Riviste scientifiche

Stars can start shining at a smaller mass than we thought

New Scientist - Me, 17/05/2017 - 15:30
Objects with only 6.7 per cent of the sun’s mass can be stars, according to a fresh measurement of how massive an object must be to achieve nuclear fusion

Ebola once again on the prowl as emergency teams stand ready

New Scientist - Me, 17/05/2017 - 13:45
Three deaths and 19 suspected cases of Ebola in the DR Congo have health officials worried – but the chances of another deadly rampage are thankfully slim

Hear the roar of the lionfish recorded for the first time

New Scientist - Me, 17/05/2017 - 12:30
The vocalisations of the voracious lionfish could help us keep tabs on this invasive species as it works its way up the US east coast

Corals that grow faster in warm water could beat climate change

New Scientist - Me, 17/05/2017 - 11:00
The unique history of the Red Sea means that reefs in its northern part may be able to adapt to higher water temperatures, at least for a while

[Correspondence] Dr Tedros Adhanom Ghebreyesus is the best candidate for WHO DG

The Lancet - Me, 17/05/2017 - 10:41
As Sally Davies has already pointed out,1 the World Health Assembly will shortly meet to elect the next Director-General (DG) of WHO. Three candidates (Tedros Adhanom Ghebreyesus [Ethiopia], Sania Nishtar [Pakistan], and David Nabarro [UK]) were selected by the WHO Executive Board in January, 2017, for the final stage of the election. All three are well qualified and experienced in their own ways and all fulfil WHO's established criteria.1 So the important issue for the world's ministers of health, meeting in Geneva, Switzerland, will be deciding which of the three candidates could best lead the needed reforms at WHO while also protecting and enhancing the health of the world's people.

Ebola exposure, illness experience, and Ebola antibody prevalence in international responders to the West African Ebola epidemic 2014–2016: A cross-sectional study

PLoS Medicine - Ma, 16/05/2017 - 23:00

by Catherine F. Houlihan, Catherine R. McGowan, Steve Dicks, Marc Baguelin, David A. J. Moore, David Mabey, Chrissy h. Roberts, Alex Kumar, Dhan Samuel, Richard Tedder, Judith R. Glynn

Background

Healthcare and other front-line workers are at particular risk of infection with Ebola virus (EBOV). Despite the large-scale deployment of international responders, few cases of Ebola virus disease have been diagnosed in this group. Since asymptomatic or pauci-symptomatic infection has been described, it is plausible that infections have occurred in healthcare workers but have escaped being diagnosed. We aimed to assess the prevalence of asymptomatic or pauci-symptomatic infection, and of exposure events, among returned responders to the West African Ebola epidemic 2014–2016.

Methods and findings

We used snowball sampling to identify responders who had returned to the UK or Ireland, and used an online consent and questionnaire to determine their exposure to EBOV and their experience of illness. Oral fluid collection devices were sent and returned by post, and samples were tested using an EBOV IgG capture assay that detects IgG to Ebola glycoprotein. Blood was collected from returnees with reactive samples for further testing. Unexposed UK controls were also recruited.In all, 300 individuals consented, of whom 268 (89.3%) returned an oral fluid sample (OFS). The majority had worked in Sierra Leone in clinical, laboratory, research, and other roles. Fifty-three UK controls consented and provided samples using the same method.Of the returnees, 47 (17.5%) reported that they had had a possible EBOV exposure. Based on their free-text descriptions, using a published risk assessment method, we classified 43 (16%) as having had incidents with risk of Ebola transmission, including five intermediate-risk and one high-risk exposure. Of the returnees, 57 (21%) reported a febrile or diarrhoeal illness in West Africa or within 1 mo of return, of whom 40 (70%) were not tested at the time for EBOV infection.Of the 268 OFSs, 266 were unreactive. Two returnees, who did not experience an illness in West Africa or on return, had OFSs that were reactive on the EBOV IgG capture assay, with similar results on plasma. One individual had no further positive test results; the other had a positive result on a double-antigen bridging assay but not on a competitive assay or on an indirect EBOV IgG ELISA. All 53 controls had non-reactive OFSs. While the participants were not a random sample of returnees, the number participating was high.

Conclusions

This is the first study, to our knowledge, of the prevalence of EBOV infection in international responders. More than 99% had clear negative results. Sera from two individuals had discordant results on the different assays; both were negative on the competitive assay, suggesting that prior infection was unlikely. The finding that a significant proportion experienced “near miss” exposure events, and that most of those who experienced symptoms did not get tested for EBOV at the time, suggests a need to review and standardise protocols for the management of possible exposure to EBOV, and for the management of illness, across organisations that deploy staff to outbreaks.

Comparison of artemether-lumefantrine and chloroquine with and without primaquine for the treatment of <i>Plasmodium vivax</i> infection in Ethiopia: A randomized controlled trial

PLoS Medicine - Ma, 16/05/2017 - 23:00

by Tesfay Abreha, Jimee Hwang, Kamala Thriemer, Yehualashet Tadesse, Samuel Girma, Zenebe Melaku, Ashenafi Assef, Moges Kassa, Mark D. Chatfield, Keren Z. Landman, Stella M. Chenet, Naomi W. Lucchi, Venkatachalam Udhayakumar, Zhiyong Zhou, Ya Ping Shi, S. Patrick Kachur, Daddi Jima, Amha Kebede, Hiwot Solomon, Addis Mekasha, Bereket Hailegiorgis Alemayehu, Joseph L. Malone, Gunewardena Dissanayake, Hiwot Teka, Sarah Auburn, Lorenz von Seidlein, Ric N. Price

Background

Recent efforts in malaria control have resulted in great gains in reducing the burden of Plasmodium falciparum, but P. vivax has been more refractory. Its ability to form dormant liver stages confounds control and elimination efforts. To compare the efficacy and safety of primaquine regimens for radical cure, we undertook a randomized controlled trial in Ethiopia.

Methods and findings

Patients with normal glucose-6-phosphate dehydrogenase status with symptomatic P. vivax mono-infection were enrolled and randomly assigned to receive either chloroquine (CQ) or artemether-lumefantrine (AL), alone or in combination with 14 d of semi-supervised primaquine (PQ) (3.5 mg/kg total). A total of 398 patients (n = 104 in the CQ arm, n = 100 in the AL arm, n = 102 in the CQ+PQ arm, and n = 92 in the AL+PQ arm) were followed for 1 y, and recurrent episodes were treated with the same treatment allocated at enrolment. The primary endpoints were the risk of P. vivax recurrence at day 28 and at day 42.The risk of recurrent P. vivax infection at day 28 was 4.0% (95% CI 1.5%–10.4%) after CQ treatment and 0% (95% CI 0%–4.0%) after CQ+PQ. The corresponding risks were 12.0% (95% CI 6.8%–20.6%) following AL alone and 2.3% (95% CI 0.6%–9.0%) following AL+PQ. On day 42, the risk was 18.7% (95% CI 12.2%–28.0%) after CQ, 1.2% (95% CI 0.2%–8.0%) after CQ+PQ, 29.9% (95% CI 21.6%–40.5%) after AL, and 5.9% (95% CI 2.4%–13.5%) after AL+PQ (overall p < 0.001). In those not prescribed PQ, the risk of recurrence by day 42 appeared greater following AL treatment than CQ treatment (HR = 1.8 [95% CI 1.0–3.2]; p = 0.059). At the end of follow-up, the incidence rate of P. vivax was 2.2 episodes/person-year for patients treated with CQ compared to 0.4 for patients treated with CQ+PQ (rate ratio: 5.1 [95% CI 2.9–9.1]; p < 0.001) and 2.3 episodes/person-year for AL compared to 0.5 for AL+PQ (rate ratio: 6.4 [95% CI 3.6–11.3]; p < 0.001). There was no difference in the occurrence of adverse events between treatment arms.The main limitations of the study were the early termination of the trial and the omission of haemoglobin measurement after day 42, resulting in an inability to estimate the cumulative risk of anaemia.

Conclusions

Despite evidence of CQ-resistant P. vivax, the risk of recurrence in this study was greater following treatment with AL unless it was combined with a supervised course of PQ. PQ combined with either CQ or AL was well tolerated and reduced recurrence of vivax malaria by 5-fold at 1 y.

Trial registration

ClinicalTrials.gov NCT01680406

Pregnant rays tangled in trawler nets have small, sickly babies

New Scientist - Ma, 16/05/2017 - 18:10
Rays, and possibly sharks, could suffer reproductive loss from being dragged around by fishing nets before being released

Google DeepMind NHS data deal was ‘legally inappropriate’

New Scientist - Ma, 16/05/2017 - 16:55
DeepMind’s 2015 data-sharing agreement with the Royal Free NHS trust has an “inappropriate legal basis”, according to a letter from the UK’s National Data Guardian

UK may force charities to prove complementary therapies work

New Scientist - Ma, 16/05/2017 - 15:58
UK charity commission is considering putting in place measures that will force providers of complementary medicine to offer stronger evidence of benefits

Brain zaps let minimally conscious people communicate for a week

New Scientist - Ma, 16/05/2017 - 15:15
Daily brain stimulation has “awakened” people with brain damage, allowing them to communicate for a week. The tech could eventually be used at home

Memo to whoever lands the world’s top health job – do this first

New Scientist - Ma, 16/05/2017 - 15:04
The World Health Organization is picking its next leader to ease sickness and suffering. Here's what the new chief should prioritise, says Bjorn Lomborg

Neptune-like exoplanet spotted that has a watery atmosphere

New Scientist - Ma, 16/05/2017 - 13:45
Signs of water in a gas giant exoplanet’s atmosphere suggest the world formed much closer to its star than gas giants in our solar system did

Microbes might thrive after crash-landing on board a meteorite

New Scientist - Ma, 16/05/2017 - 13:22
Some extremophile bacteria could survive the a crash-landing of a meteorite or spacecraft, helping them travel between worlds

AI detective analyses police data to learn how to crack cases

New Scientist - Ma, 16/05/2017 - 13:00
A system called VALCRI should do the laborious parts of a crime analyst's job in seconds, while also suggesting new lines of enquiry and possible motives

When it comes to work, we should value quality over quantity

New Scientist - Ma, 16/05/2017 - 11:00
As we discover that working shorter hours doesn't have to mean less productivity, a future of lifelong learning could be on its way

[Correspondence] Ahmadreza Djalali: questions everyone must ask

The Lancet - Ma, 16/05/2017 - 00:30
Dr Ahmadreza Djalali is hovering near death in an Iranian jail.1 The efforts of the international community in securing his release, as extensive as we can muster, seem increasingly ineffective, in great part due to the fact that all international petitions appear to have been ignored by the Iranian Government. Strong positions from the international community—ranging from Physicians for Human Rights,2 Amnesty International,3 the Swedish,1 Belgian,4 and Italian5 Governments, and multiple academic institutions worldwide—have fallen on deaf ears.

Ladybird’s transparent shell reveals how it folds its wings

New Scientist - Lu, 15/05/2017 - 22:00
The unusual way ladybird wings fold and unfold could help us design solar array paddles that unfold in space and even pave the way to better umbrellas

What vision of doom made Hawking seek a faster Earth exit plan?

New Scientist - Lu, 15/05/2017 - 18:30
Stephen Hawking now says humanity must colonise other worlds within a century, rather than 1000 years, to ensure survival. Why the rush, asks Dirk Schulze-Makuch

Diesel fumes lead to thousands more deaths than thought

New Scientist - Lu, 15/05/2017 - 18:01
Cars, lorries and buses that drive on diesel churn out far more air pollution than standard testing procedures suggest, even without any emissions cheating devices
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