiography, sputum smear examination, culture and susceptibility testing. If the patient had died, the relatives were interviewed to try to determine the reasons for death. RESULTS: Of 18 patients eligible for analysis, five (27.8%) were documented to have recurrence (two of seven patients resistant to HRSE, one of five patients resistant to HRS and two of six patients resistant to HR). Patients receiving the Category I regimen were more likely to relapse than those receiving the Category II regimen (40% vs. 12.5%). The median time to relapse was 8 months; 2.46 recurrences were observed in 100 person-months (3.17 in category I and 1.3 in Category II patients). CONCLUSIONS: The frequency of TB recurrence among MDR-TB patients declared 'cured' after short-course chemotherapy is high. Improvements in treatment success, after removal of programme-related pitfalls in the treatment delivery process, must incorporate methods for early detection of MDR, along with adequate treatment regimens including second-line drugs. Culture-based bacteriological confirmation at the end of treatment is recommended.

European framework for tuberculosis control and elimination in countries with a low incidence. Recommendations of the World Health Organization (WHO), International Union Against Tuberculosis and Lung Disease (IUATLD) and Royal Netherlands Tuberculosis Association (KNCV) Working Group.

As countries approach the elimination phase of tuberculosis, specific problems and challenges emerge, due to the steadily declining incidence in the native population, the gradually increasing importance of the importation of latent tuberculosis infection and tuberculosis from other countries and the emergence of groups at particularly high risk of tuberculosis. Therefore, a Working Group of the World Health Organization (WHO), the International Union Against Tuberculosis and Lung Disease (IUATLD) and the Royal Netherlands Tuberculosis Association (KNCV) have developed a new framework for low incidence countries based on concepts and definitions consistent with those of previous recommendations from WHO/IUATLD Working Groups. In low-incidence countries, a broader spectrum of interventions is available and feasible, including: 1) a general approach to tuberculosis which ensures rapid detection and treatment of all the cases and prevention of unnecessary deaths; 2) an overall control strategy aimed at reducing the incidence of tuberculosis infection (risk-group management and prevention of transmission of infection in institutional settings) and 3) a tuberculosis elimination strategy aimed at reducing the prevalence of tuberculosis infection (outbreak management and provision of preventive therapy for specified groups and individuals). Government and private sector commitment towards elimination, effective case detection among symptomatic individuals together with active case finding in special groups, standard treatment of disease and infection, access to tuberculosis diagnostic and treatment services, prevention (e.g. through screening and bacille Calmette-Guéria immunization in specified groups), surveillance and treatment outcome monitoring are prerequisites to implementing the policy package recommended in this new framework document.

Evolution of WHO policies for tuberculosis control, 1948-2001.

We examine the evolution of WHO managerial policies for tuberculosis control during 1948-2001 to provide a new framework that will accelerate control expansion in the near future. In the first period (1948-63), a vertical approach to tuberculosis control was the policy adopted by WHO and the international community. However, although this approach was successful in more-developed countries, it largely failed in resource-poor settings. As a result, involvement of general health services was soon deemed essential. During 1989-98, a new framework for effective tuberculosis control was created and a new five-element strategy was branded with the name of DOTS. This period was characterised by the recognition of tuberculosis control as a public-health priority, the intensification of tuberculosis control efforts worldwide, and the return of tuberculosis to the political agenda of governments. However, although nominal adoption of DOTS increased rapidly due to massive promotion by WHO and partners, expansion to provide full access was too slow and only 23% of all infectious cases in 1999 were managed under DOTS. A truly multisectoral approach based on advocacy and social mobilisation, community involvement, and engagement of private-for-profit practitioners is becoming the way forward for tuberculosis control. HIV-associated tuberculosis and multidrug-resistant tuberculosis must be tackled as priority issues. We conclude that, based on the lessons of the past, the future of tuberculosis control should be focused on a pragmatic approach combining a specialised, well-defined management system with a fully integrated service delivery. A multisectoral approach that builds on global and national partnerships is the key to future tuberculosis control.

Determinants of drug-resistant tuberculosis: analysis of 11 countries.

SETTING: Eleven countries/territories. OBJECTIVES: Global information on the determinants of drug-resistant tuberculosis (TB) based on representative data is not available. We therefore studied the relationship between demographic characteristics, prior TB treatment, and human immunodeficiency virus (HIV) infection with anti-tuberculosis drug resistance. METHODS: Population-based representative data on new and previously treated patients with TB collected within an international drug resistance surveillance network. RESULTS: Of 9,615 patients, 8,222 (85.5%) were new cases of TB and 1,393 (14.5%) were previously treated cases. Compared with new cases, previously treated cases were significantly more likely to have resistance to one (OR = 2.5,95% CI 2.1-3.0; P < 0.001), two (OR = 4.6, 95%CI 3.7-5.6; P < 0.001), three (OR = 11.5, 95%CI 8.6-15.3; P < 0.001), and four (OR = 18.5, 95% CI 12.0-28.5; P < 0.001) drugs. An approximately linear increase in the likelihood of having multidrug-resistant tuberculosis (MDR-TB) was observed as the total time (measured in months) of prior anti-tuberculosis treatment increased (P < 0.001, chi2 for trend). In multivariate analysis, prior TB treatment for 6-11 months (OR = 7.6, 95% CI 2.6, 22.4; P < 0.001) and > or = 12 months (OR 13.7, 95% CI 4.5-41.6; P < 0.001), but not HIV positivity, was associated with MDR-TB. CONCLUSION: This study shows that prior but ineffective treatment is a strong predictor of drug resistance, and that HIV is not an independent risk factor for MDR-TB. The association between length of treatment and drug resistance may reflect longer treatment as a result of treatment failure in patients with drug resistance; it may also reflect irregular prior treatment for TB, leading to drug resistance.

Global trends in resistance to antituberculosis drugs. World Health Organization-International Union against Tuberculosis and Lung Disease Working Group on Anti-Tuberculosis Drug Resistance Surveillance.

BACKGROUND: Data on global trends in resistance to antituberculosis drugs are lacking. METHODS: We expanded the survey conducted by the World Health Organization and the International Union against Tuberculosis and Lung Disease to assess trends in resistance to antituberculosis drugs in countries on six continents. We obtained data using standard protocols from ongoing surveillance or from surveys of representative samples of all patients with tuberculosis. The standard sampling techniques distinguished between new and previously treated patients, and laboratory performance was checked by means of an international program of quality assurance. RESULTS: Between 1996 and 1999, patients in 58 geographic sites were surveyed; 28 sites provided data for at least two years. For patients with newly diagnosed tuberculosis, the frequency of resistance to at least one antituberculosis drug ranged from 1.7 percent in Uruguay to 36.9 percent in Estonia (median, 10.7 percent). The prevalence increased in Estonia, from 28.2 percent in 1994 to 36.9 percent in 1998 (P=0.01), and in Denmark, from 9.9 percent in 1995 to 13.1 percent in 1998 (P=0.04). The median prevalence of multidrug resistance among new cases of tuberculosis was only 1.0 percent, but the prevalence was much higherin Estonia (14.1 percent), Henan Province in China (10.8 percent), Latvia (9.0 percent), the Russian oblasts of Ivanovo (9.0 percent) and Tomsk (6.5 percent), Iran (5.0 percent), and Zhejiang Province in China (4.5 percent). There were significant decreases in multidrug resistance in France and the United States. In Estonia, the prevalence in all cases increased from 11.7 percent in 1994 to 18.1 percent in 1998 (P<0.001). CONCLUSIONS: Multidrug-resistant tuberculosis continues to be a serious problem, particularly among some countries of eastern Europe. Our survey also identified areas with a high prevalence of multidrug-resistant tuberculosis in such countries as China and Iran.