Wiener Klinische Wochenschrift | 2019
Is there a clinical difference between influenza A and B virus infections in hospitalized patients?
Abstract
SummaryPurposeThe clinical presentation, complications and mortality in molecularly confirmed influenza\xa0A and B infections were analyzed.MethodsThis retrospective observational single-centre study included all influenza positive patients older than 18\xa0years who were hospitalized and treated at the flu isolation ward during 2017/2018. The diagnosis was based on point-of-care tests with the AlereTM.ResultsOf the 396 patients tested positive for influenza, 24.2% had influenza\xa0A and 75.8% influenza\xa0B. Influenza\xa0A patients were younger (median age 67.5\u202fyears vs. 77\u202fyears, p\u202f<\u20090.001), were more often smokers (27.7% vs. 16.8%, p\u202f=\u20090.021), had chronic pulmonary diseases more frequently (39.6% vs. 26.3%, p\u202f=\u20090.013), presented with a higher body temperature (38.6\u202f°C vs. 38.3\u202f°C, p\u202f=\u20090.004), leucocyte count (8\u202fG/L vs. 6.8\u202fG/L, p\u202f=\u20090.002), C‑reactive protein (CRP) level (41\u202fmg/l vs. 23\u202fmg/l, p\u202f<\u20090.001) and had dyspnea more often (41.7% vs. 28%, p\u202f=\u20090.012). Influenza\xa0B patients had an underlying chronic kidney disease in 37% vs. 18.8% (p\u202f<\u20090.001) and presented with vomiting on admission more frequently (21.7% vs. 11.5%, p\u202f=\u20090.027). Influenza\xa0A patients were admitted for 8\xa0days vs. 7\xa0days (p\u202f=\u20090.023). There were no differences in the rate of complications; however, 22 (5.6%) patients died during the hospital stay. The in-hospital mortality was higher in influenza\xa0A patients (8.3% vs 4.7%, p\u202f=\u20090.172).ConclusionSome differences were found between influenza\xa0A and B virus infections but symptoms were overlapping, which necessitates polymerase chain reaction point-of-care testing for accurate diagnosis. Influenza\xa0A was a\xa0more severe disease than influenza\xa0B during the period 2017/2018.