Pre-hospital time delays in imported malaria diagnosis in hospitalized sub-Saharan travelers and migrants: not only on the patient’s shoulders

To analyze the diagnostic delay in malaria related to misdiagnosis at first medical visit and its association with the risk of severe malaria in non-endemic areas.

Retrospective observational study of sub-Saharan migrants with imported malaria from January-2010 to December-2022. Patients were allocated in two groups depending on if malaria was suspected at first medical visit or not. Time delays in seeking healthcare, medical diagnostic delay (time between first attending a medical facility and the diagnosis of malaria) and total diagnostic delay (time between the onset of symptoms and the diagnosis of malaria) were calculated.

297 patients were included in the analysis. At first medical visit, malaria was misdiagnosed in 137 patients (46.1%). Medical diagnostic delay and total diagnostic delay were larger for the misdiagnosis group than for those properly diagnosed at first visit (p < 0.001). Although time in seeking healthcare was shorter in the misdiagnosis group, the presence of suggesting symptoms, such as fever, was lower (p < 0.050). Misdiagnosis was more frequent in emergency rooms linked to primary healthcare (p < 0.001). For the overall population (n = 297), total diagnostic delay was mainly due to delay in seeking healthcare. Initial misdiagnosis was associated with a higher risk of severe malaria (adjusted OR 2.23 [1.09–5.10], p = 0.031).

In a non-endemic area with a high rate of imported malaria, the percentage of patients misdiagnosed is surprisingly high. Misdiagnosis is associated with longer medical and total diagnostic delays and with a higher risk of severe malaria. It seems necessary to redesign training programs to improve knowledge among healthcare professionals and actions targeted to travelers to promote seeking healthcare advice promptly.