Laboratory diagnosis of Buruli ulcer : challenges and future perspectives

Current options to control Buruli ulcer (BU) are limited, as no effective vaccine is available and knowledge on transmission mechanisms of the causative agent, Mycobacterium ulcerans, is incomplete. Early case detection and rapid initiation of treatment are key elements to prevent the development of large, disfiguring ulcers often associated with permanent physical disability and stigma. BU has been reported from 34 countries, with the greatest disease burden in West Africa and steadily increasing case numbers in south-eastern Australia. The disease can present in a variety of clinical manifestations, including relatively unspecific, painless nodules, plaques, and edema, which may eventually progress to chronic, ulcerative lesions. The clinical diagnosis of BU is therefore complicated by a broad differential diagnosis, particularly in tropical areas, where the prevalence of other skin conditions with a similar appearance is high. With the introduction of combination antibiotic therapy, replacing excision surgery as the standard treatment for BU, pre-treatment confirmation of the clinical diagnosis has further gained in importance to avoid the redundant use of anti-mycobacterial drugs. At present, available confirmatory diagnostic tests either lack sufficient sensitivity/specificity or are centralized and thus often not accessible to patients living in remote, rural areas of Africa. In recognition of this disparity, WHO and other stakeholders have called for new diagnostic tools for BU that can be applied at district hospitals or primary healthcare facilities. This chapter highlights challenges, advances and future prospects for the necessary decentralization of the diagnosis of BU

The COVID-19 pandemic: effects on civil registration of births and deaths and on availability and utility of vital events data

The complex and evolving picture of COVID-19-related mortality highlights the need for data to guide the response. Yet many countries are struggling to maintain their data systems, including the civil registration system, which is the foundation for detailed and continuously available mortality statistics. We conducted a search of country and development agency Web sites and partner and media reports describing disruptions to the civil registration of births and deaths associated with COVID-19 related restrictions.We found considerable intercountry variation and grouped countries according to the level of disruption to birth and particularly death registration. Only a minority of the 66 countries were able to maintain service continuity during the COVID-19 restrictions. In the majority, a combination of legal and operational challenges resulted in declines in birth and death registration. Few countries established business continuity plans or developed strategies to deal with the backlog when restrictions are lifted.Civil registration systems and the vital statistics they generate must be strengthened as essential services during health emergencies and as core components of the response to COVID-19. (Am J Public Health. Published online ahead of print April 15, 2021: e1-e9. https://doi.org/10.2105/AJPH.2021.306203)

The CORALIE survey for southern extrasolar planets: XVIII. Three new massive planets and two low-mass brown dwarfs at greater than 5 AU separation

Context. Since 1998, a planet-search around main sequence stars within 50~pc in the southern hemisphere has been carried out with the CORALIE spectrograph at La Silla Observatory. Aims. With an observing time span of more than 20 years, the CORALIE survey is able to detect long term trends in data with masses and separations large enough to select ideal targets for direct imaging. Detecting these giant companion candidates will allow us to start bridging the gap between radial velocity detected exoplanets and directly imaged planets and brown dwarfs. Methods. Long-term precise Doppler measurements with the CORALIE spectrograph reveal radial velocity signatures of massive planetary companions and brown dwarfs on long-period orbits. Results. In this paper we report the discovery of new companions orbiting HD~181234, HD~13724, HD~25015, HD~92987 and HD~50499. We also report updated orbital parameters for HD~50499b, HD~92788b and HD~98649b. In addition, we confirm the recent detection of HD~92788c. The newly reported companions span a period range of 15.6 to 40.4 years and a mass domain of 2.93 to 26.77 $M_{\mathrm{Jup}}$, the latter of which straddles the nominal boundary between planets and brown dwarfs. Conclusion. We have reported the detection of five new companions and updated parameters of four known extrasolar planets. We identify at least some of these companions to be promising candidates for imaging and further characterisation

Coupled Line-Profile and Continuum Variations in EZ Canis Majoris: Implications for the Driving Mechanism of Global Wind Structures in Wolf-Rayet Winds

EZ CMa is an apparently unusual Wolf-Rayet star of the nitrogen sequence that exhibits strong variations on a period of 3.77 days with coherency lasting typically about 10 cycles. We have used an extensive set of optical spectroscopic observations to investigate a possible link between its line-profile and photometric continuum variability. Despite the strong epoch dependency of the variations, a persistent correlation is found between changes in the wind line profiles (N V lambda lambda 4604, 4620 in particular) and in continuum flux emanating near the stellar core. We suggest that these observations give further support to the idea that the physical conditions prevailing in the vicinity of the star's photosphere have a significant impact on the wind structure and that a spatial dependence of these conditions at the base of the outflow induces the formation of azimuthal wind structures in EZ CMa. The epoch-dependent nature of the variability could be related to long-term behavior of corotating magnetic structures, although pulsational instabilities constitute a viable alternative