23 research outputs found

    Acceptance of HIV Testing for Children Ages 18 Months to 13 Years Identified Through Voluntary, Home-Based HIV Counseling and Testing in Western Kenya

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    Background Home-based, voluntary counseling and testing (HCT) presents a novel approach to early diagnosis. We sought to describe uptake of pediatric HIV testing, associated factors, and HIV prevalence among children offered HCT in Kenya. Methods The USAID-AMPATH Partnership conducted HCT in western Kenya in 2008. Children 18 months to 13 years were offered HCT if their mother was known to be dead, her living status was unknown, mother was HIV-infected or of unknown HIV status. This retrospective analysis describes the cohort of children encountered and tested. Results HCT was offered to 2,289 children and accepted for 1,294 (57%). Children were more likely to be tested if more information was available about a suspected or confirmed maternal HIV-infection (for HIV-infected, living mothers OR=3.20, 95% CI: 1.64–6.23), if parents were not in household (OR=1.50, 95% CI: 1.40–1.63), if they were grandchildren of head of household (OR=4.02, 95% CI: 3.06–5.28), or if their father was not in household (OR=1.41, 95% CI: 1.24–1.56). Of the eligible children tested, 60 (4.6%) were HIV-infected. Conclusions HCT provides an opportunity to identify HIV among high-risk children; however, acceptance of HCT for children was limited. Further investigation is needed to identify and overcome barriers to testing uptake

    Remanent Magnetic Measurements on Perpendicular Recording Materials with Compensation for Demagnetizing Fields

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    Existing techniques for characterization of longitudinal recording media using remanence measurements are extended to perpendicular media, in particular to Alumite, and correction for demagnetizing fields is taken into account. It is found that these techniques have limited value because of the sensitivity of the analysis to the correction factor used. Measurement of the recoil lines is investigated as an alternative method of probing the reversal processes

    Discarded old antibiotics as a new arsenal for multi-resistant isolates in diabetic foot ulcer infections: therapeutic value of parenteral colistin versus multi-resistant Pseudomonas species isolate strains: case report

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    Antimicrobial resistance to current novel antibiotics is posing a major threat to both human and zoonotic life. In the absence of new novel antibiotics molecules, clinicians have resorted into a desperate last resort to review and re-introduce prior discarded antibiotics as their new weaponry in the fight against multi-resistant gram negative bacteria. We reported a case of a 77 year old bed ridden diabetic and hypertensive with renal impairment diagnosed with bilateral lower limbs wet gangrene. She underwent transfemoral on her right and transtibial amputation on her left lower limb. She developed surgical site infection on her right stump and wet gangrene on her left stump. Pus swab on her right stump revealed carbapenem resistant strains of Pseudomonas aeruginosa. She was instituted on parenteral colistin and showed no bacterial growth 7 days post treatment. She suffered an ischaemic cerebral vaso-occlusive stroke during her hospital stay. CT angiography of lower lung fields showed a large filling defect in the right main pulmonary artery extending to the lower lobe branches suggestive of right-sided pulmonary embolism. Our patient succumbed from her co-morbidities. Despite our patient succumbing to her multiple co-morbidities we reported this case to highlight the isolation of carbapenem resistant strains of P. aeruginosa and the efficacy and safety of colistin as a salvage antibiotic in renal impaired patients. Colistin can be safely used as a last reserve antibiotic for multi-resistant strains of P. aeruginosa infection even in patients with renal impairment

    Influence of demagnetization in remanence curves of magnetic thin films

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    Remanent magnetization curves of perpendicular magnetic thin films are simulated and measured. The simulations are used to investigate the theoretical influence of the strong demagnetizing field present in these films. Conclusions are drawn from this on how remanence curves should be measured and how they should be corrected for the demagnetizing influence. The experimental part consists of measurements on Fe‐Alumite, Co‐Pt–based multilayers, and Co‐Cr. In addition the latter material is also artificially patterned into microstrips in order to investigate the influence of demagnetization on remanence curves experimentally

    One trace is all it takes: Machine Learning-based Side-channel Attack on EdDSA

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    Profiling attacks, especially those based on machine learning proved as very successful techniques in recent years when considering side-channel analysis of block ciphers implementations. At the same time, the results for implementations public-key cryptosystems are very sparse. In this paper, we consider several machine learning techniques in order to mount a power analysis attack on EdDSA using the curve Curve25519 as implemented in WolfSSL. The results show all considered techniques to be viable and powerful options. The results with convolutional neural networks (CNNs) are especially impressive as we are able to break the implementation with only a single measurement in the attack phase while requiring less than 500 measurements in the training phase. Interestingly, that same convolutional neural network was recently shown to perform extremely well for attacking the AES cipher. Our results show that some common grounds can be established when using deep learning for profiling attacks on distinct cryptographic algorithms and their corresponding implementations

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Long-term impact of the Kenya postelection crisis on clinic attendance and medication adherence for HIV-infected children in western Kenya

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    Background: Kenya experienced a political and humanitarian crisis after presidential elections on December 27, 2007. We sought to describe both the immediate and long-term impact of this conflict for HIV-infected children in western Kenya. Methods: We conducted a retrospective study of a cohort of these children for 3 periods: period 1, before the election (October 26, 2007, to December 25, 2007); period 2, immediately after the election (December 26, 2007, to April 15, 2008); and period 3, long-term postelection (April 16, 2008, to December 31, 2008). Two outcome variables of loss-to-follow-up (LTFU) were assessed: initial LTFU and complete LTFU. We assessed clinic adherence by evaluating the difference between actual visits and expected visits. Among children on antiretroviral therapy (ART), we assessed overall medication adherence and changes in medication adherence. Results: Two thousand five hundred forty-nine HIV-infected children (3.0% compared with 5.1%, P \u3c 0.01) and less complete LTFU (2.6% compared with 6.8%, P \u3c 0.001) than children not on ART. For children not on ART, clinic adherence improved in period 3 compared with period 2. For children on ART with a more strict measure of clinic adherence, clinic adherence declined over time. Orphans had better clinic adherence than nonorphans. Among children on ART, there were few demographic differences when comparing medication adherence between time. Conclusions: HIV-infected children are at risk for disruptions in clinic follow-up and medication adherence after a humanitarian crisis. Individual and contextual factors moderate the effects of these disruptions
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