23 research outputs found
West Africa International Centers of Excellence for Malaria Research: Drug Resistance Patterns to Artemether-Lumefantrine in Senegal, Mali, and The Gambia.
In 2006, artemether-lumefantrine (AL) became the first-line treatment of uncomplicated malaria in Senegal, Mali, and the Gambia. To monitor its efficacy, between August 2011 and November 2014, children with uncomplicated Plasmodium falciparum malaria were treated with AL and followed up for 42 days. A total of 463 subjects were enrolled in three sites (246 in Senegal, 97 in Mali, and 120 in Gambia). No early treatment failure was observed and malaria infection cleared in all patients by day 3. Polymerase chain reaction (PCR)-adjusted adequate clinical and parasitological response (ACPR) was 100% in Mali, and the Gambia, and 98.8% in Senegal. However, without PCR adjustment, ACPR was 89.4% overall; 91.5% in Mali, 98.8% in Senegal, and 64.3% in the Gambia (the lower value in the Gambia attributed to poor compliance of the full antimalarial course). However, pfmdr1 mutations were prevalent in Senegal and a decrease in parasite sensitivity to artesunate and lumefantrine (as measured by ex vivo drug assay) was observed at all sites. Recrudescent parasites did not show Kelch 13 (K13) mutations and AL remains highly efficacious in these west African sites
The Economic Impact of Eradicating Peste des Petits Ruminants:A Benefit-Cost Analysis
Peste des petits ruminants (PPR) is an important cause of mortality and production loss among sheep and goats in the developing world. Despite control efforts in a number of countries, it has continued to spread across Africa and Asia, placing an increasing burden on the livelihoods of livestock keepers and on veterinary resources in affected countries. Given the similarities between PPR and rinderpest, and the lessons learned from the successful global eradication of rinderpest, the eradication of PPR seems appealing, both eliminating an important disease and improving the livelihoods of the poor in developing countries. We conducted a benefit-cost analysis to examine the conomic returns from a proposed programme for the global eradication of PPR. Based on our knowledge and experience, we developed the eradication strategy and estimated its costs. The benefits of the programme were determined from (i) the averted mortality costs, based on an analysis of the literature, (ii) the downstream impact of reduced mortality using a social accounting matrix, and (iii) the avoided control costs based on current levels of vaccination. The results of the benefit-cost analysis suggest strong economic returns from PPR eradication. Based on a 15-year programme with total discounted costs of US76.5 billion, yielding a net benefit of US$74.2 billion. This suggests a benefit cost ratio of 33.8, and an internal rate of return (IRR) of 199%. As PPR mortality rates are highly variable in different populations, we conducted a sensitivity analysis based on lower and higher mortality scenarios. All the scenarios examined indicate that investment in PPR eradication would be highly beneficial economically. Furthermore, removing one of the major constraints to small ruminant production would be of considerable benefit to many of the most vulnerable communities in Africa and Asia
Structural Extremes in a Cretaceous Dinosaur
Fossils of the Early Cretaceous dinosaur, Nigersaurus taqueti, document for the first time the cranial anatomy of a rebbachisaurid sauropod. Its extreme adaptations for herbivory at ground-level challenge current hypotheses regarding feeding function and feeding strategy among diplodocoids, the larger clade of sauropods that includes Nigersaurus. We used high resolution computed tomography, stereolithography, and standard molding and casting techniques to reassemble the extremely fragile skull. Computed tomography also allowed us to render the first endocast for a sauropod preserving portions of the olfactory bulbs, cerebrum and inner ear, the latter permitting us to establish habitual head posture. To elucidate evidence of tooth wear and tooth replacement rate, we used photographic-casting techniques and crown thin sections, respectively. To reconstruct its 9-meter postcranial skeleton, we combined and size-adjusted multiple partial skeletons. Finally, we used maximum parsimony algorithms on character data to obtain the best estimate of phylogenetic relationships among diplodocoid sauropods. Nigersaurus taqueti shows extreme adaptations for a dinosaurian herbivore including a skull of extremely light construction, tooth batteries located at the distal end of the jaws, tooth replacement as fast as one per month, an expanded muzzle that faces directly toward the ground, and hollow presacral vertebral centra with more air sac space than bone by volume. A cranial endocast provides the first reasonably complete view of a sauropod brain including its small olfactory bulbs and cerebrum. Skeletal and dental evidence suggests that Nigersaurus was a ground-level herbivore that gathered and sliced relatively soft vegetation, the culmination of a low-browsing feeding strategy first established among diplodocoids during the Jurassic
Adherence to Perinatal Asphyxia or Sepsis Management Guidelines in Low- and Middle-Income Countries
Importance :Most of the 2.3 million annual neonatal deaths occur in sub-Saharan Africa and South Asia, with perinatal asphyxia and neonatal sepsis being the leading causes of neonatal mortality. Most neonatal deaths are considered preventable through high-quality clinical care, which includes adherence to clinical care guidelines. Objective: To assess adherence to World Health Organization clinical care guidelines for management of perinatal asphyxia and neonatal sepsis and to identify patient-level factors in adherence among neonates who died from these conditions. Design, Setting, and Participants: This cross-sectional study obtained data from December 2015 through October 2023 from the Child Health and Mortality Prevention Surveillance (CHAMPS) catchment areas in 7 low- and middle-income countries in sub-Saharan Africa (Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) and South Asia (Bangladesh). Participants were neonates who were born alive and were aged 0 to 28 days at the time of death and had either perinatal asphyxia or neonatal sepsis. Exposure: Medical records of neonates who died from perinatal asphyxia or neonatal sepsis determined by postmortem diagnostics. Main Outcomes and Measures: The main outcome was the proportion of deceased neonates who received guideline-adherent treatments before they died. Mixed-effect multivariable logistic regression analyses were performed to identify factors associated with administration of at least bag-valve-mask (BVM) ventilation for perinatal asphyxia. Results: Of the 1194 neonates (median [IQR] age at the time of death, 2 [1-6] days; 692 males [58.0%]) who died and were enrolled in CHAMPS with available clinical data, 476 (39.9%) died from perinatal asphyxia, 562 (47.0%) died from neonatal sepsis, and 156 (13.1%) from both conditions. These neonates had a median (IQR) birth weight of 2130 (1266-2988) g. For cases with perinatal asphyxia, guideline adherence ranged from 12.2% (n = 77) for adrenaline administration to 85.4% (540) for supplemental oxygen administration. Only 4.4% of neonates (28) with perinatal asphyxia received all recommended treatments. Among cases with neonatal sepsis, antibiotics were administered to 86.8% (623), although the recommended treatment was administered to only 61.0% (438). In multivariable analyses, neonates in whom clinicians accurately identified perinatal asphyxia were more likely to receive BVM ventilation than those who had received discordant antemortem and postmortem diagnoses (adjusted odds ratio, 2.00; 95% CI, 1.29-3.12). Conclusions and Relevance: In this cross-sectional study, clinical care guideline adherence was suboptimal among neonates who died from perinatal asphyxia or neonatal sepsis. This finding underscores the critical need to increase adherence in regions with high rates of neonatal mortality and may inform strategies for strengthening health systems to support compliance with clinical care guidelines
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.
Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
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
