Plasmodium knowlesi has been reported as an emerging infection throughout the Southeast Asian region, especially in the Malaysian state of Sabah, where it accounts for the majority of the malaria cases reported. This is in contrast to Europe, where imported P. knowlesi is a rarely reported infection. We present a case of P. knowlesi infection in a Danish woman returning from a short trip to Malaysian Borneo. Microscopy of blood smears revealed 0.8% infected erythrocytes, but due to the atypical morphological presentation, a conclusive species identification was made by molecular methods. Plasmodium knowlesi is a potentially fatal infection and taking the increasing travel activity into consideration after the coronavirus disease 2019 (COVID-19) pandemic, P. knowlesi should be a differential diagnosis in patients with travel-associated illness returning from highly endemic Southeast Asian areas.
Plain X-rays, computed tomography (CT) and magnetic resonance imaging (MRI) scans performed for non-ENT reasons often reveal incidental sinus mucosal changes. These changes need to be correlated clinically before diagnosing rhinosinusitis. This study examined the prevalence of such changes in MRI scans in children up to age 16. Scans were scored using an adapted Lund-Mackay classification and were positive when one or more sinuses showed abnormalities. Randomly selected scans in the retrospective arm revealed a prevalence of 20 of 62 (32.3 per cent). In the prospective arm 45 of 60 children were defined as truly asymptomatic, of which 14 scans (31 per cent) were positive. Other studies in adults and children using CT and MRI report a prevalence range of roughly 30 to 45 per cent. This variability may be attributed to differences of study design, definitions of population age, definitions of asymptomatic and definition of abnormal sinus. Other plausible factors to explain regional differences are climate and frequency of upper respiratory tract infections.