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National Immunization Technical Advisory Groups (NITAGs) are independent bodies that help improve national immunization programmes in decision making on immunization policy. The new NITAG Maturity Assessment Tool (NMAT) provided an opportunity to conduct a region-wide assessment to improve NITAG capacity and foster institutional growth. We share experience of the Eastern Mediterranean Region (EMR) of the World Health Organization (WHO) in using NMAT and the use of findings to develop improvement plans. NITAG chairs and secretariats from 22 EMR countries attended a virtual NMAT training in 2023. They self-assessed their NITAGs using the tool and developed improvement plans. An algorithm used the data to determine maturity levels for seven indicators. We consolidated results for the region by income groups. Of 22 countries (or NITAGs), 20 (91%) submitted NITAG assessment findings and 19 an improvement plan. The proportion of criteria met per indicator varied from 36% for independence and non-bias to 74% for establishment and composition. Maturity level varied by indicator. Of 20 NITAGs, less than half had an intermediate or higher-level maturity for the indicators of independence and non-bias 1 (5%), operations 3 (15%), making recommendations 4 (20%), stakeholder recognition 6 (30%), and resources and secretariat support 7 (35%). Meanwhile 11 (55%) NITAGs had an intermediate or higher maturity level for the indicators of establishment and composition and for integration into policy making process. Participants described NMAT as a concise, useful, user-friendly tool. NMAT is a practical tool that can be used by NITAGs to provide insights and strategic direction for individual countries and regionally. Prevention and management of conflict of interest is the domain that requires the most improvement in EMR. Planned activities should be implemented, monitored and a follow up assessment conducted in 2025.
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Comitês Consultivos , Política de Saúde , Humanos , Programas de Imunização , Imunização , Organização Mundial da SaúdeRESUMO
The World Health Organization (WHO) recommends the consideration of introducing routine hepatitis A vaccination into national immunization schedules for children ≥ 1 years old in countries with intermediate HAV endemicity. Recent data suggest that South Africa is transitioning from high to intermediate HAV endemicity, thus it is important to consider the impact and cost of potential routine hepatitis A vaccination strategies in the country. An age-structured compartmental model of hepatitis A transmission was calibrated with available data from South Africa, incorporating direct costs of hepatitis A treatment and vaccination. We used the calibrated model to evaluate the impact and costs of several childhood hepatitis A vaccination scenarios from 2023 to 2030. We assessed how each scenario impacted the burden of hepatitis A (symptomatic hepatitis A cases and mortality) as well as calculated the incremental cost per DALY averted as compared to the South African cost-effectiveness threshold. All costs and outcomes were discounted at 5%. For the modelled scenarios, the median estimated cost of the different vaccination strategies ranged from USD 1.71 billion to USD 2.85 billion over the period of 2023 to 2030, with the cost increasing for each successive scenario and approximately 39-52% of costs being due to vaccination. Scenario 1, which represented the administration of one dose of the hepatitis A vaccine in children < 2 years old, requires approximately 5.3 million vaccine doses over 2023-2030 and is projected to avert a total of 136,042 symptomatic cases [IQR: 88,842-221,483] and 31,106 [IQR: 22,975-36,742] deaths due to hepatitis A over the period of 2023 to 2030. The model projects that Scenario 1 would avert 8741 DALYs over the period of 2023 to 2030; however, it is not cost-effective against the South African cost-effectiveness threshold with an ICER per DALY averted of USD 21,006. While Scenario 3 and 4 included the administration of more vaccine doses and averted more symptomatic cases of hepatitis A, these scenarios were absolutely dominated owing to the population being infected before vaccination through the mass campaigns at older ages. The model was highly sensitive to variation of access to liver transplant in South Africa. When increasing the access to liver transplant to 100% for the baseline and Scenario 1, the ICER for Scenario 1 becomes cost-effective against the CET (ICER = USD 2425). Given these findings, we recommend further research is conducted to understand the access to liver transplants in South Africa and better estimate the cost of liver transplant care for hepatitis A patients. The modelling presented in this paper has been used to develop a user-friendly application for vaccine policy makers to further interrogate the model outcomes and consider the costs and benefits of introducing routine hepatitis A vaccination in South Africa.
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Tetanus, pertussis, influenza, and COVID-19 vaccines are recommended for the prevention of related morbidity and mortality during pregnancy and postpartum. Despite the established benefits of vaccination for prenatal and postnatal women, maternal vaccination is not universally included in routine antenatal programs, especially in low- and middle-income countries. Furthermore, the uptake of recommended vaccines among pregnant and postpartum women remains below optimum globally. This review aimed to map the evidence on interventions to improve knowledge, attitudes, and uptake of recommended vaccines among pregnant and postpartum women. We conducted a comprehensive and systematic search for relevant literature in PubMed, Scopus, Web of Science, EBSCOhost, and Google Scholar. Overall, 29 studies published between 2010 and 2023 were included in this review. The majority (n = 27) of these studies were from high-income countries. A total of 14 studies focused on the influenza vaccine, 6 on the Tdap vaccine, 8 on both influenza and Tdap vaccines, and only one study on the COVID-19 vaccine. Patient-centered interventions predominated the evidence base (66%), followed by provider-focused (7%), health system-focused (10%), and multilevel interventions (17%). Overall, the effect of these interventions on knowledge, attitudes, and uptake of maternal vaccines was variable.
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Tuberculosis (TB) is a global health emergency. Across the globe, approximately 2 billion people are currently infected with Mycobacterium tuberculosis (Mtb), and of those, 5-10% may progress to become ill and potentially transmit the bacterium. In 2021, nearly 10.6 million people developed TB disease and 1.6 million died. There is an urgent need for accelerated development of new TB-focused interventions, in particular, improved TB vaccines. However, progress in developing highly effective TB vaccines has been slow and is chronically under-resourced. The mRNA vaccine platform may offer an opportunity to accelerate development of new TB vaccines. In April 2023, the World Health Organization convened global experts to discuss the feasibility and potential value of mRNA-based vaccines for TB. Here we report on meeting deliberations related to the current TB vaccine pipeline and potential novel antigens, the status of efforts to identify correlates of protection, potential clinical development strategies and considerations for community acceptance of new TB vaccines based on this relatively new platform. The role of industry collaborations, ethics, social science, and responsibility to the global community regarding transparency and manufacturing capacity building were discussed through expert presentations and panel sessions. The overall conclusion of the meeting is that mRNA-based vaccines constitute a potentially powerful new tool for reducing the global burden of TB.
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Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose , Humanos , Vacinas contra a Tuberculose/genética , Mycobacterium tuberculosis/genética , Organização Mundial da Saúde , RNA Mensageiro/genéticaRESUMO
BACKGROUND: It is evident that COVID-19 will remain a public health concern in the coming years, largely driven by variants of concern (VOC). It is critical to continuously monitor vaccine effectiveness as new variants emerge and new vaccines and/or boosters are developed. Systematic surveillance of the scientific evidence base is necessary to inform public health action and identify key uncertainties. Evidence syntheses may also be used to populate models to fill in research gaps and help to prepare for future public health crises. This protocol outlines the rationale and methods for a living evidence synthesis of the effectiveness of COVID-19 vaccines in reducing the morbidity and mortality associated with, and transmission of, VOC of SARS-CoV-2. METHODS: Living evidence syntheses of vaccine effectiveness will be carried out over one year for (1) a range of potential outcomes in the index individual associated with VOC (pathogenesis); and (2) transmission of VOC. The literature search will be conducted up to May 2023. Observational and database-linkage primary studies will be included, as well as RCTs. Information sources include electronic databases (MEDLINE; Embase; Cochrane, L*OVE; the CNKI and Wangfang platforms), pre-print servers (medRxiv, BiorXiv), and online repositories of grey literature. Title and abstract and full-text screening will be performed by two reviewers using a liberal accelerated method. Data extraction and risk of bias assessment will be completed by one reviewer with verification of the assessment by a second reviewer. Results from included studies will be pooled via random effects meta-analysis when appropriate, or otherwise summarized narratively. DISCUSSION: Evidence generated from our living evidence synthesis will be used to inform policy making, modelling, and prioritization of future research on the effectiveness of COVID-19 vaccines against VOC.
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COVID-19 , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , SARS-CoV-2 , Eficácia de Vacinas , Viés , Metanálise como AssuntoRESUMO
Introduction: It is estimated that one in five African children lack access to recommended life-saving vaccines. This situation has been exacerbated by the COVID-19 pandemic which disrupted routine immunization services in several parts of the region. To better support recovery efforts and get immunization programmes back on track, policy makers, programme managers, immunization providers and academics need continuous upskilling. Unfortunately, the vaccinology training needed by these cadres remains limited and oftentimes inaccessible within our context. In addition, cadres should be continuously updated on advances in vaccinology so as to keep abreast with this rapidly evolving field. This calls for new and accessible approaches to training vaccinologists in Africa where the demand is high. Methods: The aim of this proof-of-concept study was to ascertain the training needs of alumni of the Annual African Vaccinology Course and assess the effectiveness of an online webinar series in meeting those needs. Results: We found that alumni from across Africa required refresher training to gain up-to-date information about new developments in vaccinology, leverage opportunities to reinforce and consolidate their knowledge, and exchange country-specific experiences with their counterparts. A prominent motivation for refresher training was the rapid developments and challenges brought on by the COVID-19 pandemic. Drawing on the expressed needs of our alumni, we developed a webinar training series. This series aimed to provide participants with training on current and emerging trends in vaccinology with a focus on the regional context. Online participation in the webinar series was found to be comparable to previous in-person training, reaching a diverse group of cadres, and allowing for participation of a richer global faculty due to fewer cost constraints. Further to this, a post-training survey indicated that generally, alumni training needs were successfully met. Discussion: The findings suggest that an online approach can be used to expand the reach of vaccinology training in Africa.
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Mycobacterium tuberculosis and HIV constitute a public health challenge. Health workers (HWs) in HIV clinics maybe at greater risk of M. tuberculosis infection, considering the high rates of HIV/tuberculosis (TB) coinfection among patients. Hence, we measured the prevalence of M. tuberculosis infection and the effect of working in an HIV clinic. We conducted a cross-sectional study in high-HIV burden health-care facilities in Abuja and Nasarawa states and recruited HWs over 4 months. We administered questionnaires and screened for M. tuberculosis infection using QuantiFERON-TB Gold-Plus. A total of 1,043 HWs were enrolled, with the majority being clinical staff (77.4%). Prevalence of interferon gamma release assay (IGRA) positivity was 44.8% (43.8% among HWs from HIV clinic and 45.3% from non-HIV clinics, P = 0.24). Nonoccupational factors such as living in a moderately (odds ratio [OR] = 0.71] or sparsely populated neighborhood (OR = 0.56), remained associated with a reduced risk of IGRA positivity, whereas male gender (OR = 1.37) and having high blood pressure (HBP) (OR = 1.52) remained associated with an increased risk after adjusting. Occupational factors such as length of career as a HW of 10 to 20 years (OR = 1.45) or 20 to 30 years (OR = 1.74) remained associated with an increased risk of IGRA positivity after adjusting. In a final multivariate model, the factors of age between 20 to < 30 years (OR = 0.61), having HBP (OR = 1.56), having a length of career as a HW of 10 to 20 years (OR = 1.66) or 20 to 30 years (OR = 2.09) and being a clinical HW (OR = 0.62) remained associated with IGRA positivity. There is a high prevalence of IGRA positivity among HWs in Nigeria. Working in HIV clinics, however, is not associated with increased risk.
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Infecções por HIV , Tuberculose Latente , Mycobacterium tuberculosis , Tuberculose , Humanos , Masculino , Adulto Jovem , Adulto , Tuberculose Latente/epidemiologia , Testes de Liberação de Interferon-gama , Prevalência , Estudos Transversais , Nigéria/epidemiologia , Tuberculose/epidemiologia , Tuberculose/complicações , Fatores de Risco , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Teste TuberculínicoRESUMO
National immunization technical advisory groups (NITAGs) develop immunization-related recommendations and assist policy-makers in making evidence informed decisions. Systematic reviews (SRs) that summarize the available evidence on a specific topic are a valuable source of evidence in the development of such recommendations. However, conducting SRs requires significant human, time, and financial resources, which many NITAGs lack. Given that SRs already exist for many immunization-related topics, and to prevent duplication and overlap of reviews, a more practical approach may be for NITAGs to use existing SRs. Nevertheless, it can be challenging to identify relevant SRs, to select one SR from among multiple SRs, or to critically assess and effectively use them. To support NITAGs, the London School of Hygiene and Tropical Medicine, Robert Koch Institute and collaborators developed the SYSVAC project, which consists of an online registry of systematic reviews on immunization-related topics and an e-learning course, that supports the use of them (both freely accessible at https://www.nitag-resource.org/sysvac-systematic-reviews). Drawing from the e-learning course and recommendations from an expert panel, this paper outlines methods for using existing systematic reviews when making immunization-related recommendations. With specific examples and reference to the SYSVAC registry and other resources, it offers guidance on locating existing systematic reviews; assessing their relevance to a research question, up-to-dateness, and methodological quality and/or risk of bias; and considering the transferability and applicability of their findings to other populations or settings.
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Política de Saúde , Programas de Imunização , Humanos , Revisões Sistemáticas como Assunto , Imunização , Vacinação/métodosRESUMO
BACKGROUND: While some evidence has been demonstrated the cost-effectiveness of routine hepatitis A vaccination in middle-income countries, the evidence is still limited in other settings including in South Africa. Given this, the evidence base around the cost of care for hepatitis A needs to be developed towards considerations of introducing hepatitis A vaccines in the national immunisation schedule and guidelines. OBJECTIVES: To describe the severity, clinical outcomes, and cost of hepatitis A cases presenting to two tertiary healthcare centers in Cape Town, South Africa. METHODS: We conducted a retrospective folder review of patients presenting with hepatitis A at two tertiary level hospitals providing care for urban communities of metropolitan Cape Town, South Africa. Patients included in this folder review tested positive for hepatitis A immunoglobulin M between 1 January 2008 and 1 March 2018. RESULTS: In total, 239 folders of hepatitis A paediatric patients < 15 years old and 212 folders of hepatitis A adult patients [Formula: see text] 15 years old were included in the study. Before presenting for tertiary level care, more than half of patients presented for an initial consultation at either a community clinic or general physician. The mean length of hospital stay was 7.45 days for adult patients and 3.11 days for paediatric patients. Three adult patients in the study population died as a result of hepatitis A infection and 29 developed complicated hepatitis A. One paediatric patient in the study population died as a result of hepatitis A infection and 27 developed complicated hepatitis A, including 4 paediatric patients diagnosed with acute liver failure. The total cost per hepatitis A hospitalisation was $1935.41 for adult patients and $563.06 for paediatric patients, with overhead costs dictated by the length of stay being the largest cost driver. CONCLUSION: More than 1 in every 10 hepatitis A cases (13.3%) included in this study developed complicated hepatitis A or resulted in death. Given the severity of clinical outcomes and high costs associated with hepatitis A hospitalisation, it is important to consider the introduction of hepatitis A immunisation in the public sector in South Africa to potentially avert future morbidity, mortality, and healthcare spending.
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Hepatite A , Adolescente , Adulto , Criança , Análise Custo-Benefício , Hepatite A/epidemiologia , Humanos , Estudos Retrospectivos , África do Sul/epidemiologia , VacinaçãoRESUMO
Adherence to recommended age-specific immunisation schedules is critical in ensuring vaccine effectiveness against vaccine preventable diseases (VPDs). There is limited data on immunisation timeliness in sub-Saharan Africa. Therefore, this study assessed the timeliness of age-specific routine childhood immunisation within the Western Cape Province of South Africa. Participant records (N = 709) from a prospective health-facility based study conducted in Cape Town, SA in 2012-2016 were analysed. The outcome measure was receiving age-specific immunisations ≥4 weeks of that recommended for age as per the South African Expanded Programme on Immunisation (EPI-SA) schedule. Proportions, medians, inter-quartile ranges (IQR) and regression were used to obtain the prevalence, time-at-risk, and risk factors for delayed immunisation. A total of 652 /709 (91.9%) participants were eligible. Immunisation coverage declined with age from 94.9% (95% CI 92.9-96.4) at birth to 72.0% (95% CI 65.7-77.6) at 18 months. The highest delay in the uptake of vaccine doses was observed among the 3 rd dose of the DTP vaccine [163 (34.6% (95% CI 30.3-39.1)], while the lowest was seen among BCG [40 (6.5% (95% CI 4.7-8.8)]. The longest median time-at-risk of VPDs was among the 2 nd dose of the measles vaccine [12.9 (IQR 6.7-38.6) weeks] and the lowest was OPV birth dose [IQR 6.3 (5.3-9.1) weeks]. Low and upper-middle socio-economic quartiles were associated with delayed uptake of vaccine doses. Delayed vaccination increases the time of susceptibility to VPDs during infancy and childhood. There is a need to develop strategies aimed at mitigating factors associated with delay in uptake of routine childhood vaccines in the Western Cape. Mitigation strategies should provide vaccine education and mobile reminder systems. Education about timely vaccine uptake will aid in the provision of informed council from healthcare providers to caregivers. Multiple reminder systems could cater for low network coverage areas and caregivers with busy schedules.
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Multiple public health emergencies (PHEs) experienced annually in the World Health Organisation (WHO) Africa region affect the provision of health services, including immunization. However, there is limited information on the performance of national immunization programs (NIPs) in WHO Africa countries that experience PHEs. This study assessed PHEs (armed conflicts, disasters, and disease outbreaks) and the performance of NIPs using global and regional immunization targets outlined for the Decade of Vaccines. Thirteen beneficiary countries of PHE mitigation funds from the African Public Health Emergency Fund were used as case studies. Data on PHEs and immunization indicators between 2010 and 2019 in selected countries were extracted from different PHE databases and the WHO/UNICEF immunization database, respectively. The data were stratified by country and summarized using descriptive statistics. Mann-Whitney U test was done to determine the association between the frequency of PHEs and the performance of NIPs. There were 175 disease outbreaks, 288 armed conflicts, and 318 disasters in the examined countries between 2010 and 2019. The Democratic Republic of Congo had the highest total PHE count (n = 208), while Liberia had the lowest (n = 20). Only three of the 13 countries had a median coverage value for the third dose of the combined Diphtheria, Tetanus, and Pertussis vaccine (DTP3) that had attained the target for ≥90% immunization coverage. Higher counts of armed conflict and total PHEs were associated with not meeting immunization targets for national DTP3 coverage of ≥90% and Maternal and Neonatal Tetanus elimination, p < 0.01. It was clear that in the WHO Africa region, PHEs are prevalent, irrespective of a country's level of immunization maturity, and have the potential to derail the progress of NIPs in the absence of effective interventions. As we transition toward the Immunization Agenda 2030, we recommend that the WHO Africa region prioritizes interventions to mitigate the impacts of PHEs on NIPs.
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Vacina contra Difteria, Tétano e Coqueluche , Saúde Pública , África/epidemiologia , Emergências , Saúde Global , Humanos , Programas de Imunização , Organização Mundial da SaúdeRESUMO
For 15 years, the Annual African Vaccinology Course (AAVC) hosted by the Vaccines for Africa Initiative, has been at the forefront of vaccinology training in Africa. The AAVC was developed in 2005 in response to the growing demand for vaccinology training in Africa. To date, 958 policy makers, immunization managers, public and private health practitioners, scientists, postgraduate and postdoctoral students have been trained. These participants are from 44 of the 54 African countries. The course content covers diverse topics such as considerations for new vaccine introduction, mathematical modelling, and emerging and re-emerging vaccine preventable diseases. As the landscape of vaccinology continues to evolve, the AAVC aims to expand the reach of vaccinology training using blended learning approaches which will incorporate online and face-to-face formats, while expanding access to this popular course. Ultimately, the AAVC endeavours to develop a big pool of vaccinology expertise in Africa and to strengthen regional ownership for immunization programmes.
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Vacinação/métodos , Vacinas/administração & dosagem , Vacinologia/educação , África , Humanos , Programas de Imunização/organização & administração , Doenças Preveníveis por Vacina/prevenção & controleRESUMO
National immunization technical advisory groups (NITAGs) develop immunization-related recommendations. Systematic reviews are recommended to be used in this process, but conducting them requires significant resources, which many NITAGs lack. Using existing systematic reviews could help address this problem. The Robert Koch Institute and collaborators set up the SYSVAC2 project to facilitate the retrieval of existing systematic reviews and offer guidance on using them. This will include an online registry of systematic reviews relevant to immunization policy and an online course on how to use existing reviews. This report describes an international expert workshop held in December 2019 to develop consensus on methods for using existing reviews and other relevant factors for the registry and course. Members from NITAGs representing different regions of the world presented their experiences of using systematic reviews and reflected on challenges inhibiting use. Three methodologists considered different aspects of using systematic reviews. Interactive sessions followed, where implications for SYSVAC2 were discussed. Participants supported having critical appraisal ratings, plain language summaries, keyword search, and data visualization functions in the registry. They suggested tailoring course content to different audiences and including overviews of reviews as a topic and examples of how NITAGs have used or could use existing reviews. Participants agreed that whether a review is out-of-date should be decided by those using the review rather than registry staff. The registry could help by highlighting the date of literature search or included primary studies. Participants recommended a visualization function to highlight overlap across reviews and guidance on handling challenges to using reviews, ideally, involving a practical element. No consensus was reached on which critical appraisal tool to use for reviews in the registry, but a majority of participants wanted registry staff to perform appraisals. Formative research is planned before the registry and online course are launched in 2020.
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Programas de Imunização , Vacinação , Humanos , Imunização , Políticas , Revisões Sistemáticas como AssuntoRESUMO
OBJECTIVE: To characterise the environmental presence of hepatitis A virus (HAV) in low- and middle-income countries (LMICs). DESIGN: Systematic review and meta-analysis. DATA SOURCES: EBSCOhost, PubMed, Scopus, ScienceDirect, Clinical Key and Web of Science were searched. Grey literature was sourced by searching the following electronic databases: Open Grey, National Health Research Database and Mednar. ELIGIBILITY CRITERIA FOR INCLUDING STUDIES: Cross-sectional and ecological studies reporting HAV environmental presence and conducted in LMICs between January 2005 and May 2019, irrespective of language of publication. DATA EXTRACTION AND DATA SYNTHESIS: Relevant data were extracted from articles meeting the inclusion criteria, and two reviewers independently assessed the studies for risk of bias. High heterogeneity of the extracted data led to the results being reported narratively. RESULTS: A total of 2092 records were retrieved, of which 33 met the inclusion criteria. 21 studies were conducted in Tunisia, India and South Africa, and the rest were from Philippines, Pakistan, Morocco, Chad, Mozambique, Kenya and Uganda. In Tunisian raw sewage samples, the prevalence of HAV ranged from 12% to 68%, with an estimated average detection rate of 50% (95% CI 25 to 75), whereas HAV detection in treated sewage in Tunisia ranged from 23% to 65%, with an estimated average detection rate of 38% (95% CI 20 to 57). The prevalence of HAV detection in South African treated sewage and surface water samples ranged from 4% to 37% and from 16% to 76%, with an estimated average detection rates of 15% (95% CI 1 to 29) and 51% (95% CI 21 to 80), respectively. Over the review period, the estimated average detection rate of environmental HAV presence appeared to have declined by 10%. CONCLUSION: The quality of included studies was fair, but sampling issues and paucity of data limited the strength of the review findings. PROSPERO REGISTRATION NUMBER: CRD42019119592.
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Países em Desenvolvimento , Vírus da Hepatite A , Estudos Transversais , Humanos , Índia , Quênia , Marrocos , Moçambique , Paquistão , Filipinas , África do Sul , Tunísia , UgandaRESUMO
INTRODUCTION: Host blood transcriptomic biomarkers have potential as rapid point-of-care triage, diagnostic, and predictive tests for Tuberculosis disease. We aimed to summarise the performance of host blood transcriptomic signatures for diagnosis of and prediction of progression to Tuberculosis disease; and compare their performance to the recommended World Health Organisation target product profile. METHODS: A systematic review and meta-analysis of the performance of host blood mRNA signatures for diagnosing and predicting progression to Tuberculosis disease in HIV-negative adults and adolescents, in studies with an independent validation cohort. Medline, Scopus, Web of Science, and EBSCO libraries were searched for articles published between January 2005 and May 2019, complemented by a search of bibliographies. Study selection, data extraction and quality assessment were done independently by two reviewers. Meta-analysis was performed for signatures that were validated in ≥3 comparable cohorts, using a bivariate random effects model. RESULTS: Twenty studies evaluating 25 signatures for diagnosis of or prediction of progression to TB disease in a total of 68 cohorts were included. Eighteen studies evaluated 24 signatures for TB diagnosis and 17 signatures met at least one TPP minimum performance criterion. Three diagnostic signatures were validated in clinically relevant cohorts to differentiate TB from other diseases, with pooled sensitivity 84%, 87% and 90% and pooled specificity 79%, 88% and 74%, respectively. Four studies evaluated signatures for progression to TB disease and performance of one signature, assessed within six months of TB diagnosis, met the minimal TPP for a predictive test for progression to TB disease. CONCLUSION: Host blood mRNA signatures hold promise as triage tests for TB. Further optimisation is needed if mRNA signatures are to be used as standalone diagnostic or predictive tests for therapeutic decision-making.
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Biomarcadores/sangue , Mycobacterium tuberculosis/isolamento & purificação , Transcriptoma , Tuberculose/diagnóstico , Progressão da Doença , Humanos , Tuberculose/sangue , Tuberculose/epidemiologiaRESUMO
BACKGROUND: An effective vaccine against Bordetella pertussis was introduced into the Expanded Programme on Immunisation (EPI) by WHO in 1974, leading to a substantial global reduction in pertussis morbidity and mortality. In low- and middle-income countries (LMICs), however, the epidemiology of pertussis remains largely unknown. This impacts negatively on pertussis control strategies in these countries. This study aimed to systematically and comprehensively review published literature on the burden of laboratory-confirmed pertussis in LMICs over the 45 years of EPI. METHODS: Electronic databases were searched for relevant literature (1974 to December 2018) using common and MeSH terms for pertussis. Studies using PCR, culture or paired serology to confirm Bordetella pertussis and parapertussis in symptomatic individuals were included if they had clearly defined numerators and denominators to determine prevalence and mortality rates. RESULTS: Eighty-two studies (49,167 participants) made the inclusion criteria. All six WHO regions were represented with most of the studies published after 2010 and involving mainly upper middle-income countries (n = 63; 77%). PCR was the main diagnostic test after the year 2000. The overall median point prevalence of PCR-confirmed Bordetella pertussis was 11% (interquartile range (IQR), 5-27%), while culture-confirmed was 3% (IQR 1-9%) and paired serology a median of 17% (IQR 3-23%) over the period. On average, culture underestimated prevalence by 85% (RR = 0.15, 95% CI, 0.10-0.22) compared to PCR in the same studies. Risk of pertussis increased with HIV exposure [RR, 1.4 (95% CI, 1.0-2.0)] and infection [RR, 2.4 (95% CI, 1.1-5.1)]. HIV infection and exposure were also related to higher pertussis incidences, higher rates of hospitalisation and pertussis-related deaths. Pertussis mortality and case fatality rates were 0.8% (95% CI, 0.4-1.4%) and 6.5% (95% CI, 4.0-9.5%), respectively. Most deaths occurred in infants less than 6 months of age. CONCLUSIONS: Despite the widespread use of pertussis vaccines, the prevalence of pertussis remains high in LMIC over the last three decades. There is a need to increase access to PCR-based diagnostic confirmation in order to improve surveillance. Disease control measures in LMICs must take into account the persistent significant infant mortality and increased disease burden associated with HIV infection and exposure.
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Bordetella pertussis/patogenicidade , Programas de Imunização/métodos , Coqueluche/epidemiologia , Países em Desenvolvimento , Feminino , História do Século XX , Humanos , MasculinoRESUMO
BACKGROUND: There is limited evidence on whether screening for type 2 diabetes mellitus affects health outcomes. A recent systematic review of randomised clinical trials found only one trial that met their inclusion criteria; therefore, current guidelines for screening interventions for type 2 diabetes mellitus are based on expert opinions and best practice rather than synthesised evidence. This systematic review seeks to collate evidence from non-randomised studies to investigate the effect of screening for adults with type 2 diabetes on outcomes including diabetes-related morbidity, mortality (all-cause and diabetes-related) and harms. METHODS: This systematic review will follow Effective Practice and Organisation of Care (EPOC) guidelines for the synthesis of non-randomised studies. We will search PubMed/MEDLINE, Scopus, Web of Science, CINAHL, Academic Search Premier and Health Source Nursing Academic (from inception onwards). We will include non-randomised trials, controlled before-after studies, interrupted time-series studies, repeated measures studies and concurrently controlled prospective cohort studies. The primary outcome will be diabetes-related morbidity (microvascular complications of diabetic retinopathy, nephropathy or neuropathy or macrovascular complications of non-fatal myocardial infarction, peripheral arterial disease or non-fatal stroke). The secondary outcomes will be mortality (all-cause and diabetes-related) and harms of screening strategies to patients (including psychological harms or adverse events following treatments) or to health care system (including resource allocation for false-positives or overdiagnosis). Two reviewers will independently screen all citations and full-text articles. Data will be abstracted by one reviewer and checked by a second. The risk of bias of individual studies will be appraised using the ROBINS-I tool. GRADE will be used to determine the quality of the scientific evidence. If feasible, we will conduct random effects meta-analysis where appropriate. If necessary, analyses will be conducted to explore the potential sources of heterogeneity (e.g. age, sex, socio-economic status, rural versus urban or low-middle income versus high-income country). We will disseminate the findings via publications and through relevant networks. DISCUSSION: The protocol outlines the methods for systematically reviewing and synthesising evidence of screening strategies for type 2 diabetes mellitus and their effect on health outcomes associated with the disease. The potential impact of this systematic review is improved evidence-informed decision-making for policies and practice for screening of type-2 diabetes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020147439.