Prevalence and seasonality of viral respiratory infections in a temperate climate region: A 24-year study (1997-2020).

BACKGROUND: Few long-term reports have been published on the epidemiology of respiratory viruses despite their frequent involvement in extremely common infections. The aim here was to determine the frequency and distribution of respiratory viruses in a temperate climate area (Barcelona, Spain) throughout a 24-year period. METHODS: We collected data on all respiratory viruses detected from 1997 to 2020 in our institution. Clinical specimens were analyzed mainly by conventional techniques, and molecular techniques were also used. RESULTS: Of the 59,579 specimens analyzed, 21,382 (35.9%) were positive for at least one virus. The number of positive samples during cold months was significantly higher than in warm months. Respiratory virus infections were detected in patients of all ages, above all in children under 3 years of age, who were most frequently infected with the respiratory syncytial virus, whereas Influenza A virus predominated in the other groups, especially in adults. A clear demographic and seasonal pattern was established for some viruses. Circulation of other respiratory viruses during the FLUAV H1N1pdm09 and SARS-CoV-2 pandemics was observed. CONCLUSIONS: This long-term study provides new knowledge about the prevalence of respiratory viruses in a Mediterranean region. Throughout the study period, the frequency of some viruses remained constant, whereas others varied with the year. A clear demographic and seasonal pattern was established for some viruses. Patients suffering from severe respiratory infections should be examined for a range of respiratory viruses regardless of gender, age, or season.

Excellent Response to Plasma Exchange in Three Patients With Enterovirus-71 Neurological Disease.

The clinical spectrum of Enterovirus-71-associated neurological disease includes acute flaccid paralysis, encephalomyelitis, or brainstem encephalitis with autonomic dysfunction. As no specific antiviral treatments are available, intravenous human immunoglobulin is used in early stages of the illness, decreasing serum proinflammatory cytokines, and improving clinical outcomes. Plasma exchange aims to eliminate pathogenic autoantibodies and proinflammatory cytokines, and is used in diverse immune-mediated neurologic conditions. However, its effect in Enterovirus-71 infections is unknown. We report three cases of severe Enterovirus-71 neurological disease treated with plasma exchange during an outbreak in Catalonia (Spain) in 2016. We observed a striking improvement in all three patients within 48 h of starting plasma exchange. Patients received four to six sessions every other day. Good outcomes were confirmed at the 1-year follow-up visit. Our observations suggest that plasma exchange is an effective complementary therapy for severe Enterovirus-71 neurological disease.