Search

Malaria diagnosis based on microscopy is impaired by the gradual disappearance of experienced microscopists in non-endemic areas. Aside from the conventional diagnostic methods, fluorescence flow cytometry technology using Sysmex XN-31, an automated haematology analyser, has been registered to support malaria diagnosis. The aim of this prospective, monocentric, non-interventional study was to evaluate the diagnostic accuracy of the XN-31 for the initial diagnosis or follow-up of imported malaria cases compared to the reference malaria tests including microscopy, loop mediated isothermal amplification, and rapid diagnostic tests. Over a one-year period, 357 blood samples were analysed, including 248 negative and 109 positive malaria samples. Compared to microscopy, XN-31 showed sensitivity of 100% (95% CI: 97.13-100) and specificity of 98.39% (95% CI: 95.56-100) for the initial diagnosis of imported malaria cases. Moreover, it provided accurate species identification asfalciparumor non-falciparumand parasitaemia determination in a very short time compared to other methods. We also demonstrated that XN-31 was a reliable method for patient follow-up on days 3, 7, and 28. Malaria diagnosis can be improved in non-endemic areas by the use of dedicated haematology analysers coupled with standard microscopy or other methods in development, such as artificial intelligence for blood slide reading. Given that XN-31 provided an accurate diagnosis in 1 min, it may reduce the time interval before treatment and thus improve the outcome of patient who have malaria.Précision diagnostique de la technique de cytométrie de flux en fluorescence utilisant le Sysmex XN-31 pour le paludisme d’importation en zone non endémique.Le diagnostic du paludisme basé sur la microscopie est rendu difficile par la disparition progressive des microscopistes expérimentés en zone non-endémique. À côté des méthodes conventionnelles, la technique de cytométrie de flux en fluorescence utilisant le Sysmex XN-31, un automate d’analyse hématologique, a été enregistrée pour participer au diagnostic du paludisme. L’objectif de cette étude prospective, monocentrique et non-interventionelle était d’évaluer la précision diagnostique du XN-31 pour le diagnostic initial et le suivi des cas de paludisme d’importation en comparaison des tests de référence dont la microscopie, l’amplification isothermale en boucle, et des tests de diagnostic rapide. Durant une période d’un an, 357 échantillons de sang ont été analysés, dont 248 négatifs et 109 positifs pour le paludisme. En comparaison de la microscopie, le XN-31 a montré une sensibilité de 100 % (95 % CI : 97.13-100) et une spécificité de 98.39 % (95 % CI : 95.56-100) pour le diagnostic initial des cas de paludisme d’importation. De plus, l’identification des espècesfalciparumet non-falciparumainsi que la parasitémie ont été précises dans un temps très court en comparaison des autres méthodes. Nous avons aussi démontré que le XN-31 était une méthode fiable pour le suivi des patients à J3, J7 et J28. Le diagnostic du paludisme peut être amélioré en zone non-endémique par l’utilisation d’automates d’hématologie spécialisés, associés à la microscopie standard ou d’autres méthodes en développement telle que l’intelligence artificielle appliquée à la lecture des lames de sang. Dans la mesure où le XN-31 produit un diagnostic précis en une minute, cela peut réduire le délai avant le traitement et donc améliorer l’issue pour les patients souffrant de paludisme.

Background: In patients with suspected stroke, brain imaging is recommended in the acute phase for appropriate management and treatment. Both computed tomography (CT) and magnetic resonance imaging (MRI) are considered reasonable choices for initial brain imaging. When both techniques are available, choosing one or the other might be associated with specific factors related either to patients, stroke symptoms, and severity or management organization. Methods: The study was performed within the STROKE 69 database, a population-based cohort of all adult patients with suspected stroke admitted in one of the emergency departments (ED), primary stroke center, or stroke center of the Rhône County, from November 2015 to December 2016. Patients were included if they were admitted within 24 h following either symptom onset or last known normal. To identify factors potentially associated with the choice of initial brain imaging, a multivariate logistic regression was performed. Results: Among the 3,244 patients with suspected stroke enrolled in the STROKE69 cohort, 3,107 (95.8%) underwent brain imaging within the first 24 h after admission. Among those 74.6% underwent CT as initial imaging while 25.4% had an MRI. In multivariate analyses, several factors were associated with a lower probability of having an MRI as initial brain imaging versus CT. These were either patient characteristics: older age (>80 years old, OR 0.39 [95% CI 0.28–0.54]), preexisting disability (OR 0.55 [95% CI 0.36–0.84]), use of anticoagulants (OR 0.52 [95% CI 0.33–0.81]), stroke characteristics: stroke of unknown onset (OR 0.42 [95% CI 0.31–0.58]) or factors associated with overall management: onset-to-door time (>6 h, OR 0.38 [95% CI 0.23–0.60]), initial admission to ED (OR 0.02 [95% CI 0.02–0.04]) or intensive care unit (OR 0.01 [95% CI 0.001–0.08]), personal transport (OR 0.66 [95% CI 0.45–0.96]), and admission during working hours (OR 0.65 [95% CI 0.51–0.84]). Conclusions: Besides CT or MRI availability, a number of other parameters could influence the choice of first imaging in case of stroke suspicion. These are related to patient characteristics, type of stroke symptoms, and type of organization.