ObjectiveTo evaluate the effect of low-to-moderate doses of corticosteroids on human infections with avian influenza A (H7N9) virus, and explore when to initiate the treatment of corticosteroids and the duration of corticosteroids administration.MethodsThe study collected clinical data of 8 cases with avian influenza A (H7N9) virus infection admitted from January 25, 2017 to May 12, 2017. The final analysis included 5 severe patients who had received adjuvant corticosteroid treatment. The variation curves of WBC, CRP, PCT, CK, HBDH, LDH, temperature, ratio of SpO2/FiO2 were depicted and analyzed. The progress of clinical improvements, deterioration and prognosis were observed and discussed.ResultsThere were 1 female and 4 males in the 5 included patients with a median age of 58.0 years, among them 3 survived. The median time of illness onset to hospitalization and diagnosis confirmed were 4 days and 8 days respectively; the median duration of hospitalization to admission to infective ICU were 3 days. The first course of adjuvant corticosteroid treatment was initiated 11 days (median) after admission with a duration of 4 days (median), during which, the serum levels of HBDH and LDH decreased remarkably except the patient 3, and the oxygenation (SpO2/FiO2) improved except the patient 3. The second course of systemic administration of corticosteroid was given at a median of 26.5 days after admission with a duration of 9 days (median), during which, the patients survived with improved oxygenation (SpO2/FiO2), and weaned from mechanical ventilation.ConclusionsFor patients suffered severe human infection with avian influenza A (H7N9) virus, low-to-moderate doses of corticosteroids may decrease the level of inflammation, regulate the aberrant immune response, improve the oxygenation, make an early unassisted breathing. And corticosteroids treatment can be initiated at the time of disease deterioration, after/at the peak inflammatory response, and within 10-14 days of ARDS. Also, the adjuvant corticosteroids may be administered when oxygenation is dificult to be improved by other ways, or dificult to be liberated from mechanical ventilation, suffering severe septic shock, and refractory fever. And the duration of corticosteroids may be prolonged to 10-14 days, or until the higher level of HBDH and LDH decreased again.