Baobab Index

Tropical rivers in Australia and New Guinea (Sahul) provide a rare natural experiment in vertebrate evolution: Unlike other continental systems, their freshwater ichthyofaunas are composed almost entirely of marine-derived lineages rather than primary freshwater fishes. This unique biogeographic setting enables replicated tests of why some marine-to-freshwater transitions give rise to extensive adaptive radiations whereas others remain species-poor, and whether these outcomes reflect ecological opportunity or temporally structured paleoenvironmental constraints. Using a densely sampled, time-calibrated phylogenomic framework spanning 2,303 teleost species, we identified 27-34 marine-to-freshwater transitions during the Cenozoic, including a pronounced Middle Miocene peak (16-11 Ma). Although ecological opportunity in Sahul rivers enabled repeated colonization in the absence of dominant primary freshwater incumbents, younger freshwater lineages nevertheless diversify faster than older ones, contradicting the expectation that early arrivers should undergo elevated diversification when accessing vacant niche space. Although some colonizations coincide with bursts of speciation consistent with adaptive radiation, many yielded few species despite long residence times. Functional trait analyses likewise revealed no consistent relationship between colonization timing, ecological breadth, or lineage diversification rate, although expanded functional space characterizes previously proposed Sahul adaptive radiations. Comparisons with paleoenvironmental curves indicate that colonization success correlates with sea-level minima and low-oxygen conditions, suggesting that Earth history dynamics modulated when ecological opportunity was accessible. Our results show that although ecological opportunity enabled repeated freshwater invasions into the Sahul region, diversification outcomes are governed by the interaction of paleoenvironmental dynamics and possibly lineage-specific traits, generating stark asymmetries in freshwater radiations.

Mental disorders are a leading cause of disability worldwide, and their burden continues to increase across Africa. Despite growing need, access to care remains limited, with treatment gaps reaching up to 90% in some settings. These gaps reflect longstanding constraints in workforce, financing, infrastructure, and sociocultural factors, alongside uneven policy implementation. At the same time, countries and communities across the continent are developing new approaches to mental health care that can complement conventional, specialist-centered models and offer transferable lessons for mental health system transformation globally. This Special Communication proposes 4 transferable design principles for scalable and culturally responsive mental health systems, synthesized into a comprehensive conceptual framework and context-sensitive implementation road map: (1) workforce and educational transformation, (2) community-based care architecture, (3) systems integration, and (4) cultural and pluralistic care. Evidence from multiple African countries demonstrates that nonspecialist clinicians, including community health workers and peer supporters, can deliver screening and brief psychological interventions when reinforced by training and supervision. Community-based models are increasingly shifting care closer to where people live, incorporating recovery-oriented approaches that emphasize social reintegration. Integration of mental health into primary care, HIV services, and maternal health platforms has shown promise, though sustainability remains dependent on broader health system capacity. At the same time, pluralistic care systems, in which individuals engage biomedical and traditional professionals, highlight the need for approaches that are culturally responsive and grounded in human rights. Across these design principles, progress is evident, but implementation remains uneven, and much of the current evidence is limited by short-term evaluations and reliance on symptom-based measures. Closing the treatment gap in Africa will require more than scaling existing services. It will depend on strengthening locally led research and context-sensitive implementation, embedding innovations within national systems, and investing in workforce development, supervision, and governance. African mental health innovations are not only responses to constrained resources, but also contributions to the broader understanding of how scalable, equitable, and culturally responsive mental health systems can be designed across diverse global settings.

Heart failure (HF) is a common condition with substantial geographical variation in its prevalence and underlying etiologies. Consistent and comparable data on the burden of HF within populations are needed to inform health system priorities. To estimate the global burden of HF. This cross-sectional study estimates disease burden using Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) methodologies to integrate multiple information sources. Data come from 204 countries and territories from 1990 to 2023 representing the global population with prevalent HF. HF and underlying etiologies. Estimates with 95% uncertainty intervals (UIs) for the prevalence and years lived with disability (YLDs) for HF by age, sex, location, year, and underlying etiology. Globally, there were 56.0 million (95% UI, 49.9-62.2 million) estimated cases of HF in 2023. The estimated prevalence of HF generally increased with age for all locations. While ischemic heart disease and hypertensive heart disease were the 2 most common etiologies globally among older adults, there was substantial variation in etiological pattern by location and age. Congenital heart anomalies and rheumatic heart disease (RHD) were common etiologies in children and young adults, while the proportion of HF due to alcohol use peaked in middle adulthood. Location-specific estimates highlighted regions with higher burden of HF due to specific etiologies, including RHD (south Asia, east Asia, Oceania, southeast Asia, central sub-Saharan Africa, eastern sub-Saharan Africa, southern sub-Saharan Africa, and western sub-Saharan Africa), alcohol use (eastern Europe, Australasia, the Caribbean, and central Europe), and Chagas disease (southern, Andean, tropical, and central Latin America). Heart failure is a significant global public health burden, and the impact is likely to increase as populations age. However, most HF etiologies can be prevented by interventions that reduce exposure to modifiable risk factors, such as elevated blood pressure, excessive alcohol consumption, and tobacco use. Etiology- and location-specific estimates can provide necessary information for public health officials to determine how best to prioritize interventions to reduce HF disease burden.

Fresh vegetables are essential human dietary components but are increasingly implicated in foodborne infections caused by A cross-sectional survey was conducted between March and October 2023, yielding 509 vegetable samples collected aseptically during three visits. Samples were enriched, cultured on MacConkey agar, and identified using standard microbiological methods. Thereafter, antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Genomic DNA was extracted from the microbe, followed by Polymerase Chain Reaction (PCR) to detect key virulence ( Of the 509 vegetables analysed, 73 (14.4%) tested positive for Fresh vegetables across the three senatorial districts of Ogun State were contaminated with

To review the pathogenesis, epidemiology, clinical presentation, management and outcomes of HIV-associated nephropathy (HIVAN), with emphasis on global disparities, genetic susceptibility (APOL1) and emerging therapeutic and technological advances. Narrative literature review synthesizing contemporary evidence from clinical cohorts, translational research and guideline-based practice, with comparative perspectives from high-resource (UK) and low-resource (sub-Saharan Africa) settings. Relevant studies were analysed to evaluate mechanisms of disease, epidemiological trends, diagnostic approaches, treatment strategies and long-term outcomes. Particular focus was placed on APOL1-associated risk, antiretroviral therapy (ART) impact and recent developments including artificial intelligence (AI) applications and targeted therapies. HIVAN arises from direct HIV infection of renal epithelial cells in genetically susceptible individuals, particularly those with APOL1 risk variants. ART has significantly reduced incidence in high-income settings, whereas HIVAN remains prevalent in sub-Saharan Africa due to delayed diagnosis and limited healthcare access. Clinically, HIVAN presents with proteinuria and progressive kidney dysfunction, requiring biopsy for confirmation. Early ART initiation improves renal outcomes, supported by adjunctive therapies such as renin-angiotensin system blockade and SGLT2 inhibitors. Emerging therapies targeting APOL1 and advances in AI-driven risk prediction and diagnostics show promise. HIVAN reflects an interplay between viral, genetic and socio-economic factors. While ART has transformed outcomes in well-resourced settings, significant global disparities persist. Future progress depends on improving HIV care access, expanding renal services and advancing precision medicine approaches, including APOL1-targeted therapies and AI-enabled risk stratification.

Multidrug-resistant organism (MDRO) outbreaks in NICUs cause high mortality and strain hospital resources globally, particularly in low-income countries (LICs). In Central African Republic (CAR), limited data on antimicrobial resistance indicate high rates of MDRO. We describe an outbreak of Extended Spectrum Beta-Lactamase-producing Klebsiella pneumoniae (ESBL-KP) in a Ministry of Health (MoH) hospital NICU in Bangui, supported by Médecins Sans Frontières (MSF). This retrospective case-control study was conducted at the Centre Hospitalier Universitaire Communautaire-MSF project of Bangui. The study included all neonates admitted to the NICU from 25/10/2023, the admission date of the first confirmed case, to 14/01/2024, the discharge date of the last case. Cases were defined as laboratory-confirmed ESBL-KP bloodstream infections (BSI) with similar resistance profiles, differing by no more than three antibiotic classes based on phenotypic testing. Line lists and routinely encoded data were used, and variables were tested to identify significant exposures. Data on outbreak management, infection prevention and control (IPC) interventions and human resources (HR) management were collected. A total of 242 neonates were admitted during the outbreak period: 44 cases and 153 controls. The incidence rate of ESBL-KP BSI was 29.7 per 1000 patient-days. Mortality among cases was 3.5 times higher (p < 0.0001). Twenty-five cases (56.8%) had early sepsis (sepsis suspected < = 3 days of hospitalisation). Case-control analysis identified maternal risk factors for neonatal infection as the most important independent risk factor. The neonatology unit occupancy rate exceeded 100% in early October, and IPC assessments revealed poor adherence to IPC measures at the beginning of the outbreak. A series of IPC interventions in the first month of the outbreak successfully controlled further spread of the infection, and the outbreak was declared over in approximately two months. The ESBL-KP NICU outbreak reveals gaps in hospital management, with ESBL-KP probably spreading due to high occupancy rate, poor IPC standards, and possibly by multiple simultaneous sources. Access to microbiology and the implementation of IPC practical interventions are critical to identifying and managing outbreaks in LIC.

Considering the global increase of COVID-19 cases in the healthcare facilities between 2020 and 2021, and the widespread presence of pest rodents in Brazzaville, we conducted this study at the end of the pandemic peak to assess the potential for urban rodents to be infected with SARS-CoV-2 in the Republic of the Congo. Between April and December 2022, a total of 96 rodent were captured in three COVID-19 healthcare facilities in Brazzaville. Intestinal samples were tested for SARS-CoV-2 RNA using RT-qPCR, followed by nested RT-PCR targeting the RdRp gene and Sanger sequencing. Concurrently, serum samples were analysed to detect SARS-CoV-2 antibodies using the Luminex technology. SARS-CoV-2 RNA was detected in intestinal samples from nine (9.4%) rodent: 7/80 (8.7%) R. rattus, 1/13 (7.7%) R. tanezumi, and 1/2 (50%) M. musculus. Phylogenetic analyses using Nextclade and maximum likelihood phylogeny methods revealed substantial diversity among SARS-CoV-2 partial genome belonging to clades 20B, 20G, Recombinant, 21 K and 22B. Additionally, 9/96 (9.4%) rodents tested seropositive for SARS-CoV-2 antibodies. These findings provide evidence for the establishment of new SARS-CoV-2 reservoirs in certain animal populations, emphasizing the urgent need for continuous surveillance to prevent future outbreaks from animal sources.

Diphtheria surveillance in resource-limited settings may stop at clinical diagnosis, organism identification, or molecular detection of the diphtheria toxin gene, although these findings do not provide the same information. Identification of Corynebacterium diphtheriae establishes the organism, tox-gene detection indicates genetic potential for toxin production, and phenotypic testing demonstrates toxin expression. We propose that existing WHO case classifications be retained, while laboratory reports record the level of diagnostic resolution achieved. A tiered system linking peripheral specimen collection, regional culture and molecular testing, and reference-level phenotypic confirmation of selected isolates could strengthen outbreak characterization in Somalia without delaying treatment based on clinical suspicion.

Corpus callosum abnormalities (CCA) represent a heterogeneous group of neurodevelopmental disorders resulting from disturbances in midline patterning, neuronal migration, and axonal guidance. Their genetic architecture includes chromosomal abnormalities, pathogenic copy-number variations (CNVs), and single-gene disorders; however, genotype-phenotype correlations remain incompletely defined, particularly in underrepresented populations. We investigated the clinical and genomic characteristics of 107 Tunisian patients with radiologically confirmed CCA recruited over a 15-year period. A sequential genomic strategy was applied, including conventional karyotyping in all patients, fluorescence Most patients presented syndromic forms of CCA (95.3%) associated with additional cerebral and/or extracerebral manifestations. Clinically relevant genomic abnormalities supporting a molecular diagnosis were identified in 11/107 patients (10.3%). Conventional karyotyping identified chromosomal abnormalities in three patients (2.8%), while array-CGH detected pathogenic or likely pathogenic CNVs in ten of 54 tested patients (18.5%). These CNVs involved genomic regions previously implicated in neurodevelopmental disorders and CCA, including 14q12, 4p16.3-p16.1, 1q43-q44, 1p32.3p31.3 -p32, 5p14.3, 5q35, 16q23.1-q24.3, and 18pterp11.1. WES identified rare variants in This study provides a comprehensive characterization of CCA in a Tunisian referral cohort and highlights the major contribution of pathogenic genomic imbalances to the molecular diagnosis of these disorders. The findings emphasize the complementary role of cytogenetic and sequencing approaches while illustrating the challenges of interpreting rare sequence variants in patients with complex neurodevelopmental phenotypes. Larger cohorts with systzbematic genomic testing, segregation analyses, and functional validation will be required to further refine genotype-phenotype correlations in CCA.