Exploring the path to optimal diabetes care by unravelling the contextual factors affecting access, utilisation, and quality of primary health care in West Africa: A scoping review protocol.

BACKGROUND: The prevalence of diabetes in West Africa is increasing, posing a major public health threat. An estimated 24 million Africans have diabetes, with rates in West Africa around 2-6% and projected to rise 129% by 2045 according to the WHO. Over 90% of cases are Type 2 diabetes (IDF, World Bank). As diabetes is ambulatory care sensitive, good primary care is crucial to reduce complications and mortality. However, research on factors influencing diabetes primary care access, utilisation and quality in West Africa remains limited despite growing disease burden. While research has emphasised diabetes prevalence and risk factors in West Africa, there remains limited evidence on contextual influences on primary care. This scoping review aims to address these evidence gaps. METHODS AND ANALYSIS: Using the established methodology by Arksey and O'Malley, this scoping review will undergo six stages. The review will adopt the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Review (PRISMA-ScR) guidelines to ensure methodological rigour. We will search four electronic databases and search through grey literature sources to thoroughly explore the topic. The identified articles will undergo thorough screening. We will collect data using a standardised data extraction form that covers study characteristics, population demographics, and study methods. The study will identify key themes and sub-themes related to primary healthcare access, utilisation, and quality. We will then analyse and summarise the data using a narrative synthesis approach. RESULTS: The findings and conclusive report will be finished and sent to a peer-reviewed publication within six months. CONCLUSION: This review protocol aims to systematically examine and assess the factors that impact the access, utilisation, and standard of primary healthcare services for diabetes in West Africa.

Feasibility, safety, efficacy and potential scaling-up of sofosbuvir-based HCV treatment in Central and West Africa: (TAC ANRS 12311 trial).

Access to Hepatis C treatment in Sub-Saharan Africa is a clinical, public health and ethical concern. The multi-country open-label trial TAC ANRS 12311 allowed assessing the feasibility, safety, efficacy of a specific care model of HCV treatment and retreatment in patients with hepatitis C in Sub Saharan Africa. Between November 2015 and March 2017, with follow-up until mid 2019, treatment-naïve patients with HCV without decompensated cirrhosis or liver cancer were recruited to receive 12 week-treatment with either sofosbuvir + ribavirin (HCV genotype 2) or sofosbuvir + ledipasvir (genotype 1 or 4) and retreatment with sofosbuvir + velpatasvir + voxilaprevir in case of virological failure. The primary outcome was sustained virological response at 12 weeks after end of treatment (SVR12). Secondary outcomes included treatment adherence, safety and SVR12 in patients who were retreated due to non-response to first-line treatment. The model of care relied on both viral load assessment and educational sessions to increase patient awareness, adherence and health literacy. The study recruited 120 participants, 36 HIV-co-infected, and 14 cirrhotic. Only one patient discontinued treatment because of return to home country. Neither death nor severe adverse event occurred. SVR12 was reached in 107 patients (89%): (90%) in genotype 1 or 2, and 88% in GT-4. All retreated patients (n = 13) reached SVR12. HCV treatment is highly acceptable, safe and effective under this model of care. Implementation research is now needed to scale up point-of-care HCV testing and SVR assessment, along with community involvement in patient education, to achieve HCV elimination in Sub-Saharan Africa.

Increasing Contraceptive Use Through Free Family Planning Special Days in Poor Urban Areas in Francophone West Africa.

INTRODUCTION: In francophone West Africa (FWA), contraceptive uptake remains limited, often due to geographic, economic, and social barriers. With technical support from The Challenge Initiative (TCI), municipalities and health systems implemented Family Planning Special Days (FPSDs) to improve family planning (FP) uptake and reduce high unmet need. The FPSD intervention consisted of organizing free FP services on a monthly or quarterly basis over 2 to 5 consecutive days within health facilities or sites close to the population. These events helped to educate, inform, and mobilize the community around FP and improve geographic and financial access to FP services. We describe the process of implementing FPSDs in FWA countries and analyze the results. METHODS: We used several techniques and data sources in our descriptive analysis, including document review of activity reports, analysis of health management information system data, and retrospective data collection on the profile of FPSD users and implementation costs. RESULTS: Between July 2020 and June 2021, municipalities and health systems collaborated to hold 1,046 FPSDs in 452 health facilities in 10 FWA cities. This collaboration was made possible through the establishment of city-level management and coordination units composed of municipal, health system, and TCI focal points. In the 10 FWA cities, 181,792 people were made aware of the FPSDs and 71,669 contraceptive users were served. The overall cost of organizing the FPSDs was about 145382501 Central African CFA francs (US$252839), 35% of which came from the municipalities' local financial contribution. DISCUSSION: Results from our analysis showed that, with appropriate financial support from municipalities, the health system could offer high-quality free FP services. Nonetheless, there are still challenges to the sustainability of conducting FPSDs, including the availability of contraceptive products and continued financing of the strategy during system shocks such as the COVID-19 pandemic.

Determinants of early initiation of breastfeeding following birth in West Africa: A multilevel analysis using data from multi-country national health surveys.

BACKGROUND: Early initiation of breastfeeding (EIBF), within the first hour of birth, is crucial for promoting exclusive breastfeeding and establishing optimal nursing practices. However, global EIBF rates remain low, with even lower rates observed in Africa. Despite existing research gaps, this study aims to determine the prevalence of EIBF and identify maternal and child-related factors associated with its practice in West Africa. METHODS: This study utilized West African Demographic and Health Survey (DHS) data from 13 countries, including 146,964 children's records. To assess model fit, likelihood test and deviance were used. Similarly, intraclass correlation coefficient, median odds ratio, and proportional change in variance were employed for random effect. A multilevel logistic regression model was used to identify individual- and community-level factors influencing EIBF due to the hierarchical nature of the data. Variables with p-values ≤0.2 in the binary model and <0.05 in the final analysis were considered significantly associated with EIBF. RESULTS: The pooled prevalence of EIBF in West African nations was 50.60% (95% CI; 50.34-50.85%). The highest prevalence rate was observed in Serra Leone (75.33%) and the lowest prevalence was found in Senegal (33.94%). In the multilevel multiple logistic regression model, maternal education (AOR = 1.10, 95% CI, 1.03,1.16), marital status AOR = 1.07, 95% CI, 1.01,1.13), birth weight (AOR = 0.91, CI 0.86,0.96), birth orders (AOR = 1.09, CI 1.03,1.16), and (AOR = 1.11, CI 1.03,1.19), place of residence (AOR = 1.14, CI 1.07,1.21), and mode of delivery type (AOR = 0.26, CI 0.24,0.29) were significantly correlated with EIBF in West Africa. CONCLUSIONS: The incidence of EIBF in West Africa was found to be low. The study emphasizes the need for targeted behavioral change communication programs to address timely breastfeeding initiation, specifically targeting mothers and child characteristics. Factors such as education, delivery mode, marital status, birth weight, birth order, and place of residence were significantly associated with EIBF. Special attention should be given to improving EIBF rates among women undergoing caesarean sections, infants with low birth weight, and primiparous mothers, along with structural improvements in the healthcare sector in West Africa.

The Anopheles coluzzii range extends into Kenya: detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa.

BACKGROUND: Anopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. The current study sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well as describe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzii populations. METHODS: Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing (WGS) data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Comparisons were made with An. coluzzii cohorts from West and Central Africa. RESULTS: This study reports the detection of An. coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points from which samples were analyzed and its presence confirmed through taxonomic analysis. Additionally, there was a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies up to 64%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya. CONCLUSIONS: These findings emphasize the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.

Ebola-specific therapeutic antibodies from lab to clinic: The example of ZMapp.

In the 1990s, monoclonal antibodies (mAbs) progressed from scientific tools to advanced therapeutics, particularly for the treatment of cancers and autoimmune and inflammatory disorders. In the arena of infectious disease, the inauguration of mAbs as a post-exposure treatment in humans against Ebola virus (EBOV) occurred in response to the 2013-2016 West Africa outbreak. This review recounts the history of a candidate mAb treatment, ZMapp, beginning with its emergency use in the 2013-2016 outbreak and advancing to randomized controlled trials into the 2018-2020 African outbreak. We end with a brief discussion of the hurdles and promise toward mAb therapeutic use against infectious disease.

Threat of mining to African great apes.

The rapid growth of clean energy technologies is driving a rising demand for critical minerals. In 2022 at the 15th Conference of the Parties to the Convention on Biological Diversity (COP15), seven major economies formed an alliance to enhance the sustainability of mining these essential decarbonization minerals. However, there is a scarcity of studies assessing the threat of mining to global biodiversity. By integrating a global mining dataset with great ape density distribution, we estimated the number of African great apes that spatially coincided with industrial mining projects. We show that up to one-third of Africa's great ape population faces mining-related risks. In West Africa in particular, numerous mining areas overlap with fragmented ape habitats, often in high-density ape regions. For 97% of mining areas, no ape survey data are available, underscoring the importance of increased accessibility to environmental data within the mining sector to facilitate research into the complex interactions between mining, climate, biodiversity, and sustainability.

Rapid detection of monkeypox virus and differentiation of West African and Congo Basin strains using endonuclease restriction-mediated real-time PCR-based testing.

The ongoing multi-country outbreak of monkeypox virus (MPXV) has continuously attracted global attention, highlighting the critical need for timely and accurate methods to detect MPXV and differentiate its clades. Herein, we devised a novel multiplex ET-PCR (endonuclease restriction-mediated real-time PCR) assay that integrates PCR amplification, restriction endonuclease cleavage and real-time fluorescence detection to diagnose MPXV infection and distinguish the Congo Basin and West African MPXV strains. In the MPXV ET-PCR system, three sets of specific primers were designed for MPXV, Congo Basin and West African strains. A short sequence, which could be recognized by restriction endonuclease enzyme BstUI, was added to the 5'end of amplification primers. Then, the modified primers were assigned different reporter dyes and corresponding quenching dyes to each of the three targets, enabling real-time fluorescence reporting of the results and multiplex detection. The designed assay enabled the detection of single or three targets in a single tube, with excellent specificity and analytical sensitivity in terms of plasmid and pseudotyped virus. Moreover, the clinical feasibility of our assay was validated using artificially simulated plasma, nasopharyngeal swab and skin swab samples. In conclusion, the multiplex ET-PCR assay devised here had the advantages of simple primer design, cost-effectiveness, low contamination risk, excellent sensitivity, high specificity and multiplex detection, making it a valuable and dependable tool for curbing the extensive spread of MPXV.

FSC-certified forest management benefits large mammals compared to non-FSC.

More than a quarter of the world's tropical forests are exploited for timber1. Logging impacts biodiversity in these ecosystems, primarily through the creation of forest roads that facilitate hunting for wildlife over extensive areas. Forest management certification schemes such as the Forest Stewardship Council (FSC) are expected to mitigate impacts on biodiversity, but so far very little is known about the effectiveness of FSC certification because of research design challenges, predominantly limited sample sizes2,3. Here we provide this evidence by using 1.3 million camera-trap photos of 55 mammal species in 14 logging concessions in western equatorial Africa. We observed higher mammal encounter rates in FSC-certified than in non-FSC logging concessions. The effect was most pronounced for species weighing more than 10 kg and for species of high conservation priority such as the critically endangered forest elephant and western lowland gorilla. Across the whole mammal community, non-FSC concessions contained proportionally more rodents and other small species than did FSC-certified concessions. The first priority for species protection should be to maintain unlogged forests with effective law enforcement, but for logged forests our findings provide convincing data that FSC-certified forest management is less damaging to the mammal community than is non-FSC forest management. This study provides strong evidence that FSC-certified forest management or equivalently stringent requirements and controlling mechanisms should become the norm for timber extraction to avoid half-empty forests dominated by rodents and other small species.

The dawn of the tropical Atlantic invasion into the Mediterranean Sea.

The Mediterranean Sea is a marine biodiversity hotspot already affected by climate-driven biodiversity collapses. Its highly endemic fauna is at further risk if global warming triggers an invasion of tropical Atlantic species. Here, we combine modern species occurrences with a unique paleorecord from the Last Interglacial (135 to 116 ka), a conservative analog of future climate, to model the future distribution of an exemplary subset of tropical West African mollusks, currently separated from the Mediterranean by cold upwelling off north-west Africa. We show that, already under an intermediate climate scenario (RCP 4.5) by 2050, climatic connectivity along north-west Africa may allow tropical species to colonize a by then largely environmentally suitable Mediterranean. The worst-case scenario RCP 8.5 leads to a fully tropicalized Mediterranean by 2100. The tropical Atlantic invasion will add to the ongoing Indo-Pacific invasion through the Suez Canal, irreversibly transforming the entire Mediterranean into a novel ecosystem unprecedented in human history.

Evaluation of analytical performance of the STANDARDTM M10 MPX/OPX assay for the simultaneous DNA detection and clade attribution of Monkeypox virus.

Monkeypox virus (MPXV) infection confirmation needs reliable polymerase chain reaction (PCR) assays; in addition, viral clade attribution is a key factor in containment measures, considering a more severe syndrome in clade I and the possibility of simultaneous circulation. This study evaluates the performance of all-in-one STANDARD M10 MPX/OPX (SD BIOSENSOR, South Korea - M10). Frozen samples from 205 subjects were selected and stratified according to routine test results (RealStar® Orthopoxvirus PCR Kit 1.0, Altona DIAGNOTICS, Germany - RS; RS-1): in detail, 100 negative skin lesions (SL) and 200 positive samples at the variable stage of infection were analysed. Positive samples were retested with RS (RS-2). Positive and Negative Percent Agreements (PPA, NPA) were calculated. The median (IQR) Ct values of RS and M10 (OPXV target) assays were highly similar. The PPA of M10 compared to RS-1 was 89.5% considering system interpretation, and 96.0% when the operator classified results as positive if any target was detected; NPA was 100%. Comparing the RS-2 run and M10, an overall concordance of 95.3% between assays was found; however, considering operator interpretation, M10 returned more positive results than RS-2. The occurrence of False-Negative results was likely associated with the influence of thawing on low viral concentration; no False-Positive tests were observed. All samples collected at the time of Mpox diagnosis were positive and M10 correctly attributed the clade (West-Africa/II). The M10 MPX/OPX assay demonstrated high reliability in confirming MPXV infection and clade attribution.

Rodent control strategies and Lassa virus: some unexpected effects in Guinea, West Africa.

The Natal multimammate mouse (Mastomys natalensis) is the host of Lassa mammarenavirus, causing Lassa haemorrhagic fever in West Africa. As there is currently no operational vaccine and therapeutic drugs are limited, we explored rodent control as an alternative to prevent Lassa virus spillover in Upper Guinea, where the disease is highly endemic in rural areas. In a seven-year experiment, we distributed rodenticides for 10-30 days once a year and, in the last year, added intensive snap trapping for three months in all the houses of one village. We also captured rodents both before and after the intervention period to assess their effectiveness by examining alterations in trapping success and infection rates (Lassa virus RNA and IgG antibodies). We found that both interventions reduced the rodent population by 74-92% but swiftly rebounded to pre-treatment levels, even already six months after the last snap-trapping control. Furthermore, while we observed that chemical control modestly decreased Lassa virus infection rates annually (a reduction of 5% in seroprevalence per year), the intensive trapping unexpectedly led to a significantly higher infection rate (from a seroprevalence of 28% before to 67% after snap trapping control). After seven years, we conclude that annual chemical control, alone or with intensive trapping, is ineffective and sometimes counterproductive in preventing Lassa virus spillover in rural villages. These unexpected findings may result from density-dependent breeding compensation following culling and the survival of a small percentage of chronically infected rodents that may spread the virus to a new susceptible generation of mice.

Sequencing and Analysis of Lumpy Skin Disease Virus Whole Genomes Reveals a New Viral Subgroup in West and Central Africa.

Lumpy skin disease virus (LSDV) is a member of the capripoxvirus (CPPV) genus of the Poxviridae family. LSDV is a rapidly emerging, high-consequence pathogen of cattle, recently spreading from Africa and the Middle East into Europe and Asia. We have sequenced the whole genome of historical LSDV isolates from the Pirbright Institute virus archive, and field isolates from recent disease outbreaks in Sri Lanka, Mongolia, Nigeria and Ethiopia. These genome sequences were compared to published genomes and classified into different subgroups. Two subgroups contained vaccine or vaccine-like samples ("Neethling-like" clade 1.1 and "Kenya-like" subgroup, clade 1.2.2). One subgroup was associated with outbreaks of LSD in the Middle East/Europe (clade 1.2.1) and a previously unreported subgroup originated from cases of LSD in west and central Africa (clade 1.2.3). Isolates were also identified that contained a mix of genes from both wildtype and vaccine samples (vaccine-like recombinants, grouped in clade 2). Whole genome sequencing and analysis of LSDV strains isolated from different regions of Africa, Europe and Asia have provided new knowledge of the drivers of LSDV emergence, and will inform future disease control strategies.

Effects of the COVID-19 Pandemic on ART Initiation and Access to HIV Viral Load Monitoring in Adults Living With HIV in West Africa: A Regression Discontinuity Analysis.

OBJECTIVES: Efforts to control the COVID-19 pandemic have potentially compromised the availability and/or quality of HIV services. We aimed to assess the pandemic's impact on antiretroviral therapy (ART) initiation and HIV viral load (VL) monitoring in 3 West African countries. METHODS: We used routinely collected data from 5 clinics contributing to the International epidemiologic Database to Evaluate AIDS collaboration in Burkina Faso, Côte d'Ivoire, and Nigeria. We included ART-naïve adults living with HIV initiating ART from January 1, 2018. We conducted regression discontinuity analysis to estimate changes in the number of ART initiations and VL measures per week, before and during the pandemic period in each country. RESULTS: In clinics in Burkina Faso and Côte d'Ivoire, ART initiations per week remained constant throughout the studied periods (-0.24 points (p) of ART initiations/week 95% CI: -5.5 to 5.9, -0.9 p, 95% CI: -8.5 to 8.6, respectively), whereas in Nigeria's clinic, they decreased significantly (-6.3 p, 95% CI: -10.8 to -1.7) after the beginning of the pandemic. The volume of VL tests performed decreased significantly in all 3 countries (-17.0 p, 95% CI: -25.3 to -8.6 in Burkina Faso, -118.4 p, 95% CI: -171.1 to -65.8 in Côte d'Ivoire and -169.1 p, 95% CI: -282.6 to -55.6 in Nigeria). CONCLUSIONS: HIV clinics in two out of three countries in West Africa demonstrated resilience as they successfully maintained access to ART for ALWH despite the challenges imposed by the pandemic. However, VL monitoring was severely disrupted and did not return to prepandemic levels approximately 1 year after the beginning of the pandemic. Continued monitoring of the HIV care continuum in the postpandemic period is essential to mitigate potential enduring effects on ALWH's virological and clinical outcomes.

Cardiac Amyloidosis Due to Transthyretin Protein: A Review.

Importance: Systemic amyloidosis from transthyretin (ATTR) protein is the most common type of amyloidosis that causes cardiomyopathy. Observations: Transthyretin (TTR) protein transports thyroxine (thyroid hormone) and retinol (vitamin A) and is synthesized predominantly by the liver. When the TTR protein misfolds, it can form amyloid fibrils that deposit in the heart causing heart failure, heart conduction block, or arrhythmia such as atrial fibrillation. The biological processes by which amyloid fibrils form are incompletely understood but are associated with aging and, in some patients, affected by inherited variants in the TTR genetic sequence. ATTR amyloidosis results from misfolded TTR protein deposition. ATTR can occur in association with normal TTR genetic sequence (wild-type ATTR) or with abnormal TTR genetic sequence (variant ATTR). Wild-type ATTR primarily manifests as cardiomyopathy while ATTR due to a genetic variant manifests as cardiomyopathy and/or polyneuropathy. Approximately 50 000 to 150 000 people in the US have heart failure due to ATTR amyloidosis. Without treatment, heart failure due to ATTR amyloidosis is associated with a median survival of approximately 5 years. More than 130 different inherited genetic variants in TTR exist. The most common genetic variant is Val122Ile (pV142I), an allele with an origin in West African countries, that is present in 3.4% of African American individuals in the US or approximately 1.5 million persons. The diagnosis can be made using serum free light chain assay and immunofixation electrophoresis to exclude light chain amyloidosis combined with cardiac nuclear scintigraphy to detect radiotracer uptake in a pattern consistent with amyloidosis. Loop diuretics, such as furosemide, torsemide, and bumetanide, are the primary treatment for fluid overload and symptomatic relief of patients with ATTR heart failure. An ATTR-directed therapy that inhibited misfolding of the TTR protein (tafamidis, a protein stabilizer), compared with placebo, reduced mortality from 42.9% to 29.5%, reduced hospitalizations from 0.7/year to 0.48/year, and was most effective when administered early in disease course. Conclusions and Relevance: ATTR amyloidosis causes cardiomyopathy in up to approximately 150 000 people in the US and tafamidis is the only currently approved therapy. Tafamidis slowed progression of ATTR amyloidosis and improved survival and prevented hospitalization, compared with placebo, in people with ATTR-associated cardiomyopathy.

Genomic characterization of SARS-CoV-2 in Guinea, West Africa.

SARS-CoV-2 has claimed several million lives since its emergence in late 2019. The ongoing evolution of the virus has resulted in the periodic emergence of new viral variants with distinct fitness advantages, including enhanced transmission and immune escape. While several SARS-CoV-2 variants of concern trace their origins back to the African continent-including Beta, Eta, and Omicron-most countries in Africa remain under-sampled in global genomic surveillance efforts. In an effort to begin filling these knowledge gaps, we conducted retrospective viral genomic surveillance in Guinea from October 2020 to August 2021. We found that SARS-CoV-2 clades 20A, 20B, and 20C dominated throughout 2020 until the coincident emergence of the Alpha and Eta variants of concern in January 2021. The Alpha variant remained dominant throughout early 2021 until the arrival of the Delta variant in July. Surprisingly, despite the small sample size of our study, we also found the persistence of the early SARS-CoV-2 clade 19B as late as April 2021. Together, these data help fill in our understanding of the SARS-CoV-2 population dynamics in West Africa early in the COVID-19 pandemic.

Two new Later Stone Age sites from the Final Pleistocene in the Falémé Valley, eastern Senegal.

The understanding of cultural dynamics at work at the end of the Final Pleistocene in West Africa suffers from a significant lack of excavated and dated sites, particularly in the Sahelian and Sudanian ecozones. While the Later Stone Age shows varied behavioral developments in different parts of the continent, the chrono-cultural framework of this period remains largely unknown in West Africa. We report on archaeological, geomorphological, and chronological research on two Final Pleistocene Later Stone Age sites in the Falémé Valley, eastern Senegal. Optically stimulated luminescence ages place the site of Toumboura I-2017 between 17 ± 1 and 16 ± 1 ka and the Ravin de Sansandé site between 13 ± 1 ka and 12 ± 1.1 ka. The excavated lithics show typical Later Stone Age industries, characterized by chaînes opératoires of core reduction mainly producing flakes and bladelets as well as blades and laminar flakes. Segments dominate the toolkits but a few backed bladelets and end-scrapers on flake blanks were recognized. Local raw materials were used, with a preference for chert and quartz, as well as greywacke. These Later Stone Age lithic assemblages are the oldest known in Senegal so far and add to the small number of sites known in West Africa for this period, which are mainly located farther south, in sub-tropical ecozones. The Later Stone Age sites of the Falémé Valley are contemporaneous with typical Middle Stone Age technologies in Senegal dated to at least the Pleistocene/Holocene transition. Our results thus provide new archaeological evidence highlighting the complex cultural processes at work during the Final Pleistocene in West Africa.

Stop, in the Name of COVID! Using Social Media Data to Estimate the Effects of COVID-19-Related Travel Restrictions on Migration.

In the wake of the COVID-19 pandemic, the International Organization for Migration has postulated that international migrant stocks fell short of their pre-pandemic projections by nearly 2 million as a result of travel restrictions. However, this decline is not testable with migration data from traditional sources. Key migration stakeholders have called for using data from alternative sources, including social media, to fill these gaps. Building on previous work using social media data to analyze migration responses to external shocks, we test the hypothesis that COVID-related travel restrictions reduced migrant stock relative to expected migration without such restrictions using estimates of migrants drawn from Facebook's advertising platform and dynamic panel models. We focus on four key origin countries in North and West Africa (Côte d'Ivoire, Algeria, Morocco, and Senegal) and on their 23 key destination countries. Between February and June 2020, we estimate that a destination country implementing a month-long total entry ban on arrivals from Côte d'Ivoire, Algeria, Morocco, or Senegal might have expected a 3.39% reduction in migrant stock from the restricted country compared with the counterfactual in which no travel restrictions were implemented. However, when broader societal disruptions of the pandemic are accounted for, we estimate that countries implementing travel restrictions might paradoxically have expected an increase in migrant stock. In this context, travel restrictions do not appear to have effectively curbed migration and could have resulted in outcomes opposite their intended effects.