Influenza virus , the causative agent of influenza , has characteristics of fast transmission and strong infectivity, posing a major threat to public health .Currently, with widely use of the first-line antiviral neuraminidase inhibitors , drug-resistant strains have appeared and brought difficulties to the precaution and treatment of influenza .This article reviews influenza virus structural characteristics , drug-resistance mechanisms , resistance situation and detection methods of drug-resistant virus strains , aiming to provide a reference for future research on influenza virus drug-resistance and clinical medication .

Epidemiological evidence suggests that patients with hypertension infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are at increased risk of acute lung injury. However, it is still not clear whether this increased risk is related to the usage of renin-angiotensin system (RAS) blockers. We collected medical records of coronavirus disease 2019 (COVID-19) patients from the First Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou, China), and evaluated the potential impact of an angiotensin II receptor blocker (ARB) on the clinical outcomes of COVID-19 patients with hypertension. A total of 30 hypertensive COVID-19 patients were enrolled, of which 17 were classified as non-ARB group and the remaining 13 as ARB group based on the antihypertensive therapies they received. Compared with the non-ARB group, patients in the ARB group had a lower proportion of severe cases and intensive care unit (ICU) admission as well as shortened length of hospital stay, and manifested favorable results in most of the laboratory testing. Viral loads in the ARB group were lower than those in the non-ARB group throughout the disease course. No significant difference in the time of seroconversion or antibody levels was observed between the two groups. The median levels of soluble angiotensin-converting enzyme 2 (sACE2) in serum and urine samples were similar in both groups, and there were no significant correlations between serum sACE2 and biomarkers of disease severity. Transcriptional analysis showed 125 differentially expressed genes which mainly were enriched in oxygen transport, bicarbonate transport, and blood coagulation. Our results suggest that ARB usage is not associated with aggravation of COVID-19. These findings support the maintenance of ARB treatment in hypertensive patients diagnosed with COVID-19.
Aged ; Aged, 80 and over ; Angiotensin Receptor Antagonists/therapeutic use* ; Angiotensin-Converting Enzyme 2/blood* ; Antibodies, Viral/blood* ; Antihypertensive Agents/therapeutic use* ; Biomarkers ; COVID-19/complications* ; China ; Female ; Humans ; Hypertension/drug therapy* ; Intensive Care Units ; Length of Stay ; Male ; Middle Aged ; Retrospective Studies ; Transcriptome ; Viral Load