Anne Hauner

Diagnostics are a neglected but essential part of any healthcare system, critical for individual and public health, but in low- and middle-income countries (LMICs), up to 80% of people lack access to diagnostics. Molecular diagnostics, the gold standard for many infectious diseases, remain especially underused despite the region's disproportionate disease burden, commonly attributed to high costs, infrastructure demands and the need for skilled personnel. Sample-to-result (S2R) platforms, integrating nucleic acid extraction, amplification, and analysis into a single closed cassette system, have been proposed as a technological solution to enable decentralized testing, yet their uptake remains largely confined to upper-middle-income countries and donor-funded vertical disease programs. The COVID-19 pandemic demonstrated that molecular diagnostic capacity can be built rapidly given sufficient funding and political will, raising the question of whether persistent challenges in low-resource settings are primarily technological or reflect deeper systemic limitations, addressed here by comparing experiences with S2R platforms and conventional real-time PCR in the Democratic Republic of the Congo (DRC), Cuba, and Peru with the available literature. A narrative review of commercially available S2R platforms found fairly good and similar performance across platforms in terms of ease-of-use and consumables, but differences in cost, distribution, and test panels tailored to LMIC needs. A multiplex HAT-ARBO assay was developed for simultaneous detection of T.b. gambiense, T.b. rhodesiense, chikungunya, dengue, and yellow fever virus on the ARIES (Luminex/Diasorin), showing satisfactory performance on retrospective and prospective samples in DRC. Implementation was stopped prematurely when the manufacturer discontinued the ARIES line, highlighting the risks of single-manufacturer dependence. A conventional multiplex RT-PCR was developed for Zika, chikungunya, dengue and yellow fever virus and implemented in an epidemiological study in Goma, DRC; tested retrospectively with good results at a reference laboratory in Havana and at a peripheral laboratory established during COVID-19; and used to evaluate dengue diagnostic approaches at a small hospital in the Peruvian Amazon, confirming the superiority of molecular diagnostics and feasibility of implementation at this health system level. Comparing both approaches, S2R platforms had the greatest impact on technological barriers at the laboratory level, but this effect was limited to the machine itself, leaving most systemic barriers unaddressed while increasing manufacturer dependence and cost. Conventional PCR offered greater flexibility in reagents and test menus. Framing diagnostic access as a technological problem obscures structural barriers to sustainable implementation; progress requires investing in resilient laboratory and health systems with sustainable financing and accountable governance.

In dengue endemic, resource-limited settings, accurate and timely diagnosis is critical for effective clinical management and outbreak control, especially where multiple arboviruses co-circulate and overlap in clinical presentations. However, most dengue diagnosis in such settings rely on approaches with limited sensitivity such as clinical assessment, or easily deployable methods such as ELISA or rapid diagnostic tests (RDTs). Molecular diagnostics with superior diagnostic performance are rarely implemented beyond reference laboratories due to perceived logistical and operational barriers. This study provides real-world evidence comparing the performance of clinical, serological and molecular approaches for dengue diagnosis in a decentralized setting. We prospectively enrolled 271 patients with acute febrile illness at Santa Gema Hospital in Yurimaguas, Peru, during a dengue outbreak in 2023–2024. Patients underwent clinical evaluation (WHO 2009 dengue classification), and laboratory testing including NS1/ IgM RDTs and ELISAs, a triplex RT-PCR for ZIKV/DENV/CHIKV (ZDC-PCR), a newly developed multiplex RT-PCR for ZIKV/YFV/DENV/CHIKV (ZYDC-PCR), and a serotype-specific dengue RT-PCR used as reference. Diagnostic performance was assessed using sensitivity, specificity, ROC-AUC analysis, and logistic regression models. A subset of 131 samples underwent inter-laboratory comparison of the ZYDC-PCR between the regional (Yurimaguas) and central (Lima) laboratories. Of the 271 dengue-suspected cases, 88 (32.6%) were confirmed by the reference PCR. The ZYDC-PCR had a strong agreement with the reference (sensitivity 86.0%, Cohen’s kappa 0.893) and consistent performance across the central and regional laboratory. NS1-based tests showed high specificity (≥96%) but moderate sensitivity (~72%). ROC analysis confirmed the accuracy of PCR (AUC = 0.97), outperforming RDTs, ELISAs (AUC = 0.85 to 0.89) and clinical assessment (AUC = 0.65). Our study demonstrates the added value and feasibility of implementing a multiplex PCR at a regional hospital to significantly improve diagnostic accuracy, enabling earlier detection of disease presence or absence, critical for clinical management and outbreak response.

In 2024, the WHO’s Division on Access to Medicines and Health Products issued a call to action for sustainability in the pharmaceutical sector. The initiative, ‘Greener Pharmaceuticals’ Regulatory Highway’, underscored the need to reduce the environmental footprint of medical products. It explicitly called on the regulatory community to adopt initiatives towards ‘innovative approaches in the manufacturing, distribution, and usage of medical products.’ 1 This timely initiative aligns with the growing recognition of interconnectedness between climate change, pollution—including ‘pharmaceutical pollution’—and public health. However, the need to decrease greenhouse gas emissions should not overshadow other relevant areas for action in the pharmaceutical sector. Here, we focus on the negative environmental impact of the inappropriate elimination of pharmaceutical waste generated at the last mile in healthcare.