Defining access without excess: expanding appropriate use of antibiotics targeting multidrug-resistant organisms.

Antimicrobial resistance remains a significant global public health threat. Although development of novel antibiotics can be challenging, several new antibiotics with improved activity against multidrug-resistant Gram-negative organisms have recently been commercialised. Expanding access to these antibiotics is a global public health priority that should be coupled with improving access to quality diagnostics, health care with adequately trained professionals, and functional antimicrobial stewardship programmes. This comprehensive approach is essential to ensure responsible use of these new antibiotics.

The WHO essential medicines list AWaRe book: from a list to a quality improvement system.

Antibiotics are often prescribed inappropriately, either when they are not necessary or with an unnecessarily broad spectrum of activity. AWaRe (AccessWatchReserve) is a system developed by WHO to classify antibiotics based on their spectrum of activity and potential for favouring the development of antibiotic resistance (Access: narrow spectrum/low potential for resistance; Watch: broader spectrum/higher potential for resistance; Reserve: last resort antibiotics to use very selectively). The WHO target is that by 2023, at least 60% of prescribed antibiotics globally should be from the Access category. The WHO AWaRe Book aims to improve empiric antibiotic prescribing by providing simple guidance for common infections based on the principles of AWaRe in alignment with the Model Lists of Essential Medicines for adults and children.

HIV-associated tuberculosis.

Tuberculosis (TB) remains a leading cause of morbidity and mortality among people living with HIV. HIV-associated TB disproportionally affects African countries, particularly vulnerable groups at risk for both TB and HIV. Currently available TB diagnostics perform poorly in people living with HIV; however, new diagnostics such as Xpert Ultra and lateral flow urine lipoarabinomannan assays can greatly facilitate diagnosis of TB in people living with HIV. TB preventive treatment has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Shorter regimens using rifapentine can support increased availability and scale-up. Mortality is high in people with HIV-associated TB, and timely initiation of ART is critical. Programs should provide decentralized and integrated TB and HIV care in settings with high burden of both diseases to improve access to services that diagnose TB and HIV as early as possible. The new prevention and diagnosis tools recently recommended by WHO offer an immense opportunity to advance our fight against HIV-associated TB. They should be made widely available and scaled up rapidly supported by adequate funding with robust monitoring of the uptake to advance global TB elimination.

Identifying global research gaps to mitigate antimicrobial resistance: A scoping review.

OBJECTIVE: Identify research gaps relevant to the global effort to combat antimicrobial resistance. METHODS: Web of Science, PubMed, Scopus, and Ovid MEDLINE were searched for reviews on antimicrobial resistance published between January 1, 2015 and December 31, 2019. Recommendations for future research were identified. FINDINGS: Seventy-four reviews met inclusion criteria; 300 research gaps and recommendations were identified. The largest number were from the human health sector (105; 35%) followed by environmental health (72; 23%), animal health (66; 22%), food and feed (14; 5%), and plants and crops (8; 3%); 35 (12%) involved more than one sector. The largest number of gaps concerned surveillance of resistance (68; 23%), followed by study design or methodology (52; 17%), interventions (41; 14%), risk assessment and modeling (35; 12%), ecological (26; 9%) and biochemical (28; 9%) aspects of resistance, interface between reservoirs of resistant pathogens (24; 8%), and economic (15; 5%) and awareness- and behavior-related (11; 4%) aspects of antimicrobial resistance. CONCLUSIONS: Important research gaps remain in our complete understanding of antimicrobial resistance, and more research is needed about its development, transmission, and impact across the interface of human, animal, and environmental reservoirs.

Prevention of tuberculosis in household members: estimates of children eligible for treatment.

OBJECTIVE: To estimate of the number of children younger than 5 years who were household contacts of people with tuberculosis and were eligible for tuberculosis preventive treatment in 2017. METHODS: To estimate the number of eligible children, we obtained national values for the number of notified cases of bacteriologically confirmed pulmonary tuberculosis in 2017, the proportion of the population younger than 5 years in 2017 and average household size from published sources. We obtained global values for the number of active tuberculosis cases per household with an index case and for the prevalence of latent tuberculosis infection among children younger than 5 years who were household contacts of a tuberculosis case through systematic reviews, meta-analysis and Poisson regression models. FINDINGS: The estimated number of children younger than 5 years eligible for tuberculosis preventive treatment in 2017 globally was 1.27 million (95% uncertainty interval, UI: 1.24-1.31), which corresponded to an estimated global coverage of preventive treatment in children of 23% at best. By country, the estimated number ranged from less than one in the Bahamas, Iceland, Luxembourg and Malta to 350 000 (95% UI: 320 000-380 000) in India. Regionally, the highest estimates were for the World Health Organization (WHO) South-East Asia Region (510 000; 95% UI: 450 000-580 000) and the WHO African Region (470 000; 95% UI: 440 000-490 000). CONCLUSION: Tuberculosis preventive treatment in children was underutilized globally in 2017. Treatment should be scaled up to help eliminate the pool of tuberculosis infection and achieve the End TB Strategy targets.

Identifying priorities for HIV-associated tuberculosis research through the WHO guidelines process.

PURPOSE OF REVIEW: Guidelines developed by the WHO aim to provide recommendations to support best practice in health delivery, with a focus on low-income and middle-income countries. As part of the guideline development process, critical knowledge gaps are identified and one of the core functions of WHO guidelines is to set forth priorities for future research. A review of research priorities identified through the WHO guideline development has recently been promoted as one approach to building an overarching priority research agenda in a given area. This paper outlines priorities for HIV-associated TB research identified in WHO HIV and TB guidelines published since 2015. RECENT FINDINGS: Nine guidelines were reviewed and 29 priority research questions were identified. Research priorities were identified for prevention of HIV-associated TB (11 questions), screening of latent and active TB in people living with HIV (six questions), treatment of drug sensitive (four questions), and drug-resistant (two questions) TB, and treatment of HIV in people coinfected with TB (three questions). SUMMARY: Multiple approaches to defining priority research questions for health research exist. Research priorities that arise from the WHO guideline development process are limited to those areas for which guidelines are developed. One strength of this approach is that it takes as a starting point a desire to make actionable recommendations for policy makers. WHO is working to further refine the formulation of research questions within the guideline development process.

Sensitivity and specificity of WHO's recommended four-symptom screening rule for tuberculosis in people living with HIV: a systematic review and meta-analysis.

BACKGROUND: Since 2011, WHO recommends a four-symptom screening rule to exclude active tuberculosis in people living with HIV before starting tuberculosis preventive treatment (ie, absence of current cough, weight loss, night sweats, or fever). We assessed the sensitivity and specificity of the screening rule among people living with HIV based on antiretroviral therapy (ART) status and the added contribution of chest radiography. METHODS: We did a systematic review and meta-analysis. We searched PubMed, Embase, and the Cochrane Library from Jan 1, 2011, to March 12, 2018, for studies published after the WHO issued recommendations on the use of the four-symptom screening rule. We also searched abstracts from relevant international conferences. We included studies that collected sputum or any specimens (eg, urine, blood, or fine-needle aspirates from lymph nodes) from people with HIV regardless of signs or symptoms. Case-control studies were excluded because they are prone to bias. Active tuberculosis was diagnosed with bacteriological confirmation by culture or Xpert MTB/RIF of any specimens. Two investigators extracted the data, including age, sex, and ART status. We calculated sensitivity, specificity, and 95% CI. When at least four studies were available, we estimated pooled sensitivity and specificity using random and effects bivariate models; otherwise we used univariate random-effects models. FINDINGS: Of 4615 records identified by the search, 21 were included in the review (involving 15 427 people including 1559 with active tuberculosis). 18 eligible studies were included in the final meta-analysis. Seven studies provided data on people receiving ART. The pooled sensitivity of the four-symptom screening rule was lower for 4640 people on ART (51·0%, 95% CI 28·4-73·2) than for 8664 who were ART-naive (89·4%, 83·0-93·5). Pooled specificity for those on ART was 70·7% (95% CI 47·8-86·4) and for ART-naive people was 28·1% (18·6-40·1). On the basis of data from 646 individuals in two studies, the addition of any abnormal chest radiographic findings in people on ART improved sensitivity from 52·2% (95% CI 38·0-66·0) to 84·6% (69·7-92·9) but decreased specificity from 55·5% (95% CI 51·8-59·2) to 29·8% (26·3-33·6). INTERPRETATION: Our review suggested a lower sensitivity of the WHO four-symptom screening rule among people with HIV who are on ART than in those who are ART naive. The addition of chest radiography could improve the screening rule in people living with HIV who are on ART, provided it does not pose a barrier to preventive treatment. FUNDING: None.

Case Definition of Chronic Pulmonary Aspergillosis in Resource-Constrained Settings.

Chronic pulmonary aspergillosis (CPA) is a recognized complication of pulmonary tuberculosis (TB). In 2015, the World Health Organization reported 2.2 million new cases of nonbacteriologically confirmed pulmonary TB; some of these patients probably had undiagnosed CPA. In October 2016, the Global Action Fund for Fungal Infections convened an international expert panel to develop a case definition of CPA for resource-constrained settings. This panel defined CPA as illness for >3 months and all of the following: 1) weight loss, persistent cough, and/or hemoptysis; 2) chest images showing progressive cavitary infiltrates and/or a fungal ball and/or pericavitary fibrosis or infiltrates or pleural thickening; and 3) a positive Aspergillus IgG assay result or other evidence of Aspergillus infection. The proposed definition will facilitate advancements in research, practice, and policy in lower- and middle-income countries as well as in resource-constrained settings.

Implementation of tuberculosis prevention for exposed children, Burkina Faso.

OBJECTIVE: To develop and test a simple system for recording and reporting the diagnosis and treatment of latent tuberculosis infection and to compare the effects of passive and active tracing of child contacts on indicators of such infection. METHODS: We revised Burkina Faso's latent tuberculosis infection register and quarterly tuberculosis reporting form. Subsequently, coverage of the routine screening of contacts, who were younger than five years, for active tuberculosis and the corresponding percentages of such contacts who, if eligible, initiated preventive therapy were measured, nationwide, between 1 April 2016 and 31 March 2017. In 2016, we evaluated indicators of latent tuberculosis infection in the Hauts-Bassins region before and after community health workers had begun the active tracing of contacts who were younger than five years. FINDINGS: In Burkina Faso, during our study period, 3717 cases of pulmonary tuberculosis and 1166 corresponding contacts who were younger than five years were reported as the result of routine screening and passive contact tracing. The overall contact:index ratio was 0.31 and corresponding screening coverage was 82.0% (956/1166) and proportion of children starting on preventive treatment was 90.5% (852/941). Active tracing in Hauts-Bassins led to a substantially higher contact/index ratio (1.83) and screening coverage (99.3%; 145/146). CONCLUSION: The newly established recording and reporting system proved feasible and user-friendly and allowed measurement of global indicators of latent tuberculosis infection. Compared with active tracing, passive tracing led to much lower estimates of the numbers of child contacts.

National policies on the management of latent tuberculosis infection: review of 98 countries.

OBJECTIVE: To review policies on management of latent tuberculosis infection in countries with low and high burdens of tuberculosis. METHODS: We divided countries reporting data to the World Health Organization (WHO) Global Tuberculosis Programme into low and high tuberculosis burden, based on WHO criteria. We identified national policy documents on management of latent tuberculosis through online searches, government websites, WHO country offices and personal communication with programme managers. We made a descriptive analysis with a focus on policy gaps and deviations from WHO policy recommendations. FINDINGS: We obtained documents from 68 of 113 low-burden countries and 30 of 35 countries with the highest burdens of tuberculosis or human immunodeficiency virus (HIV)-associated tuberculosis. Screening and treatment of latent tuberculosis infection in people living with HIV was recommended in guidelines of 29 (96.7%) high-burden and 54 (79.7%) low-burden countries. Screening for children aged < 5 years with household tuberculosis contact was the policy of 25 (83.3%) high- and 28 (41.2%) low-burden countries. In most high-burden countries the recommendation was symptom screening alone before treatment, whereas in all low-burden countries it was testing before treatment. Some low-burden countries' policies did not comply with WHO recommendations: nine (13.2%) recommended tuberculosis preventive treatment for travellers to high-burden countries and 10 (14.7%) for patients undergoing abdominal surgery. CONCLUSION: Lack of solid evidence on certain aspects of management of latent tuberculosis infection results in national policies which vary considerably. This highlights a need to advance research and develop clear, implementable and evidence-based WHO policies.

Tuberculosis elimination and the challenge of latent tuberculosis.

Latent tuberculosis infection (LTBI) affects one third to one fourth of the human population and is the reservoir for a significant proportion of emerging active tuberculosis (TB) cases, especially in low incidence countries. The World Health Organization launched in 2015 the END-TB strategy that aims at TB elimination and promotes, for the first time ever, the management of LTBI. The preventive package, basically consisting of testing and treatment for LTBI in groups at high risk of reactivation, is a mainstay of the first pillar of the strategy, alongside prompt diagnosis and early treatment of both drug-susceptible and drug-resistant TB disease. Testing and treatment for LTBI should be pursued with a programmatic perspective. This implies strong political commitment, adequate funding and an effective monitoring and evaluation system. People living with HIV and children under five years of age who are household contact of a contagious TB cases are primarily targeted in all epidemiological setting. In high resource and low incidence setting, additional at risk populations should also be the target for systematic LTBI testing and treatment. Research is urgently needed to develop diagnostic tests with higher predictive value to identify individuals that progress from infection to disease. Similarly, shorter and safer treatment regimens are needed to make the trade-off between potential benefits and harms more favourable for an increasing proportion of infected individuals.

Tuberculosis.

Tuberculosis (TB) is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis complex. Although primarily a pulmonary pathogen, M. tuberculosis can cause disease in almost any part of the body. Infection with M. tuberculosis can evolve from containment in the host, in which the bacteria are isolated within granulomas (latent TB infection), to a contagious state, in which the patient will show symptoms that can include cough, fever, night sweats and weight loss. Only active pulmonary TB is contagious. In many low-income and middle-income countries, TB continues to be a major cause of morbidity and mortality, and drug-resistant TB is a major concern in many settings. Although several new TB diagnostics have been developed, including rapid molecular tests, there is a need for simpler point-of-care tests. Treatment usually requires a prolonged course of multiple antimicrobials, stimulating efforts to develop shorter drug regimens. Although the Bacillus Calmette-Guérin (BCG) vaccine is used worldwide, mainly to prevent life-threatening TB in infants and young children, it has been ineffective in controlling the global TB epidemic. Thus, efforts are underway to develop newer vaccines with improved efficacy. New tools as well as improved programme implementation and financing are necessary to end the global TB epidemic by 2035.

Assessing the impact of defining a global priority research agenda to address HIV-associated tuberculosis.

OBJECTIVES: In 2010, the WHO issued 77 priority research questions (PRQs) to address HIV-associated TB. Objective of the this study was to assess the impact of defining the research agenda in stimulating and directing research around priority research questions. METHODS: We used number and type of scientific publications as a proxy to quantitatively assess the impact of research agenda setting. We conducted 77 single systematic reviews - one for every PRQ - building 77 different search strategies using PRQs' keywords. Multivariate logistic regression models were applied to assess the quantity and quality of research produced over time and accounting for selected covariates. RESULTS: In 2009-2015, PRQs were addressed by 1631 publications (median: 11 studies published per PRQ, range 1-96). The most published area was 'Intensified TB case finding' (median: 23 studies/PRQ, range: 2-74). The majority (62.1%, n = 1013) were published as original studies, and more than half (58%, n = 585) were conducted in the African region. Original studies' publication increased over the study period (P trend = <0.001). They focused more on the 'Intensified TB case finding' (OR = 2.17, 95% CI: 1.56-2.93) and 'Drug-resistant TB and HIV infection' (OR = 2.12, 95% CI: 1.47-3.06) areas than non-original studies. Original studies were published in journals of lower impact factor and received a smaller number of citations than non-original studies (OR = 0.54, 95% CI: 0.42-0.69). CONCLUSION: The generation of evidence to address PRQs has increased over time particularly in selected fields. Setting a priority research agenda for HIV-associated TB might have positively influenced the direction and the conduct of research and contributed to the global response to such a major threat to health.