Role of healthcare workers in early epidemic spread of Ebola: policy implications of prophylactic compared to reactive vaccination policy in outbreak prevention and control.

Ebola causes severe illness in humans and has epidemic potential. How to deploy vaccines most effectively is a central policy question since different strategies have implications for ideal vaccine profile. More than one vaccine may be needed. A vaccine optimised for prophylactic vaccination in high-risk areas but when the virus is not actively circulating should be safe, well tolerated, and provide long-lasting protection; a two- or three-dose strategy would be realistic. Conversely, a reactive vaccine deployed in an outbreak context for ring-vaccination strategies should have rapid onset of protection with one dose, but longevity of protection is less important. In initial cases, before an outbreak is recognised, healthcare workers (HCWs) are at particular risk of acquiring and transmitting infection, thus potentially augmenting early epidemics. We hypothesise that many early outbreak cases could be averted, or epidemics aborted, by prophylactic vaccination of HCWs. This paper explores the potential impact of prophylactic versus reactive vaccination strategies of HCWs in preventing early epidemic transmissions. To do this, we use the limited data available from Ebola epidemics (current and historic) to reconstruct transmission trees and illustrate the theoretical impact of these vaccination strategies. Our data suggest a substantial potential benefit of prophylactic versus reactive vaccination of HCWs in preventing early transmissions. We estimate that prophylactic vaccination with a coverage >99% and theoretical 100% efficacy could avert nearly two-thirds of cases studied; 75% coverage would still confer clear benefit (40% cases averted), but reactive vaccination would be of less value in the early epidemic. A prophylactic vaccination campaign for front-line HCWs is not a trivial undertaking; whether to prioritise long-lasting vaccines and provide prophylaxis to HCWs is a live policy question. Prophylactic vaccination is likely to have a greater impact on the mitigation of future epidemics than reactive strategies and, in some cases, might prevent them. However, in a confirmed outbreak, reactive vaccination would be an essential humanitarian priority. The value of HCW Ebola vaccination is often only seen in terms of personal protection of the HCW workforce. A prophylactic vaccination strategy is likely to bring substantial additional benefit by preventing early transmission and might abort some epidemics. This has implications both for policy and for the optimum product profile for vaccines currently in development

The Ebola outbreak, 2013-2016: old lessons for new epidemics.

Ebola virus causes a severe haemorrhagic fever in humans with high case fatality and significant epidemic potential. The 2013-2016 outbreak in West Africa was unprecedented in scale, being larger than all previous outbreaks combined, with 28 646 reported cases and 11 323 reported deaths. It was also unique in its geographical distribution and multicountry spread. It is vital that the lessons learned from the world's largest Ebola outbreak are not lost. This article aims to provide a detailed description of the evolution of the outbreak. We contextualize this outbreak in relation to previous Ebola outbreaks and outline the theories regarding its origins and emergence. The outbreak is described by country, in chronological order, including epidemiological parameters and implementation of outbreak containment strategies. We then summarize the factors that led to rapid and extensive propagation, as well as highlight the key successes, failures and lessons learned from this outbreak and the response.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'

Systematic reviews of point-of-care tests for the diagnosis of urogenital Chlamydia trachomatis infections.

BACKGROUND: WHO estimates that 131 million new cases of urogenital Chlamydia trachomatis (CT) infections occur globally every year. Most infections are asymptomatic. Untreated infection in women can lead to severe complications. Screening and treatment of at-risk populations is a priority for prevention and control. OBJECTIVES: To summarise systematic reviews of the performance characteristics of commercially available point-of-care tests (POCT) for screening and diagnosis of urogenital CT infection. METHODS: Two separate systematic reviews covering the periods 2004-2013 and 2010-2015 were conducted on rapid CT POCTs. Studies were included if tests were evaluated against a valid reference standard. RESULTS: In the first review, 635 articles were identified, of which 11 were included. Nine studies evaluated the performance of eight antigen detection rapid POCTs on 10 280 patients and two studies evaluated a near-patient nucleic acid amplification test (NAAT) on 3518 patients. Pooled sensitivity of antigen detection tests was 53%, 37% and 63% for cervical swabs, vaginal swabs and male urine, and specificity was 99%, 97% and 98%, respectively. The pooled sensitivity and specificity of the near-patient NAAT for all specimen types were >98% and 99.4%, respectively. The second review identified two additional studies on four antigen detection POCTs with sensitivities and specificities of 22.7%-37.7% and 99.4%-100%, respectively. A new two-step 15 min rapid POCT using fluorescent nanoparticles showed performance comparable to that of near-patient NAATs. CONCLUSIONS: The systematic reviews showed that antigen detection POCTs for CT, although easy to use, lacked sufficient sensitivity to be recommended as a screening test. A near-patient NAAT shows acceptable performance as a screening or diagnostic test but requires electricity, takes 90 min and is costly. More affordable POCTs are in development

Prioritizing WHO normative work on maternal and perinatal health: a multicountry survey

<p>Abstract</p> <p>Background</p> <p>WHO develops evidence-based guidelines for setting global standards and providing technical support to its Member States and the international community, as a whole. There is a clear need to ensure that WHO guidance is relevant, rigorous and up-to date. A key activity is to ascertain the guidance needs of the countries. This study provides an international comparison of priority guidance needs for maternal and perinatal health. It incorporates data from those who inform policy and implementation strategies at a national level, in addition to targeting those who use and most need the guidance at grassroot level.</p> <p>Methods</p> <p>An online multi-country survey was used to identify WHO guidance priorities for the next five years in the field of maternal and perinatal health. WHO regional and country offices were requested to respond the survey and obtain responses from Ministries of Health around the world. In addition, the survey was disseminated through other networks and relevant electronic forums.</p> <p>Results</p> <p>A total of 393 responses were received, including 56 from Ministries of Health and 54 from WHO/UN country offices. 75% of responses were from developing countries and 25% from developed countries. Guidance on strategies focusing on 'quality of care' issues to reduce all-cause maternal/perinatal mortality was considered the most important domain to target, which includes for instance guidance to improve access, dissemination, implementation of effective practices and health professionals' education.</p> <p>Conclusions</p> <p>This study provides a panorama of international priority guidance needs for maternal and perinatal health. Although clinical guidance remains a priority, there are other areas related to health systems guidance, which seem to be even more important. Overall, the domain ranked highest in terms of greatest need for guidance was around quality of care, which included questions related to educational needs, access to and implementation of guidance.</p

Ethical considerations in global HIV phylogenetic research.

Phylogenetic analysis of pathogens is an increasingly powerful way to reduce the spread of epidemics, including HIV. As a result, phylogenetic approaches are becoming embedded in public health and research programmes, as well as outbreak responses, presenting unique ethical, legal, and social issues that are not adequately addressed by existing bioethics literature. We formed a multidisciplinary working group to explore the ethical issues arising from the design of, conduct in, and use of results from HIV phylogenetic studies, and to propose recommendations to minimise the associated risks to both individuals and groups. We identified eight key ethical domains, within which we highlighted factors that make HIV phylogenetic research unique. In this Review, we endeavoured to provide a framework to assist researchers, public health practitioners, and funding institutions to ensure that HIV phylogenetic studies are designed, done, and disseminated in an ethical manner. Our conclusions also have broader relevance for pathogen phylogenetics