Effect of Adopting the New Race-Free 2021 Chronic Kidney Disease Epidemiology Collaboration Estimated Glomerular Filtration Rate Creatinine Equation on Racial Differences in Kidney Disease Progression among People with Human Immunodeficiency Virus: An Observational Study

Background: The impact of adopting a race-free estimated glomerular filtration rate (eGFR) creatinine (eGFRcr) equation on racial differences in chronic kidney disease (CKD) progression among people with human immunodeficiency virus (PWH) is unknown. Methods: We defined eGFR stages using the original race-adjusted Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFRcr equation and the new race-free CKD-EPI eGFRcr equation. We then estimated 5-year probabilities of transitioning from baseline kidney function to more advanced eGFR stages and examined the association of race (black vs white) with rates of CKD progression using Markov models. Results: With the race-adjusted eGFRcr equation, black participants (n = 31 298) had a lower risk of progressing from eGFR stage 1 to 2 (hazard ratio [HR], 0.77; 95% confidence interval [CI],. 73-.82), an equal risk of progressing from stage 2 to 3 (1.00;. 92-.07) and a 3-fold risk of progressing from stage 3 to 4 or 5 (3.06; 2.60-3.62), compared with white participants (n = 27 542). When we used the race-free eGFRcr equation, 16% of black participants were reclassified into a more severe eGFR stage at baseline. The reclassified black individuals had a higher prevalence of CKD risk factors than black PWH who were not reclassified. With the race-free eGFRcr equation, black participants had a higher risk of disease progression across all eGFR stages than white participants. Conclusions: The original eGFRcr equation systematically masked a subgroup of black PWH who are at high-risk of CKD progression. The new race-free eGFRcr equation unmasks these individuals and may allow for earlier detection and management of CKD

Risk of End-Stage Renal Disease in HIV-Positive Potential Live Kidney Donors

New federal regulations allow HIV-positive individuals to be live kidney donors; however, potential candidacy for donation is poorly understood given the increased risk of end-stage renal disease (ESRD) associated with HIV infection. To better understand this risk, we compared the incidence of ESRD among 41 968 HIV-positive participants of North America AIDS Cohort Collaboration on Research and Design followed for a median of 5 years with the incidence of ESRD among comparable HIV-negative participants of National Health and Nutrition Examination III followed for a median of 14 years. We used risk associations from multivariable Cox proportional hazards regression to derive cumulative incidence estimates for selected HIV-positive scenarios (no history of diabetes, hypertension, AIDS, or hepatitis C virus coinfection) and compared these estimates with those from similarly selected HIV-negative scenarios. For 40-year-old HIV-positive individuals with health characteristics that were similar to those of age-matched kidney donors, viral load <400 copies/mL, and CD4+ count ≥500 cells/μL, the 9-year cumulative incidence of ESRD was higher than that of their HIV-negative peers, yet still low: 2.5 versus 1.1 per 10 000 among white women, 3.0 versus 1.3 per 10 000 among white men, 13.2 versus 3.6 per 10 000 among black women, and 15.8 versus 4.4 per 10 000 among black men. HIV-positive individuals with no comorbidities and well-controlled disease may be considered low-risk kidney donor candidates

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

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

Hanuabada village, Port Moresby, Papua New Guinea, November 1913 [picture] /

Inscriptions: title and attribution in pencil on reverse.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.pic-vn3279291

Multi-scale evaluation of soil functional indicators for the assessment of water and soil retention in Mediterranean semiarid landscapes

Ecosystem monitoring and assessment are often based on functional indicators, which provide integrated and yet simple and affordable measures of key ecosystem functions. The landscape function analysis (LFA) assesses ecosystem functioning through three indices that represent basic soil functions: surface stability, infiltration, and nutrient cycling. Given the high scale-dependency of hydrological and erosion processes in semiarid ecosystems, the validation of the stability and infiltration indices requires a multi-scale approach, which has not been applied by previous works. Using records from a four-year monitoring of a semiarid landscape in SE Spain, we evaluated the LFA infiltration and stability indices against quantitative measurements of water and sediment flows at multiple scales. At the finest scale, the indices correctly reflected the higher infiltration and lower sediment production of plant patches as compared with bare-soil interpatches. The infiltration index also captured the spatial variation in the infiltration capacity of bare-soil interpatches. At the hillslope scale, total runoff was inversely related to the average infiltration index for bare-soil interpatches, but it was not related to the global infiltration index, which combines the values from both bare-soil interpatches and plant patches. These results suggest that the hydrological response of semiarid hillslopes depends mainly on the variation in the functioning of bare-soil interpatches. Total sediment yield from the hillslope plots was not related to the stability index. At the catchment scale, both the bare-soil interpatch and the global infiltration indices correctly captured the variability in total runoff produced by three micro-catchments of comparable size. The bare-soil infiltration index predicted bare-soil infiltration rate and hillslope runoff better than common simple indicators of soil functioning such as soil organic carbon, stone cover, crusted bare-soil cover, bulk-density and plant cover, and exhibited a similarly high indicatory potential that a variety of plant spatial-pattern indicators. In contrast to the multi-scale validation of the infiltration index, the indicatory potential of the stability index was only proved for the most contrasting soil conditions in the study site, pointing to a lower sensitivity of this latter index

Multi-scale evaluation of soil functional indicators for the assessment of water and soil retention in Mediterranean semiarid landscapes

Ecosystem monitoring and assessment are often based on functional indicators, which provide integrated and yet simple and affordable measures of key ecosystem functions. The landscape function analysis (LFA) assesses ecosystem functioning through three indices that represent basic soil functions: surface stability, infiltration, and nutrient cycling. Given the high scale-dependency of hydrological and erosion processes in semiarid ecosystems, the validation of the stability and infiltration indices requires a multi-scale approach, which has not been applied by previous works. Using records from a four-year monitoring of a semiarid landscape in SE Spain, we evaluated the LFA infiltration and stability indices against quantitative measurements of water and sediment flows at multiple scales. At the finest scale, the indices correctly reflected the higher infiltration and lower sediment production of plant patches as compared with bare-soil interpatches. The infiltration index also captured the spatial variation in the infiltration capacity of bare-soil interpatches. At the hillslope scale, total runoff was inversely related to the average infiltration index for bare-soil interpatches, but it was not related to the global infiltration index, which combines the values from both bare-soil interpatches and plant patches. These results suggest that the hydrological response of semiarid hillslopes depends mainly on the variation in the functioning of bare-soil interpatches. Total sediment yield from the hillslope plots was not related to the stability index. At the catchment scale, both the bare-soil interpatch and the global infiltration indices correctly captured the variability in total runoff produced by three micro-catchments of comparable size. The bare-soil infiltration index predicted bare-soil infiltration rate and hillslope runoff better than common simple indicators of soil functioning such as soil organic carbon, stone cover, crusted bare-soil cover, bulk-density and plant cover, and exhibited a similarly high indicatory potential that a variety of plant spatial-pattern indicators. In contrast to the multi-scale validation of the infiltration index, the indicatory potential of the stability index was only proved for the most contrasting soil conditions in the study site, pointing to a lower sensitivity of this latter index

Post-fire hydrological and erosional responses of a Mediterranean landscpe: Seven years of catchment-scale dynamics

Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu