Pandemics

In dense urban settings, diagnostic systems reduce transmission only when sampling, result return, and isolation are operationally feasible during the period of peak infectiousness. We define a waiting-window transmission externality that arises when infectious individuals remain mobile between diagnostic sampling and actionable isolation. The term is formalized as E = N × P × TR × D, where N is daily testing volume, P is test positivity, TR is residual transmission during the waiting period, and D is sample-to-action turnaround time. The equation is used as a first-order operational risk-accounting framework rather than as a complete epidemic model. Using Monte Carlo uncertainty propagation, we compare centralized 48 h testing, surge conditions with coupled delay and crowding, near-patient rapid testing, and home sampling with isolation at sampling. Centralized 48 h workflows produce approximately 80 excess waiting-window infections per 1000 tests/day at p = 10% and approximately 401 at p = 50%, increasing to approximately 126 and 628 under surge coupling. Near-patient testing and home sampling reduce these values to approximately 5–26 across the same positivity range. We also distinguish two operationally different but epidemiologically related approaches: home sampling with immediate precautionary isolation reduces TR while laboratory turnaround may remain nonzero, whereas home-based molecular testing reduces D by returning results at the point of collection. Sensitivity checks for surge coupling and household transmission floors show that the qualitative ordering of workflows is preserved, although the magnitude of benefit depends on adherence and local operating conditions. These findings support redesigning diagnostic workflows around sample-to-action time, isolation feasibility, decentralized logistics, and equity rather than assay performance alone. Full article

This study examines how some schools in highly challenging environments avoided learning loss—or even improved—during the COVID-19 pandemic. Using an explanatory mixed-methods research design, we first analyzed statewide administrative data to identify schools that demonstrated exceptional post-pandemic learning resiliency. Quantitative models incorporating multiple levels of school, health, and environmental data explained relatively little variation in resiliency outcomes, with district fixed effects accounting for a large share of the observed differences. To better understand these unexplained patterns, the second phase of the study involved qualitative fieldwork in four high schools identified as positive outliers. Interviews, observations, and document analysis revealed several organizational practices common across these schools, including strong relational continuity between schools and communities, visible and engaged leadership, sustained teacher collaboration, and structured routines for addressing attendance and learning loss. These findings suggest that stronger-than-expected academic recovery was not driven by prevailing demographic trends or new instructional programs, but rather by the mobilization of existing organizational assets that supported student engagement before and after the pandemic. Full article

SARS-CoV-2 infection has emerged worldwide. To reduce the number of cases and limit the transmission of the virus, health and local authorities have implemented several strategies. Mass screening is a key strategy for mitigating the damage caused by this pandemic. This strategy is based on the use of qRT-PCR and pooling to diagnose SARS-CoV-2 infection. The present work explores the performance and limitations of this strategy for the molecular diagnosis of SARS-CoV-2 infection. Three important technical aspects were retained: the comparison of two commercial extraction kits (BIGFISH and BIOER), the simulation of a non-compliant nasopharyngeal swab, and the evaluation of the pooling strategy. A total of 97 SARS-CoV-2-positive nasopharyngeal samples were used. The comparison of the two extraction kits was based on threshold cycles (Ct) values. The results showed a significant difference (IC = 95%) in the Ct of the nucleocapsid gene (N; p = 0.0000384) and RNA-dependent RNA polymerase (RdRp; p = 0.0254). However, no significant difference was observed between the Internal Control gene (IC; p = 0.0723) and Envelope gene (E; p = 0.150). The Ct values resulting from the BIGFISH extraction kit were generally lower than those obtained from BIOER. In terms of sensitivity, the RT-qPCR technique allows for the detection of viral RNA up to 10⁻³ as a dilution factor. This study demonstrated that the pooling strategy is an effective diagnostic technique. Positive samples remained detectable even in pools of 1000 or even 10,000 samples. However, the size of the pool under diagnostic conditions should not exceed a limit that must be dynamically adapted to prevalence to ensure economic and analytical viability. Full article

Antimicrobial resistance (AMR) is a growing global health threat with important implications for pediatric populations. Children are frequently exposed to antibiotics in both hospital and community settings, where inappropriate prescribing, suboptimal dosing, and excessive use of broad-spectrum agents remain common. These practices contribute to the emergence of resistant pathogens, increase adverse drug events, and may negatively affect the developing immune system and microbiota. This narrative review summarizes current evidence on pediatric antimicrobial stewardship (AMS), highlighting recent trends in antimicrobial use and key stewardship strategies across inpatient and outpatient care. Core interventions, including prospective audit and feedback, preauthorization, guideline implementation, AWaRe-based prescribing, therapeutic drug monitoring, and early intravenous-to-oral switch, are discussed. The review also examines the expanding role of diagnostic stewardship, focusing on rapid molecular diagnostics, point-of-care testing, and host-response biomarkers to improve differentiation between bacterial and viral infections and support targeted therapy. Despite progress, pediatric AMS faces persistent challenges, such as regional variability in prescribing practices, limited pediatric-specific data for new antimicrobials and diagnostics, and organizational and behavioral barriers. Emerging tools, particularly artificial intelligence, may enhance decision-making and optimize antimicrobial use, although further validation in pediatric settings is needed. Strengthening pediatric AMS is essential to improving care quality and mitigating the impact of AMR. Full article

This study examines the community integration and One Health strategies employed to combat Ebola virus disease in the Democratic Republic of Congo from 2007 to 2022. We synthesized 12 outbreak reports, conducted qualitative interviews with 36 managers, organized three focus groups, and adapted an analytical framework (MATCH) to evaluate three essential dimensions: the integration of the One Health approach, community involvement, and bottom-up approaches. This study evidences progressive improvement in all domains. The first outbreaks (2007–2009) were marked by moderate community engagement and a One Health approach that was largely limited to the human health sector, deemed suboptimal. The 10th outbreak represented an era of transformation, when the Incident Management System (IMS) was adopted to better manage the response to the virus. The latest outbreaks (13th to 15th) demonstrate an “optimal” implementation of the “One Health” approach through effective collaboration between those in charge of ensuring human, animal, and environmental health and that of the community. This study demonstrates that success is largely dependent on bottom-up initiatives in which local populations, their leaders (both traditional and religious), community liaisons, and specific groups (women and youth) are involved in the design and implementation of such measures. The inclusion of anthropologists and psychologists in addressing the psychosocial dimensions—fear, stigma, and distress—has been critical in ensuring the success of these initiatives and the degree to which the public trusts and accepts them. However, many issues still need to be addressed, including poor coordination among sectoral ministries and the partial implementation of IMS at the grassroots level. In summary, the authors of this study propose that these integrated and participatory models are sustainable and imperative to building the resilience of the Congolese health system to future outbreaks. Full article

The COVID-19 pandemic exposed large cross-country differences in mortality that cannot be explained by short-run policy responses alone. This study investigates how pre-pandemic electrification and human capital jointly shaped pandemic outcomes, emphasizing their potential non-linear complementarity. Using cross-country data and pre-pandemic averages of electricity access and schooling, we examine how long-run development conditions influenced COVID-19 mortality during 2020–2021. We estimate fixed-effects models and a threshold regression framework that allows the interaction between electrification and human capital to vary across infrastructure regimes. The results identify a sharp electrification threshold at approximately 96 percent. Below this threshold, higher levels of schooling are not associated with lower pandemic mortality and may even coincide with increased vulnerability, consistent with binding infrastructure constraints that prevent human capital from being effectively deployed during a health crisis. Above the threshold, the interaction between electrification and schooling becomes statistically insignificant, indicating that in highly electrified economies, the benefits of human capital are already embedded within integrated systems of healthcare delivery, communication, and public health governance. These findings reveal a non-linear complementarity between infrastructure and human capital. Education alone does not enhance pandemic resilience when basic infrastructure remains incomplete, while in near-universally electrified societies its protective role is largely internalized. The results highlight the importance of long-run infrastructure completion as a structural prerequisite for translating human capital into effective pandemic preparedness and resilience. Full article