Riviste scientifiche

Mathematician set to publish ABC proof almost no one understands

New Scientist - Gi, 28/12/2017 - 17:41
After a five year struggle, Shinichi Mochizuki’s epic ABC proof may finally appear in a journal, but it is still not clear if mathematicians understand his work

2018 preview: Gene therapy treats disease while in the womb

New Scientist - Gi, 28/12/2017 - 16:00
Brittle bone disease can cause bone fractures in the womb, but a trial of a novel therapy may strengthen bones before birth

Plants use sand armour to break teeth of attacking caterpillars

New Scientist - Gi, 28/12/2017 - 13:15
Some plants are coated in sand, and it seems the sand grains act like medieval armour that protects these “psammophorous” plants from munching caterpillars

Love at first sight is really just lust or even false memory

New Scientist - Gi, 28/12/2017 - 11:49
One in three people say they’ve felt love at first sight, but experiments suggest the phenomenon is actually just physical attraction or distorted memories

Plants use sand armour to break teeth of attacking caterpillars

New Scientist - Gi, 28/12/2017 - 10:00
Some plants are coated in sand, and it seems the sand grains act like medieval armour that protects these “psammophorous” plants from munching caterpillars

Sexually transmitted infections—Research priorities for new challenges

PLoS Medicine - Me, 27/12/2017 - 23:00

by Nicola Low, Nathalie J. Broutet

In an Editorial, Guest Editors Nicola Low and Nathalie Broutet discuss the Collection on sexually transmitted infections in the context of research priorities in the field.

Healthcare provider perspectives on managing sexually transmitted infections in HIV care settings in Kenya: A qualitative thematic analysis

PLoS Medicine - Me, 27/12/2017 - 23:00

by Kipruto Chesang, Sureyya Hornston, Odylia Muhenje, Teresa Saliku, Joy Mirjahangir, Amanda Viitanen, Helgar Musyoki, Christine Awuor, George Githuka, Naomi Bock

Background

The burden of sexually transmitted infections (STIs) has been increasing in Kenya, as is the case elsewhere in sub-Saharan Africa, while measures for control and prevention are weak. The objectives of this study were to (1) describe healthcare provider (HCP) knowledge and practices, (2) explore HCP attitudes and beliefs, (3) identify structural and environmental factors affecting STI management, and (4) seek recommendations to improve the STI program in Kenya.

Methods and findings

Using individual in-depth interviews (IDIs), data were obtained from 87 HCPs working in 21 high-volume comprehensive HIV care centers (CCCs) in 7 of Kenya’s 8 regions. Transcript coding was performed through an inductive and iterative process, and the data were analyzed using NVivo 10.0. Overall, HCPs were knowledgeable about STIs, saw STIs as a priority, reported high STI co-infection amongst people living with HIV (PLHIV), and believed STIs in PLHIV facilitate HIV transmission. Most used the syndromic approach for STI management. Condoms and counseling were available in most of the clinics. HCPs believed that having an STI increased stigma in the community, that there was STI antimicrobial drug resistance, and that STIs were not prioritized by the authorities. HCPs had positive attitudes toward managing STIs, but were uncomfortable discussing sexual issues with patients in general, and profoundly for anal sex. The main barriers to the management of STIs reported were low commitment by higher levels of management, few recent STI-focused trainings, high stigma and low community participation, and STI drug stock-outs. Solutions recommended by HCPs included formulation of new STI policies that would increase access, availability, and quality of STI services; integrated STI/HIV management; improved STI training; increased supervision; standardized reporting; and community involvement in STI prevention. The key limitations of our study were that (1) participant experience and how much of their workload was devoted to managing STIs was not considered, (2) some responses may have been subject to recall and social desirability bias, and (3) patients or clients of STI services were not interviewed, and therefore their inputs were not obtained. While considering these limitations, the number and variety of facilities sampled, the mix of staff cadres interviewed, the use of a standardized instrument, and the consistency of responses add strength to our findings.

Conclusions

This study showed that HCPs understood the challenges of, and solutions for, improving the management of STIs in Kenya. Commitment by higher management, training in the management of STIs, measures for reducing stigma, and introducing new policies of STI management should be considered by health authorities in Kenya.

Internet-accessed sexually transmitted infection (e-STI) testing and results service: A randomised, single-blind, controlled trial

PLoS Medicine - Me, 27/12/2017 - 23:00

by Emma Wilson, Caroline Free, Tim P. Morris, Jonathan Syred, Irrfan Ahamed, Anatole S. Menon-Johansson, Melissa J. Palmer, Sharmani Barnard, Emma Rezel, Paula Baraitser

Background

Internet-accessed sexually transmitted infection testing (e-STI testing) is increasingly available as an alternative to testing in clinics. Typically this testing modality enables users to order a test kit from a virtual service (via a website or app), collect their own samples, return test samples to a laboratory, and be notified of their results by short message service (SMS) or telephone. e-STI testing is assumed to increase access to testing in comparison with face-to-face services, but the evidence is unclear. We conducted a randomised controlled trial to assess the effectiveness of an e-STI testing and results service (chlamydia, gonorrhoea, HIV, and syphilis) on STI testing uptake and STI cases diagnosed.

Methods and findings

The study took place in the London boroughs of Lambeth and Southwark. Between 24 November 2014 and 31 August 2015, we recruited 2,072 participants, aged 16–30 years, who were resident in these boroughs, had at least 1 sexual partner in the last 12 months, stated willingness to take an STI test, and had access to the internet. Those unable to provide consent and unable to read English were excluded. Participants were randomly allocated to receive 1 text message with the web link of an e-STI testing and results service (intervention group) or to receive 1 text message with the web link of a bespoke website listing the locations, contact details, and websites of 7 local sexual health clinics (control group). Participants were free to use any other services or interventions during the study period. The primary outcomes were self-reported STI testing at 6 weeks, verified by patient record checks, and self-reported STI diagnosis at 6 weeks, verified by patient record checks. Secondary outcomes were the proportion of participants prescribed treatment for an STI, time from randomisation to completion of an STI test, and time from randomisation to treatment of an STI. Participants were sent a £10 cash incentive on submission of self-reported data. We completed all follow-up, including patient record checks, by 17 June 2016. Uptake of STI testing was increased in the intervention group at 6 weeks (50.0% versus 26.6%, relative risk [RR] 1.87, 95% CI 1.63 to 2.15, P < 0.001). The proportion of participants diagnosed was 2.8% in the intervention group versus 1.4% in the control group (RR 2.10, 95% CI 0.94 to 4.70, P = 0.079). No evidence of heterogeneity was observed for any of the pre-specified subgroup analyses. The proportion of participants treated was 1.1% in the intervention group versus 0.7% in the control group (RR 1.72, 95% CI 0.71 to 4.16, P = 0.231). Time to test, was shorter in the intervention group compared to the control group (28.8 days versus 36.5 days, P < 0.001, test for difference in restricted mean survival time [RMST]), but no differences were observed for time to treatment (83.2 days versus 83.5 days, P = 0.51, test for difference in RMST). We were unable to recruit the planned 3,000 participants and therefore lacked power for the analyses of STI diagnoses and STI cases treated.

Conclusions

The e-STI testing service increased uptake of STI testing for all groups including high-risk groups. The intervention required people to attend clinic for treatment and did not reduce time to treatment. Service innovations to improve treatment rates for those diagnosed online are required and could include e-treatment and postal treatment services. e-STI testing services require long-term monitoring and evaluation.

Trial registration

ISRCTN Registry ISRCTN13354298.

The vaginal microbiome and sexually transmitted infections are interlinked: Consequences for treatment and prevention

PLoS Medicine - Me, 27/12/2017 - 23:00

by Janneke H. H. M. van de Wijgert

In a Perspective for our Collection on STI research, Janneke van de Wijgert discusses the latest on how the vaginal microbiota predisposes women to acquisition of STIs and discusses future potential for clinical intervention.

Dual-strain genital herpes simplex virus type 2 (HSV-2) infection in the US, Peru, and 8 countries in sub-Saharan Africa: A nested cross-sectional viral genotyping study

PLoS Medicine - Me, 27/12/2017 - 23:00

by Christine Johnston, Amalia Magaret, Pavitra Roychoudhury, Alexander L. Greninger, Daniel Reeves, Joshua Schiffer, Keith R. Jerome, Cassandra Sather, Kurt Diem, Jairam R. Lingappa, Connie Celum, David M. Koelle, Anna Wald

Background

Quantitative estimation of the extent to which the immune system’s protective effect against one herpes simplex virus type 2 (HSV-2) infection protects against infection with additional HSV-2 strains is important for understanding the potential for HSV-2 vaccine development. Using viral genotyping, we estimated the prevalence of HSV-2 dual-strain infection and identified risk factors.

Methods and findings

People with and without HIV infection participating in HSV-2 natural history studies (University of Washington Virology Research Clinic) and HIV prevention trials (HIV Prevention Trials Network 039 and Partners in Prevention HSV/HIV Transmission Study) in the US, Africa, and Peru with 2 genital specimens each containing ≥105 copies herpes simplex virus DNA/ml collected a median of 5 months apart (IQR: 2–11 months) were included. It is unlikely that 2 strains would be detected in the same sample simultaneously; therefore, 2 samples were required to detect dual-strain infection. We identified 85 HSV-2 SNPs that, in aggregate, could determine whether paired HSV-2 strains were the same or different with >90% probability. These SNPs were then used to create a customized high-throughput array-based genotyping assay. Participants were considered to be infected with more than 1 strain of HSV-2 if their samples differed by ≥5 SNPs between the paired samples, and dual-strain infection was confirmed using high-throughput sequencing (HTS). We genotyped pairs of genital specimens from 459 people; 213 (46%) were men, the median age was 34 years (IQR: 27–44), and 130 (28%) were HIV seropositive. Overall, 272 (59%) people were from the US, 59 (13%) were from Peru, and 128 (28%) were from 8 countries in Africa. Of the 459 people, 18 (3.9%) met the criteria for dual-strain infection. HTS and phylogenetic analysis of paired specimens confirmed shedding of 2 distinct HSV-2 strains collected at different times in 17 pairs, giving an estimated dual-strain infection prevalence of 3.7% (95% CI = 2.0%–5.4%). Paired samples with dual-strain infection differed by a median of 274 SNPs in the UL_US region (range 129–413). Matching our observed dual-strain infection frequency to simulated data of varying prevalences and allowing only 2 samples per person, we inferred the true prevalence of dual-strain infection to be 7%. In multivariable analysis, controlling for HIV status and continent of origin, people from Africa had a higher risk for dual-strain infection (risk ratio [RR] = 9.20, 95% CI = 2.05–41.32), as did people who were HIV seropositive (RR = 4.06, 95% CI = 1.42–11.56).

Conclusions

HSV-2 dual-strain infection was detected in 3.7% of paired samples from individual participants, and was more frequent among people with HIV infection. Simulations suggest that the true prevalence of dual-strain infection is 7%. Our data indicate that naturally occurring immunity to HSV-2 may be protective against infection with a second strain. This study is limited by the inability to determine the timing of acquisition of the second strain.

Re-emerging and newly recognized sexually transmitted infections: Can prior experiences shed light on future identification and control?

PLoS Medicine - Me, 27/12/2017 - 23:00

by Kyle Bernstein, Virginia B. Bowen, Caron R. Kim, Michel J. Counotte, Robert D. Kirkcaldy, Edna Kara, Gail Bolan, Nicola Low, Nathalie Broutet

How do we spot the next sexually transmitted infection? Kyle Bernstein and colleagues look for lessons from past discovery.

Shortages of benzathine penicillin for prevention of mother-to-child transmission of syphilis: An evaluation from multi-country surveys and stakeholder interviews

PLoS Medicine - Me, 27/12/2017 - 23:00

by Stephen Nurse-Findlay, Melanie M. Taylor, Margaret Savage, Maeve B. Mello, Sanni Saliyou, Manuel Lavayen, Frederic Seghers, Michael L. Campbell, Françoise Birgirimana, Leopold Ouedraogo, Morkor Newman Owiredu, Nancy Kidula, Lee Pyne-Mercier

Background

Benzathine penicillin G (BPG) is the only recommended treatment to prevent mother-to-child transmission of syphilis. Due to recent reports of country-level shortages of BPG, an evaluation was undertaken to quantify countries that have experienced shortages in the past 2 years and to describe factors contributing to these shortages.

Methods and findings

Country-level data about BPG shortages were collected using 3 survey approaches. First, a survey designed by the WHO Department of Reproductive Health and Research was distributed to 41 countries and territories in the Americas and 41 more in Africa. Second, WHO conducted an email survey of 28 US Centers for Disease Control and Prevention country directors. An additional 13 countries were in contact with WHO for related congenital syphilis prevention activities and also reported on BPG shortages. Third, the Clinton Health Access Initiative (CHAI) collected data from 14 countries (where it has active operations) to understand the extent of stock-outs, in-country purchasing, usage behavior, and breadth of available purchasing options to identify stock-outs worldwide. CHAI also conducted in-person interviews in the same 14 countries to understand the extent of stock-outs, in-country purchasing and usage behavior, and available purchasing options. CHAI also completed a desk review of 10 additional high-income countries, which were also included. BPG shortages were attributable to shortfalls in supply, demand, and procurement in the countries assessed. This assessment should not be considered globally representative as countries not surveyed may also have experienced BPG shortages. Country contacts may not have been aware of BPG shortages when surveyed or may have underreported medication substitutions due to desirability bias. Funding for the purchase of BPG by countries was not evaluated. In all, 114 countries and territories were approached to provide information on BPG shortages occurring during 2014–2016. Of unique countries and territories, 95 (83%) responded or had information evaluable from public records. Of these 95 countries and territories, 39 (41%) reported a BPG shortage, and 56 (59%) reported no BPG shortage; 10 (12%) countries with and without BPG shortages reported use of antibiotic alternatives to BPG for treatment of maternal syphilis. Market exits, inflexible production cycles, and minimum order quantities affect BPG supply. On the demand side, inaccurate forecasts and sole sourcing lead to under-procurement. Clinicians may also incorrectly prescribe BPG substitutes due to misperceptions of quality or of the likelihood of adverse outcomes.

Conclusions

Targets for improvement include drug forecasting and procurement, and addressing provider reluctance to use BPG. Opportunities to improve global supply, demand, and use of BPG should be prioritized alongside congenital syphilis elimination efforts.

Parallel universes could solve a big problem with black holes

New Scientist - Me, 27/12/2017 - 19:00
The black hole firewall paradox has been vexing physicists for years. But if quantum laws lead to the creation of other universes, the headache disappears

Exclusive: NASA has begun plans for a 2069 interstellar mission

New Scientist - Me, 27/12/2017 - 11:30
NASA is sketching out plans to send a probe to visit Alpha Centauri, our nearest star system, along with a massive telescope to watch its journey from home

Well-being will suffer if we don’t trump the anti-science trend

New Scientist - Me, 27/12/2017 - 11:00
The White House’s clampdown on the term “evidence-based” is but one example of the anti-science movement. Unstopped, it will prevent advances in health

Our lust for tastier chocolate has transformed the cocoa tree

New Scientist - Me, 27/12/2017 - 10:00
Ever since we domesticated the cocoa tree over 3000 years ago, we have been breeding them to make tastier chocolate – but in the process we have made them vulnerable

2018 preview: Opioids will kill tens of thousands more people

New Scientist - Sa, 23/12/2017 - 16:00
As the prescription painkiller crisis worsens in the US, many more are expected to die as people turn to drugs more powerful than heroin

[Editorial] Artificial intelligence in health care: within touching distance

The Lancet - Sa, 23/12/2017 - 00:00
Replacing the doctor with an intelligent medical robot is a recurring theme in science fiction, but the idea of individualised medical advice from digital assistants like Alexa or Siri, supported by self-surveillance smartphone data, no longer seems implausible. A scenario in which medical information, gathered at the point of care, is analysed using sophisticated machine algorithms to provide real-time actionable analytics seems to be within touching distance. The creation of data-driven predictions underpins personalised medicine and precision public health.

[Editorial] Our responsibility to protect the Rohingya

The Lancet - Sa, 23/12/2017 - 00:00
Much has been made of the Rohingya being stateless. But how they are being treated is utterly heartless. The almost 1 million Rohingya Muslims displaced from Myanmar's Rakhine State to Bangladesh are housed in squalid camps quickly becoming reservoirs of disease and despair. A new outbreak of diphtheria comes on the heels of cholera and measles outbreaks. Insufficient food, shelter, health care, and hope add to the almost unimaginable suffering of these most disenfranchised refugees.

[Editorial] Dangerous words

The Lancet - Sa, 23/12/2017 - 00:00
Medicine is underpinned by both art and science. Art that relies upon strong therapeutic relationships with patients and populations. And science that brings statistical rigour to clinical and public health practice. If allegations reported in The Washington Post on Dec 15 are credible, the Trump administration has seriously undermined both foundations by banning the words “vulnerable”, “entitlement”, “diversity”, “transgender”, “fetus”, “evidence-based”, and “science-based” from government documents for the US$7 billion budget discussions about the Centers for Disease Control and Prevention (CDC).
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